Open Access Repository of Indian Theses

SIVARAMAN, LAKSHMI

Abstract
In the present thesis, we have performed the electronic structure calculations of the
metal oxide semiconductor clusters, employing ab initio methods based on density func-
tional theory within pseudopotential approximation. The primary focus of this study was
to understand the evolution of structural, magnetic and optical properties of metal oxide
clusters particularly, aluminum oxide and gallium oxide clusters. To begin with a system-
atic study of evolution of the structural and electronic properties of Al2O3 and Ga2O3,
clusters and their comparison with the bulk was initiated. As a continuation we have
studied Mn doped gallium oxide clusters and Gd doped alumina clusters. We have also
studied size dependent optical properties of gallium oxide clusters using Time Dependent
DFT.
In the initial stage, we have performed systematic study of structural and electronic
properties of (Al2O3)n and (Ga2O3)n clusters in the size range of n = 1−10. In general, it
is found that the lowest energy isomers for both (Al2O3)n and (Ga2O3)n clusters are similar
except for n = 1, 2, 4, and 10. The lowest energy configurations for both series shows
preference for 4- and 6-membered rings. The stability of the cluster increases with the
size. The stability of the clusters is dominated by the ionic Al-O and Ga-O interactions
with weak covalent bonding. For (Al2O3)n clusters we have calculated IR and Raman
spectra for small sized (n = 1− 4) clusters and compared with the experimental spectra.
Our results for n = 1 agree with experiments well and for n = 4, there is a possibility of
the presence of combination of isomers. It is shown that Raman spectra could be helpful
in identifying the lowest energy isomers of these clusters.
As a next step, we have studied the variation in the structural, electronic, and magnetic
properties of Mn-doped gallium oxide and Gd-doped alumina clusters with the cluster size
and concentration of the dopents. Specifically, we have focused on the study of the atomic
structure and magnetic properties of Mn(GaO)n and Mn2(GaO)n clusters with n = 1− 7
as well as GdAl2n−1O3n and Gd2Al2n−2O3n clusters with n = 1 − 10 using DFT. Our
results on Mn doped (GaO)n clusters suggest that doping of a Mn atom is found to be
energetically favourable in (GaO)n clusters and the equilibrium configurations are found
to be determined by the metal-oxygen interactions. For Mn2(GaO)n clusters results into
the ground state to be either ferromagnetic or antiferromagnetic depending on the Mn
coordination number and the Mn-Mn bond-length in the given Mn2(GaO)n cluster. For,
Gd doped Al2O3 clusters, our results show that substitution of an Al with a Gd atom
is energetically favourable in clusters, but in the case of bulk α-Al2O3, Gd doping is
energetically unfavourable, and with the increase in the concentration of Gd atoms, the
stability decreases. These results suggest that doping of Gd and, in general, rare earths
in nanoparticles offers an attractive route to prepare rare-earth doped ceramic materials,
such as YAG, which has been attracting much interest in recent years.
As a continuation of our earlier work we have calculated the absorption spectra for
(Ga2O3)n, n = 1 − 10 clusters using TDLDA technique. We have also calculated the
polarizability of these clusters using finite field method. The polarizability decreases with
size of the cluster. The overall shape of the calculated spectra strongly depends on cluster
geometries. With the increase in size, the discrete spectra of small clusters evolves into
quasicontinuous spectra. For n = 10, the spectra shows a smooth absorption edge which is
a characteristic of the bulk. It is observed that the optical gap oscillates with an increase
in the cluster size. These results provide a proper theoretical support to understand the
optical properties of nanostructures of gallium oxide as well as other metal oxides.


English

Genome Characterization in Plants with Special Reference to Four Millet

POTDAR, H. S.

Abstract
STABILIZATION OF α-AMINO SULFOXIDES THROUGH BRIDGEHEAD EFFECT: SYNTHESIS, CHARACTERIZATION AND MECHANISTIC STUDIES OF α-AMINO SULFOXIDES AND RELATED COMPOUNDS

Many amines with an additional sulfoxide functional group are effective bidentate ligands and have also been used in organocatalysis and as intermediates in the synthesis of natural products. Sulfoxide moiety is recognized as a primary auxiliary for new synthetic methodologies and for asymmetric inductions. In asymmetric synthesis, many reactions are efficiently stereocontrolled due to the presence of a stereogenic center at sulfur in the chiral auxiliary which can be easily removed under mild conditions. Furthermore, amino sulfoxides are constituents of many biologically or medicinally active compounds. Compounds with non α disposition of amino and sulfoxide moieties are also receiving much attention as intermediates in organic transformations or as pharmaceutical goals.1 However, α-amino sulfoxides remain unexplored due to inherent instability.2 Thus, the present work is mainly focused on stabilization of this class of labile compounds by placing the nitrogen at a bridgehead and is an extension of earlier studies in this laboratory. The selenium analogs of such amino sulfoxides have also been synthesized and their stability was studied. This work was further extended for the synthesis of some β-amino sulfoxides derived from N-methyl 1,2,3,4-tetrahydroisoquinolines because of their similarity in terms of nitrogen-oxygen juxtaposition to venlafaxines, which are very widely used as antidepressants. The emphasis in the current work is also on the role of reactive intermediate stabilization effects and bridgehead strain thereof, especially the difference in carbocation and radical stabilization effects



STUDIES ON ELECTROCHEMICALLY PREPARED SOLAR SELECTIVE BLACK LAYERS

SRINIVASAN, K. R.


Genetic Variations in Indian Population: Implication for Health 

In past, our knowledge about human genetic variation was limited to mainly the rare changes in the number and structure of chromosomes which included aneuploidies, heteromorphisms, rearrangements and other polymorphism, large enough to be visualized by microscopic techniques. With the advances in molecular biology came the single nucleotide polymorphism (SNPs) in DNA, which is the most prevalent type of genetic variation and identified mainly using PCR-based methods. Recently, copy number variants (CNVs) are highlighted to be a significant source of human genetic variation accounting for disease susceptibility and disease development, thus revealing the gap between long-recognized microscopic chromosomal alterations and invisible changes at nucleotide level. Copy number variation (CNV) can be defined as segments of DNA ranging in size from kilobases (larger than 1 kb) to several megabases (Mb) varying in copy number in comparison to the reference genome. Deletions, duplications, segmental duplication, insertions, and translocations all result in CNVs. Rapid advances in the technologies have enabled the detection of CNVs on larger scale. Thus, depending on the method of detection, it has been estimated that CNVs may cover about 12% of the human genes. 
The discovery of submicroscopic copy-number variations (CNVs) present in human genome has dramatically changed our perspective on DNA structural variation and development of disease. Advancement in technology has allowed for the analysis of CNVs in thousands of individuals with or without a specific disease. Till date many researchers have addressed the presence of CNVs in the human genome and their association with common human diseases including neuropsychiatric, autoimmune, infectious, and many more, whereas others found evidence that CNVs are not associated with common diseases. CNVs and their involvement in disease susceptibility and drug response have been widely studied in other populations but not to any extent in Indian population. Therefore, the main aim of our study was to evaluate the distribution of copy number variable genes in Indian population and their link, if any, to health, disease and drug response. Based on our selection criteria, few copy number variable genes were selected and studied for their role in human diseases like cancer (breast and head and neck cancer), psoriasis, asthma, HIV-1/AIDS and others. In this study, the candidate copy number variable genes studied, MTUS1 for breast cancer and head and neck cancer; LCE3C and LCE3B for psoriasis susceptibility; GSTT1 and GSTM1 for asthma susceptibility; and CCL3L1 for HIV-1/AIDS susceptibility. The copy number frequency distribution of FCGR3B and SULT1A1 involved in SLE susceptibility and drug metabolism respectively, was evaluated in the Indian population. In this study CNV for these selected genes were analyzed in 100 – 280 normal healthy individuals from Western Indian population and in variable number of patients suffering from respective diseases. In many cases the frequency of CNV variants was significantly different in Indian population as compared to studies reported in other population. Also, significant inter-ethnic differences were observed in the distribution of variants in comparison to other population. The association of the MTUS1 deletion variant in susceptibility or decreased risk to head and neck and breast cancer was evaluated where indicative correlation with deletion of MTUS1 gene was observed only in breast cancer patients. Further, the significant association between CCL3L1 copy number and risk to HIV-1 is observed in our study. The sample size in the above mentioned study was very small, therefore the results needs to be further validated in large sample size before making firm conclusion about the link between the CNV of MTUS1 and CCL3L1 and risk to breast cancer and HIV-1 respectively. The discovery of submicroscopic copy-number variations (CNVs) present in human genome has dramatically changed our perspective on DNA structural variation and development of disease. Advancement in technology has allowed for the analysis of CNVs in thousands of individuals with or without a specific disease. Till date many researchers have addressed the presence of CNVs in the human genome and their association with common human diseases including neuropsychiatric, autoimmune, infectious, and many more, whereas others found evidence that CNVs are not associated with common diseases. CNVs and their involvement in disease susceptibility and drug response have been widely studied in other populations but not to any extent in Indian population. Therefore, the main aim of our study was to evaluate the distribution of copy number variable genes in Indian population and their link, if any, to health, disease and drug response. Based on our selection criteria, few copy number variable genes were selected and studied for their role in human diseases like cancer (breast and head and neck cancer), psoriasis, asthma, HIV-1/AIDS and others. In this study, the candidate copy number variable genes studied, MTUS1 for breast cancer and head and neck cancer; LCE3C and LCE3B for psoriasis susceptibility; GSTT1 and GSTM1 for asthma susceptibility; and CCL3L1 for HIV-1/AIDS susceptibility. The copy number frequency distribution of FCGR3B and SULT1A1 involved in SLE susceptibility and drug metabolism respectively, was evaluated in the Indian population. In this study CNV for these selected genes were analyzed in 100 – 280 normal healthy individuals from Western Indian population and in variable number of patients suffering from respective diseases. In many cases the frequency of CNV variants was significantly different in Indian population as compared to studies reported in other population. Also, significant inter-ethnic differences were observed in the distribution of variants in comparison to other population. The association of the MTUS1 deletion variant in susceptibility or decreased risk to head and neck and breast cancer was evaluated where indicative correlation with deletion of MTUS1 gene was observed only in breast cancer patients. Further, the significant association between CCL3L1 copy number and risk to HIV-1 is observed in our study. The sample size in the above mentioned study was very small, therefore the results needs to be further validated in large sample size before making firm conclusion about the link between the CNV of MTUS1 and CCL3L1 and risk to breast cancer and HIV-1 respectively.  




SOME APPLICATIONS OF GAS CHROMATOGRAPHIC TECHNIQUES IN CATALYSIS Sorption and Diffusion in Zeolites

RAMDASI, SUDHAKAR S.

Abstract
The thesis is presented in three parts the first part describes a method developed for determination of activities of sample-additive reagents used as oxidants for promoting smooth elemental analysis the second part relates to organic elemental analysis the second part relates to kinetic studies of combustion of phenanthrene using ten such oxidants and the third part gives an account of a study pertaining to catalytic vapour-phase oxidation of four aliphatic alcohols on silicon carbide supported vanadium pentoxide in a semi-microreactor 
part I- A NOVEL METHOD FOR DETERMINATION OF ACTIVITY OF A SIMPLE E-ADDITIVE REAFENTS IN ORGANIC ELEMENTAL ANALYSIS It has been a common experience that certain refractory compounds resist smooth combustion and yield low values in the elemental analysis method reported to overcome compounds resist smooth combustion and yield low fillings and also the use of suitable sample -additive reagents although a number of such additive reagents are reported in the literature information available to grade them according to their activities is insufficient activity of oxidation catalysts for combustion of organic compounds has been studied by earlier investigators by packing a layer in a combustion tube and correlating the minimum temperature required for complete would be different when it is used as an additive reagent in a sample boat due to its limited quantity and shorter contact time with the test-compound only one method for determination of activities of such additive reagents is reported which is suitable only attempts seem to have been made so fat to develop a suitable method to study the relative activities of sample-additive reagents in oxygen atmosphere which is a necessity for the conventional rapid combustion methods. This part of the thesis describes developments of such a method based on partial oxidation of a test-compound under carefully controlled conditions using various sample-additive reagents in oxygen atmosphere behavior of five structurally different organic test-compounds i.e. acetanilide phenanthrene 8-hydroxyquinoline, cholesterol of five structurally different organic test-compounds i.e. acetanilide, phenantherene 8-hydroxyquinoline cholesterol and 1-octadecyl alcohol has been studied under these conditions and acetanilide has been recommended as the best test-compound due to its combustion characteristics physical properties of these sample-additive regents have been studied using differential thermal analysis and thermogravimetry these studies furnished data regarding oxygen form the partial oxidation studies other parameters of these catalysts e.g mean particle size by scanning electron mircoscope and surface area also have been determined further the surface properties of the mixed oxides from the catalysts studied (which include some new ones)have been examined using ESCA thus X-ray photoelectron spectra of these oxides have been recorded and the binding energies of electrons for the core levels 2p,3d etc. of the metal and oxygen (ls) have been discussed in the light of high activities of these mixed oxides which include thermal decomposition products of AgMnO4, (MnO2+Ag), (MnO2+Cu) and (MnO2+Co). 
part 2- KENETIC STUDIES OF COMBUSTION OF PHENANTHERNE WITH VARIOUS SAMPLE-ADDITIVE REAGENTS Information in the literature on the determination of rate of combustion of organic compounds on microscale using different catalysts is very scants the only exception is that of Vecera et al. who have carried out systematic study on rate of combustion with a view to developing a rapid method for the microdetermination of carbon and hydrogen. this part describes the kinetic studies to understand the combustion behaviour of phenanthrene on microscale using ten sample-additive reagents activities of which have been determined at higher temperatures as described in part 1 the temperature of oxidation is reduced to 300o for a conveniently measureable rate of combustion the rate has been studied by estimating at fixed time-intervals the carbon dioxide obtained after combustion of the oxidation products formed the rate constants equations for the best straight lines for the curves showing relationship of the sample combusted with time have been found out by the method of least squares activities of the catalysts showed a general correlation with intercepts of the slopes of the equations could not give any guiding information regarding such a correlation the control of combustion of an organic compound on a micrpscale using a sample-additive reagents thus seemed to be extremely difficult for desired accurate kinetic studies. 
part 3 CATALYTIC VAPOUR-PHASE OXIDATION OF SOME ALIPHATIC ALCOHOLS ON CANADIUM PENTOXIDE IN A SEMIMECROREACTOR Aldehydes from a very important class of organic compounds as they are among the most reactive compounds although a number of methods are available for their preparation on industrial scale the well known oxo processes (by formylation of a suitable olefin ) dehydrogenation of alcohols over copper chromite catalyst and oxidation of alochols over silver catalyst seem to be the major processes the oxidation of lower aliphatic alcohols has a special industrial significance for these aldehydes are important intermediates catalytic vapour-phase oxidation of ethyl alcohol to acetaldehyde on industrial scale using silver catalyst is a case in point although catalytic vapour-phase oxidation is a domain of chemical engineers a study of catalytic vapour-phase oxidation of alcohols to obtain the respective aldehydes using silican carbide supported vanadium pentoxide in a semimicro reactor was undertaken to assess the possibility of getting useful information for its further scaling up thus this part of the thesis presents some aliphatic alcohols, l-butanol,l-hexanol,l-octanol and l-decanol,which has been carried out on V2O5/sic catalyst (~10% w/w) at 250o, 300o and 350o in a specially designed semi-mireo reactor. the oxidation products have been studied using gas chromatography. In addition to the expected aldehydes and small quantities of acids some unidentified product was obtained in each case the nature of which was decided using GC-MS. it was observed that the conversion of the oxidized alcohol to aldehyde per pass was excellent (~90%) in l-butanol and appreciably good (~70%) in l-hexanol the conversion was rather low(~40%) in l-cotanol and l-decanol as the formation of the undesirable product had increased considerably unlike that in l-butanol and l-hexanol. it was concluded that such a study on semi-mecroscale could be quite useful for scaling up similar processes. 




ANALYTICAL STUDIES OF OXIDANTS FOR CATALYTIC OXIDATION OF ORGANIC COMPOUNDS

PARANDE, MADAN

Abstract


Investigation of Antiviral Properties of Medicinal Plant Extracts 

Plants have been used as folk remedies and ethnobotanical literature has described the usage of plant extracts, infusions and powders for centuries for diseases now known to be of viral origin. There is an increasing need for search of new compounds with antiviral activity as the treatment of viral infections with the available antiviral drugs is often unsatisfactory due to the problem of viral resistance coupled with the problem of viral latency and conflicting efficacy in recurrent infection in immunocompromised patients. Ethnopharmacology provides an alternative approach for the discovery of antiviral agents, namely the study of medicinal plants with a history of traditional use as a potential source of substances with significant pharmacological and biological activities. The Indian subcontinent is endowed with rich and diverse local health tradition, which is equally matched with rich and diverse plant genetic source. A detailed investigation and documentation of plants used in local health traditions and ethnopharmacological evaluation to verify their efficacy and safety can lead to the development of invaluable herbal drugs or isolation of compounds of therapeutic value. 

A number of plant extracts reported in traditional medicine to have antiinfective properties against Herpes Simplex Virus Type- I & II, Polio virus type I, Adeno Virus type VIII and Influenza Virus Type A (H1N1) were studied in our laboratory and were also screened for antiviral activity. The present study was undertaken to test the twenty five extracts of four medicinal plants namely Sida cordifolia L., Sida actua Burm., Sida retusa L., and Sida spinosa L., were for their antiviral activity against mentioned viruses. 
Whole plant parts of four medicinal plants belonging to family Malvaceae used in the traditional system of medicine collected from south India were tested for their antiviral activity. 

Among all the twenty five extracts tested from four different plants, Sida cordifolia showed promising antiviral activity against DNA (HSV I & II, HSV TK- and Adenovirus type VIII) and RNA (Poliovirus type-I and Influenza virus type A (H1N1). The extracts Tol, HA and MeOH showed promising activity which contains alkaloids and phytosterols and those extracts were further fractioned to separate the alkaloids from HA and MeOH and phytosterols from Tol extracts. The activity of isolated fractions and the crude extracts were compared. 
The hydro alcohol and toluene extracts were further screened for in vivo antiviral studies against HSV-I 7401 wild type virus where toluene extract significantly delayed the development and progression of skin lesions and prolonged mean survival time (P < 0.05 by paired t-test) as compared with control (1% DMSO in distilled water treatment). 
Against Influenza Hydroalcohol extract of Sida cordifolia showed highest selectivity index of 41. 

The results from this preliminary investigation provide evidence of the importance of ethnopharmacology as a guide to the screening of biologically active plant materials. We used 100 per cent inactivation to define an extract with antiviral activity, but many extracts had partial antiviral activity. 
With the present in vitro and in vivo investigation it is concluded that the toluene extract of sida cordifolia L. is most potent followed by hydroalcohol and methanol extract when compared to the standard drugs available. However, further in depth clinical investigation may be required to confirm these studies.



REACTION ENGINEERING STUDIES IN A SLURRY REACTOR

SINHA, BHARATI

Abstract/Synopsis

Background
	Healthcare facilities are a unique environment, where patients including those with chronic illness requiring longer durations of hospital stay or those with altered immune status are admitted. Sometimes patients may acquire a healthcare associated infection after hospitalisation. The environment may occasionally contribute to such infections inadvertently. This study was undertaken to generate baseline data on airborne microorganisms, characterise aerobic bacteria and fungi in different locations of the hospital environment, determine whether temporal variation exists in airborne microbial concentrations of a hospital location, determine the most common isolate across hospitals, study the relationship between environmental and clinical isolates in a select area using molecular typing methods such as Polymerase Chain Reaction (PCR) and Pulsed Field Gel Electrophoresis (PFGE), and determine if endotoxin can be airborne.

Methods
	 Institutional Ethics Committee approval was sought prior to start of the study. Indoor air samples (in duplicates) were collected simultaneously using exposed plate (for 30 minutes), impingement (BioSampler @ 12.5 L/min for                 20 min) and filtration (personal sampling filter cassette loaded with gelatin filter  @ 3.5 L/min for 15 min) methods in different locations of different hospitals to characterise airborne microflora. Sampling was also conducted over different periods of the year in the same location of one hospital to determine temporal variation. A walk-through was conducted to assess the extent of activity prior to sampling. Temperature and relative humidity were recorded during sampling. Bacterial plates were incubated at 37°C and observed for growth after 48 h; fungal plates were incubated at 25°C and 37°C and observed upto 7 days. Microorganisms were identified using standard microbiological procedures. PCR targeting Pseudomonas specific 16s rDNA was performed to obtain 618 bp amplicons. Representative strains were sequenced and compared with established sequences of pathogenic Pseudomonas strains from NCBI database for evolutionary details. Few strains of phenotypically similar coagulase-negative Staphylococci (CNS) of environmental (air) and clinical origin were subjected to genotyping by PCR and PFGE to confirm the similarity. Air samples were collected from a low-cost intensive care unit (ICU) by impingement in sterile normal saline (BioSampler @ 12.5L/min for 16 min) and blood samples were collected from patients (after 48h of admission) and health personnel (with consent) from the same ICU. Pre-treated sera (diluted in sterile pyrogen-free distilled water to 1:10 and heated at 70°C for 10 min) and air samples were tested for presence of endotoxin using LAL gel-clot detection method. Formation of stable clot was considered positive. Questionnaire was circulated among health personnel to determine any adverse health effects.

Results
	Bacteria were found to be in higher concentrations when compared to fungi, irrespective of the sampling method and the sampled location. Among bacteria, Gram-positive cocci (CNS and Micrococci) were more predominant than Gram-negative bacilli (Pseudomonas sp.). In fungi, moulds (Aspergillus sp.) were frequently encountered. Exposed plate method was found to recover a variety of bacteria and fungi than impinger and filter methods. Airborne microbial loads were not influenced significantly by the changing seasons and the size of the hospitals. However, there was significant variation in their loads with the sampling location (OR < ICU < ward). Pseudomonas sp. was present in indoor air of different hospitals, including the ICUs and ORs. Phylogenetic analysis showed the similarity between the study isolates of Pseudomonas strains that were environmental (air) in origin and the clinical isolates in the NCBI database. Environmental strain of methicillin resistant Staphylococcus haemolyticus isolated from air sample was found to be similar to that of the strain recovered from clinical (tissue) sample of a patient admitted subsequently within a week in the same location. Further, endotoxin was present in indoor air of ICU of a low-cost healthcare facility and among health personnel working in the same ICU. Health personnel are under higher risk (10.31 times more than patients) of adverse health effects due to exposure to airborne endotoxins.

Conclusion
	Exposed plate method is a useful method for collecting air samples in areas of low bioaerosol concentrations such as healthcare facilities, since it is cost effective, reproducible and can be preferred for preliminary assessment of indoor microbial air quality in hospitals. Profiling of bioaerosols in different locations of hospitals under study showed that GPC were in higher concentrations than GNB among bacteria, while fungi were seen in less numbers. Since GPC are primarily shed from skin and hair of occupants, there is a need for guidelines on proper ventilation and permissible limits for number of personnel. The presence of GNB indicates the need for infection control practices to reduce aerosolisation of these organisms during healthcare delivery. The mere presence of fungi indicates the need for use of proper air handling systems to restrict the entry of fungal spores and prevent fungal growth. Similarity between the study isolates (environmental) and clinical isolates of Pseudomonas stutzeri in the NCBI database suggests that a pathway may exist, allowing for the introduction of these organisms from the hospital environment into patients during healthcare delivery. Similarity of coagulase-negative Staphylococci of environmental and clinical origin indicates that air may be a possible source of nosocomial infection. The study also documented presence of airborne endotoxin. Health personnel are at a higher risk of adverse health effects due to exposure to airborne endotoxins when compared to patients.



STUDIES IN (1) CARBOHYDRATES AND (2) LIPID ASSOCIATES OF LEGUMINOSEAE (LOTOIDEAE)

NAYAK, VIKRAM

Synopsis 
The present dissertation is an attempt to understand nanoscale chirality and its 
biomolecular and cellular implication. Asymmetry is induced in nanoparticles by 
conjugating it with different chiral biomolecules e.g., amino acids, DNA and nano scale 
drug. In most cases silver nanoparticle (SNP) is taken as a model system and chiral 
induction is tested by varying conjugations and conjugation method.  One of such 
conjugation namely, Trp-SNP shows double plasmon behavior while retaining spherical 
shape. The origin of such double plasmon is associated with a biperiodic nanostructure 
formation and can be accounted for by a sandwich model. The model being validated using 
Trp analogs. Interestingly, the Trp-SNP could be used for red laser induced hyperthermia. 
This adds another dimension to functional property is rarely been used for hyperthermia.  
Next, silver nano-clusters are formed on plasmid DNA (pUC19) which leads to 
induced chirality on SNP. As a result such cluster induces a conformational stress on the 
embedded pUC19 from supercoiled to relaxed state. The cross talk between the embedding 
nanocluster and the plasmid DNA is studied in detailed using different biophysical 
techniques. It turns out that SNP behaves as a topological enzyme in course of the 
interaction, while attains its chiral property.   
 I further investigated the chirality of nanoparticle by taking amino acids containing 
thiol and non thiolated group and found that the chiral signal of biomolecules upon nano-
conjugation increases remarkably when the conjugation is thiol mediated. Both thiolated 
and non thiolated small molecules leads to emergence of plasmonic CD signal confirming 
the induction of chirality in nanoparticle.   
 The interaction of chiral nanoparticle with cell is studied further to understand the 
role of nano-chirality. For this I tactfully choose penicillamine (PA) whose enantiomeric 
forms behave differently when treated with cancer cells. Among two enantiomeric forms 
DPA shows therapeutic effect while LPA is mostly toxic. Upon achievement of nano-
chirality we found reversal in cellular activity of DPA-SNP & LPA-SNP. Both conjugation 
leads to higher cellular damage, the damage being more for DPA-SNP. Finally, we 
developed a method by which we can discriminate chiral molecule as well as chiral 
nanoclusters. The method is based on polarization of excitation and emission fluorescence 
and does not required a circular dichroism setup. 


STUDIES IN SYNTHETIC ZEOLITES

PONKSHE, N. K.

xiii 
 
 
Abstract 
Sophorolipids (SLs) belong to the category of glycolipid biosurfactants. They 
consist of a dimeric sugar- sophorose as a carbohydrate head and a long hydroxy 
fatty acid chain as tail. This amphiphilic nature allows them to form unique 
structures such as micelles and bilayers in heterogenous systems. SLs find 
applications in wide range of fields including Petroleum, food, pharmaceuticals, 
cosmetics, laundry and bioremediation. SLs are synthesized by employing non 
pathogenic yeast strains and they confer several physiological advantages to the 
producer. Biosurfactants are coming up as emerging class of biomedical 
compounds. They are a suitable alternative to synthetic medicines and 
antimicrobial agents, and could be used as safe and effective therapeutic agents 
or probiotics, especially at a time when drug resistance among causal organisms 
for many life-threatening diseases is on the rise. SLs offer the advantages of 
biodegradability, low ecotoxicity and the production based on renewable-resource 
substrates. The US FDA has also approved biosurfactants/sugar esters for the 
use in food and pharmaceuticals. Keeping this in mind; several basic and applied 
aspects of sophorolipids have been explored and the work has been reported in 
the thesis. 
The thesis has been divided into 5 chapters 
Chapter I. Introduction 
The first chapter is an introduction to the thesis. It includes brief account on 
surfactants, current market share of Biosurfactants, types, their advantages over 
chemical ones and producing microorganisms. SL stands as a promising 
biosurfactant. The features which make it so are described along with its 
physiological role and the biosynthetic pathway. Owing to the unique nature; 
sophorolipids find applications in wide range of areas. The chapter gives brief 
literature review of the applications. With this background, the scope and 
objectives of the thesis have been defined.  
 
Chapter II. Production of sophorolipids using non edible oils and their use as an 
alternative/ additive to laundry detergents 
The second chapter is about the attempt to reduce the SL production cost by 
using non-edible oils namely Jatropha and Pongamia. Through optimization of 
xiv 
 
 
parameters and resting cell method, the yields 15.25g/l and 19.3g/l could be 
achieved for Jatropha oil derived SL (SLJO) and Pongamia oil derived sophorolipid 
(SLPO) respectively. Both SLs showed good surfactant property with the CMC 
values 9.5mg/l for SLJO and 62.5mg/l for SLPO. Keeping the prospective use of 
these SLs in mind, the physicochemical characterization, emulsion stability, 
antibacterial and stain removal studies in comparison with commercial detergent 
were done. Based on the results, it can be said that SLs have utility as fabric 
cleaner with advantageous properties such as skin friendly nature, antibacterial 
action and biodegradability. SLs enhance the detergent performance, so less 
quantity of detergent can be sufficient for desired cleaning effect. Thus the harm 
caused to environment through detergent usage can be reduced by replacing 
synthetic surfactants with green surfactant molecules. 
 
Chapter III(a). Sophorolipid biosurfactants act in synergy with antibiotics to 
enhance their efficiency  
In the third chapter (part a) the effect of co-administration of SL and antibiotics 
has been evaluated. SLs are amphiphilic in nature and therefore can span 
through the bacterial cell membrane. Thus the co-administration is expected to 
facilitate the entry of antibiotic molecules. During the experiments, effect of SL-
antibiotic co-administration was evaluated against 3 different index bacteria 
namely, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa. Also 
the antibiotics differed in their mode as well as site of action. In accordance with 
the anticipation, SL-antibiotic combination achieved the bacterial inhibition within 
shorter period as compared to the antibiotic alone. The Scanning electron 
micrographs of the bacterial cells treated with combinations confirmed the 
damage to cell membrane with all 3 test bacteria at sublethal concentrations of 
both inhibitory agents.   
 
Chapter III(b). Exploration of antiviral activity of SLs 
The third chapter (part b) describes antiviral action of Oleic, Linoleic acid derived 
SL against viruses differing in their genetic makeup such as plus stranded RNA, 
segmented single negative stranded RNA and double stranded DNA viruses. The 
antiviral activity was tested in 3 different modes- direct treatment of virus, rapid 
xv 
 
 
culture assay for Influenza virus and treatment of host cell line with SL prior to 
viral challenge in order to check if SL gives any antiviral immunity. 
Coxsackieviruses CV (B1-CVB6, CA7, CA9), murid herpesvirus, strain MHV-68, 
Influenza virus A/Mississippi/1/85 (H3N2) have been used for the studies. 
It was observed that direct treatment of virus indicated 1 log10- 4.5 log10 
reduction in the virus titers. Pretreatment of cell cultures GMK and Hep-2 prior to 
Coxsackie virus infection showed a reduction in virus titer 1log10 - 2 logs10. Similar 
results were obtained on the VERO, BHK and 3T3 cells with gamma-herpesvirus 
MHV-68. Visible reduction of Influenza A virus replication on MDCK cells was 
obtained at the concentration 100 μg/ml of SLLA (SL derived from Linoleic acid). 
Thus it can be concluded that direct treatment of viruses was more effective than 
indirect treatment and the inhibitory action can be attributed to the amphiphilic 
structure of SL which might be killing the viruses by disturbing the membrane lipid 
order. 
 
Chapter IV. Differentiation inducing ability of SLs against glioma cells 
The forth chapter deals with the differentiation inducing ability of SLs. The effects 
have been investigated on LN229 - a glioma cell line which has been reported for 
the first time. In response to different SL forms, marked difference in cell density 
was observed as compared to the control cells along with various morphological 
changes such as formation of long thread like extensions arising from ends of the 
cells, cell alignment, cell elongation and bundle formation in dose dependent 
manner.  In this chapter the morphological evidence of the potential of SLs as 
differentiation inducers has been presented. The finding suggests the utility of 
SLs as a pharmaceutical agent for the treatment of glioblastomas. With the use of 
SL, the cancerous cells undergoing uncontrolled proliferation can be forced to 
differentiate thus tumor progression may be arrested. 
 
 
Chapter V(a). Glycolipid production by a novel yeast- Pichia caribbica (HQ222812) 
with xylose as a head group and its advantageous properties 
The fifth chapter (part a) deals with the use of a new xylose fermenting yeast- 
Pichia caribbica for biosurfactant production so as to achieve the less explored 
head group diversity in SL structure. The media and fermentation parameters 
xvi 
 
 
have been optimized to achieve maximum yield of 7.5g/l. The physicochemical 
properties of the xylolipid biosurfactant have been assessed. It reduced the 
surface tension of distilled water from 70mN/m to 35.9mN/m with the 
remarkably low CMC value 1.0 mg/l as compared to typical SLs (reported CMC 
range-40-100mg/l). Structural characterization was done using FTIR and HR-MS 
to identify the structure putatively. 17-L-[(β-D-xylopyranosyl)-oxy]-Δ9-
heptadecanoic acid correlated to m/z 415 majorly constituted the product. 
Control experiment was performed in which glucose was provided as the 
hydrophilic carbon. This product was also subjected to HR-MS analysis to 
determine its chemical nature and found to be different from xylolipid. Presence 
of xylose as head group was anticipated to give altered physicochemical and 
biological activities. In accordance to the same, low CMC value and better 
inhibitory action was demonstrated against Staphylococcus aureus, a gram 
positive bacterium. 
 
Chapter V(b). Crystalline xylitol production by a novel yeast- Pichia caribbica 
(HQ222812) and its application for quorum sensing inhibition in gram negative 
marker strain Chromobacterium violecium CV026 
The fifth chapter (part b) is about quantitative production of xylitol from D-xylose 
with the yield of 0.852 gm/gm and volumetric productivity of 1.83 gm/l/h. A safe 
procedure for product extraction has been described. The ability of xylitol to act as 
a quorum sensing antagonist in gram negative marker strain Chromobacterium 
violaceum CV026 has been demonstrated for the first time.  
 
Conclusions 
The last chapter summarizes the work presented in the thesis and emphasizes on 
possible further research in this area. 


SYNTHESIS OF HETEROCYCLIC COMPOUNDS

SHAH, RAMJI TOKARSHI







Abstract


Role of external heat and mass transfer in laboratory Reactors The present-day laboratory reactors have teen developed to fulfill the sole objective of determining intrinsic kinetics of catalytic reactions. The transport processes are therefore treated as 'falsifiers'. As a result, the catalyst is used in the form of small particles to ensure that the internal heat and mass transfer do not influence the measurement of intrinsic reaction kinetics. With the catalyst in the form of multitudes of particles, the only way to account for external heat and mass transfer is to resort to the film theory which however cannot give a true quantitative estimate of these transfer rates. The difficulty is then circumvented by operating the reactor at relatively low temperatures at which the intrinsic rate of reaction is very low compared to that of external mass transfer. This indirect approach very much restricts the range of temperature under which reaction kinetics can be studied. On the other hand, for the design and operation of the industrial reactors which operate for maximum throughput per unit weight of catalyst, the intrinsic kinetic data are not enough, the information on its interactions with transport processes also being required. A few reactors have "been developed in the recent years in which "both the intrinsic kinetics and its interactions with transport processes can be studied. But these reactors are unwieldy in size and hence they have not found acceptance as laboratory reactors. Rotating-disk flow system. The following advantages must be taken into account while considering this flow system in developing a laboratory reactor: 
i) The surface is uniformly accessible for heat and. mass transfer, i.e. the local [point] rates are same over the entire surface. ii) The rates of heat and mass transfer can be computed from the boundary layer theory. iii) The flow is generated by the disk itself, and. it can be computed from theory. iv) Extensive studies carried out on this flow system have made it possible to specify the range of parameters in which the exact solution of heat and mass transfer is applicable. Design and, construction of rotating disk reactor Initially plug-flow condition was considered to be the only choice and a reactor was made accordingly. During the course of this work, it was observed that the flow generated, by a disk was enough to operate the reactor under mixed-flow condition. Accordingly a new reactor was designed and fabricated and construction details are given in this thesis. The disk used in this work was of 75 mm diameter and was operated in the speed range 2000-9500 rprn. In view of the mechanical problems and the limitations of precision in the fabrication of such high-speed devices the construction of this reactor was simplified and the maximum operating temperature restricted tc 230?C. The catalyst pellet was prepared by in situ pressing in the tapered bore of the disk. Two bore sizes were used viz. 23/25 and 43/45 mm diameter. Experimental studies on rotating disk reactor The residence time distribution studies confirmed, that the flow pattern of the reactor can be represented by perfect mixed-flow [CSTR] condition.. , The mass transfer studies using the naphthalene sublimation technique confirmed that the rate of mass transfer is in agreement with that predicted by theory. The reaction studies were carried out with oxidation of hydrogen by air as the typical reaction. Three types of catalyst formulations were devised and tested. These are; i) bulk metal ii) thin coating, and iii) supported-metal . 
The in situ pelleting of supported metal catalysts was found to be suitable, and a catalyst containing O.08% platinum on calcium carbonate was extensively tested in the temperature range 27-230oC and in the Reynolds number range 8000-84000. The reaction was found to be mixed controlled by external as well as internal heat and mass transfer. Multiple steady states and oscillations around a steady state were observed. Detailed study of the interactions of external and internal transport processes with reaction kinetics was not possible in the temperature range 27-230 O C. The three studies mentioned above have confirmed for the first time that it is feasible to use the rotating disk reactor as a laboratory reactor to study not only the reaction kinetics but also their interactions with transport processes. 















Development of a Laboratory Catalytic Reactor Based on Rotating Disk Flow

SUDARSHAN, D. PRASAD

SYNOPSIS 
I 
 
 
 The work carried in the research tenure has been compiled in the form of a thesis 
entitled “Synthesis and biological evaluation of a new class of pyrrolo[2,1-
c][1,4]naphthodiazepines and flavones”. The research reported in this thesis has two 
main aims. The first aim is to develop novel C8- and C9-chloroethoxy functionalised 
pyrrolonaphthodiazepines and their analogs as efficient and sequence selective DNA 
binding anticancer agents with fewer and less severe side effects. The second aim is to 
synthesize two natural flavones and their derivatives for the first time and evaluated 
their anticancer, antimicrobial and antioxidant activities. The thesis has been divided 
into four chapters. 
 CHAPTER I: This chapter covers the background information about cancer and 
pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) as potent antitumor antibiotics.  
 CHAPTER II: This chapter describes the design, synthesis and biological evaluation 
of a new class of pyrrolo[2,1-c][1,4]naphthadiazepines (PNDs) and their derivatives as 
potential anticancer agents. Some mechanistic studies like DNA cross-linking ability, 
cellular stress and apoptosis are carriedout. 
 CHAPTER III: This chapter describes the design, synthesis, DNA binding affinity, 
anticancer activity and its mechanism of action against five human cancer cell lines of 
novel bifunctional anticancer agents composed of pyrrolo[2,1-c][1,4]naphthodiazepine 
(PNDs) and DC-81 subunits.  
 CHAPTER IV: This chapter illustrates the first synthesis and biological evaluation of 
two recently isolated bioactive flavones and their derivatives as potential 
antimicrobial and antioxidant agents. 
 
 
SYNOPSIS 


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