Structure elucidation and complete NMR spectral assignment of two triterpenoid saponins from Radix Hedysari

A new oleanane-type triterpenoid saponin with a carbonyl group at C-15, named polybosaponin A (1), together with a known triterpenoid saponin, dehydrosoyasaponin I (2), were isolated from Radix Hedysari. On the basis of one- and two-dimensional NMR and high resolution electrospray ionization mass spectrometry, the structure of 1 were elucidated and the ¹H and ¹³C NMR spectral signals were assigned totally. In addition, the complete assignment of ¹H NMR signals and revision of incorrect assignment of ¹³C NMR signals for 2 were also achieved based on one- and two-dimensional NMR spectrometry.     

Assignment of the 1H and 13C NMR spectra of 2-aminobenzamide-labeled galacto- and arabinooligosaccharides

1,4-Linked β-d-galactooligosaccharides with a degree of polymerization (DP) between 1 and 7 and 1,5-linked α-l-arabinooligosaccharides with a DP between 1 and 8 were labeled at their reducing ends with 2-aminobenzamide (2AB) in the presence of sodium cyanoborohydride. The 2AB-labeled oligosaccharides were shown to be homogeneous using high-performance anion-exchange chromatography (HPAEC) and by electrospray ionization mass spectrometry (ESI-MS). The signals in the ¹H and ¹³C nuclear magnetic resonance (NMR) spectra of the 2AB-labeled oligosaccharides were then assigned using one- and two-dimensional NMR spectroscopy. These NMR data will be useful for the structural analysis of enzymatically synthesized galactan and arabinan side chains derived from rhamnogalacturonan I.     

Acylated flavonol glycoside from Platanus orientalis

The ethylacetate and n-butanol fractions of ethanolic extract of Platanus orientalis leaves led to the isolation of new acylated flavonol glycoside as 3',5,7-trihydroxy-4'-methoxyflavonol 3-[O-2-O-(2,4-Dihydroxy)-E-cinnamoyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl (1→2)]-β-D-glucopyranoside, along with seven known compounds. All the compounds were characterized by NMR including 2D NMR techniques. The isolates were evaluated for NF-κB, nitric oxide (NO), aromatase and QR2 chemoprevention activities and some of them appeared to be modestly active.     

A novel antifungal anthraquinone from seeds of Aegle marmelos Correa (family Rutaceae)

A new anthraquinone, 1-methyl-2-(3′-methyl-but-2′-enyloxy)-anthraquinone (1) has been isolated from seeds of Aegle marmelos Correa and was characterized on the basis of spectral analysis (UV, IR, ¹H NMR, ¹³C NMR, 2D NMR and mass spectroscopy). The compound exhibited significant antifungal activity against pathogenic strains of Aspergillus species and Candida albicans in disc diffusion assay (MIC value of 6.25 μg/disc), microbroth dilution and percent spore germination inhibition assays (MIC value of 31.25–62.5 μg/ml).     

Monoterpenoids from the seeds of Heracleum candolleanum.

The isolation and NMR spectra of 2-exo,3-endo-camphanediol (1) and 2-pinene-4,10-diol (2) from the seeds of Heracleum candolleanum are reported.     

Coumarins from the aerial part of Halocnemum strobilaceum

Four known coumarins, coumarin (1), 7-hydroxy-3-methylcoumarin (2), oreoselone (3) and heraclenin (4), were isolated from aerial part of Halocnemum strobilaceum. Their structures were determined by 1 and 2-D NMR techniques.     

Pyrrolizidine alkaloids from Senecio lorenthii.

The isolation and NMR spectra of otosenine (1) and seneciphylline (2) from Senecio lorenthii are reported.     

益智药乙拉西坦的合成和结构表征

以2-溴丁酸甲酯为起始原料,经氨解反应、N-烷基化反应合成了乙拉西坦,总收率为45.6%,改进后的工艺路线反应时间缩短、收率提高;并用IR、1H NM R、13C NM R对乙拉西坦进行了结构表征.     

Anti-HBV activities of Streblus asper and constituents of its roots

The extracts from leaves, heartwood, barks and roots of the Streblus asper were investigated for anti-HBV activities, separately. The results suggested that the MeOH extracts of the heartwood, barks, and roots exhibited good anti-HBV activities. Further investigations displayed that ethyl acetate and n-butanol soluble parts of their MeOH extracts showed more significant anti-HBV activities. Moreover, a new lignan, together with 11 known compounds, was isolated from n-butanol-soluble part of MeOH extract of the roots of S. asper. The structures were elucidated by spectroscopic methods, including 1D NMR ((1)H NMR, (13)C NMR), 2D NMR (HMQC, HMBC) and HR-EI-MS experiments. Compounds 1-3 were evaluated for their anti-HBV activities. Honokiol showed significant anti-HBV activity with IC(50) values of 3.14μM and 4.74μM for HBsAg and HBeAg with no cytotoxicity respectively, while lamivudine (3TC, positive control) exhibited weak anti-HBV activity with IC(50) values of 11.81μM and 25.80μM for HBsAg and HBeAg respectively.     

Two new bisindole alkaloids from the seeds of Strychnos nux-vomica

The reinvestigation of Strychnos nux-vomica resulted in the isolation of two colorless monoquaternary bisindole alkaloids from the seeds. The structures of the two new compounds named 4-N-hydroxymethyl strychnidin-17-acetic acid (1) and 10, 11-dimethoxy-4-N-hydroxymethyl strychnidin-17-acetic acid (2), were defined by detailed spectral analyses, especially ¹H NMR, ¹³C NMR, DEPT, HSQC, ¹H NMR–¹H NMR, NOESY, HMBC and TOF-MS.     

Steroidal saponins from the leaves of Agave macroacantha

A new monodesmosidic spirostanol saponin, along with three known saponins was isolated from Agave macroacantha Zucc leaves. The structure of the new saponin was established as hecogenin-3-O-α-l-rhamnopyranosyl (1→4) β-d-xylopyranosyl (1→3)[β-d-glucopyranosyl (1→2)] β-d-glucopyranosyl (1→4) β-d-galactopyranoside. The ¹H and ¹³C resonances of the four compounds were assigned using a combination of 1D and 2D NMR techniques including ¹H, ¹³C, COSY, TOCSY, ROESY, HSQC and HMBC NMR and confirmed by mass spectrometry.     

Two amides from Piper tuberculatum fruits

The fruits of Piper tuberculatum yielded pellitorine, N-isobutyl-2E,4E-decadienamide (1), and piperidide-2E,4E-decadienamide (2). Their complete NMR analysis, based on one- and two-dimensional experiments, is reported.     

Amides from Piper tuberculatum fruits

The fruits of Piper tuberculatum Jacq yielded piperine S (1) and N-(12,13,14-trimethoxydihydrocinnamoyl)-delta(3)-piperidin-2-one (2). Their complete NMR analysis based on one- and two-dimensional experiments is reported.     

一种松香基阴离子表面活性剂的合成与性能研究

以脱氢枞酸(DA)和6-氨基己酸为原料,经酰氯化、酰胺化和皂化等反应合成了一种松香基阴离子表面活性剂6-脱氢枞酰胺基己酸钠(R-6).首先利用二维核磁技术对脱氢枞酸的氢谱和碳谱信号进行了全面解析,并用1 H NMR和FT-IR确证了终产品的结构,进一步考查了R-6的溶解性能、表面张力和泡沫性能.研究结果表明:在室温下,...     

Triterpenoid glycoside from the roots of Terminalia alata

The isolation and NMR spectra of the triterpenoidal glycoside, 2alpha,3beta,19alpha-trihydroxyolean-12-en-28-oic acid 3-O-beta-D-galactopyranosyl- (1-->3)-beta-D-glucopyranoside (1), from the roots of Terminalia alata are reported.     

New bibenzyl glycosides from leaves of Camellia oleifera Abel. with cytotoxic activities

Studies on the chemical constituents of leaves of Camellia oleifera Abel. led to the isolation of 3 new bibenzyl glycosides. Their structures have been elucidated as 1-(3′,5′-dihydroxy)phenyl-2-(4″-O-β-D-glucopyranosyl)phenylethane (1), 1-(3′,5′-dimethoxy)phenyl-2-(4″-O-β-D-glucopyranosyl)phenylethane (2) and 1-(3′,5′-dimethoxy)phenyl-2-[4″-O-β-D-glucopyranosyl(6→1)-O-α-L-rhamnopyranosyl]phenylethane (3) through spectral studies including HR-ESI-MS, ¹H NMR, ¹³C NMR and 2D NMR experiments. All the above 3 bibenzyl glycosides showed cytotoxic activities to Hela and hep2 cell lines.     

A new pyrrole alkaloid from seeds of Castanea sativa

A new pyrrole alkaloid, methyl-(5-formyl-1H-pyrrole-2-yl)-4-hydroxybutyrate (1), was isolated from sweet chestnut seeds and its structure elucidated on the basis of data from NMR spectroscopy and by comparison with synthetic analogues.     

Furanocoumarins from the aerial parts of Dorstenia contrajerva

A new glycosylated furanocoumarin, alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl-bergaptol (1), has been isolated from Dorstenia contrajerva together with three known furanocoumarins, catechin and epicatechin. Their structures were established using high field 2D NMR techniques.     

1-(β,γ-环氧丙氧甲基)-7-异丙基-4-甲基薁的合成及结构鉴定(英文)

在相转移催化作用下，将７异丙基４甲基１甲醇（２）和环氧氯丙烷进行反应，成功地合成了新的反应型类化合物１（β，γ环氧丙氧甲基）７异丙基４甲基（１）。本反应条件比较简单，较佳条件下分离的目的物摩尔得率达到了６４％。目的物（１）的化学结构（Ｆｉｇ．２）经过ＵＶＶｉｓ、ＩＲ、ＨＲＭＳ和１ＨＮＭＲ等数据分析得到了完满的鉴定。     

Triterpenoid saponins from the roots of Silene cucubalus

A new triterpenoid saponin was isolated from the roots of Silene cucubalus and its structure was determined on the basis of one- and two-dimensional NMR spectroscopy as gypsogenin 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside. A known saponin, quillaic acid 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside, was also isolated.