Tetracyclic Triterpenoids, Steroids and Lignanes from the Aerial Parts of Oxypetalum caeruleum.

The MeOH extract from dried aerial parts of Oxypetalum caeruleum (Apocynaceae) plants yielded seventeen compounds, including four new tetracyclic triterpenoids, one pregnane glycoside, two lignane glycosides, and ten known compounds. The structures of the new compounds were established using NMR, MS spectroscopic analysis and chemical evidence.

New 8,12;8,20-diepoxy-8,14-secopregnane hexa- and hepta-glycosides from the roots of Asclepias tuberosa.

Previously, phytochemical investigation of the roots of Asclepias tuberosa (Asclepiadaceae) led to the isolation of some 8,12;8,20-diepoxy-8,14-secopregnane tri-, tetra-, and penta-glycosides. An additional eight new minor 8,12;8,20-diepoxy-8,14-secopregnane glycosides were afforded in the recent investigation of this plant. These glycosides consisted of six or seven 2,6-dideoxy-hexopyranoses together with the aglycone, tuberogenin. The structures of each of these compounds were established using NMR, mass spectroscopic analysis and chemical evidence. As 8,12;8,20-diepoxy-8,14-secopregnane-type glycosides were observed only in A. tuberosa, these compounds were considered to be characteristic phytochemicals of this plant.

Flavonoid Glycosides from Sedum bulbiferum.

The MeOH extract from dried whole Sedum bulbiferum MAKINO (Crassulaceae) plants yielded 34 compounds, including six new flavonoid glycosides and 28 known compounds. The structures of new compounds were established using NMR, Mass spectroscopic analysis and chemical evidence.

Flavonoid glycosides from Botrychium ternatum.

The MeOH extract from dried whole Botrychium ternatum plants yielded 33 compounds, including seventeen new flavonoid glycosides and sixteen known compounds. The structures of new compounds were established using NMR spectroscopic analysis and chemical evidence.

Triterpene saponins from the pericarps of Akebia trifoliata.

Eleven new triterpene saponin components (1-11) were isolated from the MeOH extract of pericarp of Akebia trifoliata (THUNB.) KOIDZ. Each of their structures was determined using NMR techniques and mass spectrometry.

Triterpene saponins with hyaluronidase inhibitory activity from the seeds of Camellia sinensis.

The MeOH extract of the seeds of Camellia sinensis (L.) KUNTZE gave twelve new saponins (1-12) along with ten known saponins (13-22). These saponins (1-22) showed stronger hyaluronidase inhibitory activity than the positive control, rosmarinic acid.

Constituents from the roots of Taraxacum platycarpum and their effect on proliferation of human skin fibroblasts.

A MeOH extract from the roots of Taraxacum platycarpum has shown significant effects on the proliferation of normal human skin fibroblasts. Chemical analysis of the extract resulted in the isolation of 26 compounds, including eight new triterpenes, one new sesquiterpene glycoside, and seventeen known compounds. The structure of each new compound was established using NMR spectroscopy. Some triterpenes had a significant effect on the proliferation of normal human skin fibroblasts.

8,12;8,20-diepoxy-8,14-secopregnane glycosides from roots of Asclepias tuberosa and their effect on proliferation of human skin fibroblasts.

A pregnane glycoside fraction from the roots of Asclepias tuberosa L. caused normal human skin fibroblasts to proliferate. This fraction contained 21 pregnane glycosides whose structures were established using NMR spectroscopic analysis and chemical evidence. The aglycones of most of these compounds were identified as 8,12;8,20-diepoxy-8,14-secopregnanes, such as tuberogenin or 5,6-didehydrotuberogenin, the same aglycones as constituents of the aerial parts of this plant. Some of these compounds also caused proliferation of skin fibroblasts.

Hyaluronidase inhibitors from "Cimicifugae Rhizoma" (a mixture of the rhizomes of Cimicifuga dahurica and C. heracleifolia).

From the 80% acetone extract of "Cimicifugae Rhizoma" (a mixture of Cimicifuga dahurica and C. heracleifolia used medicinally), seven new fukiic acid derivatives (1-7) and a new phenylethanoid derivative (8) were isolated along with eight known compounds (9-16). Fukinolic acid (9) and cimicifugic acids A-J (10-16, 5-7) showed stronger hyaluronidase inhibitory activities than the positive control, rosmarinic acid.

Phenolic constituents of the aerial parts of Cimicifuga simplex and Cimicifuga japonica.

Chemical investigation of the aerial parts of Cimicifuga simplex afforded four new fukinolic acid analogues, cimicifugic acids K-N (1-4), and 10 known compounds, and C. japonica afforded three new fukinolic acid analogues, cimicifugic acids K-M (1-3), a new phenolic glycoside, shomaside F (5), and 10 known compounds. Cimicifugic acids K-N showed more potent hyaluronidase inhibitory activities than rosmarinic acid.

Flavonoids from the heartwood of the Thai medicinal plant Dalbergia parviflora and their effects on estrogenic-responsive human breast cancer cells.

From the heartwood of Dalbergia parviflora, eight new compounds, khrinones A (1), B (2), C (3), D (4), and E (5), isodarparvinol B (6), dalparvin (7), and (3S)-sativanone (22), along with 32 known compounds, have been isolated and characterized as 17 isoflavones, nine isoflavanones, five flavanones, six isoflavans, and three miscellaneous substances. Isolates were evaluated for their cell proliferation stimulatory activity against the MCF-7 and T47D human breast cancer cell lines, and their luciferase inductive effects using luciferase transiently transfected MCF-7/luc and T47D/luc cells were also determined. Isoflavones such as genistein (10), biochanin A (11), tectorigenin (12), and 2'-methoxyformononetin (13) stimulated the proliferation of both cells, and concentrations of lower than 1 muM of these compounds showed equivalent activity to 10 pM of estradiol (E2). The new isoflavanone (22) also showed activity against both cell types, although it was weaker than that of the corresponding isoflavone (2'-methoxyformononetin, 13). Two optically active isoflavanones (22 and 24: (3S)-violanone) stimulated the proliferation of both cell lines at lower concentrations than three racemates (21: vestitone, 23: 7,3'-dihydroxy-4'-methoxyisoflavanone, and 25: 3-O-methylviolanone). Bowdichione (20), an isoflavone with a quinone structure in its B-ring, showed activity against only one cell line associated with MCF-7 in these assays.

Sesquiterpenes from the roots of Cichorium endivia.

Twelve new sesquiterpene and sesquiterpene glycosides were obtained along with eleven known compounds from the roots of Cichorium endivia (Compositae). The compounds were identified as guaianolide, germacrenolide and elemanolide, based on spectroscopic methods and chemical evidence.

Antiplasmodial triterpenoids from Ekebergia capensis.

From the stem bark of Ekebergia capensis, 10 new triterpenoid compounds, ekeberins A (1), B (2), C1 (3), C2 (4), C3 (5), D1 (6), D2 (7), D3 (8), D4 (9), and D5 (10), were isolated together with 17 known compounds. The structures of these new compounds were elucidated on the basis of the results of spectroscopic analysis, and the absolute configuration of compounds 6-10 were determined by partial synthesis from known compounds and using the Mosher ester method. Several of these compounds were screened in vitro against both chloroquine (CQ)-sensitive and -resistant Plasmodium falciparum isolates and were found to exhibit moderate antiplasmodial activity, with compounds 20 (7-deacetoxy-7-oxogedunin) and 27 (2-hydroxymethyl-2,3,22,23-tetrahydroxy-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene) showing IC50 values of 6 and 7 microM, respectively. Compound 27 at a dose of 500 mg/kg showed moderate parasitemia suppression of 52.9% against P. berghei NK 65 in a mouse model.

Phytoestrogens from Aspalathus linearis.

From the leaves of Aspalathus linearis, 24 known compounds and a new one, aspalalinin (25), were isolated. The structures of the compounds were determined mainly based on spectral evidence. The absolute configuration of aspalalinin was presented on the basis of X-ray analysis. Each isolate was assessed for its estrogenic activity by an estrogen ELISA assay. Compounds 12, 15, and 24 showed the estrogenic activity.

Phenolic constituents of the rhizomes of the Thai medicinal plant Belamcanda chinensis with proliferative activity for two breast cancer cell lines.

From the rhizomes of Belamcanda chinensis, three new compounds, belalloside A (1), belalloside B (2), and belamphenone (3), along with 13 known compounds, resveratrol (4), iriflophenone (5), irisflorentin (6), tectorigenin (7), irilin D (8), tectoridin (9), iristectorin A (10), iristectorin B (11), hispiduloside, androsin, irigenin, iridin, and jaceoside, have been isolated and characterized. Isolates were evaluated for their cell proliferation stimulatory activity against the MCF-7 and T-47D human breast cancer cell lines. Along with 4, 5, 7, and 9, 3 was shown to stimulate not only MCF-7 but also T-47D human breast cancer cell proliferation.

Further constituents from the bark of Tabebuia impetiginosa.

Further study on the constituents from the bark of Tabebuia impetiginosa (Mart. ex DC) Standley afforded twelve compounds, consisting of four iridoid glycosides, one phenylethanoid glycoside, five phenolic glycosides, and one lignan glycoside, along with seven known compounds. The structures of these compounds were determined based on the interpretation of their NMR and MS measurements and by chemical evidence.

Acylated-oxypregnane glycosides from the roots of Araujia sericifera.

Twenty-three new acylated-oxypregnane glycosides were obtained from the roots of Araujia sericifera. (Asclepiadaceae). These glycosides were confirmed to be tetraglycosides possessing twelve known compounds, 12-O-benzoyllineolon, 12-O-benzoyldeacylmetaplexigenin, ikemagenin, kidjolanin, cynanchogenin, caudatin, rostratamine, penupogenin, 12-O-benzoylisolineolon, 12-O-tigloyldecylmetaplexigenin (incisagenin), 12-O-benzoyl-20-O-acetylsarcostin, 20-O-benzoyl-12-O-(E)-cinnamoyl-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptahydroxy-(20S)-pregn-6-ene and ten new acylated-oxypregnanes, 12-O-benzoyl-20S-hydroxyisolineolon, 12-O-tigloyllineolon, 12-O-salicyloyllineolon, 12-O-salicyloyldeacylmetplexigenin, 12-O-benzoyl-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta-hexahydroxypregn-6-en-20-one, 12-O-benzoyl-19-benzoyloxydeacylmetapleligenin, 12-O-benzoyl-19-benzoyloxy-20-O-acetylsarcostin, 12-O-benzoyl-19-salicyloyloxy-20-O-acetylsarcostin, 12-O-benzoyl-5 alpha,6 alpha-epoxydeacylmetaplexigenin, and 12-O-benzoyl-5 alpha,6 alpha-epoxylineolon as their aglycones, using both spectroscopic and chemical methods.

Prolyl endopeptidase inhibitors from the roots of Lindera strychnifolia F. Vill.

Prolyl endopeptidase (PEP, EC 3.4.21.26) has been proposed to play a role in degradation of proline-containing neuropeptides involved in the processes of learning and memory, e.g., vasopressin, substance P, and thyrotropin-releasing hormone (TRH). In the course of our search for bioactive constituents in medicinal plants, we studied the PEP inhibitory constituents of the roots of Lindera strychnifolia F. VILL and isolated two known tannins, epicatechin (1) and aesculitannin B (2), and four known sesquiterpenes, linderene (3), linderene acetate (4), linderalactone (5) and isolinderalactone (6) as inhibitors. On the inhibitory activities of six compounds against PEP from Flavobacterium meningosepticum and that from rat brain supernatant, compounds 1, 2 and 4 inhibited the enzyme from Flavobacterium more strongly than that from rat brain supernatant. However, compounds 3, 5 and 6 inhibited the enzymes from both origins to the same extent and furthermore, compound 6 was the strongest natural inhibitor against PEP from rat brain supernatant. The kinetic study of these inhibitors indicated that compounds 1, 2 are noncompetitive inhibitors and compounds 3-6 are competitive inhibitors. This is the first example of non-phenolic constituents showing significant competitive inhibitory activity being isolated from natural medicines.