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261.
262.
Synthesis and antibacterial activity of substituted 1,2,3,4-tetrahydropyrazino [1,2-a] indoles 总被引:1,自引:0,他引:1
Tiwari RK Singh D Singh J Yadav V Pathak AK Dabur R Chhillar AK Singh R Sharma GL Chandra R Verma AK 《Bioorganic & medicinal chemistry letters》2006,16(2):413-416
A series of substituted 1,2,3,4-tetrahydropyrazino [1,2-a] indole derivatives have been synthesized and tested against the Gram positive and Gram negative strains of bacteria namely Staphylococcus aureus (MTCCB 737), Salmonella typhi (MTCCB 733), Pseudomonas aeruginosa (MTCCB 741), Streptomyces thermonitrificans (MTCCB 1824) and Escherichia coli (MTCCB 1652). All synthesized compounds showed mild to moderate activity. However, compounds 4d-f were found to have potent activity against pathogenic bacteria used in the study. Their MIC ranged from 3.75 to 60 microg/disc. In vitro toxicity tests demonstrated that toxicity of 4d-f was not significantly different than that of gentamycin. However, at higher concentration (1000-4000 microg/ml) difference was highly significant. 相似文献
263.
Kumar VS Sharma VL Tiwari P Singh D Maikhuri JP Gupta G Singh MM 《Bioorganic & medicinal chemistry letters》2006,16(9):2509-2512
The study investigated spermicidal and antitrichomonas activities of selective serotonin reuptake inhibitor (SSRI) antidepressants with a view to generate new lead for development of dual-function spermicidal microbicides, which is an urgent global need. Fluoxetine, Sertraline, and Fluvoxamine exhibited both spermicidal and anti-STI (antitrichomonas) activities in vitro, whereas Paroxetine and Citalopram showed only the spermicidal activity. Fluoxetine exhibited better activity profile than the other antidepressant drugs with its spermicidal and antitrichomonas activities being comparable to that of the OTC contraceptive Nonoxynol-9. The non-detergent nature of Fluoxetine and a much lower spermicidal ED50 value (than N-9) may add considerably to its merit as a candidate for microbicidal contraceptive. Thus, the antidepressants exhibiting both spermicidal and antitrichomonas activities might provide useful lead for the development of novel, dual-function spermicidal contraceptives. 相似文献
264.
Gudewar J Pan D Bera AK Das SK Konar A Rao JR Tiwari AK Bhattacharya D 《Molecular biology reports》2009,36(6):1381-1385
Sixty-six isolates of larval stage of Echinococcus granulosus, a known pathogenic parasite of man and animals were collected from cattle, buffalo, sheep, and goats. Single-stranded conformation
polymorphism (SSCP) for analysis of variation after denaturation of amplicon of intron of actin II (ACTII) revealed six SSCP
phenotypes. Intron portion was analyzed considering introns-early and introns-late theories. Isolates belonging to different
conformers were further screened for mitochondrial ATPase subunit 6 (ATP6) and NADH dehydrogenase subunit II (nadII) genotypes. Assignment of each isolate to its specific strain was achieved after comparing with standard genotypes of E. granulosus. Variants deduced by nuclear targets did not match with mitochondrial haplotypes. A possible explanation for this observation
can be attributed toward interspecific hybridization since cross-fertilization occurs less frequently in hermaphrodite organisms.
A phylogenetic tree drawn on the basis of predicted aminoacid sequence of ATP6 and nadII revealed two distinct clusters i.e. E. granulosus sensu stricto and E. ortleppi/cattle strain (EG5). To the best of our knowledge, this is the first report of genetic characterization of two distinct ATP6
and nadII genotypes of zoonotic importance living in sympatry. 相似文献
265.
R. Ranga Rao Ashok K. Tiwari P. Prabhakar Reddy K. Suresh Babu Amtul Z. Ali K. Madhusudana J. Madhusudana Rao 《Bioorganic & medicinal chemistry》2009,17(14):5170-5175
A bioassay-guided fractionation and chemical examination of antihyperglycemic root extract of Derris indica resulted in isolation and characterization of two new furanoflavanoids (1, 2) along with thirteen known compounds (3–15). Their structures were determined on the basis of extensive spectroscopic (IR, MS, 1D and 2D NMR) data analysis and by comparison with the literature data. All the compounds were tested in vitro for intestinal α-glucosidase inhibitory and DPPH radical activity. New compounds (1, 2) displayed moderate intestinal α-glucosidase inhibitory as well as free radical scavenging activity. Other compounds also displayed varying degrees of moderate intestinal α-glucosidase inhibitory activity. Pongamol (6) displayed potent intestinal α-glucosidase inhibition. 相似文献
266.
267.
Marimuthu Jeya Kyoung-Mi Lee Manish Kumar Tiwari Jung-Soo Kim Paramasamy Gunasekaran Sang-Yong Kim In-Won Kim Jung-Kul Lee 《Applied microbiology and biotechnology》2009,83(2):225-231
This study isolated a novel erythritol-producing yeast strain, which is capable of growth at high osmolarity. Characteristics
of the strain include asexual reproduction by multilateral budding, absence of extracellular starch-like compounds, and a
negative Diazonium blue B color reaction. Phylogenetic analysis based on the 26S rDNA sequence and physiological analysis
indicated that the strain belongs to the species Pseudozyma tsukubaensis and has been named P. tsukubaensis KN75. When P. tsukubaensis KN75 was cultured aerobically in a fed-batch culture with glucose as a carbon source, it produced 245 g/L of erythritol,
corresponding to 2.86 g/L/h productivity and 61% yield, the highest erythritol yield ever reported by an erythritol-producing
microorganism. Erythritol production was scaled up from a laboratory scale (7 L fermenter) to pilot (300 L) and plant (50,000 L)
scales using the dissolved oxygen as a scale-up parameter. Erythritol production at the pilot and plant scales was similar
to that at the laboratory scale, indicating that the production of erythritol by P. tsukubaensis KN75 holds commercial potential. 相似文献
268.
Siddharth Tiwari Devesh K. Mishra Sribash Roy Ankit Singh P. K. Singh Rakesh Tuli 《Plant cell reports》2009,28(12):1827-1836
A synthetic DNA construct containing cholera toxin B subunit, genetically fused to the surface glycoprotein of rabies virus
was expressed in tobacco plants from a seed specific (legumin) promoter. Seed specific expression was monitored by real-time PCR, GM1-ELISA and Western blot analyses. The fusion protein
accumulated in tobacco seeds at up to 1.22% of the total seed protein. It was functionally active in binding to the GM1-ganglioside
receptors, suggesting its assembly into pentamers in seeds of the transgenic plants. Immunoblot analysis confirmed that the
~80.6 kDa monomeric fusion polypeptide was expressed in tobacco seeds and accumulated as a ~403 kDa pentamer. Evaluation of
its immunoprotective ability against rabies and cholera is to be examined. 相似文献
269.
P. Prabhakar Reddy Ashok K. Tiwari R. Ranga Rao K. Madhusudhana V. Rama Subba Rao Amtul Z. Ali K. Suresh Babu J. Madhusudana Rao 《Bioorganic & medicinal chemistry letters》2009,19(9):2562-2565
Phytochemical investigation of antihyperglycemic extract of rhizomes of Hedychium spicatum led to the isolation of two new labdane type diterpenes 2, 3 along with seven known compounds (1, 4–9). Their structures were established on the basis of NMR (1D and 2D) and mass spectroscopic analysis. The new compound 2 displayed strong intestinal α-glucosidase inhibitory activity. Other compounds also displayed varying degree of intestinal α-glucosidase inhibitory potential. 相似文献
270.
Vaibhav Tiwari Nissar A. Darmani Deepak Shukla 《Biochemical and biophysical research communications》2009,390(3):382-25415
Human herpesvirus-8 (HHV-8) is known to interact with cell surface heparan sulfate (HS) for entry into a target cell. Here we investigated the role of HS during HHV-8 glycoproteins-induced cell fusion. Interestingly, the observed fusion demonstrated an unusual dependence on HS as evident from following lines of evidence: (1) a significant reduction in cell-to-cell fusion occurred when target cells were treated with heparinase; (2) in a competition assay, when the effector cells expressing HHV-8 glycoproteins were challenged with soluble HS, cell-to-cell fusion was reduced; and, (3) co-expression of HHV-8 glycoproteins gH-gL on target cells resulted in inhibition of cell surface HS expression. Taken together, our results indicate that cell surface HS can play an additional role during HHV-8 pathogenesis. 相似文献