@article {46307, title = {Novel fatty alkene from marine bacteria: a thermo stable biosurfactant and its applications}, journal = {Journal of Hazardous Materials}, volume = {380}, year = {2019}, month = {DEC}, pages = {UNSP 120868}, type = {Article}, abstract = {

In this study, a novel thermo stable biosurfactants, 1-Pentanonacontene (C95H190) a fatty alkene and 3-Hydroxy16-methylheptadecanoic acid (C18H36O3) were isolated from a marine isolate SGD-AC-13. Biosurfactants were produced using 1\% yeast extract in tap water as production medium at 24 h in flask and 12 h in bioreactor. Using 16S rRNA gene sequence (1515 bp) and BCL card (bioMerieux VITEK (R)), strain was identified as Bacillus sp. Crude biosurfactant reduced the surface tension of distilled water to 31.32 +/- 0.93 mN/m with CMC value of 0.3 mg/ml. Cell free supernatant showed excellent emulsification and oil displacement activity with stability up to 160 degrees C, pH 6-12 and 50 g/L NaCl conc. Biosurfactants were characterized using FTIR, TLC, HPLC LC-MS and NMR spectroscopy. Cell free supernatant reduced the contact angle of distilled water droplet from 117 degrees to 52.28 degrees and of 2\% pesticide from 78.77 degrees to 73.42 degrees while 750 mu g/ml of crude biosurfactant reduced from 66.06 degrees to 56.33 degrees for 2\% pesticide and recovered 35\% ULO and 12\% HWCO from the contaminated sand. To our best of knowledge, this is the first report of thermo stable fatty alkene as a biosurfactant and is structurally different from previously reported, with having potential application in agriculture, oil recovery and bioremediation.

}, keywords = {Bioremediation, Biosurfactants, Fatty alkene, Thermo stability, Wettability}, issn = {0304-3894}, doi = {10.1016/j.jhazmat.2019.120868}, author = {Ram, Hari and Sahu, Amit Kumar and Said, Madhukar S. and Banpurkar, Arun G. and Gajbhiye, Jayant M. and Dastager, Syed G.} } @article {46625, title = {Approach to nigericin derivatives and their therapeutic potential}, journal = {RSC Advances}, volume = {10}, year = {2020}, month = {NOV }, pages = {43085-43091}, type = {Article}, abstract = {

A new nigericin analogue that has been chemically modified was synthesized through a fluorination process from the parent nigericin, produced from a novel Streptomyces strain DASNCL-29. Fermentation strategies were designed for the optimised production of nigericin molecule and subjected for purification and structural analysis. The fermentation process resulted in the highest yield of nigericin (33\% (w/w)). Initially, nigericin produced from the strain DASNCL-29 demonstrated polymorphism in its crystal structure, i.e., monoclinic and orthorhombic crystal lattices when crystallised with methanol and hexane, respectively. Furthermore, nigericin produced has been subjected to chemical modification by fluorination to enhance its efficacy. Two fluorinated analogues revealed that they possess a very potent antibacterial activity against Gram positive and Gram negative bacteria. To date, the nigericin molecule has not been reported for any reaction against Gram-negative bacteria, which are increasingly becoming resistant to antibiotics. For the first time, fluorinated analogues of nigericin have shown promising activity. In vitro cytotoxicity analysis of fluorinated analogues demonstrated tenfold lesser toxicity than the parent nigericin. This is the first type of study where the fluorinated analogues of nigericin showed very encouraging activity against Gram-negative organisms; moreover, they can be used as a candidate for treating many serious infections.

}, doi = {10.1039/d0ra05137c}, author = {Sahu, Amit Kumar and Said, Madhukar S. and Hingamire, Tejashri and Gaur, Megha and Khan, Abujunaid and Shanmugam, Dhanasekaran and Barvkar, Vitthal T. and Dharne, Mahesh S. and Bharde, Atul A. and Dastager, Syed G.} } @article {46795, title = {Total synthesis of (-)-2-methoxy-2-butenolide-3-cinnamate and its antimicrobial potentials}, journal = {Natural Product Research}, year = {2020}, month = {JUL}, type = {Article; Early Access 2020}, abstract = {

The first total synthesis of (-)-2-methoxy-2-butenolide-3-cinnamate (butenolide cinnamate) was achieved using commercially available starting material. The synthesized compound was found to have promising antibacterial activity against Gram-negative strainsEscherichia coli(ATCC 8739),Salmonella typhimurium(ATCC 23564) andPseudomonas aeruginosa(ATCC 19154) with a minimum inhibitory concentration of 2.0 mu g/mL, 1.0 mu g/mL and 2.0 mu g/mL, respectively. Notably, the compound was more potent against Gram-negative test strains than the Gram-positive test strains.

}, keywords = {antibacterial activity, butenolide cinnamate, Total synthesis}, issn = {1478-6419}, doi = {10.1080/14786419.2020.1789979, Early Access Date = JUL 2020}, author = {Said, Madhukar S. and Udavant, Rohini and Sahu, Amit Kumar and Khan, Abujunaid and Nayak, Rashmi and Dastager, Syed G. and Kumar, Pradeep and Gajbhiye, Jayant} } @article {48108, title = {2,4-Di-tert-butylphenol (2,4-DTBP) purified from streptomyces sp. KCA1 from phyllanthus niruri: isolation, characterization, antibacterial and anticancer properties}, journal = {Journal of King Saud University Science}, volume = {34}, year = {2022}, month = {JUL}, pages = {102088}, type = {Article}, abstract = {

Objectives: The present study reports the bioactivity of 2,4-Di-tert-butylphenol (2,4-DTBP) purified from an endophytic Streptomyces species KCA1 isolated from the leaves of Phyllanthus niruri and its antibacterial and anticancer properties. Methods: The extracellular metabolites were produced from the strain KCA1 by submerged fermentation using ethyl acetate. The crude extract was further evaluated for antibacterial activity against set of pathogens. Active metabolite from the extract was purified using chromatography techniques and detected its antibacterial activity by disc diffusion assay. The molecular structure of the active molecule was identified through various spectral study. Moreover, the bioactive metabolite 2,4-DTBP was analyzed antibacterial and anti-proliferative activity. Results: Strain KCA1 was identified as Streptomyces sp. In the preliminary screening, the crude extract exhibited broad spectrum activity against various bacterial pathogens. Based on the spectral properties, the active metabolite was identified as 2,4-Di-tert-butylphenol. The MIC of active compound 2,4-DTBP inhibited E. coli ATCC 25922 and S. aureus ATCC 29213 at 50 lg/ml and 0.78 lg/ml, respectively. The IC50 value of 2,4-DTBP was found to be 11.0 lg/ml and 116.8 lg/ml, against breast cancer cell line (MCF7) and normal VERO cell line, respectively. Conclusions: This study concluded that 2,4-DTBP, produced from the endophytic Streptomyces sp. KCA1, is the potential candidate to develop as promising antibacterial and anticancer agent. (C) 2022 The Authors. Published by Elsevier B.V. on behalf of King Saud University.

}, keywords = {2, 4-Di-tert-butylphenol, Antibacterial, antiproliferative activity, Endophytic Streptomyces}, issn = {1018-3647}, doi = {10.1016/j.jksus.2022.102088}, author = {Seenivasan, Ayswarya and Manikkam, Radhakrishnan and Kaari, Manigundan and Sahu, Amit Kumar and Said, Madhukar and Dastager, Syed G.} }