ABSTRACT
Bioactivity guided fractions of cell-free hemolymph of bacterially challenged marine mussel, Perna viridis led to the isolation of a novel quaternary alkaloid 1, which was identified by its spectral data. The isolated molecule 1 has been found to be a potent serine protease inhibitor (SPI) showing IC(50) and K(i) values of 102.5 and 97.1-104.68 microM, respectively. The E(t)/K(i) value of SPI is 6.3, whereas E(t)/K(m) value is 1.04. The Van't Hoff analysis showed that the value of K(i) decreases with increase in temperature, and the binding of the inhibitor is entropically driven.
Subject(s)
Hemolymph/metabolism , Serine Proteinase Inhibitors/chemical synthesis , Alkaloids/chemistry , Animals , Biological Availability , Cell-Free System , Chemistry, Pharmaceutical/methods , Drug Design , Inhibitory Concentration 50 , Kinetics , Models, Chemical , Perna , Serine Proteinase Inhibitors/pharmacology , Temperature , Thermodynamics , Trypsin/chemistryABSTRACT
While data are available on the effect of medicinal plants on intestinal motility and their antibacterial action, there is a paucity of information on their mode of action on various aspects of diarrheal pathogenicity, namely colonization to intestinal epithelial cells and production/action of enterotoxins. Crude decoction of dried leaves of Pongamia pinnata was evaluated for its antimicrobial (antibacterial, antigiardial and antirotaviral) effect; and its effect on production and action of enterotoxins (cholera toxin, CT; Escherichia coli labile toxin, LT; and E. coli stable toxin, ST); and adherence of enteropathogenic E. coli and invasion of enteroinvasive E. coli and Shigella flexneri to epithelial cells. The decoction had no antibacterial, antigiardial and antirotaviral activity, but reduced production of CT and bacterial invasion to epithelial cells. The observed results indicated that the crude decoction of P. pinnata has selective antidiarrheal action with efficacy against cholera and enteroinvasive bacterial strains causing bloody diarrheal episodes.
Subject(s)
Anti-Infective Agents/pharmacology , Antidiarrheals/pharmacology , Millettia , Phytotherapy , Plant Extracts/pharmacology , Bacterial Adhesion/drug effects , Cell Line , Enterotoxins/biosynthesis , Humans , Millettia/chemistry , Plant LeavesABSTRACT
Three new eudesmanoids have been isolated from Sphaeranthus indicus and their structures were established as 11alpha,13-dihydro-3alpha,7alpha-dihydroxy-4,5-epoxy-6beta,7-eudesmanolide, 11alpha,13-dihydro-7alpha-acetoxy-3beta-hydroxy-6beta,7-eudesm-4-enolide and 3-keto-beta-eudesmol by comparison of spectral data with those of other 7alpha-hydroxyeudesmanolides.
Subject(s)
Asteraceae , Naphthalenes/chemistry , Plants, Medicinal/chemistry , Sesquiterpenes, Eudesmane , Sesquiterpenes/chemistry , Humans , Plant Extracts/chemistryABSTRACT
A new germacranolide has been isolated from the aerial parts of Artemisia pallens and the structure was established as 4,5 beta-epoxy-10 beta-hydroxy-1-en-3-one-trans-germacran-6 alpha,12-olide (1) by comparison with its 10 alpha-epimer isolated from the same plant.
