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.

Phytocompounds of Anonna muricata leaves extract and cytotoxic effects on breast cancer cells

“…The phytochemical results shown are in agreement with the studies reported previously [4]. Steroids, terpenoids, and phenolic compounds are phytochemical groups that are known to have a wide range of biological activities including cytotoxic [23], antioxidant [24], and antimicrobial properties [25].…”

The Molecular Mechanisms of the Antibacterial Effect of Picosecond Laser Generated Silver Nanoparticles and Their Toxicity to Human Cells

“…aeruginosa (ATCC, 9027) [29] and methicillin resistant S . aureus (ATCC, 43300) [30] used in this study were kindly provided by the Medical Group Biology Services in the Faculty of Life Sciences, the University of Manchester.…”

The prevention of fish spoilage by high antioxidant Australian culinary plants: Shewanella putrefaciens growth inhibition

“…Sterols isolated from several plant species have been reported to inhibit the growth of a myriad of bacterial species. 24-Propylidene cholest-5en-3b-ol isolated from Laurencia papillosa is a potent bacterial growth inhibitor, with IC50 values ranging from 1.2 to 1.7 lg mL À1 against the pathogens Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Shigella flexineri (Kavita et al, 2013). Similarly, the common phytosterol b-sitosterol was reported to have good antibacterial activity when complexed with trace metals (Mahmood et al, 2013).…”