XVI International Botanical Congess

Desmos dumosus (Roxb.) Saff (Annonaceae) is liana-like or straight up shrub jungle of the southern and the southwestern parts of China. The roots and leaves of D. dumosus used as antimalarial, insect-killing, antirheumatic, antispasmodic and pain-relieving agent in Chinese folk medicine. Desmos Lour attracted much attention recently because of the marked insect antifeedant and cytotoxic activities. It has been reported that several flavonoids were isolated from these plants. In this paper we report the isolation and structural elucidation of some other compounds: lawinal (I), isolawinal(II), 5-hydroxy- 7-methoxy- 8-formyl-3-benzoyl-2,6-dimethylchromone (III),5-hydroxy-7-one-6,8,8-trimethylflavone(IV), desmethoxymatteucinol(V), desmethoxy matteucinol-7-methylether (VI), 2-methoxy-3-methyl-4,6-dihydroxy-5(3¡¯-hydroxy) cinnamoybenzadehyde (VII), mosloflavone (VIII), negletein (IX), stigmast-4-ene-3,6-dione (X), stigmastane-4-ene-3,6-dione (XI)£ benzoic acid (XII), |Â-sitosterol (XIII) and stigmasterol (XIV). Their structure identified by chemical and spectroscopic analysis (UV, IR, MS, 1H NMR, 13C NMR, HMBC, HMQC, 1H-1H COSY NOESY and X-ray). III and IV are new compounds named desmosdumotin A and desmosdumotin B. II, V, VI, VII, X and XI were found from this species for the first time.