l-oxo-(22I?)-witha-3,5,24-trienolide] [1] and withasomidienone [27-hydroxy-3-oxo-(22R)witha-1,4,24-trienolide] [2] have been isolated from Withania coagulante and Withania somnífera, respectively. The structures have been determined on the basis of spectroscopic studies.Withania coagulante Dun. (Solanaceae) is widely distributed throughout the drier parts of the South Asian subcontinent (1). The fruit of the plant is commonly used in Sind (Pakistan), North India, and Afghanistan instead of rennet to coagulate milk (2). It is also used as an emetic and in smaller doses as a remedy for dyspepsia arising from chronic liver diseases (3).Withania somnífera Dun., a perennial plant, is widely distributed along the shores of the Mediterranean sea, as well as in India, South Africa, Pakistan and other countries (4). Various therapeutic properties have been attributed to this plant and it has been used in the indigenous system of medicine for the treatment of ulcers, rheumatism, cough, dropsy, consumption, and sensile debility (5).A number of withanolides have been isolated previously from Withania spp. Some of these compounds have shown interesting biological activities. For instance, withaferin A has shown antibactérica! properties against acid-fast bacilli and Gram-positive microorganisms (6-8). 3 ß-Hyd oxy-2,3-dihydrowithanolide F has hepatoprotective activity against CCl4-induced hepatotoxicity in adult albino rats (9). We now describe the isolation and structure elucidation of two new withanolides, coagulin [1] and withasomidienone [2],RESULTS AND DISCUSSION Coagulin [1], C28H36Oé, isolated from W. coagulance, showed a uv spectrum with an absorption at 226 nm characteristic of an ,ß-unsaturated lactone chromophore (10). The ir spectrum displayed bands at 3350,1705, and 1690 cm 1 indicative of a hydroxyl, a six-membered cyclic ketone, and an ,ß-unsaturated lactone, respectively. Positive
