Identification of the Chemical Constituents of the Ethyl Acetate Extraction Portion of Polygonum bistorta / 中国药房

OBJECTIVE:To study the chemical constituents of the ethyl acetate extraction portion of Polygonum bistorta,pro-vide scientific basis for the basic research of its effective substances. METHODS:Taking the ethyl acetate extraction portion of P. bistorta 95％ ethanol extract,positive phase and reversed phase column chromatography were used for repeated isolation and purifi-cation,and the structures of the purified compounds were identified on the basis of physicochemical properties or spectral data. RE-SULTS:11 monomer compounds were isolated and identified as β-sitosterol(1),dihydromyricetin(2),quercetin(3),kaempferol (4),epicatechin(5),chlorogenic acid(6),rutin(7),gallic acid(8),1,2,3,4-tetrahydro-8-hydroxy-4-isopropyl-1-methylnaph-thalene-6-carboxylic acid (9),protocatechuic acid (10) and ellagic acid (11). CONCLUSIONS:The literature is confirmed that compound 2 is isolated from P. bistorta for the first time and compound 9 is isolated from Polygonum for the first time. The related research results have provided experimental references for further clarifying the effective substances of P. bistorta.

Flavonoids from Capsella bursa-pastoris and their hepatoprotective activities in vitro

ABSTRACT Two new flavonoids (1 and 2), named 4',7-dihydroxy-5-hydroxymethyl-8-prenylflavonoid and 4',7-dihydroxy-5-hydroxymethyl-6,8-diprenylflavonoid, together with seven known flavonoids (3–9) were isolated from the aerial parts of Capsella bursa-pastoris (L.) Medik., Brassicaceae, for the first time. The chemical structures of the purified compounds (1–9) were identified by their spectroscopic data and references. Moreover, compounds (1–9) were evaluated for their hepatoprotective activities against D-galactosamine induced toxicity in WB-F344 cells by using a MTT colorimetric method. As a result, compounds 2, 3, 6, and 9 (10 µM) exhibited moderate hepatoprotective activities.

Synthesis and biological evaluation of new 4-bromo-3, 5-diaryl-1-phenyl-2-pyrazoline derivatives as antioxidant and anti-inflammatory agents.

A number of substituted 1, 3-diphenylprop-2-en-1-one were prepared by Claisen-Schmidt condensation of p-substituted acetophenone with o,m,psubstituted aryl aldehydes which undergoes bromination and subsequent cyclization with phenyl hydrazine to yield 4-bromo-3(substituted phenyl)-5(substituted phenyl)-1-phenyl-2-pyrazoline (3a-l). The structures of compounds were confirmed by elemental analysis, IR, 1HNMR and mass spectral data. The synthesized compounds (3a-l) were screened for anti-oxidant and anti-inflammatory activity. The free radical scavenging properties were screened by using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical. The antioxidant activity of compound 3b was found to be the strongest. The IC50 values of the synthesized compounds ranged between 8.87 and 81.07 (μg mL-1). The anti-inflammatory activities were evaluated by using diclofenac sodium as a standard dug. All the compounds (20mg/kg po) possess significant anti-inflammatory activity, as reflected by their ability to provide protection (66-99%) against carragenan induced edema in rat paw. The anti-inflammatory activity of compound 3g was found to be the highest. The safety of substituted bromo-pyrazolines is reflected by toxicity studies.

Spectral Analysis and Chemical Studies of the Sweet Constituent, Rebaudioside A.

Aim: To study NMR spectral analysis and hydrolysis products of Rebaudioside A (1) that has been isolated from Stevia rebaudiana. Study Design: Acquiring NMR and high resolution mass spectral (HRMS) data of Rebaudioside A for structural characterization, and identification of hydrolysis products. Place of Study: Organic Chemistry Department of The Coca-Cola Company, Atlanta, GA 30313, USA. Methodology: The 1D (1H & 13C) and 2D (COSY, HSQC, and HMBC) NMR spectral data of was acquired using Varian Unity Plus 600 MHz instrument using standard pulse sequences. Hydrolysis studies were performed on Rebaudioside A using acid, base and enzymatic studies to identify partial degradation products, aglycone and sugar residues. Results: The proton and carbon values of Rebaudioside A were assigned based on NMR and HRMS data as well as chemical studies. The aglycone was identified as steviol on the basis of enzymatic hydrolysis, sugar was identified as D-glucose from acid hydrolysis and the partial hydrolyzed product was identified as Rebaudioside B from alkaline hydrolysis.

Acid and Alkaline Hydrolysis Studies of Stevioside and Rebaudioside A.

Hydrolysis studies of the two diterpene glycosides stevioside and rebaudioside A that were isolated from Stevia rebaudiana were performed using acid and alkaline conditions. Acid hydrolysis was carried out using H2SO4 whereas alkaline hydrolysis was performed using NaOH. Using these methods, partial hydrolyzed glycosides of stevioside and rebaudioside A and their sugar residues were identified from the alkaline and acid hydrolysis studies respectively. The structures of the acid and alkaline hydrolysis products were achieved on the basis of extensive NMR and high resolution mass spectral data, and in comparison with the data reported in the literature as well as TLC comparison with their corresponding standard compounds.

Synthesis and characterization of some hydrazine derivatives with α, β unsaturated acids.

Some new metal cinnamate monohydrazinate, M(cin)2N2H4 (M = Co or Zn), metal cinnamate dihydrazinates, M(cin)2(N2H4)2 (M = Co, Ni, Zn or Cd), metal crotonate dihydrazinates, M(crot)2(N2H4)2 (M = Co or Ni), nickel crotonate monohydrazinate monohydrate Ni(crot)2.N2H4.H2O and Cd(crot)2(N2H4)2.H2O have been prepared and characterized by physico – chemical studies. Electronic spectral data suggest that the octahedral environment around the central metal ion. The IR spectral data confirm the bridging bidentate coordination of hydrazine molecules (n N – N 976 – 959 cm-1). The Dn (n asy - n sym) separation suggest that the carboxyl group is monodentatively coordinated in metal cinnamate and crotonate dihydrazinate complexes, whereas monohydrazinate complexes show smaller Dn separation, indicating chelate bidentate coordination of the carboxylate groups to the central metal ion. All the complexes undergo two or three steps exothermic or endothermic decomposition to give respective carboxylates through metal carboxylate intermediate. X – ray powder diffraction pattern reveal that complexes with same formulation posses isomorphism.

Chemical constituents of Mangifera indica leaves (I) / 中草药

Objective: To study the chemical constituents of Mangifera indica leaves. Methods: Silica gel, ODS, Sephadex LH-20 column chromatography, and HPLC were used to isolate and purify the constituents, and their structures were identified by physicochemical properties and spectral data. Results: Eleven compounds were isolated from 70% ethanol extract, and identified as quercetin-3-O-β-L-rhamnopyranoside (1), hyperin (2), quercetin-3-O-β- glucopyranoside (3), 7-O-methylquercetin-3-O-β-L-rhamnopyranoside (4), rhamnetin-3-O-β-D-glucopyranoside (5), amentoflavone (6), mangiferin (7), irisflophenone-3-C-β-glucoside (8), maclurin-3-C-β-glucoside (9), 2,4′,6-trihydroxy-4-methoxybenzophenone-2-O-β-glucoside (10), and irisflophenone-3-C-(6-O-p-hydroxybenzoyl)-O-β-glucoside (11), respectively. Conclusion: Compounds 4 and 10 are obtained from the plants of Mangifera L. for the first time, and the NMR data of compound 11 is reported for the first time.