NOVEL INDOLE S,O-BISDESMOSIDE, CALANTHOSIDE, THE PRECURSOR GLYCOSIDE OF TRYPTANTHRIN, INDIRUBIN, AND ISATIN, WITH INCREASING SKIN BLOOD-FLOW PROMOTING EFFECTS, FROM 2 CALANTHE SPECIES (ORCHIDACEAE)

The methanolic extracts from Calanthe discolor LINDL. and C. liukiuens is SCHLTR. were found to exhibit hair restoring and skin blood flow pr omoting activities. Through bioassay-guided separation using the skin blood flow increasing effect, a novel indole S,O-bisdesmoside, calanth oside, was isolated together with three new components, glucoindican, calaliukiuenoside, and calaphenanthrenol, and known compounds such as tryptanthrin, indirubin, isatin, and indican. The structures of the ne w compounds were determined on the basis of physicochemical and chemic al evidence and they showed an activating effect on skin blood flow. I n addition, it was found that enzymatic hydrolysis of calanthoside wit h beta-glucosidase furnished tryptanthrin together with a small amount of indirubin and isatin, whereas indirubin and isatin were obtained f rom calanthoside by acid hydrolysis. Based on their contents in the fr esh and dried plant, calanthoside may be a common genuine glycoside of tryptanthrin, indirubin, and isatin in the plant.