Cytotoxycity and antiplasmodial activity of phenolic derivatives from Albizia zygia (DC.) J.F. Macbr. (Mimosaceae)

BACKGROUND: The proliferation and resistance of microorganisms area serious threat against humankind and the search for new therapeutics is needed. The present report describes the antiplasmodial and anticancer activities of samples isolated from the methanol extract of Albizia zygia (Mimosaseae). MATERIAL: The plant extract was prepared by maceration in methanol. Standard chromatographic, HPLC and spectroscopic methods were used to isolate and identify six compounds (1-6). The acetylated derivatives (7-10) were prepared by modifying 2-O-beta-D-glucopyranosyl-4-hydroxyphenylacetic acid and quercetin 3-O-alpha-L-rhamnopyranoside, previously isolated from A. zygia (Mimosaceae). A two-fold serial micro-dilution method was used to determine the IC50s against five tumor cell lines and Plasmodium falciparum. RESULTS: In general, compounds showed moderate activity against the human pancreatic carcinoma cell line MiaPaca-2 (10 20 muM). Additionally, the two semi-synthetic derivatives of quercetin 3-O-alpha-L-rhamnopyranoside exhibited significant activity against P. falciparum with IC50 of 7.47 +/- 0.25 muM for compound 9 and 6.77 +/- 0.25 muM for compound 10, higher than that of their natural precursor (IC50 25.1 +/- 0.25 muM). CONCLUSION: The results of this study clearly suggest that, the appropriate introduction of acetyl groups into some flavonoids could lead to more useful derivatives for the development of an antiplasmodial agent.