Phenylpropanoid conjugated iridoids with anti-malarial activity from the leaves of Morinda morindoides

AbstractTwo phenylpropanoid-conjugated iridoids, deglucosyl gaertneroside (1) and morindoidin (2), were isolated from the leaves ofMorinda morindoides (Rubiaceae) by activity-guided fractionation using an anti-malarial activity assay. The known related iridoids molucidin (3) and prismatomerin (4), two lignans, abscisic acid, two megastigmanes, and two flavonol glycosides were also identified. The structures of isolated compounds were elucidated using spectroscopic analysis. The isolated compounds were evaluated for anti-malarial activity against the chloroquine/mefloquine-sensitive strains ofPlasmodium falciparum together with cytotoxicity against adult mouse brain cells. Potent anti-malarial activity of3 and4 (IC50 of 0.96 and 0.80  μM, CC50 of 1.02 and 0.88  μM, and SI of 1.06 and 1.10, respectively) was shown, while new iridoids1 and2 and pinoresinol (5) displayed moderate activity (IC50 of 40.9, 20.6, and 24.2  μM) without cytotoxicity (CC50 >  50 μM). These results indicate that1–5 may be promising lead compounds for anti-malarial drugs. In addition, our results imply the necessity of the quality control of the extract ofM. morindoides leaves based on the contents of1–5 in terms of the safety and efficacy.
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research