A new diterpene glycoside from Stevia rebaudiana

From the commercial extract of the leaves of Stevia rebaudiana, a new diterpene glycoside was isolated besides the known steviol glycosides including stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compound was identified as 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-α-L-rhamnopyranosyl-β-D-glucopyranosyl) ester (1) on the basis of extensive spectroscopic (NMR and MS) and chemical studies.     

A silica gel orthogonal high-performance liquid chromatography method for the analyses of steviol glycosides: novel tetra-glucopyranosyl steviol

A silica gel orthogonal method using acetonitrile: water was developed for the analyses of fractions rich in very polar steviol glycosides and resolve regions of co-elution of these compounds in reversed-phase. Additionally, we also used this normal phase analytical method to scale up the purification process of steviol glycosides. Using these approaches, one novel minor tetra-glucopyranosyl diterpene glycosides together with three known compounds were purified from a commercial Stevia rebaudiana leaf extract. Compound 1 was unambiguously elucidated as 13-[(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(6-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester (rebaudioside Y) based on high-performance liquid chromatography retention times, tandem mass spectrometry dissociation pattern and 1D and 2D NMR experiments. Known compounds were isolated in gram quantities and identified as rebaudioside D, E and M.     

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.     

Terpene glycosides from the roots of Sanguisorba officinalis L. and their hemostatic activities

Guided by a hemostasis bioassay, seven terpene glycosides were isolated from the roots of Sanguisorba officinalis L. by silica gel column chromatography and preparative HPLC. On the grounds of chemical and spectroscopic methods, their structures were identified as citronellol-1-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside (1), geraniol-1-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside (2), geraniol-1-O-α-Larabinopyranosyl-(1→6)-β-D-glucopyranoside (3), 3β-[(α-L-arabinopyranosyl)oxy]-19α-hydroxyolean-12-en-28-oic acid 28-β-D-glucopyranoside (4), 3β-[(α-L-arabinopyranosyl)-oxy]-19α-hydroxyurs-12-en-28-oic acid 28-β-D-glucopyranoside (ziyu-glycoside I, 5), 3β,19α-hydroxyolean-12-en-28-oic acid 28-β-D-glucopyranoside (6) and 3β,19α-dihydroxyurs-12-en-28-oic acid 28-β-D-glucopyranoside (7). Compound 1 is a new mono-terpene glycoside and compounds 2, 3 and 5 were isolated from the Sanguisorba genus for the first time. Compounds 1–7 were assayed for their hemostatic activities with a Goat Anti-Human α2-plasmin inhibitor ELISA kit, and ziyu-glycoside I (5) showed the strongest hemostatic activity among the seven terpene glycosides. This is the first report that ziyu-glycoside Ι has strong hemostatic activity.     

Additional minor diterpene glycosides from Stevia rebaudiana

From the commercial extract of the leaves of Stevia rebaudiana, two additional new diterpenoid glycosides were isolated and their structures were characterized as 13-[(2-O-beta-glucopyranosyl-3-O-beta-D-xylopyranosyl-beta-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid beta-D-glucopyranosyl ester (1) and 13-[(2-O-beta-D-xylopyranosyl-beta-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid beta-D-glucopyranosyl ester (2) on the basis of extensive spectral data (NMR and MS) and chemical studies.     

Regioselective Enzyme-Mediated Glycosylation of Natural Polyhydroxy Compounds. Part 1. Galactosylation of stevioside and steviolbioside

Bovine β-1,4-galactosyltransierase is an efficient catalyst for the regioselective transfer of galactose from UPD-galactose, generated in situ with the UDP-glucose/UDP-glucose-4-epimerase system, to the kaurane glycosides stevioside ( 1 ) and Steviolbioside ( 2 ), affording the corresponding galactosyl derivatives 3 and 4 in high yields. By a combination of 2D NMR techniques (COSY, TOCSY, ROESY, HMQC, and HMBC), the structure of the products is established as 13-[(β -D -galactopyranosyl-(1 → 4)-β-D -glucopyranosyl-(1 → 2)- β -D -glucopyranosyl)oxy]kaur-16-en-19-oic acid β -D -glucopyranosyl ester ( 3 ) and 13-[(β-D -galactopyranosyl-(1 → 4)- β-D -glu-copyranosyl-(1 → 2)- β-D -glucopyranosyl)oxy]kaur-16-en-19-oic acid ( 4 ).     

Synthesis of ent-kaurane diterpene monoglycosides

Synthesis of two ent-kaurane diterpene glycosides, steviol 19-O-β-D-glucopyranosiduronic acid (steviol glucuronide, 5), and 13-hydroxy ent-kaur-16-en-19-oic acid-β-D-glucopyranosyl ester (7) has been achieved from a common starting material, steviol, using phase transfer catalyst. Also, synthesis of an additional 17-nor-ent-kaurane glycoside, namely 13-methyl-16-oxo-17-nor-ent-kauran-19-oic acid-β-D-glucopyranosyl ester (10) was performed using the starting material isosteviol and similar synthetic methodology. Synthesis of all three steviol glycosides was performed using straightforward chemistry and their structures were characterized on the basis of 1D and 2D NMR as well as mass spectral (MS) data.     

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 antifungal active triterpenoid saponins from the seeds of Lathyrus plants

Two novel triterpenoid glycosides have been isolated from butanolic seeds extract of two varieties of Lathyrus plants, i.e. Lathyrus ratan and Lathyrus aphaca. Their structures were elucidated as 3-O-[β-D-glucuronopyranosyl-(1?→?4)-α-L-arabinopyranosyl-(1?→?2)-α-L-arabinopyranosyl]-olean-11,13(18)-dien-28-oic acid (1) and 3-O-{β-D-xylopyranosyl-(1 → 2)-β-D-glcopyranosyl-(1?→?4)-[β-D-glucopyranosyl-(1?→?2)]-β-D-xylopyranosyl}-2,16α-dihydroxy-4-hydroxymethyl urs-12-en-28-oic acid (2) on the basis of spectral evidences, i.e. FTIR, (1)H-NMR, (13)C-NMR, ESI-MS and FAB-MS data. The isolated saponins were tested for their antifungal activity. Compound 1 showed maximum inhibition against Colletotrichum dematium (77.8%), whereas compound 2 showed maximum inhibition against Alternaria alternata (53.9%).     

Structural determination of two new triterpenoid saponins acylated with monoterpenic acid from Gymnocladus chinensis Baill

Two new triterpenoid saponins acylated with monoterpenic acid, 2β,23-dihydroxy-3-O-α-L-rhamnopyranosyl-21-O-{(6S)-2-trans-2,6-dimethyl-6-O-[3-O-(β-D-glucopyranosyl)-4-O-(2-methylbutanoyl)-β-L-arabinopyranosyl]-2,7-octadienoyl)-acacic acid 28-O-β-D-xylopyranosyl-(1?→?3)-β-D-xylopyranosyl-(1?→?4)-[β-D-glucopyranosyl-(1?→?3)]-α-L-rhamnopyranosyl-(1?→?2)-[α-L-rhamnopyranosyl-(1?→?6)]-β-D-glucopyranosyl ester and 2β,23-dihydroxy-3-O-α-L-rhamnopyranosyl-21-O-{(6S)-2-trans-2,6-dimethyl-6-O-[4-O-((6S)-2-trans-2,6-dimethyl-6-O-(β-L-arabinopyranosyl)-2,7-octadienoyl)]-β-L-arabinopyranosyl]-2,7-octadienoyl}-acacic acid 28-O-β-D-xylopyranosyl-(1?→?3)-β-D-xylopyranosyl-(1?→?4)-[β-D-glucopyranosyl-(1?→?3)]-α-L-rhamnopyranosyl-(1?→?2)-[α-L-rhamnopyranosyl-(1?→?6)]-β-D-glucopyranosyl ester were isolated from the fruit of Gymnocladus chinensis Baill. and the structural elucidation of both the compounds was accomplished by extensive studies of their spectroscopic (1D and 2D NMR, TOF-MS, QFT-MS) and chemical methods.     

Three new triterpenoid saponins from Dianthus superbus

Three new triterpenoid saponins (1-3) were isolated from the dried aerial parts of Dianthus superbus L. (Caryophyllaceae). Their structures were established as 3-O-β-D-glucopyranosyl gypsogenic acid 28-O-[β-D-6-O-((3S)-3-hydroxyl-3-methylglutaryl)glucopyranosyl(1→6)]-β-D-glucopyranoside (1), 3-O-β-D-glucopyranosyl gypsogenic acid 28-O-[β-D-glucopyranosyl(1→3)][β-D-6-O-((3S)-hydroxyl-3-methylglutaryl)glucopyranosyl(1→6)]-β-D-glucopyranoside (2), 3-O-α-L-arabinopyranosyl-3β,16α-dihydroxyolean-12-en-23,28-dioic acid 28-O-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (3), on the basis of various spectroscopic analyses and chemical degradations.     

Triterpene glycosides of Hedera taurica VI. Structures of hederosides G,H1, H2, and I from the berries of Crimean ivy

We have isolated from Crimean ivy berries in addition previously known triterpene glycosides — 3-O-α-L-arabinopyranosyl-28-O-[O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glycopyranosyl-(1 → 6)-β-D-glucopyranosyl]hederagenin, 3-O-[O-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl]-28-O-[O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glucopyranosyl-(1 → 6)-β-D-glycopyranosyl]hederagenin, the new triterpene glycosides hederoside H₂-3-O-[O-β-D-glycopyranosyl-(1 → 2)-β-D-glycopyranosyl-(1 → 2)-β-D-glucopyranosyl]-28-O-[O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]oleanolic acid- and hederoside I-3-O-[O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyl]-28-O-[O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]hederagenin. Details of their¹³C NMR spectra are given. M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 779–783, November–December, 1990.     

A new triterpenoid saponin from the roots of Ardisia crenata

A new triterpenoid saponin.3 β-O-{ β-D-glucopyranosyl-(1—4)-[ β-D-glucopyranosyl-[1-2)]- α-L-arabinopyranosyl}-16α, 28-dihydroxyolean-12-en-30-oic acid 30-O- β-D-glucopyranosyl ester(ardisicrenoside N.1),together with two known saponins, ardisicrenoside C(2) and D(3),were isolated from the roots of Ardisia crenata Sim.Their structures were elucidated by extensive spectral analysis and chemical evidences.Saponins 1 showed cytotoxicity against MCI-7 and NCI-H460 cancer cell lines at 11.0μmol/L and 22.1μmol/L in vitro.     

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.     

Separation and identification of a new saponin from the flowers of Guaiacum officinale L

A triterpenoid saponin, guaianin O (1), oleanolic acid 3-O-{α-L-rhamnopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 3)]-α-L-arabinopyranoside}-28- O-[β-D-glucopyranosyl]-ester, was isolated from the n-butanol extract of flowers of Guaiacum officinale L. The structural elucidation of 1 was accomplished by extensive studies of both one and two dimensional 1H, 13C-NMR spectra, the FAB mass spectrum, and alkaline and acid hydrolyses.     

Platycoside N: a new oleanane-type triterpenoid saponin from the roots of Platycodon grandiflorum

A new oleanane-type triterpenoid saponin, named platycoside N (1), together with six known saponins, was isolated from the roots of Platycodon grandiflorum. On the basis of acid hydrolysis, comprehensive spectroscopic data analyses and comparison with the spectral data of the known compounds, its structure was elucidated as 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-2β,3β,16α,23-tetrahydroxyolean-12-en-28-oic acid 28-O-β-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside. The six known compounds were platycodin D (2), deapioplatycodin D (3), platycodin D3 (4), deapioplatycodin D3 (5), platycoside E (6) and deapioplatycoside E (7).     

Platycoside O, a new triterpenoid saponin from the roots of Platycodon grandiflorum

A new unusual minor triterpenoid saponin, platycoside O (1), was isolated from the 75% EtOH extract obtained from the roots of Platycodon grandiflorum, together with four known saponins: platycoside M-3 (2), platycoside J (3), platycoside F (4) and platycoside B (5). The structure of 1 was determined as 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-2β,3β,16α,23-tetrahydroxyolean-12-en-24-methoxyl, 24-oxo-28-oic acid 28-O-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside on the basis of spectral analysis and chemical evidence.     

Glycosides of marine invertegrates. XI. Two new triterpene glycosides from holothurians of the familyStichopadidae

By repeated column chromatography on silica gel new glycosides have been isolated from the holothuriansAstichopus multifidus andStichopus chloronotus — astichoposide C and stichoposide C (I and II, respectively). Their structures have been studied with the aid of chemical and physicochemical methods. The complete structures of the glycosides have been established as 23(S)-acetoxy-3β-{4′-O-[O-(3-O-methyl-β-D-glucopyranosyl)-(1→3)-β-D-glucopyranosyl]-2′-O-[O-(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O-β-D-xylopyranosyl-(1→4)-β-D-quinovopyranosyl]-β-D-xylopyranosyloxy}holosta-7,25-diene and -holost-7-ene.     

两个非对映异构三萜皂甙的结构鉴定

从合欢皮95%乙醇提取物中分得2个新三糖链九糖皂甙(1,2),经化学方法和光谱分析,将其结构分别鉴定为:3-O-[β-D-吡喃木糖基-(1→2)-β-D-吡喃阿拉伯糖基-(1→6)-β-D-葡萄糖基]-21-O-(6S)-2-反式-2,6-二甲基-6-O-[4-O-((6R)-2-反式-2,6-二甲基-6-O-β-D-吡喃鸡纳糖基-2,7-辛二烯酸基)-β-D-吡喃鸡纳糖基]-2,7-辛二烯酸基金合欢酸28-O-β-D-吡喃葡萄糖基-(1→3)-[α-L-呋喃阿拉伯糖基-(1→4)]-α-L-吡喃鼠李糖基-(1→2)-β-D-吡喃葡萄糖基酯(1)和3-O-[β-D-吡喃阿拉伯糖基-(1→2)-β-D-吡喃呋糖基-(1→6)-β-D-葡萄糖基]-21-O-(6S)-2-反式-2,6-二甲基-6-O-[4-O-((6S)-2-反式-2,6-二甲基-6-O-β-D-吡喃鸡纳糖基-2,7-辛二烯酸基)-β-D-吡喃鸡纳糖基]-2,7-辛二烯酸基金合欢酸28-O-β-D-吡喃葡萄糖基-(1→3)-[α-L-呋喃阿拉伯糖基-(1→4)]-α-L-吡喃鼠李糖基-(1→2)-β-D-吡喃葡萄糖基酯(2),分别命名为合欢皂甙J₁₄(JulibrosideJ₁₄)和合欢皂甙J₁₅(JulibrosideJ₁₅)     

Glycosides of marine invertebrates. XII. Structure of a new triterpene oligoglycoside from holothurians of familyStichopodidae

From an ethanolic extract of the holothuriansStichopus chloronotus by column chromatography on silica gel a new triterpene oligoside has been isolated the structure of which has been established as 23(S)-acetoxy-3β-{4′-O-[O-(3-O-methyl-β-D-glucopyranosyl)-(1→3)-β-D-glucopyranosyl]-2′-O-[O-(3-O-methyl-β-D-glucopyranosyl(-(1→3)-O-β-D-xylopyranosyl-(1→4)-β-D-glucopyranosyl]-β-D-xylopyranosyloxy}holost-7-ene. A hypothesis has been put forward concerning the biosynthesis of the carbohydrate chains in the glycosides of holothurians of the orderAspidochirota from bioside blocks.