The Palmae plant, Borassus flabellifer L. (palmyra palm in English), is widely distributed and cultivated in tropical Asian countries such as Thailand, Bangladesh, India, Myanmar, Sri Lanka, Malaysia, etc. The fruit pulp of B. flabellifer has been used in traditional dishes and the sap, which was trapped from the flower part, has been used as a sweetener for diabetic patients. In the previous studies, several steroidal saponins, 2-4) a polysaccharide, 5) and a triterpene 6) constituents were isolated from the fruit pulp, seeds, and young shoot of B. flabellifer. However, the chemical and pharmacologic studies for the flower parts of this medicinal food were left uncharacterized. In the course of our characterization studies on Thai medicinal foods, [7][8][9][10][11][12][13][14][15][16][17][18][19][20] we found that the methanolic extract from the male flowers of B. flabellifer was found to inhibit the increase of serum glucose levels in sucrose-loaded rats. From the methanolic extract, six new spirostane-type steroid saponins, borassosides A-F (1-6), were isolated together with 20 known steroidal glycosides (7-25 and b-sitosterol 3-O-b-D-glucopyranoside) and three known steroids (26, 27, and b-sitosterol). This paper deals with the structure elucidation of borassosides A-F (1-6) from the male flowers of B. flabellifer as well as the inhibitory effects of the methanolic extract and a principal constituent, dioscin (13), on the increase of serum glucose levels in sucrose-loaded rats.Extraction and Isolation The male and female flowers of B. flabellifer (collected in Thailand) were extracted with methanol to give methanolic extracts (12.2% from the male flowers; 11.3% from the female flowers). As shown in Table 1, the methanolic extract from the male flowers of B. flabellifer was found to inhibit the increase of serum glucose levels in sucrose-loaded rats at a dose of 250 mg/kg, p.o. However, Yamashina-ku, Kyoto 607-8412, Japan: and b Pharmaceutical Research and Technology Institute, Kinki University; 3-4-1 Kowakae, Higashi-osaka, Osaka 577-8502, Japan. Received October 18, 2006; accepted November 27, 2006; published online November 30, 2006 The methanolic extract from the male flowers of Borassus flabellifer was found to inhibit the increase of serum glucose levels in sucrose-loaded rats at a dose of 250 mg/kg, p.o. From the methanolic extract, six new spirostane-type steroid saponins, borassosides A-F (1-6), were isolated together with 23 known constituents. The structures of borassosides (1-6) were elucidated on the basis of chemical and physicochemical evidences. In addition, the principal steroid saponin, dioscin (13), inhibited the increase of serum glucose levels in sucroseloaded rats at a dose of 50 mg/kg, p.o.

The roots of the alpine Rhodiola (Crassulaceae) plant, Rhodiolae Radix, have been widely used as a hemostatic, antibechic, tonic, and endermic liniment for burns and contusions in traditional Chinese medicine. Chemical and biological studies on several Rhodiola plants have been reported. [2][3][4][5] For example, the methanolic extract from the roots of R. sachalinensis was reported to show inhibitory activity on prolyl endopeptidase. 4) During the course of our serial studies on the bioactive constituents from Chinese natural medicines, 1,[6][7][8][9][10][11][12][13] we have characterized the structures of several monoterpene oligoglycosides and cyanogenic glycosides from the roots of R. quadrifida (PALL.) FISCH. et MAY and R. sacra (PRAIN ex HAMET) S. H. FU.14,15) Among the isolated constituents, monoterpene oligoglycosides, sacranosides A and B, were found to inhibit histamine release from rat exudate cells induced by an antigen-antibody reaction.15) As a continuing study on the bioactive constituents of Rhodiolae Radix, the methanolic extract from the roots of R. sachalinensis A. BOR. was found to show a protective effect on Dgalactosamine (D-GalN)-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, we have isolated two new monoterpene glycosides, sachalosides I and II, two new flavonol bisdesmosides, sachalosides III and IV, a new cyanogenic glycoside, sachaloside V, together with 34 known compounds. Furthermore, we examined the protective effects of principal constituents on D-GalN-induced cytotoxicity in primary cultured mouse hepatocytes. In this paper, we describe the isolation and structure elucidation of the new constituents (1-5) and the hepatoprotective effects of principal constituents from the roots of R. sachalinensis.The roots of R. sachalinensis were extracted with methanol under reflux. The methanolic extract (14.6% from the roots) was partitioned into an EtOAc-H 2 O mixture to furnish an EtOAc-soluble fraction (3.5%) and aqueous layer. The aqueous layer was further extracted with n-BuOH to give n-BuOH and H 2 O-soluble fractions (4.4% and 6.5%, respectively). As shown in Table 1, the methanolic extract and the EtOAc-and n-BuOH-soluble fractions were found to show hepatoprotective effects, but the H 2 O-soluble fractions showed weak effect. The EtOAc-soluble fraction was subjected to normal-phase and reversed-phase column chromatographies, and finally HPLC to give 13 known compounds, geranyl b-D-glucopyranoside (6, 0.0070%), kaempferol (34, 0.023%), 25) tricin (37, 0.0069%), 26) 1-octylb-D-glucopyranoside (38, 0.0019%).18) The n-BuOH-soluble fraction was also subjected to Diaion HP-20 column chromatography (H 2 O→MeOH) to give the water-and methanoleluted fractions (0.8% and 3.5%, respectively). The methanol-eluted fraction was subjected to normal-and reversed-phase column chromatographies, and finally HPLC to give sachalosides I (1, 0.0004%), II (2, 0.0005%), III (3, 0.0003%), IV (4, 0.0004%), and V (5, 0.0007%), together with 21 known compounds, geranyl 1...

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Neo-tanshinlactone (1) was isolated and synthesized for the first time and evaluated in vitro against several human cancer cell lines. Compound 1 showed significant inhibition against two ER+ human breast cancer cell lines and was 10-fold more potent and 20-fold more selective as compared to tamoxifen citrate. Compound 1 also potently inhibited an ER-, HER-2 overexpressing breast cancer cell line. Therefore, this novel compound merits further development as an anti-breast cancer drug candidate.