Four new flavonol glycosides castanoside A-D(1-4) namely Kaempferol 3-O-(6’’-O-E-p-coumaryoyl)-a-D-mannopyranoside, Kaempferol 3-O-(3’’,6’’-bis(E-p-coumaryoyl)-a-D-mannopyranoside, quercetin-3-b-D- mannopyranoside, myrcetin-3-O-b-D- mannopyranoside have been isolated from the flowers of Castanea mollisima Blume, the structures of new compounds were elucidated by spectroscopic and chemical methods.

Keywords: Castanea mollissima; Fagaceae; castanoside A; castanoside B; castanoside C; castanoside D

Castanea mollissima Blume is a kind of plant of Fagaceae, its mal inflorescence has been used to cure diarrhea in folk in China. Castanea mollissima Blume is widely distributed over China, especialy in Shandong province,where it has been planted centralizedly. Its resources are abundant, but up to now, studies on the chemical constituents of flower have not been reported. In the present investigation, we report the isolation and structure elucidation of four new flavonol glycosides, named as castanoside A~D(1~4). The occurrence of flavonol glycoside in Fagaceae has previously been reported.

Plant Material

The flower of Castanea mollisima Blume were collected in Fei county, Shandong Province, People’s Republic of China, in June, 1996, and identified by Doctor Junbo Xin. A voucher specimen was deposited in the herbarium of Department of Botany, China Pharmaceutical University.

Extraction and Isolation

Dry flower (6.0 kg) were grounded into crude powder and extracted with ethanol to afford 620 g of a residue on removal of solvent. The ethanol extract was suspended in water and then partitioned in turn with petroleum ether, chloroform, ethyl acetate and n-butanol. The residue (157.0 g) of the chloroform phase was repeatedly subjected to silica gel columns and eluted with a gradient of CHCl₃-MeOH (98:2) yielding to 2 (200 mg), 96:4 to 1 (15 mg), 95:5 to 3 (100 mg) and 90:10 to 4 (200 mg).