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61.
Chokkalingam Uvarani Karuppannan Arumugasamy Kumarasamy Chandraprakash Mathan Sankaran Athar Ata Palathurai Subramaniam Mohan 《化学与生物多样性》2015,12(3):358-370
Phytochemical investigation of the CHCl3 fraction of Swertia corymbosa resulted in the isolation of a new 3‐allyl‐2,8‐dihydroxy‐1,6‐dimethoxy‐9H‐xanthen‐9‐one ( 1 ), along with four known xanthones, gentiacaulein ( 3 ), norswertianin ( 4 ), 1,3,6,8‐tetrahydroxyxanthone ( 5 ), and 1,3‐dihydroxyxanthone ( 6 ). Structure of compound 1 was elucidated with the aid of IR, UV, NMR, and MS data, and chemical transformation via new allyloxy xanthone derivative ( 2 ). Compounds 1 – 6 exhibited various levels of antioxidant and anti‐α‐glucosidase activities. Absorption and fluorescence spectroscopic studies on 1 – 6 indicated that these compounds could interact with calf thymus DNA (CT‐DNA) through intercalation and with bovine serum albumin (BSA) in a static quenching process. Compound 1 was found to be significantly cytotoxic against human cancer cell lines HeLa, HCT116, and AGS, and weakly active against normal NIH 3T3 cell line. 相似文献
62.
63.
FCRL5 Delineates Functionally Impaired Memory B Cells Associated with Plasmodium falciparum Exposure
64.
Vijayasree V. Giridharan Rajarajan A. Thandavarayan Somasundaram Arumugam Makoto Mizuno Hiroyuki Nawa Kenji Suzuki Kam M. Ko Prasanna Krishnamurthy Kenichi Watanabe Tetsuya Konishi 《PloS one》2015,10(11)
Amyloid β (Aβ)-induced neurotoxicity is a major pathological mechanism of Alzheimer’s disease (AD). Our previous studies have demonstrated that schisandrin B (Sch B), an antioxidant lignan from Schisandra chinensis, could protect mouse brain against scopolamine- and cisplatin-induced neuronal dysfunction. In the present study, we examined the protective effect of Sch B against intracerebroventricular (ICV)-infused Aβ-induced neuronal dysfunction in rat cortex and explored the potential mechanism of its action. Our results showed that 26 days co-administration of Sch B significantly improved the behavioral performance of Aβ (1–40)-infused rats in step-through test. At the same time, Sch B attenuated Aβ-induced increases in oxidative and nitrosative stresses, inflammatory markers such as inducible nitric oxide syntheses, cyclooxygenase-2, interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α, and DNA damage. Several proteins such as receptor for advanced glycation end products (RAGE), nuclear factor-κB, mitogen-activated protein kinases, and apoptosis markers were over expressed in Aβ-infused rats but were significantly inhibited by Sch B treatment. Furthermore, Sch B negatively modulated the Aβ level with simultaneous up-regulation of HSP70 and beclin, autophagy markers in Aβ-infused rats. The aforementioned effects of Sch B suggest its protective role against Aβ-induced neurotoxicity through intervention in the negative cycle of RAGE-mediated Aβ accumulation during AD patho-physiology. 相似文献
65.
Nithya BabuRajendran Paaventhan Palasingam Kamesh Narasimhan Wenjie Sun Shyam Prabhakar Ralf Jauch Prasanna R. Kolatkar 《Nucleic acids research》2010,38(10):3477-3488
Smad1 is a downstream effector of the BMP signaling pathway that binds regulatory DNA to execute gene expression programs leading to, for example, the maintenance of pluripotency in mice. On the contrary, the TGF-β-activated Smad3 triggers strikingly different programs such as mesodermal differentiation in early development. Because Smad1 and Smad3 contain identical amino acids at the DNA contact interface it is unclear how they elicit distinctive bioactivities. Here, we report the crystal structure of the MH1 domain of Smad1 bound to a palindromic Smad binding element. Surprisingly, the DNA contact interface of Smad1 is drastically rearranged when compared to Smad3. The N-terminal helix 1 of Smad1 is dislodged from its intramolecular binding site and adopts a domain swapped arrangement with a symmetry-related molecule. As a consequence, helix 2 kinks away from the double helix disabling several key phosphate backbone interactions. Thermal melting analysis corroborates a decompacted conformation of Smad1 and DNA binding assays indicate a lower overall affinity of Smad1 to DNA but increased cooperativity when binding to palindromic DNA motifs. These findings suggest that Smad1 and Smad3 evolved differential qualities to assemble on composite DNA elements and to engage in co-factor interactions by remodeling their N-termini. 相似文献
66.
Purushothaman S Prasanna R Niranjana P Raghunathan R Nagaraj S Rengasamy R 《Bioorganic & medicinal chemistry letters》2010,20(24):7288-7291
Synthesis of a series of novel hexahydrochromenopyrrole analogues has been accomplished through an intramolecular 1,3-dipolar cycloaddition (1,3-DC reaction) of azomethine ylides, generated by the aldehyde induced decarboxylation of secondary amino acids. These compounds were screened for antibacterial and antifungal activities against six human pathogenic bacteria and three human pathogenic fungi and found to have good antimicrobial properties against most of the microorganisms. 相似文献
67.
R. Prasanna A. Sood P. Jaiswal S. Nayak V. Gupta V. Chaudhary M. Joshi C. Natarajan 《Applied Biochemistry and Microbiology》2010,46(2):119-134
Cyanobacteria are a simple, but primitive and diverse group of microorganisms, with characteristics in common to both bacteria and algae. Their success as a group in a wide range of habitats has been attributed to their unique physiological characters and high adaptive ability under a wide range of environmental conditions. The potential of cyanobacteria as a source of a variety of compounds such as polysaccharides, lipids, proteins, vitamins, sterols, enzymes, pharmaceuticals and other fine chemicals is well recognized, and their demand is now on an increasing trend. This compilation reviews the salient advances in the discovery of bioactive compounds from cyanobacteria and their significance in agriculture and industry. 相似文献
68.
Nair SK Prasanna BM Garg A Rathore RS Setty TA Singh NN 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,110(8):1384-1392
We have mapped the quantitative trait loci (QTLs) conferring resistance to sorghum downy mildew (Peronosclerospora sorghi; SDM) and Rajasthan downy mildew (P. heteropogoni; RDM), two species of DM prevalent throughout India. QTL mapping was carried out on a backcross population of 151 individuals derived from a cross between CM139 (susceptible parent) and NAI116 (highly resistant to both SDM and RDM). Heritability estimates were 0.74 for SDM and 0.67 for RDM. Composite interval mapping combined with a linkage map constructed with 80 simple sequence repeat (SSR) markers resulted in the identification of three QTLs (one each on chromosomes 2, 3 and 6) for SDM resistance and two QTLs (one each on chromosomes 3 and 6) for RDM resistance, all of which were contributed by NAI116. The significance of the major QTL on chromosome 6 (bin 6.05) that confers resistance to diverse DMs in tropical Asia, including SDM and RDM in India, was also verified. The results confirmed that some common QTLs contribute to both SDM and RDM resistance, while additional loci might specifically govern resistance to SDM. The QTL information generated in this study provide information that will aid in undertaking an integrated breeding strategy for the transfer of resistance to SDM and RDM in maize lines using marker-assisted selection. 相似文献
69.
Inhibition of pathogenic bacterial biofilm by biosurfactant produced by Lysinibacillus fusiformis S9
Arun Kumar Pradhan Nilotpala Pradhan Lala Behari Sukla Prasanna Kumar Panda Barda Kanta Mishra 《Bioprocess and biosystems engineering》2014,37(2):139-149
A biosurfactant producing microbe isolated from a river bank was identified as Lysinibacillus fusiformis S9. It was identified with help of biochemical tests and 16S rRNA gene phylogenetic analysis. The biosurfactant S9BS produced was purified and characterized as glycolipid. The biosurfactant showed remarkable inhibition of biofilm formation by pathogenic bacteria like Escherichia coli and Streptococcus mutans. It was interesting to note that at concentration of 40 μg ml?1 the biosurfactant did not show any bactericidal activity but restricted the biofilm formation completely. L. fusiformis is reported for the first time to produce a glycolipid type of biosurfactant capable of inhibiting biofilm formation by pathogenic bacteria. The biosurfactant inhibited bacterial attachment and biofilm formation equally well on hydrophilic as well as hydrophobic surfaces like glass and catheter tubing. This property is significant in many biomedical applications where the molecule should help in preventing biofouling of surfaces without being toxic to biotic system. 相似文献
70.
Ashwini Deshpande K. Sankaran S. F. D'Souza G. B. Nadkarni 《Biotechnology Techniques》1987,1(1):55-58
Summary A relatively simple method has been described for the rapid purification of D-amino acid oxidase from Trigonopsis variabilis by hydrophobic chromatography on Phenyl-Sepharose CL-4B and negative adsorption on DEAE-cellulose. The purified enzyme had a specific activity of 22–24 units at 25°C and exhibited three bands on enzymatic staining. 相似文献