Anti-babesial and anti-plasmodial compounds from Phyllanthus niruri

Bioassay-guided fractionation of boiled aqueous extracts from the whole plant of Phyllanthus niruri led to the isolation of 1-O-galloyl-6-O-luteoyl-alpha-d-glucose (1), with IC(50) values of 4.7 microg/mL against Babesia gibsoni and 1.4 microg/mL against Plasmodium falciparum in vitro. The known compounds beta-glucogallin (2), quercetin 3-O-beta-d-glucopyranosyl-(2-->1)-O-beta-d-xylopyranoside (3), beta-sitosterol, and gallic acid were also isolated. Structures of these compounds were elucidated on the basis of their chemical and spectroscopic data.     

Anti-babesial compounds from Curcuma zedoaria

Anti-babesial activity was confirmed in an extract of the bark of Curcuma zedoaria. The active ingredients were isolated, and their chemical structures were determined to be zedoalactones A, B, and C based on spectral data. Zedoalactone C is a hitherto unreported compound. The IC50 vales of these active compounds against Babesia gibsoni were compared with a standard drug, diminazene aceturate. The IC50 value of diminazene aceturate was 0.6 microg/mL, while those of zedoalactones A, B, and C were 16.5, 1.6 and 4.2 microg/mL, respectively.     

Screening of Indonesian medicinal plant extracts for antibabesial activity and isolation of new quassinoids from Brucea javanica

Boiled extracts derived from 28 Indonesian medicinal plants were screened for their antibabesial activity against Babesia gibsoni in vitro. Of these extracts, the fruit of Brucea javanica was the most active in inhibiting parasite growth at a concentration of 10 microg/mL. Bioassay-guided fractionation of the fruit extract of Br. javanica led to the isolation of two new quassinoids, bruceantinol B and bruceine J, and the structures of these compounds were elucidated on the basis of their spectroscopic data and by chemical transformation to known compounds. In addition, the known quassinoids bruceines A-D, bruceantinol, and yadanziolide A were isolated. Antibabesial activities were also examined in vitro, and bruceine A and bruceantinol were shown to be more potent than diminazene aceturate, a drug (IC50 = 103 ng/mL) used clinically against B. gibsoni, with IC50 values of 4 and 12 ng/mL, respectively.     

Anti-babesial activity of some central kalimantan plant extracts and active oligostilbenoids from Shorea balangeran

Bark extracts from a total of 22 species of Central Kalimantan plants were evaluated for their anti-babesial activity against Babesia gibsoni in vitro. Of these plant species, extracts of Calophyllum tetrapterum, Garcinia rigida, Lithocarpus sp., Sandoricum emarginatum, and Shorea balangeran showed more than 90% inhibition of the parasite growth at a test concentration of 1000 microg/mL. Activity-guided fractionation of the bark of S. balangeran (Dipterocarpaceae) led to the reisolation of oligostilbenoids, vaticanol A(1), B(2), and G(3). The structures were determined on the basis of spectral evidence. Compounds 1 and 3 showed complete inhibition on the growth of Babesia gibsoni in vitro at a concentration of 25 microg/mL, and compound 2 at concentration of 50 microg/mL.