Four new saponins from the root bark of Aralia elata

Four new saponins, 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (called aralia-saponin I), 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyhederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin II), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->3)-alpha-L-+ ++arabinopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin III), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-gucopyranosyl(1-->3)-beta -D-glucucopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin IV), were isolated from the root bark of Aralia elata (Miq.) Seem., together with nineteen known compounds including glycosides of (20S)-protopanaxadiol and (20S)-protopanaxatriol. Their structures were determined on the basis of chemical and spectroscopy methods.     

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.     

Triterpenoid saponin from the bark of Guaiacum officinale L

A new triterpenoid saponin, guaianin R (1) was isolated from the n-BuOH extract of bark of Guaiacum officinale L. It was characterized as akebonic acid-3-O-[alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranoside]-28-O-[beta-D-glucopyranosyl]-ester. The structure was established with the help of a comparative study of 1D and 2D 1H- 13C NMR methods. A number of other saponins were isolated and reported from the same species.     

Structure elucidation and complete NMR spectral assignments of two new dammarane-type tetraglycosides from Panax quinquefolium

Two new saponins were isolated from leaves of Panax quinquefolium and their structures were elucidated as 3beta, 12beta, 20S-trihydroxy-25-methoxydammar-23-ene 3-O-{[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-20-O-[alpha-L-arabinopyranosyl(1-->6)]-beta-D-glucopyranoside (1) and 3beta, 20S-dihydroxy-12beta, 23R-epoxydammar-24-ene 3-O-{[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyanosyl(1-->6)]-beta-D-glucopyranoside (2) on the basis of (1)D and (2)D NMR (including (1)H, (13)C-NMR, (1)H-(1)H COSY, HSQC, TOCSY, HMBC, and NOESY), ESI-MS spectrometry and chemical methods.     

Total synthesis of methyl protodioscin: a potent agent with antitumor activity

Methyl protodioscin (1), otherwise known as 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-d-glucopyranosyl]-26-O-[beta-D-glucopyranosyl]-22-methoxy-25(R)-furost-5-ene-3 beta,26-diol, has been synthesized for the first time from diosgenin through nine steps in an overall yield of 7.8%.     

Glycosides from Bougainvillea glabra

Three glycosides were isolated from Bougainvillea glabra and their structures were determined by extensive use of 1D and 2D NMR spectroscopy ((1)H and (13)C). First compound was identical to momordin IIc (quinoside D) [beta-D-glucopyranosyl 3-O-[beta-D-xylopyranosyl-(1 --> 3)-O-(beta-D-glucopyranosyluronic acid)] oleanolate], second compound was quercetin 3-O-alpha-L-(rhamnopyranosyl)(1 --> 6)-[alpha-L-rhamnopy-ranosyl(1 --> 2)]-beta-D-galactopyranoside and third compound was its derivative quercetin 3-O-alpha-L-(4-caffeoylrhamnopyranosyl)(1 --> 6)-[alpha-L-rhamnopyranosyl (1 --> 2)]-beta-D-galactopyranoside, a new natural product.     

Estrogenic and anti-estrogenic activities of Cassia tora phenolic constituents

Through an estrogenic activity bioassay-guided fractionation of the 70% ethanolic extract of Cassia tora seeds two new phenolic triglucosides, torachrysone 8-O-[beta-D-glucopyranosyl(1-->3)-O-beta-D-glucopyranosyl(1-->6)-O-beta-D-glucopyranoside] (1) and toralactone 9-O-[beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranoside] (2), along with seven known compounds were isolated. The structures of the new compounds were elucidated on the basis of spectroscopic and chemical evidence. The estrogenic activity of the fractions and the isolated compounds were investigated using the estrogen-dependent proliferation of MCF-7 cells. In addition, the yeast two hybrid assay expressing estrogen receptor alpha (ERalpha) and beta (ERbeta) and the ERalpha competitor screening assay (ligand binding screen) were used to verify the binding affinities of the isolated compounds to ER. Furthermore, a naringinase pre-treatment of the 70% alcoholic extract of Cassia tora seeds resulted in a significant increase in its estrogenic activity. From the naringinase pre-treated extract six compounds were isolated, among which 6-hydroxymusizin and aurantio-obtusin showed the most potent estrogenic activity, while torachrysone, rubrofusarin and toralactone showed a significant anti-estrogenic activity. Finally, the structure requirements responsible for the estrogenic activity of the isolated compounds were studied by investigating the activity of several synthetic compounds and chemically modifying the isolated compounds. The basic nucleus 1,3,8-trihyroxynaphthalene (T(3)HN) was found to play a principal role in the binding affinity of these compounds to ER.     

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.     

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).     

A new steroidal saponin from Dioscorea zingiberensis Wright

Two compounds were obtained from the rhizome of Dioscorea zingiberensis Wright. One of them was elucidated as dioscin, the other one was a new compound and characterized as Spirost-5-en-3-yl beta-D-glucopyranosyl (1 --> 3)-beta-D-glucopyranosyl (1 --> 4)-[alpha-L-rhamnopyranosyl (1 --> 2)]-beta-D-glucopyranoside, structure was determined on the basis 2D NMR spectroscopic technique and the result of acid hydrolysis.     

The NMR studies on two new furostanol saponins from Agave sisalana leaves

The detailed NMR studies and full assignments of the 1H and 13C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H, 13C, 1H-1H COSY, TOCSY, HSQC, HMBC and HSQC-TOCSY, and also FAB-MS spectrometry and chemical methods. The structures were established as (25S)-26-(beta-D-glucopyranosyl)-22 xi-hydroxyfurost-12-one-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galacto- pyranoside (1) and (25S)-26-(beta-D-glucopyranosyl)-22xi-hydroxyfurost-5-en-12-one-3beta-yl-O-alpha-L-rhamno- pyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl- (1-->4)-beta-D-galactopyranoside (2).     

Flavonoid constituents from Spiranthes australis LINDL

Chemical investigation of the whole plant of Spiranthes australis (R. BROWN) LINDL. resulted in the isolation and characterization of three new flavonoid constituents, 5-hydroxy-4'-[(2-isopentenyl)oxy]-3,7,3'-trimethoxyflavone (1), 3-O-[[O-beta-D-xylopyranosyl]-(1-->2)-beta-D-glucopyranosyl]-8-(p-hydroxy-benzyl)-kaempferol (2) and 3-O-[O-[2-O-(E)-p-coumaroyl-beta-D-xylopyranosyl]-(1-->2)-beta-D-glucopyranosyl]-8-(p-hydroxy-benzyl)-kaempferol (3), together with six known flavonoid compounds. The structures of new compounds were determined on the basis of spectroscopic analysis, including HR-ESI-MS, 1D- and 2D-NMR techniques and chemical methods.     

Antiinflammatory triterpenoid saponins from the seeds of Aesculus chinensis

Phytochemical study of the ethanol extract of the seeds of Aesculus chinensis led to the isolation of a new triterpenoid saponin (6), together with five known triterpenoid saponins (1-5). The structure of the new compound was elucidated on the basis of spectral data to be 21,28-di-O-acetylprotoaescigenin-3-O-[beta-D-glucopyranosyl(1-2)][beta-D-glucopyranosyl(1-4)]-beta-D-glucopyranosiduronic acid (aesculiside A, 6). The antiinflammatory activities of the four main saponins (1-4) were compared with those of total saponin extracts, and single saponins showed more potent activity than total saponin extracts in mice.     

Marked production of ginsenosides Rd, F2, Rg3, and compound K by enzymatic method

The hydrolysis of protopanaxadiol-type saponin mixture by various glycoside hydrolases was examined. Among these enzymes, crude preparations of lactase from Aspergillus oryzae, beta-galactosidase from A. oryzae, and cellulase from Trichoderma viride were found to produce ginsenoside F(2) [3-O-(beta-D-glucopyranosyl)-20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], compound K [20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], and ginsenoside Rd {3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol}, respectively, from protopanaxadiol-type saponin mixture in large quantities. Moreover, the crude preparation of lactase from Penicillium sp. having a high producing activity of ginsenoside Rh(1) (6-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol) from protopanaxatriol-type saponin mixture gave ginsenoside Rd as a main product, ginsenoside Rg(3) {3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol}, and compound K from protopanaxadiol-type saponin mixture. The hydrolytic pathways of ginsenosides Rb(1), Rb(2), and Rc to ginsenosides Rd, Rg(3), and F(2), and compound K by crude preparations of four glycoside hydrolases were also studied. This is the first report on the enzymatic preparation of an intestinal bacterial metabolite, ginsenoside F(2), in quantity, and a considerable amount of a minor saponin, ginsenoside Rg(3), from a protopanaxadiol-type saponin mixture.     

Two minor diterpene glycosides from the leaves of Stevia rebaudiana

Two new new diterpene glycosides, 13-[(2-O-(6-O-beta-D-glucopyranosyl)-beta-D-glucopyranosyl-beta-D-glucopyranosyl)oxy] kaur-16-en-18-oic acid beta-D-glucopyranosyl ester (1) and 13-[(2-O-beta-D-glucopyranosyl-3-O-beta-D-fructofuranosyl-beta-D-glucopyranosyl)oxy] kaur-16-en-18-oic acid beta-D-glucopyranosyl ester (2) were isolated from the leaves of Stevia rebaudiana, along with the known steviol glycosides stevioside, rebaudiosides A-F and dulcoside A. The structures of the two new compounds were established on the basis of extensive 2D NMR (COSY, HSQC, and HMBC), MS and chemical studies.     

Cytotoxic triterpenoid saponins from the roots of Cephalaria gigantea

Three new oleanane-type saponins, giganteosides L (1), M (2) and N (3) along with eight known ones were isolated from the roots of Cephalaria gigantea. Their structures were established as 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]-hederagenin, 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]-hederagenin, respectively, by means of spectroscopic methods (1D and 2D NMR, HR-ESI-MS). Cytotoxic activity of monodesmosides was investigated in vitro using three cancer cell lines, namely, human non pigmented melanoma MEL-5 and human leukemia HL-60. Giganteosides D (4) and E (5) showed antiproliferative effect on human cell lines with IC(50) values in the range 3.15-7.5 microM.     

Flavonoid glycosides and methylinositol from Ebenus haussknechtii

Two flavonoid glycosides (compounds 1 and 3) of which one is reported for the first time and a methylinositol (compound 2) were isolated from the aerial parts of Ebenus haussknechtii (Leguminosae). The structures were established as quercetin-7-O-[alpha-L-rhamnopyranosyl(1 --> 6)-beta-D-galactopyranoside] (1), morin-3-O-[4-[5-(4-hydroxyphenyl)pentanoyl]-alpha-L-rhamnopyranosyl(1 --> 6)-beta-D-galactopyranosyl]-7-4'-di-O-methyleter (3), and methylinositol (2) on the basis of chemical and spectroscopic means. The antimicrobial activities of the extracts have also been examined.     

Three new phenylethanoid glycosides from Caryopteris incana and their antioxidative activity

Three new phenylethanoid glycosides, incanoside C, incanoside D and incanoside E were isolated together with one known glycoside, beta-D-fructofuranosyl-alpha-D-(6-O-[E]-sinapoyl) glucopyranoside from the whole plant of Caryopteris incana (THUNB.) Miq. On the basis of chemical and spectral analyses, the structures of the new compounds were elucidated to be 1-O-(3,4-dihydroxyphenyl)ethyl-O-beta-D-glucopyranosyl(1-->2)-alpha-L- rhamnopyranosyl(1-->3)-4-O-feruloyl-beta-D-glucopyranoside (incanoside C), 1-O-(3-hydroxy-4-methoxyphenyl)ethyl-O-beta-D-glucopyranosyl(1-->2)-alph a-L- rhamnopyranosyl(1-->3)-4-O-feruloyl-beta-D-glucopyranoside (incanoside D) and 1-O-(3methoxy-4-hydroxyphenyl)ethyl-O-beta-D-glucopyranosyl(1-->2) -alpha-L- rhamnopyranosyl(l-->3)-4-O-feruloyl-beta-D-glucopyranoside (incanoside E). The three new phenylethanoid glycosides exhibited radical scavenging activities against DPPH radical and inhibitory activities against the oxidation of linoleic acid.     

Constituents of Holothuroidea, 17. Isolation and structure of biologically active monosialo-gangliosides from the sea cucumber Cucumaria echinata

Three new monosialo-gangliosides, CEG-3 (3), CEG-4 (4), and CEG-5 (5), were obtained, together with two known gangliosides, SJG-1 (1) and CG-1 (2), from the lipid fraction of the chloroform/methanol extract of the sea cucumber Cucumaria echinata. The structures of the new gangliosides were determined on the basis of chemical and spectroscopic evidence to be 1-O-[4-O-acetyl-alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (3) and 1-O-[alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (4, 5). The ceramide moieties of each compound were composed of heterogeneous sphingosine or phytosphingosine bases, and 2-hydroxy or nonhydroxylated fatty acid units. These gangliosides showed neuritogenic activity toward the rat pheochromocytoma cell line PC-12 in the presence of nerve growth factor.     

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.