Inhibition of phospholipase cgamma1 and cancer cell proliferation by triterpene esters from Uncaria rhynchophylla

Investigation of the hooks of Uncaria rhynchophylla resulted in isolation of six phospholipase Cgamma1 (PLCgamma1) inhibitors (1-6). The structures of these compounds were elucidated as pentacyclic triterpene esters by spectroscopic and chemical analysis. Three of them, namely uncarinic acids C (1), D (2), and E (3), are newly reported as natural products. All the compounds showed dose-dependent inhibitory activities against PLCgamma1 in vitro with IC(50) values of 9.5-44.6 microM and inhibited the proliferation of human cancer cells with IC(50) values of 0.5-6.5 microg/mL.     

New bioactive polyphenols from Theobroma grandiflorum ("cupuaçu")

Activity-guided fractionation of Theobroma grandiflorum ("cupua?u") seeds resulted in the identification of two new sulfated flavonoid glycosides, theograndins I (1) and II (2). In addition, nine known flavonoid antioxidants, (+)-catechin, (-)-epicatechin, isoscutellarein 8-O-beta-d-glucuronide, hypolaetin 8-O-beta-d-glucuronide, quercetin 3-O-beta-d-glucuronide, quercetin 3-O-beta-d-glucuronide 6' '-methyl ester, quercetin, kaempferol, and isoscutellarein 8-O-beta-d-glucuronide 6' '-methyl ester, were identified. Theograndin II (2) displayed antioxidant activity (IC(50) = 120.2 microM) in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assay, as well as weak cytotoxicity in the HCT-116 and SW-480 human colon cancer cell lines with IC(50) values of 143 and 125 microM, respectively. While 1 was less active as an antioxidant than 2, the known compounds were more potent in the DPPH assay (IC(50) range 39.7-89.7 microM).     

Constituents of the bark and twigs of Artocarpus dadah with cyclooxygenase inhibitory activity

Fractionation of an ethyl acetate-soluble extract of the bark of Artocarpus dadah has led to the isolation of three new prenylated stilbenoid derivatives, 3-(gamma,gamma-dimethylallyl)resveratrol (1), 5-(gamma,gamma-dimethylallyl)oxyresveratrol (2), 3-(2,3-dihydroxy-3-methylbutyl)resveratrol (3), and a new benzofuran derivative, 3-(gamma,gamma-dimethylpropenyl)moracin M (4), along with six known compounds, oxyresveratrol, (+)-catechin, afzelechin-3-O-alpha-L-rhamnopyranoside, (-)-epiafzelechin, dihydromorin, and epiafzelechin-(4beta-->8)-epicatechin. From an ethyl acetate-soluble extract of the twigs of the same plant were isolated compound 4 and two new neolignan derivatives, dadahols A (5) and B (6), as well as 10 known compounds, oxyresveratrol, (+)-catechin, afzelechin-3-O-alpha-L-rhamnopyranoside, resveratrol, steppogenin, moracin M, isogemichalcone B, gemichalcone B, norartocarpetin, and engeletin. The structures of compounds 1-6 were determined using spectroscopic and chemical methods. Isolates were evaluated for their inhibitory effects against both cyclooxygenase-1 (COX-1) and -2 (COX-2) and in a mouse mammary organ culture assay.     

Bioactive novel polyphenols from the fruit of Manilkara zapota (Sapodilla)

Activity-guided fractionation of a methanol extract from the fruit of Manilkara zapota cv. Tikal resulted in the isolation of two new antioxidants, methyl 4-O-galloylchlorogenate (1) and 4-O-galloylchlorogenic acid (2), along with eight known polyphenolic antioxidants, namely, methyl chlorogenate (3), dihydromyricetin (4), quercitrin (5), myricitrin (6), (+)-catechin (7), (-)-epicatechin (8), (+)-gallocatechin (9), and gallic acid (10). Of the 10 polyphenols, 1 showed the highest antioxidant activity (IC(50) = 12.9 microM) in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assay and displayed cytotoxicity in the HCT-116 and SW-480 human colon cancer cell lines with IC(50) values of 190 and 160 microM, respectively. Compound 2 showed high antioxidant activity (IC(50) = 23.5 microM) in the DPPH free-radical assay and displayed cytotoxicity in the HCT-116 and SW-480 human colon cancer cell lines with IC(50) values of 154 and 134 microM, respectively.     

Alkaloids from the leaves of Uncaria rhynchophylla and their inhibitory activity on NO production in lipopolysaccharide-activated microglia

Two new isomeric alkaloids, 18,19-dehydrocorynoxinic acid B (1) and 18,19-dehydrocorynoxinic acid (2), were isolated from the CHCl3 extract of the leaves of Uncaria rhynchophylla, together with four known rhynchophylline-type alkaloids, corynoxeine (3), isocorynoxeine (4), rhynchophylline (5), and isorhynchophylline (6), and an indole alkaloid glucoside, vincoside lactam (7). The structures of compounds 1 and 2 were elucidated by spectroscopic methods including UV, IR, HREIMS, 1D and 2D NMR, and CD experiments. The activity assay showed that compounds 3-6, with a C-16 carboxylic ester group, and 7 exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary cultured rat cortical microglia (IC 50: 13.7-19.0 microM). However, only weak inhibitory activity was observed for compounds 1 and 2, with a C-16 carboxylic acid group (IC 50: >100 microM).     

In vitro antiprotozoal activity from the roots of Geranium mexicanum and its constituents on Entamoeba histolytica and Giardia lamblia

This paper examines the antiprotozoal activity of the dichloromethane-MeOH extract, fractions and pure compounds from the roots of Geranium mexicanum on Entamoeba histolytica and Giardia lamblia. The result indicated that the extract, organic fraction and a pure flavonoid were active against both protozoa with IC50 values ranging from 1.9 to 79.2 microg/ml for Entamoeba histolytica and from 1.6 to 100.4 microg/ml in the case of Giardia lamblia. The main active compound was the flavan-3-ol, (-)-epicatechin. In addition, the moderate active compounds (+)-catechin, tyramine and beta-sitosterol 3-O-beta-D-glucopyranoside, also were isolated. These results support the anecdotal reports for the traditional use of Geranium mexicanum roots in the management of diarrhoea and dysentery, illnesses caused in some cases by enteric protozoa.     

红绒毛羊蹄甲中的二氢黄酮醇苷和黄烷醇类成分

目的：研究红绒毛羊蹄甲Bauhinia aurea的化学成分。方法：应用各种色谱技术进行分离纯化,用MS和NMR分析确定化合物结构。结果：从红绒毛羊蹄甲90%乙醇提取物的醋酸乙酯萃取部位中分离得到8个化合物,分别鉴定为异黄杞苷(1)、落新妇苷(2)、新落新妇苷(3)、异落新妇苷(4)、新异落新妇苷(5)、(2R,3S)-儿茶精 6)、(2R,3R)-表儿茶精(7)和(2R,3R)-3-O-没食子酰表儿茶精(8)。结论：除化合物2,6和8外,其余5个化合物均属首次从该属植物中发现。     

Protective effect of phenolic compounds isolated from the hooks and stems of Uncaria sinensis on glutamate-induced neuronal death

We isolated the phenolic compounds epicatechin, catechin, procyanidin B-1, procyanidin B-2, hyperin and caffeic acid from the hooks and stems of Uncaria sinensis (HSUS), and studied their protective effects against glutamate-induced neuronal death in cultured rat cerebellar granule cells. Cell viability evaluated by MTT assay was significantly increased by application of epicatechin (100-300 microM), catechin (300 microM), procyanidin B-1 (30-300 microM) and procyanidin B-2 (100-300 microM) compared with exposure to glutamate only. 45Ca2+ influx into cells induced by glutamate was also significantly inhibited by administration ofepicatechin (300 microM), catechin (300 microM), procyanidin B-1 (100-300 microM) and procyanidin B-2 (100-300 microM). These results suggest that epicatechin, catechin, procyanidin B-1 and procyanidin B-2 are the active components of HSUS that protect against glutamate-induced neuronal death in cultured cerebellar granule cells by inhibition of Ca2+ influx.     

Antiprotozoal activity of the constituents of Rubus coriifolius

Extraction of the aerial parts of Rubus coriifolius, a medicinal plant used by the Maya communities in Southern Mexico to treat bloody diarrhoea, resulted in the isolation of seven known compounds (-)-epicatechin, (+)-catechin, hyperin, nigaichigoside F1, beta-sitosterol 3-O-beta-d-glucopyranoside, gallic acid and ellagic acid. All compounds were tested for their antiprotozoal activity against Entamoeba histolytica and Giardia lambia. Epicatechin was the main responsible for the antiprotozoal activity of the extract against both protozoa, its activity was comparable to emetine, but no exceeded that of metronidazole.     

四块瓦的化学成分研究

 目的对报春花科珍珠菜属植物四块瓦(Lysimachia pardiformis Franch.)的全草进行化学成分研究。方法对四块瓦全草提取物进行柱色谱,根据化合物的理化性质和波谱数据鉴定结构。结果分离鉴定了7个化合物,分别鉴定为儿茶素(1),表儿茶素(2),pavetannin A(3),肉桂鞣质B₁(4),maesopsin-6-O-glucopyranoside(5),quercetin3-O-α-L-rhamnopyranosyl(1→2)-β-D-xylopyranoside(6),尿囊素(7)。结论所有化合物均为首次从珍珠菜属分离得到。     

钩藤中吲哚类生物碱化学成分及药理活性研究进展

钩藤,原名钓藤,入药历史悠久,主要用来治疗风热头痛、头晕目眩、小儿惊厥、高血压等症状.近年来,大量药理实验证明,钩藤中的主要活性成分是吲哚类生物碱.就钩藤中的吲哚类生物碱的化学成分及其药理活性进行系统性综述,为进一步开发利用中药钩藤提供理论依据.     

信宜润楠中的黄酮类成分

通过大孔吸附树脂、正相硅胶、Sephadex LH-20柱色谱,以及反相闪式柱色谱和HPLC等多种分离方法相结合,从信宜润楠95%乙醇提物中首次分离得到12个黄酮类化合物;借助红外、质谱和核磁共振等波谱学分析方法分别鉴定为(+)-儿茶素(1)、(-)-表儿茶素(2)、3’-甲氧基-(+)-儿茶素(3)、3’-甲氧基-(-)-表儿茶素(4)、3,5,7,2’,5’-五羟基黄烷(5)、(-)-柚皮素(6)、(-)-圣草酚(7)、(-)-甘草素(8)、(2R,3R)-(+)-二氢山柰酚(9)、(2R,3S)-(-)-二氢山柰酚(10)、(2R,3R)-(+)-紫杉叶素(11)和槲皮素(12);其中,化合物1~10为首次从润楠属植物中分离得到。     

黄背栎中的黄酮类化学成分研究

 目的研究黄背栎(Quercus pannosa Hand.-Mazz.)中的黄酮类化学成分。方法利用Sephadex LH-20及硅胶等柱色谱技术进行化合物的分离和纯化,根据理化性质、光谱数据对其结构进行鉴定。结果得到5个黄酮类化合物,分别鉴定为(+)-catechin(1),(-)-epicatechin(2),(2R,3R)-(-)-二氢槲皮素3-O-β-D-葡萄糖苷(3),(2R,3R)-(-)-二氢槲皮素3-O-β-D-木糖苷(4),chamaechromone(5)。结论这5个化合物均为首次从黄背栎中分离得到。     

三种一般钩藤ITS序列的RFLP分析

目的以核糖体转录间隔区(rDNA ITS)序列为分子标记,对采集自3个不同地区的一般钩藤Uncaria rhynchophylla(Miq.)Jack.进行RFLP遗传分析,研究不同地理区域一般钩藤的rDNA ITS序列是否具有生物地理差异。方法通过改良CTAB法提取一般钩藤总DNA,利用通用引物对其rDNA ITS序列进行PCR扩增,并对连接转化后扩增得到的rDNAITS序列进行限制性片段长度多态性(Restriction Fragment Length Polymorphism,RFLP)分析。结果获得采集自广东韶关阳山、广东梅州大埔、广西植物园的3种一般钩藤两种限制性内切酶(Msp I&HaeⅢ)酶切图谱。结论通过基于rDNAITS序列进行的RFLP分析,表明这3个地区的一般钩藤rDNA ITS序列无明显差异,不同区域的一般钩藤其遗传本质不具有地理差异。     

Anxiolytic effects of the aqueous extract of Uncaria rhynchophylla

The purpose of this study was to characterize the putative anxiolytic-like effects of the aqueous extract of hooks with stem of Uncaria rhynchophylla using the elevated plus maze (EPM) and the hole-board apparatus in rats and mice. Control rats were treated with an equal volume of saline, and positive control rats with buspirone (1 mg/kg). Single or repeated treatments of the aqueous extract of Uncaria rhynchophylla (200 mg/kg/day, p.o.) for 7 days significantly increased the time-spent and entries into open arms of the EPM, and reduced the time-spent and entries into the closed arms versus saline controls (P<0.05). However, no changes in spontaneous locomotor activity or myorelaxant effects were observed versus saline controls. In the hole-board test, repeated treatment with the aqueous extract of Uncaria rhynchophylla (100 or 200 mg/kg/day, p.o.) significantly increased the number of head-dips (P<0.05). In addition, the anxiolytic-like effects of Uncaria rhynchophylla extract as assessed using the EPM test were abolished by WAY 100635 (0.3 mg/kg, i.p.), a 5-HT(1A) receptor antagonist. These results suggest that Uncaria rhynchophylla is an effective anxiolytic agent, and acts via the serotonergic nervous system.     

DNA polymerase beta inhibitors from Sandoricum koetjape.

Bioassay-guided fractionation of Sandoricum koetjape using an assay sensitive to DNA polymerase beta inhibition led to the isolation of three active compounds (1-3) having IC(50) values from 20 to 36 microM. Derivatives 5-14 were prepared from compounds 1 and 2; derivatives 11, 12, and 13 showed activity against DNA polymerase beta with IC(50) values ranging from 16 to 36 microM.     

New diarylheptanoids from the stems of Carpinus cordata

Two new diarylheptanoids, carpinontriols A (1) and B (2), were isolated from the stems of Carpinus cordata, along with the known diarylheptanoid, casuarinondiol (3), and five known compounds, (+)-catechin (4), methyl gallate (5), methyl gallate 3-O-beta-D-glucopyranoside (6), methyl gallate 4-O-beta-D-glucopyranoside (7), and methyl gallate 3-O-beta-D-(6'-O-galloyl)-glucopyranoside (8). The structures of 1 and 2 were elucidated by spectral methods. Among the isolated compounds, compounds 4-6 and 8 showed radical-scavenging activity in the DPPH assay.     

瑶山润楠根的化学成分研究

对樟科润楠属植物瑶山润楠Machilus yaoshansis根乙醇提取物的化学成分进行研究。利用多种色谱技术从瑶山润楠的醋酸乙酯萃取物中分离得到15个化合物;通过理化性质和波谱数据鉴定其结构为12个木脂素类(+)-愈创木素(1),kadsuralignan C(2),(+)-异落叶松脂素(3),(+)-5’-甲氧基异落叶松脂素(4),南烛木树脂酚(5),内消旋-裂环异落叶松树脂酚(6),异落叶松脂素-9’-O-β-D-吡喃木糖苷(7),5’-甲氧基-异落叶松脂素-9’-O-β-D-吡喃木糖苷(8),南烛木树脂酚9’-O-β-D-吡喃木糖苷(9),(2R,3R)-2,3-二氢-2-(4-羟基-3-甲氧基苯基)-7-甲氧基-3-甲基-5-(E)-丙烯基苯并呋喃(10),3,5’-二甲氧基-4’,7-环氧-8,3’-新木脂素-4,9,9’-三醇(11),甘密树皮素B(12),和3个黄烷类(+)-儿茶素(13),(-)-表儿茶素(14),bis-8,8’-catechinylmethane(15)。化合物1～15均为首次从该植物中分离得到。     

HPLC测定钩藤药材中钩藤碱、异钩藤碱的含量

目的：用HPLC法建立钩藤药材中钩藤碱（Rhynchophylline）、异钩藤碱（Isorhynchophylline）的含量测定方法,用于钩藤药材的质量控制。方法：色谱柱为Diamonsil C18柱（4.6 mm×250 mm,5μm）,以甲醇：水=65：35（V/V,含0.01mmol/L三乙胺,冰醋酸调PH7.0）为流动相,流速为1.0 ml.min-1,在245nm检测波长下,测定钩藤药材中钩藤碱、异钩藤碱含量。结果：钩藤碱及异钩藤碱的回归方程分别为Y=1.0E＋6x-21142和Y=1.1E＋6x-13566,线性范围分别为0.254～1.524μg和0.216～1.296μg,相关系数分别0.9999和0.9999。结论：本法正确、简便、快速,对于控制和评价钩藤药材的品质有重要意义。