Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone （1） and 1,5,6-trihydroxy-7,8-di（3-methyl-2-butenyl）-6＇,6＇-dimethylpyrano（2＇,3＇：3,4）xanthone （2） were isolated from the bark of Garcinia xanthochymu...Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone （1） and 1,5,6-trihydroxy-7,8-di（3-methyl-2-butenyl）-6＇,6＇-dimethylpyrano（2＇,3＇：3,4）xanthone （2） were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.展开更多
A rosmarinic acid derivative, tetramethyl ether of rosmarinic acid benzyl ester, was synthesized. This is the first report of building this structural skeleton.
A salvianolic acid A derivative, hexamethyl ether of salvianolic acid A benzyl ester, was synthesized in fourteen steps. The overall yield was 3.4 parts per thousand. The compound was identified by (1)HNMR and MS. Thi...A salvianolic acid A derivative, hexamethyl ether of salvianolic acid A benzyl ester, was synthesized in fourteen steps. The overall yield was 3.4 parts per thousand. The compound was identified by (1)HNMR and MS. This is the first report of building this structural skeleton.展开更多
The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0....The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml. The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.展开更多
trans-3, 3b, 4, 9b, 10, 11-Hexahydro-6-methoxy-9b-methyl-7-(1-methylethyl) phenanthro {1,2-c[furan-1,5-dione]} was synthesized with good yield in two steps from triptophenolide methyl ether under mild conditions.
Some 1-imino-3,3-disubstituted-1,3-dihydro isobenzofuran and 2-(1,1-disubstituted hydroxymethyl) benzamide derivatives have been obtained by the aminolysis of phthalide in the presence of triethylamine/aluminum chlori...Some 1-imino-3,3-disubstituted-1,3-dihydro isobenzofuran and 2-(1,1-disubstituted hydroxymethyl) benzamide derivatives have been obtained by the aminolysis of phthalide in the presence of triethylamine/aluminum chloride. 1-Benzylimino-3,3-disubstituted-1,3-dihydro isobenzofuran can be peroxidized to the corresponding hydroperoxides on exposure to the air for a long period. The structure was characterized by single crystal X-ray diffraction and the possible mechanism was suggested.展开更多
Two new steroidal glycosides named cyanoauriculoside A （1） and B （2）, have been isolated from the roots of Cynanchum auriculatum Royle ex Wight. The structure of cyanoauriculoside A （1） was determined to be 20-O...Two new steroidal glycosides named cyanoauriculoside A （1） and B （2）, have been isolated from the roots of Cynanchum auriculatum Royle ex Wight. The structure of cyanoauriculoside A （1） was determined to be 20-O-acetyl-penupogenin-3-O-β-D- glucopyranosyl-（ 1 →4）-β-D-glucopyranosyl-（ 1 →4）-α -L-cymaropyranosyl- （ 1 →4）-β-D-cymaropyranosyl- （ 1 →4）-α-L-diginopyranosyl-（1→4）-β-D-cymaropyranoside. Cyanoauriculoside B （2） was characterized as 20-O-acetylpenupogenin-3-O-β-D-gluco- pyranosyl-（ 1 →4）-α-L-cymaropyranosyl-（ 1 →4）-β-D-cymaropyranosyl-（ 1 →4）-α-L-diginopyranosyl-（ 1 →4）-β-D-cymaropyranoside. The structures of these compounds were elucidated based on the chemical and spectroscopic evidence.展开更多
基金the National Natural Science Foundation of China （No. 30670215）
文摘Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone （1） and 1,5,6-trihydroxy-7,8-di（3-methyl-2-butenyl）-6＇,6＇-dimethylpyrano（2＇,3＇：3,4）xanthone （2） were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.
文摘A rosmarinic acid derivative, tetramethyl ether of rosmarinic acid benzyl ester, was synthesized. This is the first report of building this structural skeleton.
文摘A salvianolic acid A derivative, hexamethyl ether of salvianolic acid A benzyl ester, was synthesized in fourteen steps. The overall yield was 3.4 parts per thousand. The compound was identified by (1)HNMR and MS. This is the first report of building this structural skeleton.
文摘The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml. The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.
文摘trans-3, 3b, 4, 9b, 10, 11-Hexahydro-6-methoxy-9b-methyl-7-(1-methylethyl) phenanthro {1,2-c[furan-1,5-dione]} was synthesized with good yield in two steps from triptophenolide methyl ether under mild conditions.
基金the Postdoctoral Foundation of China for the tlnancial support.
文摘Some 1-imino-3,3-disubstituted-1,3-dihydro isobenzofuran and 2-(1,1-disubstituted hydroxymethyl) benzamide derivatives have been obtained by the aminolysis of phthalide in the presence of triethylamine/aluminum chloride. 1-Benzylimino-3,3-disubstituted-1,3-dihydro isobenzofuran can be peroxidized to the corresponding hydroperoxides on exposure to the air for a long period. The structure was characterized by single crystal X-ray diffraction and the possible mechanism was suggested.
基金financial support of this work by the National Key Technology R&D Program in the 11th Five Year Plan of China(No.2007BAI48B08)
文摘Two new steroidal glycosides named cyanoauriculoside A （1） and B （2）, have been isolated from the roots of Cynanchum auriculatum Royle ex Wight. The structure of cyanoauriculoside A （1） was determined to be 20-O-acetyl-penupogenin-3-O-β-D- glucopyranosyl-（ 1 →4）-β-D-glucopyranosyl-（ 1 →4）-α -L-cymaropyranosyl- （ 1 →4）-β-D-cymaropyranosyl- （ 1 →4）-α-L-diginopyranosyl-（1→4）-β-D-cymaropyranoside. Cyanoauriculoside B （2） was characterized as 20-O-acetylpenupogenin-3-O-β-D-gluco- pyranosyl-（ 1 →4）-α-L-cymaropyranosyl-（ 1 →4）-β-D-cymaropyranosyl-（ 1 →4）-α-L-diginopyranosyl-（ 1 →4）-β-D-cymaropyranoside. The structures of these compounds were elucidated based on the chemical and spectroscopic evidence.
