Two triterpene saponins from Achyranthes bidentata.

Bidentatoside II(1) and chikusetsusaponin V methyl ester (2) are two further triterpene saponins isolated from the roots of Achyranthes bidentata. Chemical and homo and heteronuclear two-dimensional (2D) NMR techniques have led to the structural elucidation of 1 which is a new seco-glycoside of oleanolic acid and the full 1H- and 13C-NMR assignments of 2. These compounds did not show any potentiation of the in vitro cytotoxicity of cisplatin in the HT 29 human colon cancer cell line.

A new major triterpene saponin from the roots of Cucurbita foetidissima.

Foetidissimoside B (1), a novel triterpene saponin, was isolated from the roots of Cucurbita foetidissima. Based on spectroscopic data, especially direct and long-range heteronuclear 2D NMR analysis and on chemical transformations, the structure of 1 was elucidated as 3-O-beta-D-glucuronopyranosyl-echinocystic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-xylopyranosyl(1-->3)-[beta- D-xylopyranosyl (1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside . Compound 1 did not show any ability to potentiate in vitro cisplatin cytotoxicity in a human colon cancer cell line.

Biologically active triterpene saponins from callus tissue of Polygala amarella.

A new bioactive saponin (1), together with a known saponin (polygalasaponin XXVIII) has been isolated from the callus tissue culture of Polygala amarella. Based on spectroscopic data, especially direct and long-range heteronuclear 2D NMR analysis and on chemical transformations, the structure of 1 was elucidated as 3-O-beta-D-glucopyranosyl presenegenin-28-O-beta-D-galactopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-fucopyranoside. Both saponins showed significant immunological properties based on the enhancement of granulocyte phagocytosis in vitro.

A new biologically active acylated triterpene saponin from Silene fortunei.

A new acylated triterpene-saponin (1), together with a mixture of the known jenisseensosides C and D, has been isolated from the roots of Silene fortunei. The structure of the new compound was established by chemical means and spectroscopic methods as 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28 -O- [[alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- (1-->3)-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)]-[beta-D- glucopyranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranosyl]quillaic acid. This saponin showed a significant enhancement of granulocyte phagocytosis in vitro.

Jennisseensosides C and D, biologically active acylated triterpene saponins from Silene jenisseensis.

We previously reported the isolation and structure elucidation of a new trans-p-methoxycinnamoyl triterpene-saponin along with its cis-p-methoxycinnamoyl isomer as an inseparable mixture from the roots of Silene jenisseensis. In a continuing study on this plant, two additional new acylated triterpene-saponins were obtained as an inseparable mixture. Their structures have been established by chemical means and spectroscopic methods including 1D and 2D homonuclear and heteronuclear correlation NMR spectroscopy as 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28 -O-[{alpha-L-rhamnopyranosyl-(1-->2)}-{4-O-trans-p-methoxycinnamoyl++ +}-beta-D-fucopyranosyl] quillaic acid and its cis-isomer, respectively. They showed a significant enhancement of the granulocyte phagocytosis in vitro.

Aferoside A, a steroidal saponin from Costus afer.

A new steroidal saponin, aferoside A, has been isolated from the roots of Costus afer. Its structure was established as 3-O-([beta-D-apiofuranosyl-(1-->2)]-[alpha-L-rhamnopyranosyl-(1--> 4)]-beta-D-glucopyranosyl)-25(R)-spirost-5-en-3 beta-ol by chemical transformations and various spectroscopic methods, mainly 2D NMR techniques (COSY, HMQC and HMBC).

Acylated triterpene saponins from Silene jenisseensis.

From the roots of Silene jenisseensis a new trans-p-methoxycinnamoyl triterpene saponin has been isolated along with its cis-p-methoxycinnamoyl isomer as an inseparable mixture. Their structures were established by chemical means and spectroscopic methods including 1D- and 2D-homonuclear and heteronuclear correlation NMR spectroscopy as 3-O-[beta-D-galactopyranosyl-(1 --> 2)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl-(1 --> 2)-alpha-L-rhamnopyranosyl- (1 --> 2)-beta-D-4-O-trans-p-methoxycinnamoyl-fucopyranosyl] quillaic acid and its cis-isomer, respectively. They did not show any activity in the in vitro chemoluminescence granulocytes assay, but exhibited only a weak inhibitory effect in the cyclooxygenase inhibition assay.

Squarroside A, a biologically active triterpene saponin from Acanthophyllum squarrosum.

A new bioactive saponin has been isolated from the roots of Acanthophyllum squarrosum. Based on spectroscopic data, especially direct and long-range heteronuclear 2D NMR analysis, and on chemical transformations, the structure of this new compound was elucidated as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta- D-glucuronopyranosyl gypsogenin 28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L- rhamnopyranosyl-(1-->2)-[alpha-L-arabinofuranosyl-(1-->3)]-beta-D-4-O- acetylfucopyranoside for which we proposed the name squarroside A. This molecule showed a concentration dependent immunomodulatory effect in the in vitro lymphocyte transformation test.