Karsoside and scropolioside D, two new iridoid glycosides from Scrophularia ilwensis

Two new iridoid glycosides, karsoside [1] and scropolioside D [2], were isolated from the aerial parts of Scrophularia ilwensis. Their structures were elucidated on the basis of chemical and spectral data as 6'-O-(beta-D-xylopyranosyl)-methylcatalpol and 6-O-[(2",4"-di-O-acetyl-3"-O-trans-cinnamoyl)-alpha-L-rhamnopyranosyl]- catalpol, respectively. Additionally, four known iridoids (aucubin, harpagide, 8-O-acetylharpagide, and ajugol), a phenylpropanoid glycoside (angoroside C), and two flavonoids (quercetin-3-O-rutinoside and kaempferol-3-O-rutinoside) were isolated and identified.     

Studies on the constituents of Calliandra anomala (Kunth) Macbr. I. Structure elucidation of two acylated triterpenoidal saponins

Two novel triterpenoidal saponins, called calliandra saponins A and E, were isolated from the branches of Calliandra anomala (Kunth) Macbr. On the basis of the chemical and physiocochemical evidence, their structures were defined as 3-O-alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl++ +-(1-->6)-2- acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 28-O-(beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->3)-beta-D - xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-[(6S)-2-trans- 2,6-dimethyl-6-O-beta-D-xylopyranosyl-2,7-octadienoyl-(1-->6)]-bet a-D- glucopyranosyl) ester (4) and 3-O-alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl++ +-(1-->6)-2- acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 28-O-[beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->3)-beta-D - xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-[(6'S)-2'-trans- 2',6'-dimethyl-6'-O-(2-O-(6S)-2-trans-2,6-dimethyl-6-hydroxy-2,7-octa dienoyl)- beta-D-xylopyranosyl-2',7'-octadienoyl-(1-->6)]-beta-D-glucopyr ano syl] ester (5), respectively.     

Medicinal foodstuffs. XII. Saponin constituents with adjuvant activity from hyacinth bean, the seeds of Dolichos lablab L. (1): Structures of lablabosides A, B, and C

From the glycoside mixture with adjuvant activity obtained from the hyacinth bean, the seeds of Dolichos lablab L., six new oleanane-type triterpene bisdesmosides, lablabosides A, B, C, D, E, and F, were isolated together with chikusetsusaponin IVa. The structures of lablabosides A, B, and C were determined on the basis of chemical and physicochemical evidence as follows: 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-galactopyranosyl (1-->2)-beta-D-glucopyranosiduronic acid]-28-O-(beta-D-glucopyranosyl) oleanolic acid (lablaboside A), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-galactopyranosyl (1-->2)-beta-D-glucopyranosiduronic acid]-28-O-(beta-D-glucopyranosyl) 24-epi-hederagenin (lablaboside B), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D- galactopyranosyl (1-->2)-beta-D-glucopyranosiduronic acid]-28-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] 24-epi-hederagenin (lablaboside C).     

Bioactive saponins and glycosides. VIII. Notoginseng (1): new dammarane-type triterpene oligoglycosides, notoginsenosides-A, -B, -C, and -D, from the dried root of Panax notoginseng (Burk.) F.H. Chen

The glycosidic fraction from the dried roots of Panax notoginseng (Burk.) F.H. Chen was found to show protective effect on liver injury induced by D-galactosamine and lipopolysaccharide. From the glycosidic fraction with hepatoprotective effect, nine new dammarane-type triterpene oligoglycosides, notoginsenosides-A, -B, -C, -D, -E, -G, -H, -I, and -J and an acetylenic fatty acid glycoside, notoginsenic acid beta-sophoroside, were isolated together with fourteen known dammarane-type triterpene oligoglycosides. The structures of notoginsenosides-A, -B, -C and -D were determined on the basis of chemical and physicochemical evidence, which included the chemical correlation with ginsenoside-Rb1 using photosensitized oxygenation, as follows: notoginsenoside A; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta, 12 beta,20(S),25-tetrahydroxydammar -23-ene; B; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl (1-->6)-beta-D- glucopyranosyl] 3 beta, 12 beta,20(S)-trihydroxydammar-25-en-24-one, C; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D -glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta,12 beta,20(S)- trihydroxy-24 zeta-hydroperoxydammar-25-ene, and D; 3-O-[beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]20(S)-protopanaxadiol, respectively.     

Soluble guanylate cyclase and nitric oxide synthase in synaptosomal fractions of bovine retina

Four new allose-containing triterpenoid saponosides, scabriosides A, B, C and D were isolated from the roots of Scabiosa rotata. Their structures were established as 3-O-beta-D-xylopyranosyl-28-O-[beta-D-allopyranosyl (1-->6)-beta-D-glucopyranosyl]-pomolic acid, 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-xylopyranosyl]-28-O-[beta-D-allopyranosyl (1-->6)-beta-D-glucopyranosyl]-pomolic acid, 3-O-[alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-allopyranosyl (1-->6)-beta-D-glucopyranosyl]-pomolic acid, and 3-O-[beta-D-glucopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-beta-D-xylopyranosyl]-28-O-[beta-D-allopyranosyl(1-->6) -beta-D-glucopyranosyl]-pomolic acid, respectively, by the help of spectral evidence (IR, 1D- and 2D-NMR, FAB-MS).     

Triterpenoid saponins from Ilex latifolia

Three new triterpenoid saponins, latifolosides F, G, H were isolated from the leaves of Ilex latifolia. Their structures were elucidated on the basis of chemical and spectral evidence. Latifoloside F was determined to be 3-O-[alpha-L-rhamnopyranosyl(1-2)]-[beta-D-glucopyranosyl(1-3)-]- alpha-L-arabinopyranosyl ilexgenin B 28-O-[alpha-L-rhamnopyranosyl(1-2)]-beta-D-glucopyranoside. Latifoloside G was 3-O-[alpha-L-rhamnopyranosyl(1-2)]-[beta-D-glucopyranosyl(1-3)-]- alpha-L-arabinopyranosyl pomolic acid 28-O-[alpha-L-rhamnopyranosyl(1-2)]-beta-D-glucopyranoside. Latifolioside H(3) was 3-O-[alpha-L-rhamnopyranosyl(1-2)]-[beta-D-glucopyranosyl(1-3)-]- alpha-L-arabinopyranosyl siaresinolic acid 28-O-[alpha-L-rhamnopyranosyl(1-2)]-beta-D-glucopyranoside.     

Ferulic acid dehydrodimers from wheat bran: isolation, purification and antioxidant properties of 8-O-4-diferulic acid

Wheat bran contains several ester-linked dehydrodimers of ferulic acid, which were detected and quantified after sequential alkaline hydrolysis. The major dimers released were: trans-5-[(E)-2-carboxyvinyl]-2-(4-hydroxy-3-methoxy-phenyl)-7-methoxy-2, 3- dihydrobenzofuran-3-carboxylic acid (5-8-BendiFA), (Z)-beta-[4-[(E)-2-carboxyvinyl]-2-methoxyphenoxy]-4-hydroxy-3-methox ycinnamic acid (8-O-4-diFA) and (E,E)-4,4'-dihydroxy-5,5'-dimethoxy-3,3'-bicinnamic acid (5-5-diFA). trans-7-hydroxy-1-(4-hydroxy-3methoxyphenyl)-6-methoxy-1,2-dihydro - naphthalene-2,3-dicarboxylic acid (8-8-diFA cyclic form) and 4,4'-dihydroxy-3,3'-dimethoxy-beta,beta'-bicinnamic acid (8-8-diFA non cyclic form) were not detected. One of the most abundant dimers, 8-O-4-diFA, was purified from de-starched wheat bran after alkaline hydrolysis and preparative HPLC. The resultant product was identical to the chemically synthesised 8-O-4-dimer by TLC and HPLC as confirmed by 1H-NMR and mass spectrometry. The absorption maxima and absorption coefficients for the synthetic compound in ethanol were: lambda max: 323 nm, lambda min: 258 nm, epsilon lambda max (M-1 cm-1): 24,800 +/- 2100 and epsilon 280 (M-1 cm-1): 19,700 +/- 1100. The antioxidant properties of 8-O-4-diFA were assessed using: (a) inhibition of ascorbate/iron-induced peroxidation of phosphatidylcholine liposomes and; (b) scavenging of the radical cation of 2,2'-azinobis (3-ethyl-benzothiazoline-6-sulphonate) (ABTS) relative to the water-soluble vitamin E analogue, Trolox C. The 8-O-4-diFA was a better antioxidant than ferulic acid in both lipid and aqueous phases. This is the first report of the antioxidant activity of a natural diferulate obtained from a plant.     

Medicinal foodstuffs. X. Structures of new triterpene glycosides, gymnemosides-c, -d, -e, and -f, from the leaves of Gymnema sylvestre R. Br.: influence of gymnema glycosides on glucose uptake in rat small intestinal fragments

Following the characterization of gymnemosides-a and -b, new triterpene glycosides, gymnemosides-c, -d, -e, and -f, were isolated from the leaves of Gymnema (G.) sylvestre R. BR. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence as follows: 21-O-benzoyl-28-O-acetylgymnemagenin 3-O-beta-D-glucopyranosiduronic acid (gymnemoside-c), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] gymnestrogenin (gymnemoside-d), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D- glucopyranosyl]-28-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 23-hydroxylongispinogenin (gymnemoside-e), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]-28-O-[beta-O-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta,16 beta,23,28-tetrahydroxyolean-18-ene (gymnemoside-f). The inhibitory effects of gymnemosides-c, -d, -e, and -f and principal triterpene glycosides from G. sylvestre on glucose uptake in rat small intestinal fragments were examined, and gymnemic acids II, III, and IV, gymnemasaponin V, and gymnemoside-f were found to exhibit the inhibitory activity.     

Facile synthesis of 2-methyl-[4,6-di-O-acetyl-1,2-dideoxy-3-O-(2,3,4,6-tetra-O-acetyl-D-glycopyranosyl)-alpha-D-glucopyrano-[2',1':4,5]-2-oxazolines, key intermediates for the synthesis of oligosaccharides

A simple synthesis of disaccharide oxazolines has been developed. Condensation of methyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside with 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide, followed by removal of the 4,6-O-benzylidene group from the resulting disaccharide derivative, gave crystalline methyl 2-acetamido-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha-D-glucpyranoside which, on acetolysis with acetic anhydride-acetic acid-sulfuric acid, provided 2-methyl-[4,6-di-O-acetyl-1,2-dideoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha-D-glucopyrano]-[2',1':4,5]-2-oxazoline (7). Synthesis of the related alpha-D-mannopyranosyl compound was similarly accomplished. The glycosylating capability of 7 was employed for the synthesis of 6-(benzyloxycarbonylamino)hexyl-2-acetamido-4,6-di-O-acetyl-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-beta-D-glucopyranoside (18). An alternative synthesis of compound 18 is also described.     

Saikosaponin homologues from Clinopodium spp. The structures of clinoposaponins XII-XX

Nine new saikosaponin homologues, called clinoposaponins XII-XX, were isolated from the aerial parts of Clinopodium vulgare, C. chinense and C. chinense var. parviflorum together with nine known saikosaponin homologues. On the basis of spectral and chemical evidence, the structures of clinoposaponins XII-XX were determined to be 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl] saikogenin F, 3-O-beta-D-fucopyranosyl-21 beta- hydroxysaikogenin F, 3-O-[beta-D-glucopyranosyl-(1--> 3)-beta-D-fucopyranosyl]-21 beta-hydroxysaikogenin F, 3-O-[beta-D- glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]saikogenin F, 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl- (1-->3)]-beta-D-fucopyranosyl]-21 beta-hydroxysaikogenin F, 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl- (1-->3)]-beta-D-fucopyranosyl]-23-oxosaikogenin E, 3-O- [beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->3)]-beta- D-fucopyranosyl]-16-ketosaikogenin F, 3-O-[beta-D-glucopyranosyl-(1--> 2)-[beta-D-glucopyranosyl-(1-->3)]-beta-D-fucopyranosyl]-30-hydroxysa ikogenin F, 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->3)] -beta-D-fucopyranosyl]-30-oxo-saikogenin F, respectively. The known saponins were assigned to be clinoposaponins III, V, IX, X, XI, buddlejasaponins I, IV, 3-O-beta-D-fucopyranosylsaikogenin F and saikosaponin a.     

Saponin and sapogenol. XLIX. On the constituents of the roots of Glycyrrhiza inflata Batalin from Xinjiang, China. Characterization of two sweet oleanane-type triterpene oligoglycosides, apioglycyrrhizin and araboglycyrrhizin

Two sweet oleanane-type triterpene oligoglycosides named apioglycyrrhizin and araboglycyrrhizin were isolated from the air-dried roots of Glycyrrhiza inflata Batalin, collected in Xinjiang province (Shinkyo-Kanzo in Japanese), together with glycyrrhizin (3), licorice-saponins A3 (8), G2 (10), and H2 (11) and known flavonoid glycosides. On the basis of chemical and physicochemical evidence, the structures of apioglycyrrhizin and araboglycyrrhizin have been determined to be expressed as 3-O-[beta-D-apiofuranosyl(1-->2)-beta-D- glucuronopyranosyl]glycyrrhetic acid (1) and 3-O-[alpha-L- arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl]glycyrrhet ic acid (2), respectively. During the course of these studies, it has been found that the hydroxyl groups in the oligosaccharide moiety of the glucuronide saponins may be partially methylated by prolonged treatment with diazomethane in methanol. The sweetness of the saponins hitherto isolated from various Glycyrrhizae Radix has been examined and a structure-sweetness relationship, as compared with glycyrrhizin, has been found.     

The generation of superoxide anions in glycation reactions with sugars, osones, and 3-deoxyosones

A glycosyldiacylglycerol was isolated from the marine bacterium Deleya marina (ATCC 25374). The structure was determined, mainly by spectral data, to be 1, 2-diacyl-3-O-[alpha-2-amino-2-deoxy-glucopyranose-(1-->4)-O-alpha-idu ronopyranuronic acid]-glycerol. This is, to our knowledge, the first isolation of diglycosyldiacylglycerol containing both iduronopyranuronic acid and 2-amino-2-deoxy-glucopyranose from Gram-negative bacteria.     

Calcium dobesilate: pharmacology and future approaches

Two new 4-hydroxybenzyl alcohol derivatives (1 and 2) were isolated from the methanol extract obtained from fresh tubers of Gastrodia elata together with 4-hydroxybenzyl methyl ether, 4-hydroxybenzyl alcohol, bis(4-hydroxyphenyl)methane, 4-hydroxybenzaldehyde, beta-sitosterol and palmitic acid. 1 and 2 were identified as 3-O-(4'-hydroxybenzyl)-beta-sitosterol and 4-[4'-(4"-hydroxybenzyloxy)benzyloxy]benzyl methyl ether, respectively, according to the spectroscopic data.     

Pyrazolopyridine derivatives act as competitive antagonists of brain adenosine A1 receptors: [35S]GTPgammaS binding studies

The effects of adenosine receptor ligands and three novel pyrazolopyridine derivatives on guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPgammaS) binding to rat cerebral cortical membranes were examined. [35S]GTPgammaS binding was stimulated in a concentration dependent manner by several adenosine receptor agonists. The adenosine A2a receptor selective agonist, 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS 21680), was ineffective confirming specificity for adenosine A1 receptor activation. 2-Chloro-N6-cyclopentyladenosine (CCPA; 10(-7) M)-stimulated [35S]GTPgammaS binding was inhibited by xanthine and pyrazolopyridine based adenosine receptor antagonists. The concentration-response curve for CCPA-stimulated [35S]GTPgammaS binding was shifted to the right with increasing concentrations of antagonist without significant changes in maximal response. Schild analyses determined pK(B) values of 8.97, 8.88, 8.21, 8.16, 7.79 and 7.65 for 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), (R)-1-[(E)-3-(2-phenylpyrazolo[1,5a]pyridin-3-yl) acryloyl]-2-piperidine ethanol (FK453), 6-oxo-3-(2-phenylpyrazolo[1,5a]pyridin-3-yl)-1(6H)-pyridazinebutyric+ ++ acid (FK838), 9-chloro-2-(2-furyl)[1,2,4]triazolo-[1,5c]quinazolin-5-amine (CGS 15943), 8-cyclopentyl-1,3-methylxanthine (CPT) and (R)-1-[(E)-3-(2-phenylpyrazolo[1,5a]pyridin-3-yl) acryloyl]-piperidin-2-yl acetic acid (FK352), respectively. Schild slopes were close to unity, confirming that these novel pyrazolopyridine derivatives act as competitive antagonists at rat brain adenosine A1 receptors.     

Steroidal glycosides from Allium albopilosum and A. ostrowskianum

Chemical studies of the bulbs of Allium albopilosum and A. ostrowskianum have led to the isolation of two new steroidal saponins and four new cholestane glycosides together with several known compounds. The structures of the new compounds were established by the spectroscopic data, hydrolysis and chemical correlations as (25 R and S)-5 alpha-spirostane-2 alpha,3 beta,6 beta-triol 3-O-(O-beta-D-glucopyranosyl-(1-->2)-O-[3-O-acetyl-beta-D-xylopyranosyl- (1-->3)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside), (25R)-2-O-[(S)-3-hydroxy-3-methylglutaroyl]-5 alpha-spirostane-2 alpha, 3 beta, 6 beta-triol 3-O-(O-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O- beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside), (22S)-cholest-5-ene-1 beta,3 beta,16 beta,22-tetraol 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside), 1 beta,3 beta,16 beta-trihydroxycholest-5-en-22-one 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside), 1 beta,3 beta,16 beta-trihydroxy-5 alpha-cholestan-22-one 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside) and (22S)-cholest-5-ene-1 beta,3 beta,16 beta,22-tetraol 16-O-(O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranoside).     

Saikosaponins from roots of Bupleurum scorzonerifolium

Saikosaponin u and saikosaponin v, were isolated from the roots of Bupleurum scorzonerifolium and these saponins were identified as 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl- (1-->3)-beta-D-fucopyranosyl]-3 beta,16 alpha,23,28-tetrahydroxy-olean- 11,13(18)-dien-30-oic acid-30-O-[pentito(1-->1)-beta-D-glucopyranosyl-(6-->)] ester and 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-fucopyranosyl]-3 beta,16 alpha,23,28-tetrahydroxy-olean-11,13(18)-dien-30-oic acid-30-O-[pentito(1-->1)-beta-D-glucopyranosyl(6-->)] ester, respectively.     

Purification and characterization of a feruloyl esterase from the fungus Penicillium expansum

An extracellular phenolic acid esterase produced by the fungus Penicillium expansum in solid state culture released ferulic and rho-coumaric acid from methyl esters of the acids, and from the phenolic-carbohydrate esters O-[5-O-(trans-feruloyl)-alpha-L-arabinofuranosyl]-(1-->3)-O-beta- D-xylopyranosyl-(1-->4)-D-xylopyranose (FAXX) and O-[5-O-((E)-rho-coumaroyl)-alpha-L-arabinofuranosyl]- (1-->3)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (PAXX). The esterase was purified 360-fold in successive steps involving ultrafiltration and column chromatography by gel filtration, anion exchange and hydrophobic interaction. These chromatographic methods separated the phenolic acid esterase from alpha-L-arabinofuranosidase, pectate and pectin lyase, polygalacturonase, xylanase and beta-D-xylosidase activities. The phenolic acid esterase had an apparent mass of 65 kDa under non-denaturing conditions and a mass of 57.5 kDa under denaturing conditions. Optimal pH and temperature were 5.6 and 37 degrees C, respectively and the metal ions Cu2+ and Fe3+ at concentrations of 5 mmol 1-1 inhibited feruloyl esterase activity by 95% and 44%, respectively, at the optimum pH and temperature. The apparent Km and Vmax of the purified feruloyl esterase for methyl ferulate at pH 5.6 and 37 degrees C were 2.6 mmol 1-1 and 27.1 mumol min-1 mg-1. The corresponding constants of rho-coumaroyl esterase for methyl coumarate were 2.9 mmol 1-1 and 18.6 mumol min-1 mg-1.     

Dammarane saponins from Panax ginseng

From the dried roots of Panax ginseng two new minor dammarane saponins named koryoginsenoside-R1 and -R2 were isolated, along with fourteen known saponins. On the basis of spectral and chemical evidence, the structure of the new saponins were elucidated as 6-O-[trans butenoyl-(1-->6)-beta-D-glucopyranosyl]-20-O-beta-D- glucopyranosyl dammar-24-en-3 beta,6 alpha,12 beta,20(S)-tetrol and 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D- glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] dammar-22-en-3 beta,12 beta, 20(S),- 25-tetrol, respectively.     

delta 9-Tetrahydrocannabinol is a partial agonist of cannabinoid receptors in mouse brain

We measured the ability of the cannabinoid agonists delta 9-tetrahydrocannabinol and R(+)-[2,3,-dihydro-5-methyl-3- [(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazin-yl]-(1-napht halenyl) methanone mesylate (WIN 55,212-2) to stimulate guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTP gamma S) binding in mouse brain membranes. delta 9-Tetrahydrocannabinol stimulated [35S]GTP gamma S binding by about 25% as compared to WIN 55,212-2. This is the first report demonstrating that delta 9-tetrahydrocannabinol acts as a partial agonist in stimulating [35S]GTP gamma S binding in the mouse brain.     

Acetylated flavonol triglycosides from Ammi majus L

Two new acetylated flavonol triglycosides: kaempferol and isorhamnetin 3-O-[2"-(4"'-acetylrhamnosyl)-6"-glucosyl] glucosides, were isolated and identified from the aerial parts of Ammi majus L. In addition, three known flavonol glycosides namely; isorhamnetin-3-O-rutinoside, kaempferol-3-O-glucoside and isorhamnetin-3-O-glucoside were detected.