Anti-Tobacco Mosaic Virus (TMV) Quassinoids from Brucea javanica (L.) Merr.

Abstract

Two new quassinoids, javanicolide E (1) and javanicolide F (2), along with fifteen known C-20 quassinoids were isolated from the seeds of Brucea javanica (L.) Merr. The antitobacco mosaic virus (TMV) activity of these quassinoids was screened by the conventional half-leaf and leaf-disk method along with Western blot analysis. All of the seventeen quassinoids showed potent anti-TMV activity. Among them, eight compounds, brusatol (3), bruceine B (4), bruceoside B (5), yadanzioside I (6), yadanzioside L (7), bruceine D (8), yadanziolide A (9), and aglycone of yadanziolide D (17), showed strong antiviral activities, with IC₅₀ values in the range of 3.42−5.66 μM, and were much more effective than the positive control, ningnanmycin (IC₅₀ = 117.3 μM). The antiviral structure−activity relationships of quassinoids against TMV were also discussed.