ABSTRACT
The strain VSM-25 with an exhilarating bioactive potential isolated during our systematic screening of marine actinomycetes was identified as Streptomonospora arabica based on polyphasic taxonomy. The ethyl acetate extract of culture filtrate was purified by silica gel column chromatography. The chemical structure of active compounds was determined by NMR, FTIR, and ESIMS and were established as Indole-3-carboxaldehyde (C1), 2, 3-dihydroxy benzoic acid (C2), Vanillic acid (C3), Daidzein (C4), and 3, 4-Dihydroxy benzaldehyde (C5). The antimicrobial activities of the compounds were tested against medicinally and agriculturally significant bacteria and fungi. C1 displayed a high inhibitory effect against bacteria and fungi to that of the other compounds tested. C5 exerted the strongest scavenging activity of free radicals such as DPPH and NO at a concentration of 400 µg/mL. C1 inhibited alpha-amylase effectively at 400 µg/mL although it was less potent than acarbose. C3 and C4 exerted significant anti-inflammatory and anti-arthritic activities at 400 µg/mL. The anti-inflammatory activity of compound C3 was found to be more potent than Diclofenac sodium, the reference drug. MTT assays of five compounds against MDA-MB-231 and MCF-7 cell lines using taxol as standard documented cytotoxicity. C4 showed highest activity of 67.81% and 54.33% (IC50 -1 µg/mL) against MDA-MB-231 and MCF-7. The cytotoxicity of five compounds was also evaluated by soft agar colony forming assay to determine the ability of MDA-MB-231 cells to proliferate while cell cycle arrest at sub G1 and induction of apoptosis was documented with MDA-MB-231 cells after treatment with C1, C2, C3, C4, and C5.
ABSTRACT
The strain VSM-25 with an exhilarating bioactive potential isolated during our systematic screening of marine actinomycetes was identified as Streptomonospora arabica based on polyphasic taxonomy. The ethyl acetate extract of culture filtrate was purified by silica gel column chromatography. The chemical structure of active compounds was determined by NMR, FTIR, and ESIMS and were established as Indole-3-carboxaldehyde (C1), 2, 3-dihydroxy benzoic acid (C2), Vanillic acid (C3), Daidzein (C4), and 3, 4-Dihydroxy benzaldehyde (C5). The antimicrobial activities of the compounds were tested against medicinally and agriculturally significant bacteria and fungi. C1 displayed a high inhibitory effect against bacteria and fungi to that of the other compounds tested. C5 exerted the strongest scavenging activity of free radicals such as DPPH and NO at a concentration of 400 µg/mL. C1 inhibited alpha-amylase effectively at 400 µg/mL although it was less potent than acarbose. C3 and C4 exerted significant anti-inflammatory and anti-arthritic activities at 400 µg/mL. The anti-inflammatory activity of compound C3 was found to be more potent than Diclofenac sodium, the reference drug. MTT assays of five compounds against MDA-MB-231 and MCF-7 cell lines using taxol as standard documented cytotoxicity. C4 showed highest activity of 67.81% and 54.33% (IC50 -1 µg/mL) against MDA-MB-231 and MCF-7. The cytotoxicity of five compounds was also evaluated by soft agar colony forming assay to determine the ability of MDA-MB-231 cells to proliferate while cell cycle arrest at sub G1 and induction of apoptosis was documented with MDA-MB-231 cells after treatment with C1, C2, C3, C4, and C5.
ABSTRACT
A rapid method for Pullulan-stabilized silver nanoparticles (PuAgNPs) synthesis has been developed. Different concentrations of Pullulan and Silver nitrate and effects of reaction time, pH was used to investigate the synthesis of silver nanoparticles. The synthesized Pu-AgNPs were first screened and identified using surface plasmon peaks of UV–VIS spectroscopy. The research results indicated that the surface plasmon resonance peaks were observed between 410–460 nm wavelengths in UV-VIS spectroscopy studies. The morphology of the synthesized AgNPs proved a variation in spherical shape and polydispersed with an average size of 10-55 nm, using TEM. Further, five characteristic peaks confirmed the presence of elemental silver and the crystalline structure of silver nanoparticles from XRD analysis. From FTIR spectra, stretching vibrations of hydroxyl (OH), carbonyl (C=O) and C=C stretches exhibits the reduction and stabilization of AgNPs. Further, clear zones of inhibition (about 10-25 mm) against four bacterial pathogens obtained in the antibacterial studies for the synthesized PuAgNPs. The experimental results demonstrated that pullulan could be used as reducing and stabilizing agent for formation of AgNPs and can be used as redoubtable bactericidal agents.
ABSTRACT
The purpose of the present study was to investigate the influence of cultural and environmental parameters affecting the growth and bioactive metabolite production of the rare strain VUK-10 of actinomycete Pseudonocardia, which exhibits a broad spectrum of in vitro antimicrobial activity against bacteria and fungi. Production of bioactive metabolites by the strain was high the in modified yeast extract-malt extract-dextrose (ISP-2) broth, as compared to other tested media. Glucose (1%) and tryptone (0.25%) were found to be the most suitable carbon and nitrogen sources, respectively, for optimum production of growth and bioactive metabolites. Maximum production of bioactive metabolites was found in the culture medium with initial pH 7 incubated with the strain for four days at 30degrees C, under shaking conditions. This is the first report on the optimization of bioactive metabolites by Pseudonocardia sp. VUK-10.