The Properties of Some Arjunolic Acid Derivatives

Abstract

In connection with our investigations of SouthEast Asian plants,1) the roots of Psidium guaijava L. ("banjiro" or "banzakuro") from Taiwan were studied because of the reputed cancerostatic activity of this Chinese herb. Since the ether extract was an intractable mixture, it was first methylated; the ester was then chromatographed and recrystallized. This ester eventually turned out to be methyl arjunolate,2) the methyl ester of arjunolic acid (1).3,4) Preliminary chemical and spectroscopic studies carried out prior to its identification, however, disclosed a few points worthy of comment; these points will be reported below.Although the product obtained by the periodate oxidation of the ester 2 was analyzsed in the correct manner for a dialdehyde, it afforded only a mono-2, 4-dinitrophenylhydrazone, and its NMR spectrum showed only one aldehydic proton as a singlet (9.09 p.p.m.).

Studies on Inhibitors of Skin-Tumor Promotion. Inhibitory Effects of Triterpenes from Cochlospermum tinctorium on Epstein-Barr Virus Activation

“…(Cochlospermaceae) (1,2), combined chromatographic methods allowed the purification of three pentacyclic triterpenoids. Among the three, one major constituent was elucidated as arjunolic acid, 2ot,3ß,23-trihydroxyolean-12-en-28-oic acid [1]; this triterpene was previously isolated from Terminalia arjuna (3), Mitragyna ciliata (4), Tristania confería (5), and Psidium guaijava (6); its presence in Dryohalanops aromatica was also presumed (7). Identification of 1 was achieved using 'H-nmr, BC-…”