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Preparation of new chitosan products and investigation of their biological activations
No full textFen Bilimleri Enstitüsü, Moleküler Biyoloji ve Genetik Ana Bilim Dalı, Moleküler Biyoloji ve Genetik Bilim DalıKitosan (Cs) doğada en çok bulunan polisakkaritlerden birisidir. Kaynak olarak yengeç, böceklerin dış iskeleti, mantarlar, bazı fungus ve yeşil alglerin hücre duvar yapılarında bulunan kitinden elde edilmektedir. Biyouyumluluk, antimikrobiyal, antifungal, antikoagülant ve antikanser özelliklerinden dolayı ilaç sanayisinden gıda endüstrisi uygulamaları için ilgi odağıdır. Bu nedenle metastazı önlemeye yönelik oleik asit sülfatlanmış kitosan (OlcShCs) hazırlanarak biyolojik ve kimyasal karakteristik özellikleri araştırıldı ve orijinal kitosan ile karşılaştırıldı. Bunun için kitosan ve türevi FTIR, NMR, DSC, TGA ve DTA analizleri yapıldı ve kimyasal karakterizasyonu yapıldı. Akabinde kitosan türevinin antimikrobiyal, antifungal ve antikanser aktiviteleri araştırıldı. CS ve OlcShCs'nin FT-IR spektrumları karşılaştırıldığında CS'nin karakteristik spekrumları; 1646 cm?1 C=O amide-I gerilmesi (stretching)), 1568 cm?1 N-H amide-II bağlanması ve 1374 cm?1 C-N amide-III gerilmesini göstermektedir. Modifikasyon sonrası açil olmayan birincil amin grubuna karşılık gelen 1568 cm?1 pik kaybolurken, 1634 cm-1'de açığa çıkmaktadır. Bu durum modifiye kitosanda amid bağının varlığını göstermektedir. Ayrıca 1732 cm-1 ester bağının karbonil grubunun karakteristik pikidir. Bu bağ kitosanın hidroksil grubu ile oleik asitin karboksil grubu arasında açığa çıkmaktadır. Dolayısıyla yapıda N-açilasyonun açığa çıktığını göstermektedir. 788 ve 1207 cm-1'de yeni açığa çıkan FT-IR bantları ise sırasıyla sülfo gruplarının C–O–S and O-S–O bağ gerginliğine karşılık gelmektedir. H1 NMR analiz sonucuna bakıldığında 2.4 ppm'deki pik N-asetil glukozamin grubunun N-asetil protonlarına karşılık gelmektedir. 3.6 ppm'deki pik ise deasetile glukozamin kalıntılarının H-2 protonuna denk gelmektedir. Kitosanın oleik asit ile kimyasal modifikasyonu [-CH2-CO] 1.4 ppm'deki pik ile doğrulandı. Cs molekülünün E. coli CICC 21524, B. subtilis ATCC 21332, S. epidermidis ATCC 12228, C. albicans ATCC 60193 türlerine karşı sırasıyla %99.18±3.09, %87.50 ± 0.48, %100 ± 0, %12.90 ±3.4 antimikrobiyal etkiye sahip olduğu görüldü. Aynı konsantrasyonda OlcShCs molekülünün E. coli CICC 21524, B. subtilis ATCC 21332, S. epidermidis ATCC 12228, C. albicans ATCC 60193 türleri üzerine sırasıyla antimikrobiyal etkisi %0 ±6.69, %6.66 ±1.25, %59.13 ±4.97, %21.26 ±2.17 olarak saptandı. HeLa kanser hücrelerine karşı sitotoksik etkisi 24 saat için IC50 değeri 81.57±5.30 ?g/ml bulundu. Sonuç olarak yeni sentezlediğimiz kitosan türevi molekül kitosana göre genel anlamda daha düşük antimikrobiyal etki gösterdiği, HeLa hücrelerine karşı kitosan türevinin sitotoksik etki gösterdiğinden dolayı potansiyel ilaç adayı olabilir.Chitosan is one of the most abundant polysaccharide in nature. It is derived from chitin which is found in crustaceans, insects, mushrooms and cell walls of certain fungi and green algae and their mainly skeleton structures. Because of its functional properties such as biocompatibility, antimicrobial, antifungal, research scientists are interested to increasing the application area from medicine, drug to food industry. We have prepared oleic acid sulfated chitosan (OlcShCs) to determine its characteristic properties such as chemicals and biologicals. Medium molecular weight chitosan was used to synthesis the oleic acid sulfated chitosan. The structure of the products was characterized using various spectroscopic and analytical methods such as FTIR, NMR, DTG, DSC and TGA. The new molecule was investigated in terms of antimicrobial, antifungal and anticancer activities. We can compare the FT-IR spectra of chitosan (Cs) and OlcShCs. The FT-IR spectrum of Cs exhibited characteristic bands of 1646 cm?1 (C=Ostretching of amide-I), 1568 cm?1 (N-H bending of amide-II) and 1374 cm?1 (C-N stretching of amide-III). After modi?cation, the vibrational band corresponding to the non-acylated primary amine group at 1568 cm?1 disappeared and the peak at 1634 cm?1 appeared which shows the presence of amide bond in the modi?ed Cs. Furthermore, the peak which was observed at 1732 cm?1 is the characteristic peak of carbonyl group of ester, which is formed between carboxyl groups of oleic acid and hydroxyl groups of Cs. That means N-acylation occurred in the structure. The new FT-IR spectrum bands at 788 and 1207 cm?1, are due to sulfo groups (C–O–S and O-S–O bond stretching, respectively). These results show that the sulfate groups, oleic acid are introduced into chitosan successfully. The H1 NMR spectrum peak at 2.4 ppm was due to N-acetyl protons of N-acetyl glucosamine while the peak at 3.6 ppm was due to an H-2 proton deacetylated glucosamine residues. The chemical modification of chitosan by oleic acid was confirmed by the peaks at 1.4 ppm [-CH2-CO]. The chitosan showed 99.18%±3.09, 87.50% ±0.48, 100%± 0, 12.90% ±3.4 antimicrobial activity at 1% concentration for E. coli CICC 21524, B. subtilis ATCC 21332, S. epidermidis ATCC 12228, C. albicans ATCC 60193 strains respectivelly. The modified chitosan also showed 0% ±6.69, 6.66% ±1.25, 59.13% ±4.97, 21.26% ±2.17 antimicrobial activity at 1% concentration for E. coli CICC 21524, B. subtilis ATCC 21332, S. epidermidis ATCC 12228, C. albicans ATCC 60193 respectivelly. The IC50 value was found 81.57±5.30 ?g/ml at 24 hours for HeLa cancer cell line. The new synthesed molecule showed anticancer effect to HeLa cell line and showed antimicrobial activity. Depend on these properties, ıt can be candidate for drug in future
Producdution, isolation and characterization of extracellular amylase enzyme from gaita bacreria
No full textFen Bilimleri Enstitüsü, Moleküler Biyoloji ve Genetik Ana Bilim DalıAmilazlara olan ihtiyaç günümüz biyoteknolojisinde kullanım alanlarından dolayı artmaktadır. Bu ihtiyaçların karşılanması amacıyla bakteriyel amilazların izolasyonu saflaştırılması ve karakterizasyonu günümüzde ilgi odağı oluşturmaktadır. Gaita bakterilerinden ektraselüler ? - amilaz üreten bakterilerin hem fenotipik hem de genotipik karakterizasyonu yapılarak üretilen ? - amilaz enziminin karakterizasyonu gerçekleştirilmiştir. 16SrDNA gen bölgeleri dizilendiğinde Lactobacillus fermentum olduğu saptanmıştır. Gram pozitif, %3 NaCl içeren besi yerinde üreyebilen bir bakteridir. Üretilen amilaz enzimi 20 kDa ağırlığındadır. Enzimin çalışması için optimum pH 5.0 ve 10.0'dur ve sıcaklığı 45 ºC' ve 37 ºC olarak bulunmuştur. Anahtar kelimeler: amilaz, biyoteknoloji, gaita, ekstraselüler enzim, nişastaThere are much more attention on the amylase enzymes in recent biotechnology because of application of them. To provide these needed enzymes, bacterial amylase enzymes are especially focused on. Bacteria, producing amylase enzymes and living in gaita, were characterized both phenotypic and genotypic methods, and also one of their enzymes that ? - amylase enzyme, was characterized. The bacterium was identified to be Lactobacillu s fermentum by sequencing its 16SrDNA. The bacterium grows in %3 NaCl medium and are Gram positive. Produced ? - amylase enzyme has 20 kDa molecular weight. Its optimum pH and temperature were 5.0 and 10.0 and 45ºC and 37ºC, respectively. Key Words : amylase , biotechnology, extracelular enzyme, gaita, starch
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Probiotic Properties of a Lactobacillus fermentum Isolated from New-born Faeces
No full textLactic acid bacteria (LAB) have been demonstrated to have roles in many applications, ranging from lowering of cholesterol to immunological development. In this study, Lactobacillus fermentum was isolated from a new-born's faeces and its genotypic and probiotic characterizations were performed. Our results showed that the survival rate of isolated Lactobacillus fermentum was 39.39% at pH 2 and 81.34% in the stimulated gastric juice at pH 3. It also digested bile salts. Its surface hydrophobicity was found to be 57.59% in n-hexane. These findings indicated that the isolate can be a good probiotic candidate.CUBAP, Sivas Cumhuriyet LJniversity [F-498]This work (F-498) was supported by CUBAP, Sivas Cumhuriyet LJniversity
SÜLFATİT BENZERİ KİTOSAN TÜREVİ BİLEŞİK
No full textBuluş, bazı kanser ya da kötü huylu hücrelerin hücrelerinin damar
yüzeylerine yapışmasını engelleyerek kanser hücrelerinin invasyonunu
engelleyen sülfatit benzeri kitosan türevi bir bileşik ile ilgilidir.Sivas Cumhuriyet Üniversites
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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