Antimicrobial metabolites from Lentinus crinitus.

Lentinus crinitus (L. ex Fr.) Fr. is a mushroom which is widespread in Eastern Africalf2), but so far it has not been studied for its secondary metabolites. The strain was collected in Kaffa, Ethiopia, where it grows on dead wood. Culture extract of the fungus showed antimicrobial activity, and the new metabolite 1-desoxy-hypnophilin 1 and the known hypnophilin 2 were isolated as the most active compounds. In addition to these ketones, their corresponding alcohols 3 and 4 were isolated as well. The antimicrobial activity spectra of the new sesquiterpenes are shown in Table 1. Lentinus crinitus DR-5 was grown in submerged culture on a rotatory shaker (150rpm) in 1-liter Erlenmeyer flasks filled with 200 ml of the medium containing maltose (20g), glucose (10g), peptone (2 g), yeast extract (1 g), MgSO4 à"H2O (1 g), KH2PO4 (0.5g), CaCl2 (0.005g), FeCl3 (0.01 g) and ZnSO4 (0.012 g) in 1 liter distilled water. After 14 days, the culture broth was filtered and exgracted three times with ethyl acetate. The crude extract was separated on a Si-60 column with a dichloromethane MeOH gradient (changing from 1:0 to 7:3). When necessary, the collected fractions were purified