Liu Ji-kai

A novel sterol from Chinese truffles Tuber indicum

From the fruiting bodies of Ascomycetes Tuber indicum, a new steroidal glucoside with polyhydroxy ergosterol nucleus, tuberoside (2), has been isolated along with additional four known ergosterol derivatives, (22E, 24R)-ergosta-7, 22-dien-3beta, 5alpha, 6beta-triol (1), 5alpha, 8alpha-epidioxy-(22E, 24R)-ergosta-6, 22-dien-3beta-ol (3), (22E, 24R)-ergosta-5, 22-dien-3beta-ol (4), and (22E, 24R)-ergosta-4, 6, 8(14), 22-tetraen-3-one (5). The structure of new compound was established as 3-O-beta-D-glucopyranosyl-(22E, 24R)-ergosta-7, 22-dien-5alpha, 6beta-diol (2) on the basis of chemical and spectroscopic means ((1)H NMR, (13)C NMR, HMQC, HMBC, MS, and IR). This is the first example of isolation of a polyhydroxylated ergosterol glucoside from higher fungi in nature.

Albaconol, A Novel Prenylated Resorcinol (=Benzene-1,3-diol) from Basidiomycetes Albatrellus confluens

The new substance albaconol (1) was isolated along with grifolin (2), emeheterone (3), and the pyrazinol derivative 4 from the fresh fruiting bodies of the basidiomycetes Albatrellus confluens. Structures were established by spectral analysis, including 2D NMR spectroscopy. Albaconol (1) possesses the skeleton of a drimane-type sesquiterpenoid, which is directly connected to a resorcinol (= benzene-1,3-diol) moiety; this prenylated resorcinol represents a new C skeleton.

Neoengleromycin, a novel compound from Engleromyces goetzii

A novel N-containing compound, neoengleromycin (1) was isolated from the fruiting bodies of the ascomycete Engleromyces goetzii together with two known cytochalasins: cytochalasin D (2) and 19,20-epoxycytochalasin D (3). Structures were established by spectroscopic (including 2D-NMR) and chemical means. Neoengleromycin (1) possesses the rare structure of an N-substituted hydroxamic acid and represents a new type of natural products.

Tremellin, a Novel Symmetrical Compound, from the Basidiomycete Tremella aurantialba

A novel, highly symmetrical compound, named tremellin (1), was isolated from the fruiting bodies of the basidiomycete Tremella aurantilba. Its structure was established by spectroscopic means and X-ray analysis.