Anti-tuberculosis Activity of Quassinoids.

In vitro evaluation of anti-tuberculosis activity was conducted for fifty-six quassinoids isolated in our laboratory from Simaroubaceous plants, Ailanthus altissima (= Aa, 10 compounds), Brucea antidysenterica (= Ba, 16 compounds), Picrasma ailanthoides (= Pa, 14 compounds), and Brucea javanica (= Bj, 16 compounds). Of the compounds tested, shinjulactone K (1), ailanthone (2), shinjudilactone (3), and dehydrobruceantin (4) were the most potent. Although the activities were very low (0-19%), the resulting data provided a picture of structure-activity relationships

Inhibitory Effects of Quassinoid Derivatives on Epstein-Barr Virus Early Antigen Activation.

Short-term in vitro assays for tumor promoters and antitumor promoters (Epstein-Barr virus activation test) were carried out for semisynthetic quassinoids (3-7), which were obtained by esterification of the C-15 OH group of deacetylated isobrucein-B (2). All the ester derivatives showed higher antitumor promoting activity than that of the potent compound 2. A compound containing a fluorinated aliphatic ester showed the highest potency

Conversion of Quassinoids for Enhancement of Inhibitory Effect against Epstein-Barr Virus Early Antigen Activation. Introduction of Lipophilic Side Chain and Esterification of Diosphenol.

Introduction of a senecioyl group into shinjulactones B and C, and esterification of the diosphenol moiety in brusatol and brucein A enhanced inhibitory effect against Epstein-Barr virus early antigen activation