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51.
An efficient, three-step synthesis of 5'-amino-5'-deoxyaristeromycin (5), from a protected form of aristeromycin (6), is described. Compound 5 was evaluated against a large number of viruses. It showed weak activity towards vaccinia, herpes simplex virus 2, and cytomegalovirus. No other activity was observed. Compound 5 displayed some cytotoxicity towards the host cell lines human foreskin fibroblast, Daudi, and human T-lymphocyte (CEM). 相似文献
52.
(-)-5'-noraristeromycin (1) has shown antiviral activity towards, particularly cytomegalovirus, vaccinia virus and measles while its (+)-enantiomer (2) is effective towards hepatitis B virus. To determine if the antiviral characteristics of 1 and 2 extended to the guanine analogues (3 and 4), these enantiomers were prepared and evaluated against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), cytomegalovirus (CMV), varicella zoster virus (VZV), Epstein-Barr virus (EBV), human herpes virus type 6 (HHV-6), human herpes virus type 8 (HHV-8), vaccinia virus (VV), cowpox virus (CV), vesicular stomatitis virus (VSV), respiratory syncytial virus (RSV), hepatitis B virus (HBV), and human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2). The only activity found for 3 was for Epstein-Barr virus in VCA Elisa (EC50 0.78 microg/mL), immunofluorescence assay for VCA or gp 350/250 (1.8-4.0 microg/mL) and DNA hybridization (EC50 0.82 microg/mL) assays with no accompanying toxicity seen in the host Daudi cells. No activity was noted for 4. 相似文献
53.
Subramanyam J. Tantry Ganga-Ramu Vasanthakumar Vommina V. Suresh Babu 《Letters in Peptide Science》2003,10(1):51-55
The synthesis of peptides employing 9-fluorenylmethyl chloroformate(Fmoc-Cl) as a coupling agent has been described. The method is simple, efficient and rapid. All the peptides have been obtainedin good yield (70–95%). Furthermore, both the 1H NMR and the HPLC studies on Fmoc-Phg-Phe-OMe and Fmoc-D-Phg-Phe-OMe revealed that the coupling is free from racemization. 相似文献
54.
55.
Vattakandy Jasin Rahman Azariah Babu Amsalingam Roobakkumar Kandasamy Perumalsamy Duraikkannu Vasanthakumar Mariappan Sankara Rama Subramaniam 《Archives Of Phytopathology And Plant Protection》2013,46(6):699-706
The predatory mite, N. longispinosus preys up on red spider mite, O. coffeae infesting tea in south India. An attempt has been made to determine the predatory potential, prey stage preference and optimum predator–prey ratio of N. longispinosus under laboratory and green house conditions. When 50 adult female O. coffeae were given, the number of adults reduced by eight days along with an increase in the number of predators. The larvae hatched from the eggs laid by O. coffeae were fed by predatory mite. N. longispinosus preyed up on all life stages with a preference to larvae and nymphs of red spider mite. Predator–prey ratios of 1:33 and 1:50 were effective in lab, and 1:25 was found to be effective in green house. These results revealed that N. longispinosus could be used as a successful biocontrol candidate of O. coffeae in tea through augmentation or mass rearing and field release. 相似文献
56.
Nanoparticles (NPs) are, in general, colloidal particles, less than 1000 nm, that can be used for better drug delivery and prepared either by encapsulating the drug within a vesicle and or by dispersing the drug molecules within a matrix. Nanoparticulate drug delivery systems have been extensively studied in recent years for spatial and temporal delivery, especially in tumour and brain targeting. NPs have great promise for better drug delivery as found in both pharmaceutical and clinical research. As a drug carrier, NPs have significant advantages like better bioavailability, systemic stability, high drug loading, long blood circulation time and selective distribution in the organs/tissues with longer half life. The selective targeting of NPs can be achieved by the enhanced permeability and retention effect (EPR-effect), attaching specific ligands, or by making selective distribution due to change of the physiological conditions of specific systems like nature, pH, temperature, etc. It has been observed that drug-loaded NPs can have selective distribution to organs/tissues using different types of and proportions of polymers. The current aim of researchers is to prepare NPs that are long-lived with and that demonstrate the appropriate selective distribution for better therapy and thus improved clinical outcomes. Nanoparticulate drug delivery systems have the potential to deliver a drug to the target site with specificity and to maintain the desired concentration at the site for the intended time without untoward effects. In this review article, the methods for the preparation of NPs, their characterization, biodistribution, and pharmacokinetic characteristics are discussed. 相似文献
57.
K. S. Babu P.V. Ajithkumar A. A. M. Kunhi 《World journal of microbiology & biotechnology》1995,11(6):661-664
A Pseudomonas sp. strain, CP4, was isolated that used phenol up to 1.5 g/l as sole source of carbon and energy. Optimal growth on 1.5 g phenol/l was at pH 6.5 to 7.0 and 30°C. Unadapted cells needed 72 h to decrease the chemical oxygen demand (COD) of about 2000 mg/l (from 1 g phenol/l) to about 200 mg/l. Adapted cells, pregrown on phenol, required only 65 h to decrease the COD level to below 100 mg/l. Adaptation of cells to phenol also improved the degradation of cresols. Cell-free extracts of strain CP4 grown on phenol or o-, m- or p-cresol had sp. act. of 0.82, 0.35, 0.54 and 0.32 units of catechol 2,3-dioxygenase and 0.06, 0.05, 0.05 and 0.03 units of catechol 1,2-dioxygenase, respectively. Cells grown on glucose or succinate had neither activity. Benzoate and all isomers of cresol, creosote, hydroxybenzoates, catechol and methyl catechol were utilized by strain CP4. No chloroaromatic was degraded, either as sole substrate or as co-substrate.The authors are with the Department of Microbiology and Bioengineering, Central Food Technological Research Institute, Mysore-570 013, India 相似文献
58.
Rapid clonal multiplication of Aegle marmelos (L.) Corr. (Rutaceae), a medicinal tree, was achieved by enhanced axillary bud proliferation in young single-node segments
of a 25-year-old tree cultured in Murashige and Skoog (MS) nutrient medium. Bud break was dependent on cytokinin supply, but
the synergistic combination of 2.5 mg l–1 6-benzylaminopurine (BAP) and 1.0 mg l–1 indole-3-acetic acid (IAA) induced the formation of 12.1 shoots of up to 5.2 cm length in 48% of the explants after 7 weeks
of culture. Explants of in-vitro-grown shoots – node, whole leaf, shoot tip and internode – were subcultured in the presence
of 0.05–2.5 mg l–1 BAP to produce 11.3, 18.4, 5.3 and 3.2 shoots and shoot buds at a 100%, 70%, 95% and 40% rate respectively, in 7 weeks. Different
shoot nodes and leaves were equally regenerative and adventitious organogenesis in the latter was confined to cut petiolar
ends. Nodal explants responded most favourably at low BAP (0.05–0.1 mg l–1) and produced uniform (3.8–5.3 cm) shoots facilitating their simultaneous harvest for rooting. Repeated subculturing through
five cycles of nodes and leaves of shoot cultures enabled continuous production of healthy callus-free shoots without any
sign of decline. Shoot cuttings (3.0–5.2 cm) were best rooted in half-strength MS medium with 0.5 mg l–1 IAA (70%) or 10.0 mg l–1 indole-3-butyric acid (90%). Eighty-eight percent of the rooted plants were established in polybags after hardening.
Received: 4 April 1996 / Revision received: 8 September 1997 / Accepted: 20 September 1997 相似文献
59.
A bacterial isolate, Pseudomonas aeruginosa 3mT, exhibited the ability to degrade high concentrations of 3-chlorobenzoate (3-CBA, 8 g l-1) and 4-chlorobenzoate (4-CBA 12 g l-1) (Ajithkumar 1998). In this study, by delineating the initial biochemical steps involved in the degradation of these compounds, we investigated how this strain can do so well. Resting cells, permeabilised cells as well as cell-free extracts failed to dechlorinate both 3-CBA and 4-CBA under anaerobic conditions, whereas the former two readily degraded both compounds under aerobic conditions. Accumulation of any intermediary metabolite was not observed during growth as well as reaction with resting cells under highly aerated conditions. However, on modification of reaction conditions, 3-chlorocatechol (3-CC) and 4-chlorocatechol (4-CC) accumulated in 3-CBA and 4-CBA flasks, respectively. Fairly high titres of pyrocatechase II (chlorocatechol 1,2-dioxygenase) activity were obtained in extracts of cells grown on 3-CBA and 4-CBA. Meta-pyrocatechase (catechol 2,3-dioxygenase) activity against4-CC and catechol, but not against 3-CC, was also detected in low titres. Accumulation of small amounts of 2-chloro-5-hydroxy muconic semialdehyde, the meta-cleavage product of 4-CC, was detected in the medium, when 4-CBA concentration was 4 mM or greater, indicating the presence of a minor meta-pathway in strain 3mT. However, 3-CBA exclusively, and more than 99% of 4-CBA were degraded through the formation of the respective chlorocatechol, via a modified ortho-pathway. This defies the traditional view that the microbes that follow chlorocatechol pathways are not very good degraders of chlorobenzoates. 4-Hydroxybenzoatewas readily (and 3-hydroxybenzoate to a lesser extent) degraded by the strain, through the formation of protocatechuate and gentisate, respectively, as intermediary dihydroxy metabolites. 相似文献