Six new ent-kaurane-type diterpenoids were isolated from the leaves of the endemic Vietnamese medicinal plant Croton tonkinensis GAGNEP. (Euphorbiaceae) together with three known ent-11α-acetoxy-7β,14α-dihydroxykaur- 16-en-15-one (1), ent-kaur-16-en-15-one 18-oic acid (5) and ent-18-hydroxykaur- 16-ene (7). Their structures were determined by spectroscopic analyses to be ent-7β-acetoxy-11α-hydroxykaur-16-en-15-one (2), ent-18-acetoxy- 11α-hydroxykaur-16-en-15-one (3), ent-11α-acetoxykaur-16-en-18-oic acid (4), ent-15α,18-dihydroxykaur-16-ene (6), ent-11α,18-diacetoxy- 7β-hydroxykaur-16-en-15-one (8), and ent-(16S)-1α,14α- diacetoxy-7β-hydroxy-17-methoxykauran-15-one (14). ent-Kaurane-type diterpenoids from Croton tonkinensis 2-4, 6, and 9-13, were tested for toxicity in the brine shrimp lethality assay. Compounds 9, 10, and 12 demonstrated significant activity, compounds 2, 3, 6, and 11 showed weak activity, and compounds 4 and 13 were inactive. © 2005 Pharmaceutical Society of Japan.

Giang P.M., Son P.T., Hamada Y., Otsuka H.

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Từ khóa : 11alpha acetoxy 7beta,14alpha dihydroxykaur 16 en 15 one; 11alpha acetoxykaur 16 en 18 oic acid; 11alpha,18 diacetoxy 7beta hydroxykaur 16 en 15 one; 15alpha,18 dihydroxykaur 16 ene; 18 acetoxy 11alpha hydroxykaur 16 en 15 one; 18 hydroxykaur 16 ene; 1alpha,14alpha diacetoxy 7beta hydroxy 17 methoxykauran 15 one; 7beta acetoxy 11alpha hydroxykaur 16en 15 one; Croton tonkinensis extract; diterpenoid; kaur 16 en 15 one 18 oic acid; plant extract; unclassified drug; animal tissue; Artemia; article; controlled study; Croton tonkinensis; cytotoxicity; drug activity; drug isolation; lethality; medicinal plant; nonhuman; plant leaf; toxicity testing; Animals; Artemia; Croton; Diterpenes, Kaurane; Plant Extracts; Plant Leaves; Plants, Medicinal; Vietnam