中压制备液相色谱法分离纯化新藤黄酸

目的优化制备型液相色谱PR-HPLC分离纯化新藤黄酸的方法。方法以新藤黄酸得率为考察指标,藤黄醇提取粗品用PR-HPLC分离纯化,正交设计法优化分离条件,HPLC进行含量测定。结果最佳制备色谱分离条件为:上样量50 g,流速180 ml.min-1,流动相甲醇-水(80∶20),室温进行;所得新藤黄酸为明黄色针状结晶,纯度不小于95%。结论工艺优化合理,重现性好。     

大叶藤黄中三个新酮类成分

为了研究大叶藤黄树皮中酮类成分，运用正相和反相硅胶柱色谱法对大叶藤黄树皮乙酸乙酯萃取物进行分离纯化，并用波谱技术鉴定化合物结构。共分离得到3个新酮类化合物，其结构分别鉴定为1,2,5-三羟基-6-甲氧基酮(1)，1,4,6-三羟基-5-甲氧基酮(2)，1,2,7-三羟基-4-(1,1-二甲基烯丙基)酮(3)。     

大叶藤黄中三个新《口山》酮类成分

为了研究大叶藤黄树皮中<口山>酮类成分,运用正相和反相硅胶柱色谱法对大叶藤黄树皮乙酸乙酯萃取物进行分离纯化,并用波谱技术鉴定化合物结构.共分离得到3个新<口山>酮类化合物,其结构分别鉴定为1,2,5-三羟基-6-甲氧基<口山>酮(1),1,4,6-三羟基-5-甲氧基<口山>酮(2),1,2,7-三羟基-4-(1,1-二甲基烯丙基)<口山>酮(3).     

藤黄酸的抗肿瘤作用机制研究进展

藤黄酸是从传统中药藤黄中分离得到的一种活性单体,研究表明藤黄酸具有潜在的抗肿瘤作用,能够抑制肺癌、肝癌、乳腺癌、胃癌、黑色素瘤以及白血病等多种人类常见肿瘤。该文综述了近年来国内外有关藤黄酸抗癌作用及分子机制的研究进展。     

高效液相色谱-质谱联用法鉴定中药藤黄中桥环类化合物

采用液相色谱电喷雾离子阱质谱联用仪(HPLC-ESI/MS)研究新藤黄酸和藤黄酸在正离子检测方式下的一级质谱和多级质谱，归纳其ESI碎裂规律。采用C₁₈反相色谱柱分离并检测了藤黄中的16种化合物；通过二极管阵列检测器与电喷雾质谱联用获得了相应化合物的最大紫外吸收和相对分子质量信息，并利用质谱的源内碰撞诱导解离技术(CID)结合文献报道鉴定了10种化合物的结构。这种研究方法对其他天然产物特别是微量成分结构分析具有参考作用。     

藤黄酸的制剂研究进展

摘要：藤黄酸是中药藤黄的主要活性成分之一,对多种癌症均具有良好的抑制作用。但由于藤黄酸自身的理化性质的缺陷,导致其在设计制剂方面存在一些困难。为解决这些困难研究者们进行了大量研究。本文查阅文献,对近年来藤黄酸新型纳米制剂,如纳米胶束、纳米粒、脂质体、前药等的研究进展进行综述,此外还对藤黄酸的理化性质及普通制剂中存在的问题进行简介,为藤黄酸进一步临床应用开发提供参考。     

藤黄有效成分的纳米囊制备及其抗糖尿病活性评价

目的 制备藤黄酸(GA)、新藤黄酸(NGA)的纳米囊(GA-LNCs、NGA-LNCs),并进行其抗糖尿病活性评价.方法 以水为水相、中链甘油三酯为油相、聚乙二醇单硬脂酸酯为表面活性剂,采用相转换法制备GA-LNCs、NGA-LNCs.以包封率和载药量为指标,利用单纯型网格设计法优化上述2种纳米囊的处方工艺,并对其理化...     

大鼠血浆中的新藤黄酸HPLC测定及其药代动力学研究

目的建立测定大鼠血浆中新藤黄酸浓度的HPLC方法,并用于新藤黄酸在大鼠体内的药代动力学研究。方法以藤黄酸为内标,建立大鼠血浆中新藤黄酸的HPLC测定方法。采用该方法测定大鼠单剂量静脉注射1、2、4 mg.kg-1新藤黄酸后不同时间点大鼠血浆中的新藤黄酸的浓度,对其血药浓度-时间采用BABP 3.0软件拟合,计算药动学参数。结果血浆中新藤黄酸在0.07～18.0 mg.L-1浓度范围,其线性关系良好(r=0.999),定量下限为0.07 mg.L-1,提取回收率分别为大于70%,其日内、日间RSD均小于10%。新藤黄酸以1、2和4 mg.kg-1静脉给药后,在大鼠体内的T12分别为(43.61±0.61)、(46.07±2.11)和(46.73±1.14)min,AUC0-t分别为(158.52±6.27)、(211.13±9.33)和(361.37±14.97)min.mg.L-1。结论所建立的HPLC法样品前处理简便、操作简便、能满足新藤黄酸在大鼠体内的药代动力学研究。     

ZrOCl2比色法测定藤黄中总藤黄酸的含量

目的:测定藤黄中总藤黄酸含量。方法:根据藤黄酸类化合物分子结构中含有6位羟基、8位羰基,可与锆离子进行络合反应,使分子的吸收峰向长波长移动(从360nm移至390nm)的特点,采用ZrOCl_2比色法测定总藤黄酸含量。结果:方法考察结果完全达到物质含量测定的有关要求。结论:该方法简便易行,专属性较强,可作为药材及中间体质量控制及研究的方法之一。     

新藤黄酸诱导HepG2细胞凋亡与Bax及Bcl-2的关系

<正>中药藤黄(gamboge)系藤黄科植物藤黄树(Garcinia hanburyi Hook.F.G)所分泌的干燥树脂,近年来,藤黄的抗肿瘤作用受到高度关注。已有研究证实,新藤黄酸(neo-gambogic acid,NGA)为藤黄抗肿瘤作用的主要有效成分之一[1-3]。肝细胞癌(hepatocellular carcinoma,HCC)是世界上最常见的恶性肿瘤之一[4],同时也是第三大引起患者死亡的肿瘤[5]。     

五灵脂活性成分的研究

自五灵脂中分离得到13种化合物。根据化学方法及光谱(UV,IR,MS,¹H-NMR,¹³C-NMR)分析,其中晶V为一新的异海松酸的衍生物,命名为五灵脂酸。并鉴定其它9种化合物为邻苯二酚(Ⅰ)、苯甲酸(Ⅱ),3-蒈烯-9,10-二羧酸(Ⅲ)尿嘧啶(Ⅳ),间羟基苯甲酸(Ⅵ),原儿茶酸(Ⅶ),次黄嘌呤(Ⅺ),尿囊素(Ⅻ),L-酪氨酸(ⅩⅢ)。化合物Ⅰ～Ⅶ在体外有明显的抑制血小板聚集活性;Ⅰ,Ⅲ,Ⅴ,Ⅶ显示了不同程度的抗菌活性。     

新疆藁本有效成分研究

从新疆藁本(ConiselinumvaginatumThell)的根茎中分到七个化合物,根据理化常数和光谱解析,分别鉴定为coniselin(Ⅰ),(E)-3-methoxy-4,5-methyenedioxycinnamicaldehyde(Ⅱ),(E)-3-methoxy-4,5-methylenedioxycinnamicalcohol(Ⅲ),(E)-3-methoxy-4,5-methylenedoxycinnamicacid(Ⅳ),肉豆劳动蔻酸(myristicicacid,V),阿魏酸(ferulicacid,Ⅵ)和香草醛(vanilin,Ⅶ)。其中Ⅰ为新化合物,其余均为首次从该植物中分到。经药理实验表明化合物Ⅱ～Ⅴ对四氯化碳引起的小鼠转氨酶升高有降低作用,对丙酸杆菌引起的小鼠免疫性肝损伤有保护作用。     

马缨丹根的三萜成分研究

从马缨丹(Lantana camara L.)根中分离到八个三萜成分,通过光谱(UV,IR,¹HNMR,¹³CNMR,MS)分析和理化常数测定,分别鉴定为lantanolic acid(Ⅰ),22β-O-angeloyl-lantanolic acid(Ⅱ),oleanolic acid(Ⅲ),22βO-angeloyt-oleanolic acid(Ⅳ),22β-O-senecioyl-oleanolic acid(Ⅴ),22β-hydroxy-oleanolic acid(Ⅵ),19α-hydroxyursolic acid(Ⅶ),3β-isovaleroyl-19α-hydroxyursolic acid(Ⅷ)。Ⅱ系首次从植物中分离到。Ⅷ是新化合物,命名为lantaiursolic acid。     

叶下珠化学成分的研究

从叶下珠(Phyllantlais urinaria L.)的干燥全草中分得11个化合物。经光谱分析(UV,IR,¹HNMR,¹³C-NMR,¹H-¹H COSY,¹³C-¹H COSY,long range ¹³-¹H COSY,DEPT and MS)和化学反应等,鉴定了其中10个化合物,分别为正十八烷(Ⅰ),β-谷甾醇(Ⅲ),鞣花酸(Ⅳ),胡萝卜甙(Ⅴ),短叶苏木酚酸甲酯(methyl brevifolincarboxylate,Ⅵ),山萘素(Ⅶ),槲皮素(Ⅷ),去氢诃子次酸三甲酯(trimethyl ester dehydrochebulic acid,Ⅸ),没食子酸(Ⅹ),芸香甙(Ⅺ)。晶Ⅱ为一醛类化合物,结构正在鉴定中,晶Ⅵ和Ⅸ为新化合物。     

Synthesis of N3-fumaramoyl-L-2,3-diaminopropanoic acid analogues,the irreversible inhibitors of glucosamine synthetase

Several analogues of N³-fumaramoyl-L-2,3-diaminopropanoic acid were synthesized and evaluated for inhibition of glucosamine-6-phosphate synthetase activity. The syntheses were accomplished by acylation reaction of N²-tert.-butoxycarbonyl-L-2,3-diaminopropanoic acid (Boc-A₂pr) or N²-tert.-butoxy-carbonyl-L-2,4-diaminobutanoic acid (Boc-A₂-bu) with the N-succinimidoyl esters of several derivatives of α, β-unsaturated acids 2a-d followed by deprotection of the Boc groups. The obtained compounds were tested for inhibition of glucosamine synthetase isolated from Salmonella typhimurium and Saccharomyces cerevisiae. The results indicated that among the synthesized compounds, N³-4-methoxyfumaroyl-L-2,3-diaminopropanoic acid (FMDP) was the most powerful inhibitor of glucosamine synthetase.     

西南獐牙菜化学成分的研究

从西南獐牙菜的全植物中分离出五个化合物,其中四个分别被鉴定为β-谷甾醇(Ⅶ),齐墩果酸(Ⅵ),1,3,7,8-四羟基咄酮(Ⅴ)和山楂酸(Ⅱ)。另一化合物系新的三萜酸糖酯甙,命名为獐牙菜皂甙(swericinctoside,Ⅰ),其结构为2α,3β-二羟基齐墩果-12-烯-28-羧酸-28-O-β-D-葡萄吡喃糖基-(1-6)-β-D-葡萄吡喃糖基-(1-2)-β-D-葡萄吡喃糖甙。     

Bioassay-guided fractionation and identification of α-amylase inhibitors from Syzygium cumini leaves

Context: Pancreatic α-amylase and α-glucosidase inhibitors serve as important strategies in the management of blood glucose. Even though Syzygium cumini (L.) Skeels (Myrtaceae) (SC) is used extensively to treat diabetes; scientific evidence on antidiabetic effects of SC leaves is scarce.

Objective: SC leaf extract was investigated for α-amylase inhibitory effect and continued with isolation and identification of α-amylase inhibitors.

Materials and methods: Bioassay-guided fractionation was conducted using in vitro α-amylase inhibitory assay (with 20–1000?μg/mL test material) to isolate the inhibitory compounds from ethyl acetate extract of SC leaves. Structures of the isolated inhibitory compounds were elucidated using ¹H NMR and ¹³C NMR spectroscopic analysis and direct TLC and HPLC comparison with authentic samples. Study period was from October 2013 to October 2015.

Results: An active fraction obtained with chromatographic separation of the extract inhibited porcine pancreatic α-amylase with an IC₅₀ of 39.9?μg/mL. Furthermore, it showed a strong inhibition on α-glucosidase with an IC₅₀ of 28.2?μg/mL. The active fraction was determined to be a 3:1 mixture of ursolic acid and oleanolic acid. Pure ursolic acid and oleanolic acid showed IC₅₀ values of 6.7 and 57.4?μg/mL, respectively, against α-amylase and 3.1 and 44.1?μg/mL respectively, against α-glucosidase.

Discussion and conclusions: The present study revealed strong α-amylase and α-glucosidase inhibitory effects of ursolic acid and oleanolic acid isolated from SC leaves for the first time validating the use of SC leaves in antidiabetic therapy.     

N-Acetylation and N-Formylation of m-Aminobenzoic acid by Cell Suspension Cultures of Solanum Laciniatum

Abstract

Two new biotransformation products, N-acetyl-m-aminobenzoic acid and N-formyl-m-aminobenzoic acid were isolated from cell suspension cultures of Solanum laciniatum following administration of m-aminobenzoic acid, and their structures were elucidated using one- and two-dimensional ¹H- and ¹³C-NMR data.     

Isolation of chebulic acid from <Emphasis Type="Italic">Terminalia chebula</Emphasis> Retz. and its antioxidant effect in isolated rat hepatocytes

A hepatoprotective compound was isolated from the ethanolic extract of the fruits of Terminalia chebula Retz. by consecutive solvent partitioning, followed by silica gel and Sephadex LH-20 column chromatographies. The purified compound was identified as a mixture of chebulic acid and its minor isomer, neochebulic acid, with a ratio of 2:1 by spectroscopic analysis including 1D and 2D NMR and MS spectroscopy. To our knowledge, this is the first report on the protection of rat hepatocytes against oxidative toxicity by chebulic acid obtained from T. chebula Retz. This compound exhibited in vitro a free radical-scavenging activity and ferric-reducing antioxidant activity. Also, the specific ESR spectrum for the ^•OOH radical signals consisting of three-line ESR spectra was within the field of 0.27 mT, whereas 2.5 and 0.25 mg/ml of chebulic acid significantly reduced the signal intensity of the ESR spectra to 0.06 mT and 0.11 mT, respectively. Using isolated rat hepatocyte experiment, we demonstrated that the treatment of hepatocytes with chebulic acid significantly reduced the tert-butyl hydroperoxide (t-BHP)-induced cell cytotoxicity, intracellular reactive oxygen species level, and the ratio of GSSH, oxidized form of glutathione (GSH) to the over total GSH (GSH + GSSG) (4.42%) as compared to that with t-BHP alone (8.33%).     

丝瓜叶中丝瓜皂甙O的化学结构研究

丝瓜叶中丝瓜皂甙Ｏ的化学结构研究梁龙，鲁灵恩，蔡元聪（四川省中药研究所重庆６３００６５）丝瓜（ＬｕｆｆａｃｙｌｉｎｄｒｉｃａＲｏｅｍ．）为常食蔬菜，其果实和藤叶中含有多种生理活性的化学物质。我们从丝瓜叶中分离出１３个五环三萜类化合物，前文（１～３）已...