title: Isolation and in vitro antimalarial activity of hexane extract from Thai Picrasma javanica B1 stembark.
abstract: The in vitro antimalarial activities against Plasmodium falciparum K1 of four extracts from the stembark of Picrasma javanica B1; ie water, methanol, chloroform and hexane extracts were studied using a modification of the [3H]hypoxanthine incorporation method. It was found that the hexane extract showed in vitro antimalarial activity with IC50 of 3.3 microg/ml. The extract was further fractionated using quick column chromatography, resulting in ten fractions. Fraction V was the most effective against P. falciparum K1 with IC50 of 4.4 microg/ml. Further isolation of fraction V using a column chromatographic technique provided six fractions. According to 1H- and 13C-NMR spectra, it could be concluded that the major compound in fraction V-3 was beta-sitosterol. Unfortunately, the antimalarial activity of beta-sitosterol could not be determined because of its low solubility in DMSO. However, fractions V-2 and V-4 still showed in vitro antimalarial activities with IC50 of 2.8 and 3.4 microg/ml, respectively. The further fractionation of these two active fractions could lead to promising candidates as antimalarial agents.
authors.affiliation: Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: C
authors.initials: C
authors.lastname: Saiin
authors.forename: R
authors.initials: R
authors.lastname: Rattanajak
authors.forename: S
authors.initials: S
authors.lastname: Kamchonwongpaisan
authors.forename: K
authors.initials: K
authors.lastname: Ingkaninan
authors.forename: K
authors.initials: K
authors.lastname: Sukontason
authors.forename: A
authors.initials: A
authors.lastname: Baramee
authors.forename: B
authors.initials: B
authors.lastname: Sirithunyalug
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D032270:Picrasma; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology; D010963:Plasmodium falciparum / Q000187:drug effects*; D013785:Thailand
chemical_list: D000962:Antimalarials; D010936:Plant Extracts