Flavonoids of <Emphasis Type="Italic">Scutellaria immaculata</Emphasis> Roots

(±)-5,2′-Dihydroxy-6,7,6′-trimethoxyflavanone, (-)-5,2′-dihydroxy-6,7,8,6′-tetramethoxyflavanone, chrysin, wogonin, apigenin, isoscutellarein, scutellarein, cosmosiin, and the new flavonoid wogonin-7-O-β-D-glucopyranoside, the structure of which was established using chemical transformations and spectral data, were isolated from Scutellaria immaculata roots.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 26–28, January–February, 2005.     

Isoquinoline alkaloids from Asimina triloba

A new aporphine glycoside, (-)-anolobine-9-O-β-D-glucopyranoside was isolated from the twigs of pawpaw (Asimina triloba) along with 7 known alkaloids including five aporphine alkaloids (anolobine, nornuciferine, norushinsunine, liriodenine, and lysicamine), a proaporhine alkaloid (stepharine), and a tetrahydrobenzylisoquinoline alkaloid (coclaurine). Among these compounds, nornuciferine, lysicamine, stepharine, and coclaurine are reported for the first time from this plant. The structure of the new compound was elucidated by spectroscopic methods, including 1?D, 2?D NMR, and HRESI-MS. The absolute configuration of compounds 1, 2, 7 and 8 was determined by CD experiment.     

1H and 13C NMR Assignments for a 27-Norolean-13-en-3-hydroxy-28-oic Acid Glycoside from Isertiahaenkeana

A nortriterpene glycoside, pyrocincholic acid 3β-O-β-6-deoxy-D-glucopyranoside-28-O-β-D-glucopyranoside, was isolated from the leaves of Isertia haenkeana and its structure established by ¹H and ¹³C NMR spectral studies. The complete ¹H and ¹³C NMR resonance assignments for this triterpene were confirmed by the conventional 1D NMR methods and 2D shift-correlated NMR techniques: DQF COSY, TOCSY, ROESY and HMQC.     

N-辛基-β-D-吡喃葡萄糖苷与BSA相互作用的研究

通过稳态荧光法、紫外-可见光谱法和表面张力法研究了N-辛基-β-D-吡喃葡萄糖苷(OGP)与牛血清白蛋白(BSA)在缓冲液中的相互作用. 根据OGP溶液和OGP/BSA混合溶液的表面张力曲线可以看出, 蛋白质的加入改变了单一表面活性剂溶液的表面张力曲线. 蛋白质的加入还使混合体系的临界胶束浓度(cmc*)大于单一表面活性剂的临界胶束浓度(cmc), 这主要是由于OGP与蛋白质结合减少了单体OGP分子的浓度所致. 加入荧光探针芘测量了OGP和OGP/BSA溶液的I₁/I₃值, 结果也表明BSA的加入增大了OGP的聚集浓度, 其原因与表面张力的变化原因是相同的. 在OGP/BSA体系中, 随着OGP浓度的增大, 紫外吸收减弱、荧光强度有规律的降低, 而且荧光发射峰位发生蓝移, 说明它们的结合部位趋向于Trp残基上|同时通过同步荧光和I^－猝灭实验, 进一步证明了OGP与BSA的结合部位是在BSA的疏水空腔内的色氨酸残基上.     

宽叶秦岭藤根部的化学成分

通过正相和反相硅胶柱层析从宽叶秦岭藤根部乙醇提取物中分离纯化得到19个化合物,经波谱分析并结合化学方法鉴定了其结构,其中4个为新化合物,它们分别是3,5-二羟基二十烷酸羽扇豆醇酯(3),2-羟甲基-5-甲氧基苯基-O-β-D-吡喃葡萄糖甙(11),Δ5-孕甾烯-3β,20(S)-二醇-20-O-β-D-吡喃葡萄糖基(1→6)-β-D-吡喃葡萄糖甙(18,秦岭藤甙C)和Δ5-孕甾烯-3β,20(S)-二醇-3-O-β-D-吡喃葡萄糖基-20-O-β-D-吡喃葡萄糖基(1→6)-β-D-吡喃葡萄糖甙(19,秦岭藤甙D).     

Triterpene Glycosides of Astragalus and Their Genins. LXI. Occurrence of Cycloartane 6-O-Monodesmosides

Cyclosiversigenin 6-O--L-rhamnopyranoside and 6-O--D-glucopyranoside were isolated fromAstragalus coluteocarpusBoiss. (Leguminosae) andAstragalus dissectusB. Fedtsch. et N. Ivanova, respectively. Cyclosiversigenin 5-O--L-rhamnopyranoside was shown to be an artifact forAstragalus coluteocarpus.Thus, the cyclosiversigenin 6-O--D-glucopyranoside that was isolated from certainAstragalusspecies is hypothesized also to be an artifact. Glycosylation of the 6 -hydroxyl group of cycloartanes by D-glucose and D-xylose, in contrast with other substituents, does not change the low-field position of the PMR signal of the 4-CH ₃ group (1.65 2.01 ppm) that is caused by the influence of deuteropyridine directly on the 6 -hydroxyl. Obviously one of the hydroxyls of the -D-glucopyranoside or -D-xylopyranoside residues has the same effect in this instance.     

A new hydroquinone diglucoside from <Emphasis Type="Italic">Lysimachia fordiana</Emphasis>

A new hydroquinone diglucoside along with five known compounds was isolated from the whole plant of Lysimachia fordiana Oliv. The structure of the new compound was determined to be 2-heptyl-6-methoxy-1,4-hydroquinone-1,4-di-O--D-glucopyranoside (6). The five known compounds were identified as pentacosane (1), stigmasterol (2), 2-heptyl-6-methoxy-1,4-benzoquinone (3), palmitic acid (4), and rutin (5), respectively. This is the first report of the isolation of Lysimachia fordiana Oliv. in the family Primulaceae.Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 377–379, September–October, 2004.     

The stir-frying can reduce hepatorenal toxicity of Fructus Tribuli by inactivating β-glucosidase and inhibiting the conversion of furostanol saponins to spirostanol saponins

The purpose of this study was to illustrate the mechanism of “enzyme inactivation and toxicity reduction” of Fructus Tribuli (FT) after being heating processed. Ultra-high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) was used to quantitatively analyze the contents of four steroidal saponins in crude Fructus Tribuli (CFT) and stir-fried Fructus Tribuli (SFT) under different storage times at room temperature. The enzyme activity of β-D-glucosidase in CFT and SFT were determined and calculated by ultraviolet–visible spectrometry (UV-VIS spectrometry). In addition, the enzyme hydrolysates of FOT and tribuluside A were qualitatively analyzed by ultra-high-performance liquid chromatography coupled with quadruple-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS). The hepatorenal toxicity of spirostanol saponins in FT were further confirmed by in vivo and in vitro experiment. This study confirmed that “enzyme inactivation and toxicity reduction” was one of the reasons why the stir-frying can reduce hepatorenal toxicity of FT, and further enriched the exploration on the mechanism of processing toxicity reduction.     

Antioxidant Study and Assignments of NMR Spectral Data for 3′,4′,7-Trihydroxyflavanone 3′,7-Di-O-β-D-glucopyranoside (Butrin) and Its Hydrolyzed Product

The NMR spectral data including high resolution ¹H, ¹³C and 2D NMR for butrin, 3,4,7-trihydroxyflavanone 3,7-di-O--D-glucopyranoside, isolated from flowers of Butea monosperma, are reported here for the first time. Butrin was hydrolyzed using b-glucosidase to butin in high yield. They were subjected to free radical scavenging test using 2,2-diphenyl-1-picrylhydrazyl (DPPH) spectrophotometric assay. At a dose of 4 × 10^-8 mol of tested compounds, the percentage of reduced DPPH for butin was 14.5% while no reduction was observed for butrin (0%).     

Triterpene Glycosides from Plants of the Astragalus Genus. Structure of Cyclounifolioside A from Astragalus unifoliolatus

The known compound oleanolic acid (1) and a new cycloartane glycoside cyclounifolioside A (2), which has the structure 6,16-di-O-acetyl-24R-cycloartan-6,16,24,25-pentaol 3-O--D-glucopyranoside, were isolated from Astragalus unifoliolatus Bunge. The structures of the isolated compounds were established using chemical transformations and two-dimensional spectra (TOCSY, ROESY, HMBC, HSQC, COSY).