PURIFICATION AND CHARACTERIZATION OF L-ASPARAGINASE BY PSEUDONOCARDIA ENDOPHYTICA VUK-10 ISOLATED FROM NIZAMPATNAM MANGROVE ECOSYSTEM

Objective: L-asparaginase has been a promising therapeutic agent in the treatment of acute lymphoblastic leukaemia. In the present study a rare actino bacterial strain Pseudonocardia endophytica VUK-10 isolated from Nizampatnam mangrove ecosystem was explored for the production of L-asparaginase.Methods: The extracellular L-asparaginase enzyme was purified to homogeneity from the P. endophytica VUK-10 strain. The crude culture filtrate was subjected to different purification steps including ammonium sulphate fractionation followed by separation on Sephadex G-100 gel filtration and CM-Sephadex C-50 ion exchange chromatography to obtain a pure enzyme preparation.Results: The enzyme was purified 96 fold and showed a final specific activity of 702.04 IU/mg with a 61% yield. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme revealed its nature as single peptide chain with molecular weight of 120 kDa. This is the first report on production and purification of L-asparaginase from P. endophytica of mangrove origin.Conclusion: The extracellular L-asparaginase of the P. endophytica may be effectively used as potential chemotherapeutic agent.Keywords: Mangrove ecosystem, Pseudonocardia endophytica, L-asparaginase, Purification, SDS-PAG

Isolation, structure elucidation and bioactivity of secondary metabolites produced by marine derived Streptomonospora arabica VSM-25

73-93The 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

EXPLORATION OF POTENT ACTINOBACTERIUM NOCARDIOPSIS HALOTOLERANS VJPR-2 ISOLATED FROM MANGROVE HABITATS

ABSTRACTObjectives: This study was aimed at isolation and identification of potent bioactive metabolite producing actinobacterial strain VJPR-2 isolated fromthe mangrove ecosystem of Nizampatnam, Andhra Pradesh, India.Methods: Soil sediments collected were subjected to pre-treatment with CaCO, and actinobacterial strains were isolated using selective media. Thescreening of the isolated strains was carried out and the potent bioactive metabolite producing strain was designated as VJPR-2. An identification ofthe strain was carried out by employing polyphasic approach including morphological, cultural, physiological, biochemical, and phylogenetic analysisof 16S rRNA gene sequence. Antimicrobial potency of the isolate was tested against bacterial and fungal pathogens.3Results: The strain VJPR-2 was identified as Nocardiopsis halotolerans by morphological, cultural, physiological, and biochemical studies along with16S rRNA gene sequence analysis. The rRNA sequence was deposited in the NCBI GenBank with the accession number KP313613. The strain exhibitedantimicrobial activities against Gram-positive as well as Gram-negative bacteria and fungi.Conclusion: Actinobacterium strain N. halotolerans VJPR-2 having good antimicrobial potential was identified from the 16 strains isolated from thesediment samples of Nizampatnam mangrove ecosystem using CaCObased approach. The present study reveals the isolation, identification andbiological evaluation of the bioactive metabolites produced by strain VJPR-2.3 Keywords: Mangrove ecosystem, Nocardiopsis halotolerans VJPR-2, Polyphasic approach, Bioactive metabolites

ANTIMICROBIAL POTENTIAL OF STREPTOMYCES CHEONANENSIS VUK-A FROM MANGROVE ORIGIN

Objectives: The aim of the present study was to isolate, characterize and evaluate the activity of compounds produced by Streptomyces cheonanensis VUK-A.Methods: Chemical examination of the secondary metabolites of the strain Streptomyces cheonanensis VUK-A has led to the segregation of one bioactive compound (1) and a partially purified fraction (2). The strain was isolated from the sediment samples of mangrove ecosystem of Coringa, south coastal Andhra Pradesh, India. The chemical structure of the active compound 1 was established on the basis of spectroscopic analysis including 1H NMR, 13C NMR spectroscopy, FTIR and EIMS. The partially purified sub-fraction (2) subjected to Gas Chromatography-Mass spectroscopy. The antimicrobial activity of the bioactive compounds produced by the strain was expressed in terms of minimum inhibitory concentration.Results: The compound 1 was isolated from the fermentation broth was characterized as benzoic acid (1) based on spectroscopic analysis. The partially purified sub-fraction (2) subjected to Gas Chromatography-Mass spectroscopy contained nine analogues: 1-tetradecene, tetradecane, 1-hexadecene, hexadecane, 5-octadecene, octadecane, 5-eicosene, 1-nonadecene and cyclo tetracosane. The compounds recorded moderate to significant antimicrobial activity against medicinally and agriculturally important bacteria and fungi. This is the first report of six partially purified compounds 1-tetradecene, tetradecane, hexadecane, octadecane, 5-eicosene and cyclo tetracosane from the genus Streptomyces.Conclusion: The results of the present study showed that the metabolites of Streptomyces cheonanensis VUK-A exhibited antibacterial and antifungal activities. The study also supports that Coringa, a promising mangrove ecosystem remained to be explored for new bioactive compounds.Keywords: Streptomyces cheonanensis, Mangrove Ecosystem, Natural Products, Antimicrobial activity

Isolation, structure elucidation and bioactivity of secondary metabolites produced by marine derived Streptomonospora arabica VSM-25

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

Pterocarpus marsupium Roxb. heartwood extract synthesized chitosan nanoparticles and its biomedical applications

Abstract Background The point of the present investigation was to blend effective chitosan nanoparticles (CNPs) loaded with Pterocarpus marsupium (PM) heartwood extract and evaluate its biomedical applications. Various plant extract concentrations (PM-CNPs-1, PM-CNPs-2, PM-CNPs-3) are used to synthesize chitosan nanoparticles and optimized to acquire a stable nanoparticle formulation. The entrapment efficiency and in vitro release studies of the plant extract encapsulated in CNPs are estimated. The PM-loaded CNPs were characterized by X-ray diffraction, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The synthesized chitosan nanoparticles were evaluated for their alpha-amylase inhibitory activity and inhibition of albumin denaturation activity. Results The XRD pattern of PM-CNPs shows less number of peaks at low intensity due to the interaction of chitosan with sodium tripolyphosphate. The FT-IR spectrum with peaks at 1639.55 and 1149.02 cm−1 confirms the formation of chitosan nanoparticles. The size of the nanoparticles ranges between 100 and 110 nm with spherical shape illustrated by SEM and TEM analysis. The nanoparticle formulation with 10% plant extract concentration (PM-CNPs-2) showed optimum particle size, higher stability, enhanced entrapment efficiency, and sustained drug release characteristics. Synthesized chitosan nanoparticles have shown a significant increase in alpha-amylase inhibition and appreciable anti-inflammatory activity as measured by inhibition of protein denaturation. Conclusions The investigation reports the eco-friendly, cost-effective method for synthesizing chitosan nanoparticles loaded with Pterocarpus marsupium Rox.b heartwood extract

Phytoassisted synthesis of magnesium oxide nanoparticles from Pterocarpus marsupium rox.b heartwood extract and its biomedical applications

Abstract Background Unlike chemical techniques, the combination of metal oxide nanoparticles utilizing plant concentrate is a promising choice. The purpose of this work was to synthesize magnesium oxide nanoparticles (MgO-NPs) utilizing heartwood aqueous extract of Pterocarpus marsupium. The heartwood extract of Pterocarpus marsupium is rich in polyphenolic compounds and flavonoids that can be used as a green source for large-scale, simple, and eco-friendly production of MgO-NPs. The phytoassisted synthesis of MgO is characterized by UV-Visible spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with EDS (energy dispersive X-ray spectroscopy), and transmission electron microscopy (TEM). Results The formation of MgO-NPs is confirmed by a visual color change from colorless to dark brown and they displayed a wavelength of 310 nm in UV-Spectrophotometry analysis. The crystalline nature of the obtained biosynthesized nanoparticles are revealed by X-ray diffraction analysis. SEM results revealed the synthesized magnesium oxide nanoparticles formed by this cost-effective method are spherically shaped with an average size of < 20 nm. The presence of magnesium and oxygen were confirmed by the EDS data. TEM analysis proved the spherical shape of the nanoparticles with average particle size of 13.28 nm and SAED analysis confirms the crystalline nature of MgO-NPs. FT-IR investigation confirms the existence of the active compounds required to stabilize the magnesium oxide nanoparticles with hydroxyl and carboxyl and phenolic groups that act as reducing, stabilizing, and capping agent. All the nanoparticles vary in particle sizes between 15 and 25 nm and obtained a polydispersity index value of 0.248. The zeta-potential was measured and found to be − 2.9 mV. Further, MgO-NPs were tested for antibacterial action against Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) by minimum inhibitory concentration technique were found to be potent against both the bacteria. The blended nanoparticles showed good antioxidant activity examined by the DPPH radical scavenging method, showed good anti-diabetic activity determined by alpha-amylase inhibitory activity, and displayed strong anti-inflammatory activity evaluated by the albumin denaturation method. Conclusions The investigation reports the eco-friendly, cost-effective method for synthesizing magnesium oxide nanoparticles from Pterocarpus marsupium Rox.b heartwood extract with biomedical applications. Graphical abstrac