Atsuko Nishino

Steroidal saponins from the underground parts of Chlorophytum comosum and their inhibitory activity on tumour promoter-induced phospholipids metabolism of hela cells

Three new spirostanol pentaglycosides embracing beta-D-apiofuranose were isolated from the fresh underground parts of Chlorophytum comosum together with four known saponins. The structures of new compounds were determined by spectroscopic data, including two-dimensional NMR, and partial acid-catalysed hydrolysis to be (25R)-5 alpha-spirostane-2 alpha,3 beta-diol 3-O-[O-beta-D-glucopyranosyl- (1-->2)-O-[O-beta-D-apiofuranosyl-(1-->4)-beta-D-glucopyranosyl-(1 -->3)]-O- beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside], (25R)-3 beta-hydroxy-5 alpha-spirostan-12-one (hecogenin) 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-[O-beta-D-apiofuranosyl-(1- ->4)- beta-D-xylopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D- galactopyranoside] and hecogenin 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-[O-beta-D- apiofuranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-gluc opyranosyl- (1-->4)-beta-D-galactopyranoside], respectively. The isolated saponins were examined for inhibitory activity using 12-O-tetradecanoylphorbor-13-acetate-stimulated 32P-incorporation into phospholipids of HeLa cells as the primary screening test to identify new antitumour-promoter compounds.

Anti-tumor-promoting activity of derivatives of abieslactone, a natural triterpenoid isolated from several Abies genus.

Abiesenonic acid methyl ester (AVB-I acid methyl ester), a triterpenoid compound prepared from abieslactone, suppressed tumor promoter-induced phenomena in vitro and in vivo; i.e., AVB-I acid methyl ester inhibited 12-o-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32Pi-incorporation into phospholipids of cultured cells and the promoting action of TPA on skin tumor formation in mice initiated with 7,12-dimethylbenz[a]anthracene.

Steroidal saponins from the bulbs of Lilium longiflorum and their antitumour-promoter activity

Two new spirostanol saponins and two new furostanol saponins were isolated from the fresh bulbs of Lilium longiflorum together with several known saponins. The structures of new compounds were determined to be (25S)-spirost-5-ene-3 beta, 27-diol 3-O-(O-alpha-L-rhamnopyranosyl-(1-->2)-O- [alpha-L-arabinopyranosyl-(1-->3)]-beta-D-glucopyranoside), (25R)-27-O-[(S)-3-hydroxy-3-methylglutaryl]-spirost-5-ene-3 beta,27 diol 3-O-(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[alpha-L-arabinopyranosyl -(1-->3)] - beta-D-glucopyranoside), 22-O-methyl-26-O-beta-D-glucopyranosyl-(25R)-furost-5-ene-3 beta,22 xi, 26-triol 3-O-(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[alpha-L- arabinopyranosyl-(1-->3)]-beta-D-glucopyranoside) and 22-O-methyl-26-O-beta-D-glucopyranosyl-(25R)-furost-5-ene-3 beta, zeta, 26-triol 3-O-(O-alpha-L-rhamnopyranosyl-(1 --> 2)- O-[beta-D-xylopyranosyl-(1 --> 3)]-beta-D-glucopyranoside). The isolated saponins and their derivatives were examined for inhibitory activity on 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32P-incorporation into phospholipids of HeLa cells as the primary screening test to find new antitumour-promoter compounds.

Steroidal glycosides from Allium macleanii and A. senescens, and their inhibitory activity on tumour promoter-induced phospholipid metabolism of hela cells

A new polyhydroxylated cholestane trisdesmoside and a new spirostanol pentasaccharide, together with five known spirostanol saponins, were isolated from the bulbs of Allium macleanii, and two known spirostanol saponins were isolated from the bulbs of A. senescens. The identification and structural assignments of the steroidal glycosides were performed by spectroscopic analysis and hydrolysis. Furthermore, the isolated compounds were evaluated for inhibitory activity on 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32P-incorporation into phospholipids of HeLa cells, which is recognized as an excellent primary screening test to identify new antitumour-promoter compounds.

Steroidal saponins from Hosta longipes and their inhibitory activity on tumour promoter-induced phospholipid metabolism of HeLa Cells

Three new spirostanol saponins and two new furostanol saponins were isolated from the underground parts of Hosta longipes. Their structures were determined to be (25R)-5 alpha-spirostane-2 alpha, 3 beta-diol (gitogenin) 3-O-{O-alpha-L -rhamnopyranosyl-(1-->2)-beta-D-galactopyranoside}, gitogenin 3-O-{O-alpha-L-rhamnopyranosyl-(1-->2) -O-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside-, (25R)-5 alpha-spirostan-3 beta-ol (tigogenin) 3-O-{O-alpha-L-rhamnopyranosyl-(1-->2) -O-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside-, 26-O-beta-D-glucopyranosyl-22-O-methyl-(25R)-5 alpha-furostane-2 alpha,3 beta, 22 xi,26-tetrol 3-O-{O-alpha-L-rhamnopyranosyl -(1-->2)-beta-D-galactopyranoside} and 26-O-beta -D-glucopyranosyl-22-O-methyl-(25R)-5 alpha-furostane-2 alpha,3 beta,22 xi,26-tetrol 3-O-{O-alpha-L -rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl -(1-->4)]-beta-D-galactopyranoside}, respectively. The isolated saponins and their derivatives were examined for inhibitory activity on 12-O-tetradecanoylphorbor-13-acetate-stimulated 32P-incorporation into phospholipids of HeLa cells as the primary screening test to find new antitumour-promoter compounds.

Quercetin Inhibits the Action of 12-O-Tetradecanoylphorbol-13-Acetate, a Tumor Promoter

Quercetin, a mutagenic but noncarcinogenic flavonoid, inhibited the increased incorporation of inorganic phosphate into phospholipids of human embryo fibroblasts induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a potent tumor promoter. Quercetin also inhibited TPA-induced increases of sugar transport and RNA synthesis in chick embryo fibroblasts, and TPA-induced aggregation of human platelets. These results suggest that quercetin may have antitumor promoter activity, which provides a possible reason why quercetin does not develop malignant tumors despite its mutagenicity.

Anti-Tumor and Anti-Tumor Promoting Activity of α- and β-Carotene

Carotenoids are known to inactivate certain reactive oxygen species, such as singlet oxygen. Since antioxidants have been suggested to be one of the promising agents for cancer control, it is worthwhile to evaluate the anti-cancer potency of these carotenoids.