Characterization of an insecticidal coumarin from Boenninghausenia albiflora

The leaves of Boenninghausenia albiflora afforded an insecticidal coumarin which was identified as murraxocin (7-methoxy-8-[1'-ethoxy-2'-hydroxy-3'-methyl-but-3'enyl]-coumarin) (1), on the basis of extensive 1- and 2-dimensional NMR experiments. This compound has previously been isolated from Murraya exotica but this is the first report of the full (1)H and (13)C data for this compound. This natural product was evaluated against important forest insect pests and was active against Plecoptera reflexa, Clostera cupreata and Crypsiptya coclesalis at different concentrations varying from 1.0% to 5% w/v. In the crude extract 70% mortality was observed, and for compound 1 80% mortality was observed at a concentration of 1.0% w/v. The percentage of insect mortality increased in a dose-dependent manner. Coumarins are poorly studied insecticides and there is potential to exploit this chemically simple group of natural products.     

New flavans,spirostanol sapogenins,and a pregnane genin from Tupistra chinensis and their cytotoxicity

Seven new compounds, including three new flavans [tupichinol A-C (1-3)], three new spirostanol sapogenins [tupichigenin D-F (4-6)], and one new pregnane genin [tupipregnenolone (7)], together with 18 known compounds, were isolated from the underground parts of Tupistra chinensis. The structures of the new compounds were elucidated by spectroscopic analysis and chemical evidence. The structures and relative stereochemistry of 1 and 9 were further confirmed by single-crystal X-ray crystallographic analysis. Compounds Delta(25(27))-pentrogenin, 10, and ranmogenin A showed 100%, 96%, and 80% inhibition, respectively, against human gastric tumor (NUGC) cells at a concentration of 50 microM. Delta(25(27))-pentrogenin showed 100% inhibition against human nasopharyngeal carcinoma (HONE-1) cells at a concentration of 50 microM.     

Four new bioactive pyrrole-derived alkaloids from the marine sponge Axinella brevistyla.

Four new alkaloids (1-4) were isolated from the marine sponge Axinella brevistyla, and their structures were determined on the basis of spectroscopic analysis. The alkaloids 1-4 were antifungal against the yeast Saccharomyces cerevisiae at <1.0, <1.0, 30, and 100 microg/disk, respectively. Compounds 1-3 also exhibited cytotoxicity against L1210 cells with IC(50) values of 1.1, 0.66, and 2.5 microg/mL, respectively.     

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??OBJECTIVE To establish the self contrast and correction factor method for the content determination of the related substances in compound ezetimibe and rosuvastatin calcium tablets simultaneously. METHODS RP-HPLC method was adopted. The determination was performed on Kromasil 100-5 C₁₈ Dimensions column (4.6 mm??250 mm, 5 ??m) with mobile phase A consisting of methanol-acetonitrile-0.05 mol??L^-1 potassium dihydrogen phosphate (adjusted to pH 4.0 with phosphoric acid) (10??30??60) and mobile phase B consisting of tetrahydrofuran-acetonitrile-0.05 mol??L^-1 potassium dihydrogen phosphate (adjusted to pH 4.0 with phosphoric acid) (10??50??40) at a flow rate of 1.0 mL??min^-1. The detection wavelength was set at 242 nm. The injection volume was 20 ??l. The slope of linear equation was used to determine the correction factors between ROS impurities 1, 2, 3, EZT impurities 1, 2, 3, 4, 5, 6, 7 and ezetimibe or rosuvastatin calcium. The relative retention time was used to determine the positions of impurities. RESULTS The relative retention time of ROS impurities 1, 2, 3, 4 and EZT impurities 1, 2, 3, 4, 5, 6, 7 to rosuvastatin calcium was 1.5, 1.9, 2.1, 1.1, 1.7, 2.5, 2.6, 2.8, 2.9, 3.0, and 4.0, respectively.The correction factors of ROS impurities 1, 2, 3, 4 and EZT impurities 1, 2, 3, 4, 5, 6, 7 were 1.1, 1.1, 1.0, 1.0, 1.3, 1.1, 1.0, 1.3, 1.4, 0.5, and 1.0,respectively.The content of ROS impurity 4 was 0.15% in three batches of samples, the other impurities were less than 0.1%, and the contents of total impurities were 0.27%, 0.27%, and 0.26%, respectively. CONCLUSION The method is simple,efficient, and accurate for analyzing the related substances in compound ezetimibe and rosuvastatin calcium tablets.     

Inhibitory action of water soluble fraction of Terminalia chebula on systemic and local anaphylaxis

We investigated the effects of the water soluble fraction of Terminalia chebula (Combretaceae) (WFTC) on systemic and local anaphylaxis. WFTC administered 1h before compound 48/80 injection inhibited compound 48/80-induced anaphylactic shock 100% with doses of 0.01-1.0 g/kg. When WFTC was administered 5 or 10 min after compound 48/80 injection, the mortality also decreased in a dose-dependent manner. Passive cutaneous anaphylaxis was inhibited by 63.5+/-7.8% by oral administration of WFTC (1.0 g/kg). When WFTC was pretreated at concentrations ranging from 0.005 to 1.0 g/kg, the serum histamine levels were reduced in a dose-dependent manner. WFTC (0.01-1.0 mg/ml) also significantly inhibited histamine release from rat peritoneal mast cells (RPMC) by compound 48/80. However, WFTC (1.0 mg/ml) had a significant increasing effect on anti-dinitrophenyl IgE-induced tumor necrosis factor-alpha production from RPMC. These results indicate that WFTC may possess a strong antianaphylactic action.     

Cytochalasins Z4, Z5, and Z6, three new 24-Oxa[14]cytochalasans produced by Phoma exigua var. heteromorpha

Cytochalasins Z4, Z5, and Z6, three new cytochalasans, were isolated from the wheat culture of Phoma exigua var. heteromorpha together with the known cytochalasins A, B, F, T, Z2, and Z3, 7-O-acetylcytochalasin B, and deoxaphomin. Z2 and Z3, together with Z1, have recently been described as new 24-oxa[14]cytochalasans produced by Pyrenophora semeniperda, a fungus proposed for biological control of grass weeds. All three new cytochalasins were characterized as 24-oxa[14]cytochalasans by extensive use of NMR and MS techniques. Cytochalasins Z4 and Z5 proved to be structurally related to cytochalasin B, whereas Z6 was related to cytochalasin F. When assayed on tomato seedlings at 10(-4) M, Z6 caused a very low inhibition of rootlet elongation (30%), whereas Z4 and Z5 were almost inactive. On brine shrimp, at the same concentration, only Z5 had a minor effect, with 20% mortality, whereas the other two metabolites proved to be inactive.     

Isolation and structures of erylosides from the Caribbean sponge Erylus formosus

Nine new triterpene glycosides, erylosides F1-F4 (1-4), M (5), N (6), O (7), P (8), and Q (9), along with previously known erylosides F (10) and H (11) were isolated from the sponge Erylus formosus collected from the Mexican Gulf (Puerto Morelos, Mexico). Structures of 1-4 were determined as the corresponding biosides having aglycons related to penasterol with additional oxidation patterns in their side chains. Erylosides 5-9 contain new variants of carbohydrate chains with three (5, 6), four (7), and six (8, 9) sugar units, respectively. Erylosides 5, 7, 8, and 6, 9 contain 14-carboxy-24-methylenelanost-8(9)-en-3beta-ol and penasterol as aglycons, respectively. In contrast with its epimer 2, the compound 3 induced the early apoptosis of Ehrlich carcinoma cells at a concentration of 100 microg/mL, while 1 and 10 activated the Ca2+ influx into mouse spleenocytes (130% of the control) at the same doses.     

Manoyl oxide diterpenoids from Grindelia scorzonerifolia

Two new norditerpenoids, 4beta-hydroxy-19-normanoyl oxide (1) and 4alpha-hydroxy-18-normanoyl oxide (2), the new 18-O-alpha-l-arabinopyranosylmanoyl oxide (3a), and the known diterpenoids jhanol (4) and 18-hydroxy-13-epi-manoyl oxide (5) were isolated, together with other common plant constituents from an Argentine collection of Grindelia scorzonerifolia. The structures of the new compounds were established by extensive 1D and 2D NMR techniques and chemical transformations. Structural features of compounds 2 and 4 were verified by X-ray crystallographic analyses. The insecticidal effect of compound 3a was evaluated against the polyphagous pest Spodoptera frugiperda. Pupal and adult malformations leading to death occurred when 3a was incorporated in a larval diet at a concentration of 100 ppm.     

高效液相色谱法测定芪黄胶囊中大黄素的含量

目的：建立固相萃取反相高效液相色谱法测定芪黄胶囊中大黄素的含量方法。方法：采用ODS—C18小柱处理样品，Zorbax SB—C18柱（4．6mm×250mm，5um），流动相：甲醇：0．1％磷酸溶液（90：10），流速：1．0mL·min^-1，检测波长：254nm。结果：线性范围1．0—5．0μg（r=0．9999），平均回收率100．31％，RSD=2．36％。结论：该法简便、快速、准确。     

甘草次酸在大鼠体内药动学的RP-HPLC研究

目的：建立大鼠血浆中甘草次酸浓度的高效液相测定方法，探讨甘草次酸在大鼠体内的药动学过程。方法：大鼠按1.0 mg·kg^-1尾静脉注射甘草次酸后0.08，0.17，0.25，0.33，0.5，0.75，1，2，3，4，6 h眼底采血，乙腈沉淀血浆，HPLC测定血浆中甘草次酸浓度，以DAS软件拟合药动学参数。结果：甘草次酸血药浓度在50～2 000 ng·mL^-1线性良好，r=0.999 7，测得低中高浓度回收率分别为(105.2 ±2.23)%，(102.5±2.95)%，(98.4±2.32)%，日内、日间低中高浓度RSD均小于4%。甘草次酸在大鼠体内药-时曲线符合二室开放模型，主要药动学参数为：t_1/2α=(0.153±0.023) h，t_1/2β=(2.365±0.866) h，C_max =(2.074±0.100) mg·L^-1，CL=(0.715±0.082) L·h^-1·kg^-1，V_d =(2.427±0.872) L·kg^-1，AUC_{0～6 h} =(1.302±0.151) mg·h^-1·L^-1。结论：建立的RP-HPLC适用于体内甘草次酸的含量测定及药代动力学研究，甘草次酸在体内的分布迅速、广泛。