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).     

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.     

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.     

Antioxidant secondary metabolites from Geranium lasiopus Boiss. & Heldr

Chromatographic studies on the EtOAc soluble portion of the MeOH extract of Geranium lasiopus led to the isolation of eight flavonoids (kaempferol (1), quercetin (2), quercetin 3-O-β-glucopyranoside (3), quercetin 3-O-β-galactopyranoside (4), kaempferol 3-O-α-rhamnopyranosyl-(1?→?6)-β-glucopyranoside (5), quercetin 3-O-α-rhamnopyranosyl-(1?→?6)-β-glucopyranoside (6), kaempferol 3-O-α-rhamnopyranosyl-(1?→?2)-β-glucopyranoside (7) and quercetin 3-O-α-rhamnopyranosyl-(1?→?2)-β-glucopyranoside (8)), two simple phenolic compounds (gallic acid (9) and its methyl ester (10)) and a hydrolysable tannin (pusilagin (11)). The structures of the compounds were elucidated by 1- and 2-dimensional NMR techniques ((1)H, (13)C, COSY, HMBC, HMQC) and ESI-TOF-MS spectrometry. Inhibitory effects on H(2)O(2)-induced lipid peroxidation in human red blood cells of the different extracts of G. lasiopus, as well as isolated compounds, were investigated. All tested compounds showed comparable or higher activity than that of ascorbic acid and trolox.     

The inhibition of superoxide anion generation by neutrophils from Viscum articulactum

Two new flavanones, (2S)-pinocembrin 7-O-[beta-D-apiosyl(1-->2)]-beta-D-glucoside (1), and (2S)-pinocembrin 7-O-[cinnamoyl(1-->5)-beta-D-apiosyl(1-->2)]-beta-D-glucoside (2) together with eighteen known compounds, which include five known flavanones, nine benzenoids, one inositol and three triterpenoids, were isolated and characterized from fresh Viscum articulactum. Structures of new compounds were determined by spectral analysis. Among them, oleanolic acid (18) showed a significant inhibition effect on superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP).     

Triterpene glycosides from the stems of Akebia quinata

The stems of Akebia quinata have been analyzed for their triterpene glycoside constituents, resulting in the isolation of six new triterpene glycosides, along with 19 known ones. On the basis of extensive spectroscopic analysis, including 2D NMR data, and chemical evidence, the structures of the new compounds were deter-mined to be 3beta-[(O-beta-D-glucuronopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3beta-[(O-beta-D-glucuronopyranosyl-(1-->3)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3beta-[(O-beta-D-glucuronopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3beta-[(O-beta-D-glucuronopyranosyl-(1-->3)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-29-hydroxyolean-12-en-28-oic acid, and 3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-23,29-dihydroxyolean-12-en-28-oic acid, respectively. The main triterpene glycosides contained in the stems of A. quinata were found to have two sugar units at C-3 and C-28 of the aglycone in this study, whereas those of Akebia trifoliate were reported to possess one sugar unit at C-28 of the aglycone. It may be possible to distinguish between A. quinata and A. trifoliate chemically by comparing their triterpene glycoside constituents.     

Two new triterpenoid saponins isolated from Polygala japonica

Bioassay guided investigation of whole parts of Polygala japonica afforded two new triterpenoid saponins, characterized as 3-O-beta-D-glucopyranosyl medicagenic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (1), 3-O-beta-D-glucopyranosyl 2-oxo-olean-12-en-23, 28-dioic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (2), together with four known triterpenoid saponins (3-6). Their structures were elucidated by spectroscopic and chemical methods. Saponins 3, 4 and 5 showed significant anti-inflammation effects on carrageenan-induced acute paw edema in mouse.     

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%.     

Norlanostane and lanostane glycosides from the bulbs of Chionodoxa luciliae and their cytotoxic activity

Ten lanostane glycosides (1-10), including two new norlanostane glycosides (2 and 7) and a new lanostane glycoside with a spirolactone ring system (9), were isolated from the fresh bulbs of Chionodoxa luciliae (Liliaceae). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis and the results of hydrolytic cleavage to be (23S)-3beta-[(O-beta-D-apiofuranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]-17alpha,23-epoxy-28,29-dihydroxy-27-norlanost-8-en-24-one (2), (23S)-17alpha,23-epoxy-29-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]-27-norlanost-8-ene-15,24-dione (7), and (23S,25R)-17alpha,23-epoxy-29-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]lanost-8-en-23,26-olide (9), respectively. The cytotoxic activity of the isolated compounds against HSC-2 human oral squamous cell carcinoma cells are also reported.     

Ardisimamillosides C-F, four new triterpenoid saponins from Ardisia mamillata

Four new triterpenoid saponins, ardisimamilloside C (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3beta,16al pha,28,30-tetrahydroxy-olean-12-en, ardisimamilloside D (2), 3-O-?alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3beta,15al pha,28,30-tetrahydroxy-olean-12-en, ardisimamilloside E (3), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosl]-13beta,2 8-epoxy-3beta,16alpha,29-oleananetriol, and ardisimamilloside F (4), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3beta,16al pha-dihydroxy-13beta,28-epoxy-oleanan-30-oic acid were isolated from the roots of Ardisia mamillata Hance. Structure assignments were established on the basis of highresolution (HR)-FAB-MS, 1H-, 13C-, and two-dimensional (2D)-NMR spectra, and on the chemical evidence.     

日香桂根的化学成分研究（III）

利用柱层析法（硅胶,C18）从日香桂根的乙酸乙酯提取物中分离出8个单体化合物［女贞苷(1),连翘苷（2）,(+)-羟基松脂醇-1-O-β-D-葡萄糖(3),(+) 环橄榄树脂素(4), 2α,3β-二羟基乌苏-12-烯-28酸(5),对羟基苯乙醇(6),(-) 橄榄脂素(7)和橄榄树脂素-4-O-β-D-葡萄糖苷(8)］,其结构经₁H NMR和¹³C NMR确证。5为首次在木犀科植物中发现,4为首次在木犀属植物中发现,2, 3, 7和8为首次在日香桂植物中发现。     

Two oleananes from Ammannia auriculata Willd

Two new compounds: 3-β,15-α,23,28-tetrahydroxyolean-12-en-3-O-arabinopyaranoside and 3-β,23,28-trihydroxy-olean-12-en-3-O-β-D-glucopyranoside were isolated from the aerial parts of Ammania auriculata along with the known compounds kaempferol, β-sitosterol-3-O-β- D-glucoside, 2-α,3-β,23-trihydroxyolean-12-en-28-oic acid-28-O-β-D-glucopyranoside, quercetin, kaempferol-3-O-α-L-arabinofuranoside, kaempferol-3-O-β-D-xylopyranoside and ellagic acid. Structures of these compounds were elucidated on the basis of their spectroscopic data (NMR, UV, MS and IR spectra). The antioxidant activities of the total extract, the fractions CH(2)Cl(2), EtOAc and the remaining aqueous together with the compounds 1, 6 and 9 were comparable with that of the standard antioxidant, ascorbic acid.     

Chemical constituents and antibacterial activity of Melastoma malabathricum L

The aqueous methanolic extracts of Melastoma malabathricum L. exhibited antibacterial activity when assayed against seven microorganisms by the agar diffusion method. Solvent fractionation afforded active chloroform and ethyl acetate fractions from the leaves and the flowers, respectively. A phytochemical study resulted in the identification of ursolic acid (1), 2α-hydroxyursolic acid (2), asiatic acid (3), β-sitosterol 3-O-β-D-glucopyranoside (4) and the glycolipid glycerol 1,2-dilinolenyl-3-O-β-D-galactopyanoside (5) from the chloroform fraction. Kaempferol (6), kaempferol 3-O-α-L-rhamnopyranoside (7), kaempferol 3-O-β-D-glucopyranoside (8), kaempferol 3-O-β-D-galactopyranoside (9), kaempferol 3-O-(2″,6″-di-O-E-p-coumaryl)-β-D-galactopyranoside (10), quercetin (11) and ellagic acid (12) were found in the ethyl acetate fraction. The structures of these compounds were determined by chemical and spectral analyses. Compounds 1-4, the flavonols (6 and 11) and ellagic acid (12) were found to be active against some of the tested microorganisms, while the kaempferol 3-O-glycosides (7-9) did not show any activity, indicating the role of the free 3-OH for antibacterial activity. Addition of p-coumaryl groups results in mild activity for 10 against Staphylococcus aureus and Bacillus cereus. Compounds 2-5, 7 and 9-12 are reported for the first time from M. malabathricum. Compound 10 is rare, being reported only once before from a plant, without assignment of the double bond geometry in the p-coumaryl moiety.     

Steroidal glycoalkaloids from the berries of Solanum distichum

Two steroidal glycoalkaloids, Solanidine 3-O-[alpha-L-rhamnopyranosyl-(1' --> 4)-[alpha-L-rhamnopyranosyl-(1' --> 2)]-beta-D-glucopyranoside] (1) and Solanidine 3-O-[alpha-L-rhamnopyranosyl-(1' --> 4)-beta-D-glucopyranoside] (2) commonly known as alpha-chanonine and beta 2-chanonine, were isolated from the berries of Solanum distichum. The structures of the isolated compounds were studied by 1D and 2D NMR techniques and FAB MS analysis. The 13C NMR signal assignments and direct elucidation of the glycoside linkages were established. Glycoalkaloids level in the dried berries, determined by a simple colorimetric method, was found to be 5.08 +/- 0.18 g%.     

Reactive oxygen species scavenging activity of flavone glycosides from Melilotus neapolitana

One new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-beta-D-glucopyranosyloxy-4',5-dihydroxy-3-[O-alpha-L-rhamnopyranosyl-(1-->6)-3-O-beta-D-glucopyranosyloxy]flavone (1) by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2), kaempferol-3-O-glucoside (3), rutin (4), quercetin-3-O-glucoside (5), isorhamnetin-3-O-rutinoside (6), and isorhamnetin-3-O-glucoside (7). The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated. The organic extract can inhibit MDA marker's synthesis by 57%. All the metabolites displayed good reducing power, with the kaempferol (2,3) and isorhamnetin derivatives (6,7) being less active than the corresponding quercetin derivatives 4,5.     

Tyrosinase inhibitory and antileishmanial constituents from the rhizomes of Paris polyphylla

The search for bioactive natural products from the rhizomes of Paris polyphylla (Trilliaceae) has resulted in the isolation of four known constituents, 1,5-dihydroxy-7-methoxy-3-methylanthraquinone (1), diosgenin-3-O-[alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranoside] (2), diosgenin-3-O-[alpha-L-rhamnopyranosyl-(1(Rha) --> 2(Glu))-alpha-L-arabinofuranosyl-(1(Ara) --> 4(Glu))]-beta-D-glucopyranoside (3), and diosgenin-3-O-[alpha-L-rhamnopyranosyl-(1(Rha) --> 2(Glu))-alpha-L-rhamnopyranosyl-(1(Ara) --> 4(Glu))]-beta-D-glucopyranoside (4). Their structures were identified by spectral comparison with the reported data. Compound 1 was isolated for the first time from this genus. The chloroform, ethyl acetate, and butanol extracts of the plant were found to have mild to moderate inhibitory potentials against the enzyme tyrosinase. Compound 1 showed strong (IC(50) = 0.23 microM), while compounds 2-4 and hydrolyzed product 4a showed mild to moderate (IC(50) = 0.93-36.87 microM) activities against the tyrosinase. Similarly, compounds 2-4 and 4a showed mild to moderate (IC(50) = 1.59-83.72 microg mL(-1)) antileishmanial activities.     

Two new triterpenoid glycosides isolated from Aesculus assamica GRIFF

Phytochemical study of the ethanol extract of the seeds of Aesculus assamica led to the isolation of two new triterpenoid saponins. The structure of the new compounds were elucidated on the basis of spectral data to be 28-O-acetyl-21-O-(4-O-angeloyl)-6-deoxy-beta-glucopyranosyl-3-O-[beta-glucopyranosyl(1-2)-O-[beta-glucopyranosyl(1-4)]-beta-glucuronopyranosyl]protoaescigenin (1), and 21-O-(4-O-angeloyl)-6-deoxy-beta-glucopyranosyl-3-O-[beta-glucopyranosyl(1-2)-O-[beta-glucopyranosyl(1-4)]-beta-glucuronopyranosyl]protoaescigenin (2). Their in vitro bioactivity against plant pathogenic fungus Pyricularia oryzae and cytotoxicity against K562 and HCT-15 cell lines were evaluated.     

Complete (1)H and (13)C assignments of the four major saponins from Dioscorea villosa (wild yam)

Complete (1)H and (13)C spectral assignments for the four major steroidal saponins isolated by methanolic extraction of the roots of Dioscorea villosa, collected in North Carolina, United States (in summer and autumn), are presented in this paper. The structures were determined by a combination of (1)H, (13)C and 2D NMR techniques and were found to be ((3beta,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl-O-beta-D-glucopyranosyl-(1 --> 3)-O-beta-D-glucopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1) (or methyl parvifloside), ((3beta,25R)-26-(beta-D-glucopyranosyloxy)-22 methoxyfurost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[beta-D-gluco- pyranosyl-(1 --> 4)]-beta-D-glucopyranoside (2) (or methyl protodeltonin), (3beta,25R)-spirost-5-en-3-yl-O-beta-D-glucopy ranosyl-(1 --> 3)-O-beta-D-glucopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (3) (or Zingiberensis saponin I) and (3beta,25R)-spirost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[beta-Ds-glucopyranosyl -(1 --> 4)]-beta-D-glucopyranoside (4) (or deltonin).     

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.