A cocrystal of 3α-hy-droxy-tirucalla-8,24-dien-21-oic acid and 3ß-fluoro-tirucalla-7,24-dien-21-oic acid (0.897:0.103).

The title compound, 0.897C(30)H(48)O(3).0.103C(30)H(47)O(2)F is a co-crystal of two triterpenes isolated from the resin of Canarium schweinfurthiiand Engl. Both triterpenes consists of four trans-fused rings having chair/half-chair/half-chair and envelope conformations. The mol-ecular conformations are stabilized by intra-molecular C-H⋯O hydrogen bonds, forming rings of S(7) graph-set motif. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O and C-H⋯O inter-actions, forming sheets parallel to (001). All atoms. excepting the axially-oriented hydroxyl group in the major component and the equatorially-oriented fluorine atom in the minor component, are overlapping.

3α-Hy-droxy-tirucalla-8,24-dien-21-oic acid.

The title compound, C(30)H(48)O(3), a triterpene isolated from the resin of canarium schweinfurthiiand, is an isomer of the previously reported triterpene 3α-hy-droxy-tirucalla-7,24-dien-21-oic acid [Mora et al. (2001 ▶). Acta Cryst. C57, 638-640], which crystallizes in the same trigonal space group. The title mol-ecule consists of four fused rings having chair, half-chair, half-chair and envelope conformations for rings A, B, C and D, respectively (steroid labelling). An intra-molecular C-H⋯O hydrogen bond generates an S(7) ring. In the crystal, mol-ecules are linked by O-H⋯O and C-H⋯O inter-actions, forming (001) sheets.

Synergistic and potentiating effects of ranitidine and two new anti-ulcer compounds from Enantia chlorantha and Voacanga africana in experimental animal models.

TN, an alkaloid from the fruit of Voacanga africana and a protoberberine-type alkaloid (7,8-dihydro-8-hydroxypalmatine) (1), obtained from the bark of Enantia chlorantha were tested for ulcer preventive and antisecretory activity in combination with ranitidine. When tested alone (50 and 100 mg/kg, p.o.), TN and 1 achieved their anti-ulcer actions through reduced gastric secretion and improved mucus production. 1:1 combinations of 1 and the antisecretory agents (25/25 and 50/50 mg/kg) resulted in significant reduction of ulceration under highly acidic conditions (50-70 mEq/l), suggesting potentiating effects. A combination of TN and ranitidine led to synergistic antisecretory effects.

Prophylactic and healing properties of a new anti-ulcer compound from Enantia chlorantha in rats.

Decoctions prepared from Enantia chlorantha are used in the traditional treatment of some forms of ulcers. We have tested the anti-ulcer actions of a novel protoberberine-type alkaloid (7,8,-dihydro-8-hydroxypalmatine (1)) obtained from the bark of E. chlorantha using the HCl/ethanol, absolute ethanol and pylorus ligation techniques. The healing effect on chronic acetic acid-induced gastric ulcer was also tested. 1 (50 and 100 mg/kg) dose-dependently inhibited the formation of gastric ulcers induced by HCl/ethanol (35-52% inhibition), absolute ethanol (46-53% inhibition) and pylorus ligation (38-62% inhibition). The prophylactic actions were associated with significant increases in gastric mucus production compared with the controls. The significant inhibition of pylorus-ligated ulcers occurred at gastric acid concentrations (83 mEq/l) previously known to induce severe gastric ulceration in rats. The ulcer-healing test showed significant macromorphological and histological acceleration of healing following 10-day treatment with 1 (40 - 80 mg/kg). The results show that 1 has no anti-secretory effects. The prophylactic anti-ulcer effects are associated with enhanced mucus production, which is an important factor in the mechanism of the local healing process of chronic gastric ulcers.