title: 24-Branched Δ5 sterols from Laurencia papillosa red seaweed with antibacterial activity against human pathogenic bacteria.
abstract: Methanol extract of thirty-eight seaweeds samples were first screened against Gram-positive (Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6051) and -negative (Escherichia coli ATCC 8739 and Pseudomonas aerugenosa ATCC 9027) bacteria. Laurencia papillosa (Ceramiales, Rhodomelaceae, Rhodophyta) gave maximum antimicrobial activity against these bacteria. It was finally tested against four clinical Gram-negative isolates (E. coli, P. aerugenosa, Klebsiella pneumoniae and Shigella flexineri) and exhibited antibacterial activity. The extract was fractionated by column chromatography and the active fraction was identified as a cholesterol derivative, 24-propylidene cholest-5-en-3β-ol using gas chromatography mass spectrometry (GC-MS). The electrospray ionization mass spectrometry (ESI-MS) and FT-IR spectroscopic analysis also supported the structure of the compound. The minimum inhibitory concentration ranged from 1.2 to 1.7 μg/mL (IC50) against clinical isolates. This is the first report of antibacterial activity of this cholesterol derivative. This compound could be exploited as potential lead molecule against broad spectrum drug development. The results also affirm the potential of seaweeds as an important natural source of antimicrobial compounds for pharmaceutical industries.
authors.affiliation: Discipline of Marine Biotechnology and Ecology, CSIR - Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India; Academy of Scientific and Innovative Research, CSIR, New Delhi, India.
authors.forename: Kumari
authors.initials: K
authors.lastname: Kavita
authors.affiliation: Discipline of Marine Biotechnology and Ecology, CSIR - Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India.
authors.forename: Vijay Kumar
authors.initials: VK
authors.lastname: Singh
authors.affiliation: Discipline of Marine Biotechnology and Ecology, CSIR - Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India; Academy of Scientific and Innovative Research, CSIR, New Delhi, India. Electronic address: bjha@csmcri.org.
authors.forename: Bhavanath
authors.initials: B
authors.lastname: Jha
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology*; D002853:Chromatography, Liquid; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D000461:Rhodophyta / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D013261:Sterols
keywords: Antibacterial activity; Cholesterol derivative; Clinical isolates; L. papillosa