Phenolic constituents of Cassia seeds and antibacterial effect of some naphthalenes and anthraquinones on methicillin-resistant Staphylococcus aureus.

Thirteen phenolic glycosides including six new compounds were isolated from seeds of Cassia tora (Leguminosae). The structures of the new compounds, rubrofusarin triglucoside (7), nor-rubrofusarin gentiobioside (9), demethylflavasperone gentiobioside (10), torachrysone gentiobioside (11), torachrysone tetraglucoside (12) and torachrysone apioglucoside (13), were elucidated on the basis of spectroscopic and chemical evidence. The effects of the phenolic glycosides, their aglycones and several other compounds structurally related to them on Escherichia coli K12, Pseudomonas aeruginosa PAO1 and some strains of Staphylococcus aureus were then examined. Among them, torachrysone (15), toralactone (16), aloe-emodin (18), rhein (19) and emodin (20) showed noticeable antibacterial effects on four strains of methicillin-resistant Staphylococcus aureus with a minimum inhibitory concentration of 2-64 micrograms/ml. On the other hand, the phenolic compounds tested did not show strong antibacterial effects on E. coli and P. aeruginosa.     

Antiallergic agent from natural sources. 2. Structures and leukotriene release-inhibitory effect of torososide B and torosachrysone 8-O-6"-malonyl beta-gentiobioside from Cassia torosa Cav.

Two new anti-allergic compounds, torososide B and torosachrysone 8-O-6"-malonyl gentiobioside were isolated from the seeds of Cassia torosa Cav., and their structures were established as physcion 8-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl- (1-->3)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside and torosachrysone 8-O-beta-D-glucopyranosyl-(1-->6)-6-malonyl beta-D-glucopyranoside on the basis of spectral and chemical evidence. Torososide B and torosachrysone 8-O-6"-malonyl gentiobioside were found to inhibit the release of leucotrienes from rat peritoneal mast cells induced by calcium ionophore A 23187.     

Anti-estrogenic activity of mansorins and mansonones from the heartwood of Mansonia gagei DRUMM

Through an anti-estrogenic bioassay-guided fractionation of the methanol extract of Mansonia gagei, three new coumarins, called mansorins I (1), II (2) and III (3) and a new naphthoquinone, mansonone I (4), were isolated. Their structures were determined based on their NMR data and CD spectroscopy. The anti-estrogenic activity of the fractions and the isolated compounds were investigated using a yeast two-hybrid assay method expressing estrogen receptors alpha (ERalpha) and beta (ERbeta). In addition, an ERalpha competitor screening system (ligand binding screen) was used to verify the binding affinities of the isolated compounds to the estrogen receptor. 1,2-Naphthoquinones (mansonones) showed more binding affinities to ER in both assay systems. All the tested compounds showed higher binding affinities to ERbeta than to ERalpha in the yeast two-hybrid assay. Mansonones F and S showed the most potent estrogen binding and estrogen antagonistic effects.     

Steroidal glycosides and aromatic compounds from Smilax riparia

Two new steroidal glycosides named riparosides A (1) and B (2), and two aromatic compounds (3, 4), together with four known flavonoid derivatives have been isolated from the EtOH extract of the rhizomes and roots of Smilax riparia A. DC. The structure of riparoside A (1) was determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl 3beta,20alpha-dihydroxy-5alpha-furost-22(23)-ene 26-O-beta-D-glucopyranoside. Riparoside B (2) was characterized as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl 3beta,16beta-dihydroxy-5alpha-pregnan-20-one 16-O-[5-O-beta-D-glucopyranosyl 5-hydroxy-4-methyl-pentanoic acid]-ester 26-O-beta-D-glucopyranoside. Compounds 3 and 4 were elucidated as a sucrosyl ferulic acid ester and 7-O-methyl-10-oxythymol gentiobioside, respectively.     

Total synthesis of the antiallergic naphtho-alpha-pyrone tetraglucoside,cassiaside C(2), isolated from cassia seeds

Toralactone 9-O-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranosyl-(1-->3)-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside (1, cassiaside C(2)), isolated from Cassia obtusifolia L. and showing strong antiallergic activity, was concisely synthesized employing glycosyl trifluoroacetimidates as glycosylation agents. The unique naphtho-alpha-pyrone structure of toralactone (5) was constructed by condensation of orsellinate 8 with pyrone 9 in the presence of LDA as developed by Staunton and co-workers. The naphthol of toralactone showed minimal reactivity as an acceptor and was screened with various glycosyl donors. It is finally concluded that sacrifice of an excess amount of the trifluoroacetimidate or trichloroacetimidate donors (6f/6g, 6.0 equiv) in the presence of a catalytic amount of TMSOTf (0.05 and 0.3 equiv, respectively) afforded excellent yields of the coupling product, which was otherwise only a minor product under a variety of conditions examined.     

Echiofruzine, a novel naringenin diglycoside from Echiochilon fruticosum growing in Tunisia

The aerial parts of the Tunisian plant Echiochilon fruticosum yielded a novel flavonol diglycoside: naringenin-5-O-beta-D-glycopyranoside-3-O-alpha-L-rhamnopyranoside, named Echiofruzine (1), together with the known compounds vomifoliol-9-O-beta-D-glucopyraroside (2), 1-oxo-alpha-ionyl-9-O-beta-D-glucopyranoside (3) and 1-O-[beta-D-xylopyranosyl(1 --> 6)-beta-D-glucopyranosyl] eugenol (4), described for the first time in the indicated plant. The structures of the four isolated compounds were established on the basis of chemical and spectroscopic evidence.     

Phenolic compounds from Eucalyptus gomphocephala with potential cytotoxic and antioxidant activities

Two new phenolic compounds, 2,4,6-trihydroxy-5-methyl-acetophenone 2-O-beta-D-glucopyranoside (3), and benzyl alcohol 7-O-(3',4',6'-tri-O-galloyl)-beta-D-glucopyranoside (8), together with eight known phenolic compounds, were isolated from the 70% aqueous acetone extract of Eucalyptus gomphocephala DC. (Myrtaceae). The isolated compounds were elucidated based on their 1H, 13C, DQF-COSY, selective 1D-TOCSY, HSQC, and HMBC NMR spectroscopic and ESI-MS data. The antioxidant effect of the phenolic compounds was tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical and super oxide anion radical scavenging assays. The cytotoxicity of the isolated compounds was evaluated using HeLa cell line.     

Glycosides from the leaves of Ilex hylonoma

Two new triterpenoid saponins, hylonosides I-II (1,2) have been isolated along with one known flavonoid glycoside (3) from the methanol extract of leaves of Ilex hylonoma. The structures were elucidated by ID and 2D NMR experiments, including 1H-1H COSY, TOCSY, NOESY, HMQC, and HMBC methods. Two new compounds were characterized as 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucuronopyranosyl pomolic acid-28-O-beta-D-glucopyranoside (1), 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucuronopyranosyl pomolic acid-28-O-beta-D-glucopyranoside (2).     

Phenolics of Moringa oleifera leaves

Five flavonol glycosides characterised as kaempferide 3-O-(2',3'-diacetylglucoside), kaempferide 3-O-(2'-O-galloylrhamnoside), kaempferide 3-O-(2'-O-galloylrutinoside)-7-O-alpha-rhamnoside, kaempferol 3-O-[beta-glucosyl-(1 --> 2)]-[alpha-rhamnosyl-(1 --> 6)]-beta-glucoside-7-O-alpha-rhamnoside and kaempferol 3-O-[alpha-rhamnosyl-(1 --> 2)]-[alpha-rhamnosyl-(1 --> 4)]-beta-glucoside-7-O-alpha-rhamnoside together with benzoic acid 4-O-beta-glucoside, benzoic acid 4-O-alpha-rhamnosyl-(1 --> 2)-beta-glucoside and benzaldehyde 4-O-beta-glucoside have been isolated from methanolic extract of Moringa oleifera leaves. Also obtained from the same extract were known compounds, kaempferol 3-O-alpha-rhamnoside, kaempferol, syringic acid, gallic acid, rutin and quercetin 3-O-beta-glucoside. Their structures were determined using spectroscopic methods as well as comparison with data from known compounds.     

Secondary metabolites from the roots of Paronychia chionaea

Two novel secondary metabolites, compounds (1-2) were isolated from the roots of Paronychia chionaea. On the basis of spectroscopic data including 1D and 2D NMR experiments (COSY, TOCSY, HSQC, and HMBC), and mass spectroscopy, their structures were established as 6-C-[alpha-L-arabinopyranosyl-( 1 --> 2)-beta-D-glucopyranosyl]-7-O-[beta-D-glucopyranosyl]-luteolin 3'-methyl ether (1), and 2-(methoxy)-2-(3,5-dimethoxy 4-hydroxyphenyl)-ethane-1,2-diol 1-O-beta-D-glucopyranoside (2).     

Three new triterpene saponins from the seeds of Aesculus chinensis

Three new triterpenoid saponins were isolated from the seeds of Aesculus chinensis, and characterized as 22-tigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin IVg, 1), 22-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin IVh, 2) and 16-angeloyl-21-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin VIb, 3), together with two known compounds, escin IIIa (4) and desacylescin 1 (5). Their structures were established on the basis of spectroscopic and chemical evidence.     

A novel cycloartane triterpene glycoside from the seeds of Cassia sophera L

A new cycloartane triterpene glycoside (1), named Cyclosophoside A, was isolated from the seeds of Cassia sophera L. The structure of 1 has been determined as 29-O-beta-D-glucopyranoside of 1alpha, 3beta, 24xi, 25-tetrahydroxy-9, 19-cycloartan-29-oic acid by means of physicochemical properties and spectroscopic methods (1D and 2D NMR, MS).     

New benzoyl glucosides and cytotoxic pterosin sesquiterpenes from Pteris ensiformis Burm

Three new compounds: 2R,3R-pterosin L 3-O-beta-D-glucopyranoside (1), beta-D-xylopyranosyl(1-->2)-7-O-benzoyl-beta-D-glucopyranoside (2) and 4-O-benzoyl-beta-D-xylo-pyranosyl(1-->2)-7-O-benzoyl-beta-D-glucopyranoside (3), together with nine known compounds, were isolated from the ethyl acetate extract of Pteris ensiformis. 5-[2-Hydroxyethylidene]-2(5H)-furanone (4), which had been synthesized, was isolated from natural sources for the first time. The structures of all isolated compounds were determined on the basis of mass and spectroscopic evidence. Compound 1 and pterosin B (5) show cytotoxicity against HL 60 cells (human leukemia) with the IC(50) values of 3.7 and 8.7 microg/mL, respectively.     

Fortuneanosides G-L, dibenzofuran glycosides from the fruit of Pyracantha fortuneana

Six new dibenzofuran glycosides, fortuneanosides G (1), H (2), I (3), J (4), K (5), and L (6), were isolated from the fruit of Pyracantha fortuneana (MAXIM) LI. Their structures were determined to be 3,7-dihydroxy-2,4-dimethoxy-dibenzofuran 7-O-beta-D-glucopyranoside, 3,7-dihydroxy-2,4-dimethoxy-dibenzofuran 7-O-(alpha-L-rhamnopyranosyl)-(1-6)-beta-D-glucopyranoside, 3,6-dihydroxy-2,4-dimethoxy-dibenzofuran 6-O-beta-D-glucopyranoside, 2,4-dimethoxy-3,6,9-trihydroxy-dibenzofuran 6-O-beta-D-glucopyranoside, 3,9-dihydroxy-2,4-dimethoxy-dibenzofuran 3-O-beta-D-glucopyranoside, and 2-methoxy-3,4,9-trihydroxy-dibenzofuran 4-O-beta-D-glucopyranoside based on spectroscopic analysis. Fortuneanosides G-J showed more potent tyrosinase-inhibitory activity than arbutin.     

A new anthraquinone glycoside from seeds of Cassia obtusifolia

A new anthraquinone glycoside 1, along with a known anthraquinone glycoside aurantio-obmsin-6-O-β-D-glucopyranoside 2, were isolated from the seeds of Cassia obtusifolia. On the basis of spectral and chemical evidences, the structure of 1 was established as 1-demethylaurantio-obtusin-2-O-β-D-glucopyranoside. Moreover, the 13C NMR of 2 was assigned totally and correctly for the first time based on the two-dimensional NMR.     

New saponins from the seeds of Aesculus chinensis

Eight new acylated polyhydroxyoleanene triterpenoidal saponins, aesculiosides A-H (1-8), along with four known ones, have been isolated from the seeds of Aesculus chinensis. On the basis of extensive NMR studies, the structures of the new compounds were determined to be 21-O-tigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]- beta-D-glucuronopyranosyl acid (1), 21-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-beta-D-glucuronopyranosyl acid (2), 21,22-O-ditigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-d-glucopyranosyl- (1-->4)]-beta-D-glucuronopyranosyl acid (3), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-beta-D-glucuronopyranosyl acid (4), 21,22-O-ditigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-methyl beta-d-glucuronopyranosate (5), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (6), 21-O-tigloyl-28-O-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (7) and 21-O-angeloyl-28-O-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (8).     

Structure elucidation and NMR spectral assignments of four neolignan glycosides with enantiometric aglycones from Osmanthus ilicifolius

Four new 8-O-4' type neolignan glycosides with enantiometric aglycones, (7S,8R)-erythro-guaiacylglycerol-beta-O-4'-sinapyl ether 9-O-beta-D-glucopyranoside (1), (7R,8S)-erythro-guaiacylglycerol-beta-O-4'-sinapyl ether 9-O-beta-D-glucopyranoside (2), (7S,8R)-erythro- syringylglycerol-beta-O-4'-sinapyl ether 9-O-beta-D-glucopyranoside (3) and (7R,8S)-erythro- syringylglycerol-beta-O-4'-sinapyl ether 9-O-beta-D-glucopyranoside (4), were isolated from the leaves of Osmanthus ilicifolius. Their structures were established on the basis of NMR, circular dichroism (CD), MS and chemical data. The NMR assignments for the compounds were carried out using (1)H, (13)C, COSY, HMQC, HMBC and NOESY NMR experiments.     

Bioactive saponins and glycosides. XVII. Inhibitory effect on gastric emptying and accelerating effect on gastrointestinal transit of tea saponins: structures of assamsaponins F, G, H, I, and J from the seeds and leaves of the tea plant

Following the investigation of assamsaponins A, B, C, D, and E, four new saponins termed assamsaponins F, G, H, and I were isolated from the seeds of the tea plant (Camellia sinensis L. var. assamica PIERRE), while assamsaponin J was isolated from its leaves. The structures of assamsaponins F-J were elucidated on the basis of chemical and physicochemical evidence and found to be 16,22-O-diacetyl-21-O-angeloyltheasapogenol E 3-O-[beta-D-galactopyranosyl (1-->2)][beta-D-glucopyranosyl(1 -->2)- alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, 21-O-angeloyl-22-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1--> 2)][beta-D-glucopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->3)]- beta-D-glucopyranosiduronic acid, 21-O-angeloyl-28-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1-->2)][beta-D-glucopyranosyl(1--> 2)-alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, 21-O-tigloyl-28-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1--> 2)][beta-D-glucopyranosyl(1--> 2)-alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, and 16,21-O-diacetyl-22-O-cinnamoyltheasapogenol B 3-O-[beta-D-galactopyranosyl(l-->2)][beta-D-rhamnopyranosy(1-->2)- alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, respectively. The saponin mixture from the seeds of the tea plant was found to exhibit an inhibitory effect on gastric emptying and an accelerating effect on gastrointestinal transit in mice. Theasaponin E1 the principle saponin of the tea plant, showed potent activity, while theasaponin E2 showed none, so that the position of the acyl groups in the sapogenin moiety is important from a pharmacological point of view.