[Study on Flavonoids of Ophioglossum thermal].

To investigate the chemical components of Ophioglossum thermale,one of the original species of Chinese medicine "Yizhijian".

The air-dried whole plant material of Ophioglossum thermale was extracted by thermal reflux with 95%Et OH,then separated and purified by joint utilization of various chromatography techniques including macroporous resin,silica gel,Sephadex LH-20 column chromatography and HPLC. Their structures were elucidated on the basis of spectroscopic methods.

Six flavonoids were isolated and identified as 3-O-methylquercetin( 1),ophioglonol( 2),3-O-methylquercetin 7-O-β-D-glucopyranoside( 3),3-O-methylquercetin 7-O-β-D-glucopyraosyl-4’-O-β-D-glucopyranoside( 4),kaempferol 3-O-( 6-O-caffeoyl)-β-D-glucopyranosyl-( 1 →2)-α-L-rhamnopyranosyl-7-O-α-L-rhamnopyranoside( 5) and quercetin 3-O-( 6-O-caffeoyl)-β-D-glucopyranosyl( 1→2)-α-L-rhamnopyranosyl-7-O-α-L-rhamnopyranoside( 6).

Compounds 2 ~ 6 are isolated from this plant for the first time,compounds 5 and 6are firstly isolated from Ophioglossaceae family.