Sachiko Sugimoto

Acylated oleanane-type triterpene saponins with acceleration of gastrointestinal transit and inhibitory effect on pancreatic lipase from flower buds of chinese tea plant (Camellia sinensis).

The MeOH extract and its BuOH-soluble fraction (crude saponin fraction) from the flower buds of Chinese tea plant (Camellia sinensis (L.) O. KUNTZE; Fujian Province) were found to exhibit accelerating effects on gastrointestinal transit in mice and inhibitory effects against pancreatic lipase. From the BuOH-soluble fraction, three new acylated oleanane-type triterpene oligoglycosides, chakasaponins I, II, and III (1-3, resp.), were isolated together with 13 known compounds. The chemical structures 1-3 were elucidated on the basis of chemical and physicochemical evidence. Compounds 1-3 showed accelerating effects on gastrointestinal transit in mice and inhibitory effects against porcine pancreatic lipase (IC(50)=150-530 microM).

Structures of dammarane-type triterpene triglycosides from the flower buds of Panax ginseng

New dammarane-type triterpene triglycosides, floralginsenosides G, H, I, J, K, La, and Lb, were isolated from the flower buds of Panax ginseng C. A. MEYER together with ten known dammarane-type triterpene oligoglycosides. The structures of new compounds were elucidated on the basis of chemical and physicochemical evidence.

Medicinal flowers (25) Structures of floratheasaponin J and chakanoside 2 from Japanese tea flower, flower buds of Camellia sinensis

Following the investigation of floratheasaponins A, B, and C, a new acylated oleanane-type triterpene saponin termed floratheasaponin J and an aromatic glycoside called chakanoside II were isolated from the flower buds of Japanese tea plant (Camellia sinensis). The structures of the new glycosides were determined by chemical and physicochemical evidence.

Megastigmane glucosides and an unusual monoterpene from the leaves of Cananga odorata var. odorata, and absolute structures of megastigmane glucosides isolated from C. odorata var. odorata and Breynia officinalis

From a 1-BuOH-soluble fraction of a MeOH extract of Canangaodorata var. odorata, collected at the Botanical Garden of Chiang Mai University, a new megastigmane glucoside, named canangaionoside, and an irregular monoterpene were isolated. A known compound, breyniaionoside A, which has been obtained from the leaves of Breyniaofficinalis, was also isolated, and its absolute structure was substantiated for the first time in this study. On this occasion, the absolute stereochemistries of structurally related megastigmane glucosides, breyniaionosides B and C, isolated from B.officinalis were examined.

Chemical constituents from Chorisia chodatii flowers and their biological activities

From the flowers of Chorisia chodatii Hassl. (family: Bombacaceae), seventeen compounds were isolated and identified, including: two sterols, β-sitosterol (1) and β-sitosterol 3-O-β-D-glucopyranoside (10); two furanoids, 5-hydroxymethyl furfural (3) and (3R,4R,5S)-3,4-dihydroxy-5-methyl-dihydrofuran-2-one (12); two coumarins, scopoletin (8) and aesculetin (9); four phenolic acids and esters, ethyl vanillate (4), vanillic acid (5), protocatechuic acid ethyl ester (6) and p-hydroxy benzoic acid (7); five flavonoids, kaempferol 3-O-β-D-(6″-acetyl)-glucopyranoside (13), kaempferol 3-O-β-D-(6″-E-p-coumaroyl)-glucopyranoside (14), kaempferol 3-O-β-D-glucopyranoside (15), luteolin 7-O-β-D-glucopyranoside (16) and apigenin 7-O-neohesperidoside (17), in addition to mono-octyl phthalate (2) and succinic acid (11). All the isolated metabolites were reported for the first time from this plant, and among them, compounds (3), (4), (6), (7), (12) and (13) were isolated for the first time from family Bombacaceae. Besides, this is the first report for isolation of (2) in a pure form from a natural source. These phytochemical data revealed important chemotaxonomic value and may broaden the use of this plant in future phytotherapy. Moreover, all of the obtained phytocompounds were evaluated for their DPPH free radical scavenging properties and cytotoxic activities against the human lung cancer cell line A549.

Entadosides A-D, triterpene saponins and a glucoside of the sulphur-containing amide from the kernel nuts of Entada phaseoloides (L.) Merrill.

From a MeOH extract of kernel nuts of Entada phaseoloides (L.) Merrill, one new and one known sulphur-containing glucoside were isolated. From the 1-BuOH-soluble fraction of a H2O extract, four new triterpene saponins containing N-acetylglucosamine in their sugar chains were isolated. The antiproliferative activities of the triterpene saponins were assayed.

Structure elucidation of secondary metabolites isolated from the leaves of Ixora undulate and their inhibitory activity toward advanced glycation end-products formation

Three aromatic glycosides (1-3), two sulfur and nitrogen-containing compound glucosides (4, 5), and one flavonoid glycoside (6) were isolated from the leaves of Ixora undulata. Their structures were established by extensive 1D, 2D NMR, and HRESIMS experiments, and structure 4 was further confirmed by single crystal X-ray diffraction analysis. Of the assayed compounds, 7, 11 and 12 showed strong inhibitory activity toward advanced glycation end-products formation with IC50 values of 86.0 μM, 76.6 μM and 98.6 μM, respectively.

New Isolinariins C, D and E, Flavonoid Glycosides from Linaria japonica

Three new flavonoid glycosides named isolinariins C, D and E (1-3), two known flavonoid glycosides (4, 5) and three known flavonoids (6-8) were isolated from the whole plant of Linaria japonica. The structures of these compounds were determined mainly by spectroscopic analyses. The bioactivities of these isolated compounds were evaluated for their inhibitory activities against human cell line A549, collagenase, and advanced glycation end product (AGE) formation. Among the isolated compounds, isolinariins C, D and E (1, 2 and 3) showed inhibition toward AGE formation (IC50 values of 34.8, 35.0 and 19.5 µM, respectively). And linariin (4), pectolinarin (5) and luteolin (8) were found to be active against collagenase with IC50 values of 79.4, 78.6 and 40.5 µM, respectively, without significant cytotoxicity at these concentrations.

Microtropins A–I: 6′-O-(2″S,3″R)-2″-Ethyl-2″,3″-dihydroxybutyrates of aliphatic alcohol β-d-glucopyranosides from the branches of Microtropis japonica

From the branches of Microtropis japonica (Celastraceae), nine aliphatic glucosides, named microtropins A-I, were isolated. The 6-position of glucose was esterified with (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid. Microtropins A-D contained a rare natured product nitrile functional group in their aglycones. The absolute structures of the (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid moiety and aglycone of microtropin A were determined by an X-ray crystallographic method.

Medicinal plants of Thailand. II: chemical studies on the seed kernels of Entada rheedei Sprengel

Chemical investigation of a methanolic extract of the seed kernels of Entada rheedei (Fabaceae), a Thai medicinal plant taken for stomachache, led to the isolation of five new compounds, 1-(3,4-dimethoxyphenyl)propan-9-ol O-(6″-O-α-l-arabinopyranosyl)-β-d-glucopyranoside, 1-(3,4,5-trimethoxyphenyl)prop-7-en-9-ol O-(6″-O-α-l-arabinopyranosyl)-β-d-glucopyranoside, and N-(2′-hydroxyethyl)-7-phenylacetamide 2′-O-β-d-glucopyranoside, and entadamide A 2′-O-(4″-O-β-d-glucopyranosyl)-β-d-glucopyranoside and 2′-O-(6″-O-β-d-glucopyranosyl)-β-d-glucopyranosides, together with one known compound, corchoionoside C. Their structures were elucidated on the basis of chemical and spectral evidence.