IR@NEIST - North East Institute of Science and Technology (CSIR)
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Optimization of process parameters for improved production of bioactive metabolite by a novel endophytic fungus Fusarium sp. DF2 isolated from Taxus wallichiana of North East India
Get PDFAn endophytic fungus having antifungal and antibacterial
properties was isolated from Taxus wallichiana of Arunachal
Pradesh, India. On the basis of morphological and molecular
characteristics, the fungus was identified as Fusarium sp. and
designated as DF2. The fungus was optimized for growth and
maximum production of the antimicrobial agent. Media with
5% leaf extract (w/v) supplemented with 0.1% dextrose as
carbon and yeast extract as nitrogen source favored the
growth with temperature optimum 25 ± 2°C and pH 6.
Incubation period of 10 days was observed optimum for growth
and production of antimicrobial agent. Phenylalanine and
dextrose enriched basal medium promoted the antimicrobial
agent production, whereas methionine amended in combination
with glucose promoted higher biomass accumulation. The TLC
purified active compound with UV λ-max 270 nm in ethyl
acetate has got the lowest minimum inhibitory concentration
(MIC) against Bacillus subtilis, Staphylococcus aureus and
Escherichia coli and highest against Pseudomonas aeruginosa
Ionic liquid - an efficient recycalable system for the synthesis of 2,4-disubstituted quinolines via Meyer - Schuster rearrangement
Get PDFAntimicrobial Resistance in Gram Positive and Gram Negative Bacteria Progress and Challenges
Get PDFSerious infections caused by bacteria that have become resistant to commonly used
antibiotics have become a major global healthcare problem in the 21st century.
Antibiotic resistance, initially a problem of the hospital setting associated with an
increased number of hospitals acquired infections usually in critically ill and
immuno-suppressed patients, has now extended into the community causing severe
infections difficult to diagnose and treat. In hospitals, most common resistant
bacteria include methicillin-resistant Staphylococcus aureus, vancomycin-resistant
enterococci and gram-negative rods including Enterobacteriaceae and Pseudomonas
aeruginosa. Vancomycin intermediate and resistant S. aureus, represent a new
treatment challenge. In the community, penicillin and macrolide-resistant
pneumococci developed several decades ago and are now present all over the world.
More recently, community-acquired methicillin-resistant S. aureus has become a
problem in several countries causing skin infections but also severe diseases. The
molecular mechanisms by which bacteria have become resistant to antibiotics are
diverse and complex. Bacteria have developed resistance to all different classes of
antibiotics discovered to date. The most frequent type of resistance is acquired and
transmitted horizontally via the conjugation of a plasmid. In recent times new
mechanisms of resistance have resulted in the simultaneous development of
resistance to several antibiotic classes creating very dangerous multidrug-resistant
(MDR) bacterial strains, some also known as 18 18superbugs 19 19. In many cases the use of
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antibiotics is unnecessary or questionable. The indiscriminate and inappropriate use
of antibiotics in outpatient clinics, hospitalized patients and in the food industry is
the single largest factor leading to antibiotic resistance. In recent years, the number
of new antibiotics licensed for human use in different parts of the world has been
lower than in the recent past. In addition, there has been less innovation in the field
of antimicrobial discovery research and development. The pharmaceutical industry,
large academic institutions or the government are not investing the necessary
resources to produce the next generation of newer safe and effective antimicrobial
drugs. In many cases, large pharmaceutical companies have terminated their antiinfective
research programs altogether due to economic reasons. The potential
negative consequences of all these events are relevant because they put society at
risk for the spread of potentially serious MDR bacterial infections
X-Ray scattering study of the average polycyclic aromatic unit in Ledo coal
Get PDFThis report is an attempt to understand the short-range structural features, to determine the
relationship(s) between the aryl/alkyl carbon ratio, and to determine the size of the average
polycyclic aromatic unit in Ledo coal from Makum coalfield, Assam, India. An X-ray scattering
analysis of the average polycyclic aromatic unit in the coal indicates that the aromatic fraction in
this coal is 74% with the aliphatic fraction correspondingly estimated to be 26%. The average
carbon atom has 2.3 nearest carbon atom neighbours at an average bond distance of 1.50 (1) Å.
The average stacking height of the parallel aromatic layers and the average diameter of the aromatic
layers are estimated to be 7.58 Å and 4.86 Å, respectively. For this coal, the average number of
stacking layers and the average number of atoms per layer are estimated to be 2 and 8, respectively.
In addition, the Gamma band is observed at a d value of 4.42 Å
Microwave promoted one-pot synthesis of novel A-ring fused steroidal dehydropiperazines
Get PDFThe preparation of ring-A fused steroidal dehydropiperazine at the 3,4-position is herein
described. The novel steroidal dehydropiperazines were prepared from the annulation reaction
of ethylenediamine with 3-keto-4-en steroids in a one-pot reaction under microwave
irradiation. The key step involves base catalysed aerial oxidation of the C-6 methylene group
followed by cyclocondensation of ethylenediamine via Michael addition reaction
An efficient reduction protocol for the synthesis of beta-hydroxycarbamates from beta-nitro alcohols in one pot : a facile synthesis of (-)-beta-conhydrine
Get PDFAn efficient and practical one-pot protocol for the reduction of b-nitro alcohols to their corresponding
N-(tert-butoxycarbonyl) amino alcohols using Zn 13NH4Cl in aqueous methanol is described. Other
reducible groups such as ketones and isolated double bonds remained intact. This methodology allows
a short synthesis of (�)-b-conhydrine to be achieved
Synthesis of chiral polymer by Mukaiyama alcohol polymerization and its characterization
Get PDFIn this paper we have reported the synthesis of chiral polymer by asymmetric aldol polymerization
of bis(silyl enol ether) and dialdehyde by Mukaiyama aldol reaction which is one of the most
important aldol reaction for chiral polymer synthesis. We have studied the polymerization reaction
in two different catalytic conditions such as by using a chiral catalyst viz. 1,1′-binaphthyl-2,′-diol
(BINOL) which is modified by reacting it with diethyl zinc solution in hexane. Another catalyst
used for the polymerization reaction is lipase, which is a triacylglycerol hydro lases; EC 3.1.1.3,
belongs to a most popular group of enzyme and are used for chiral synthesis. A comparative
study has also been made for the polymerization reaction in both the catalytic systems. The
results obtained in various reaction conditions by changing amount of catalyst, monomer ratio
etc. has also been discussed. The polymers were characterized by IR, NMR, GPC, TGA-DTA,
specific rotation and circular dichrosm study and it was found that both catalytic conditions give
the chiral polymer of approximately same enatioselectivity
