chlorogenic-acid and chicoric-acid

Protein tyrosine phosphatase 1B (PTP1B) is a known regulator of the insulin and leptin signaling pathways and is an active target for the design of inhibitors for the treatment of type II diabetes and obesity. Recently, cichoric acid (CHA) and chlorogenic acid (CGA) were predicted by docking methods to be allosteric inhibitors that bind distal to the active site. However, using a combination of steady-state inhibition kinetics, solution nuclear magnetic resonance experiments, and molecular dynamics simulations, we show that CHA is a competitive inhibitor that binds in the active site of PTP1B. CGA, while a noncompetitive inhibitor, binds in the second aryl phosphate binding site, rather than the predicted benzfuran binding pocket. The molecular dynamics simulations of the apo enzyme and cysteine-phosphoryl intermediate states with and without bound CGA suggest CGA binding inhibits PTP1B by altering hydrogen bonding patterns at the active site. This study provides a mechanistic understanding of the allosteric inhibition of PTP1B.

Topics: Algorithms; Allosteric Regulation; Binding Sites; Binding, Competitive; Caffeic Acids; Catalytic Domain; Chlorogenic Acid; Enzyme Inhibitors; Humans; Hydrogen Bonding; Kinetics; Magnetic Resonance Spectroscopy; Molecular Dynamics Simulation; Protein Binding; Protein Domains; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Succinates

The aim was to develop a high performance liquid chromatography method for simultaneous determination of five organic acids in Kudiezi injection. The Diamonsil C18 column (4.6 mm x 200 mm, 5 microm) was adopted with acetonitrile and water as the mobile phase at a gradient mode program. The flow rate was 1.0 mL min-1 , detection wavelength was 325 nm, and column temperature was 35 degree C. The linear range of monocaffeyltartaric acid, chlorogenic acid, caffeic acid, ferulic acid, and chicoric acid were 0. 64-81.60 (r =0. 999 9),0.09-11. 10 (r =0.999 8) ,0.09-11.30 (r =0. 999 8),0.10-12.80 (r =0.999 9),0.43-55. 50 mg L-1 (r = 0.999 8) , respectively. The average recoveries were 101.8% ,100. 9% ,99. 24% ,99. 83% ,101.9%, respectively, with RSD of less than 2.0%. The developed HPLC method was simple, sensitive and accurate with good repeatability. This work provided helpful information for comprehensive quality control of Kudiezi injection. [Key words] Kudiezi injection; organic acids; content determination; HPLC

Topics: Caffeic Acids; Chlorogenic Acid; Chromatography, High Pressure Liquid; Coumaric Acids; Drugs, Chinese Herbal; Quinic Acid; Succinates

3,4,5-Tricaffeoylquinic acid (TCQA) that is not found in intact plant of lettuce leaves was isolated from the cultured cells. The intact plant produced chicoric acid (dicaffeoyl tartaric acid: L-CCA) as well as chlorogenic acid (3-caffeoylquinic acid: 3-CQA) as the major metabolites. After subculturing of the cells for 40 days, the amount of 3,4,5-TCQA reached to 0.14 mg/g fresh weight. The inhibitory effect of 3,4,5-TCQA for human immunodeficiency virus (HIV) Type 1 integrase was assayed. Anti-HIV activity using HIV and MT-2 cells was 1.15 microM and IC(50) against HIV integrase was 0.063 microM whereas cell toxicity of this chemical was expressed as 5% death of all living cells to be 18.4 microM. The HIV inhibitory effect of 3,4,5-TCQA was the highest in values among L-CCA, and other dicaffeoylquinic acids. This data will provide a new possibility for creating a new drug design for HIV.

Topics: Anti-HIV Agents; Caffeic Acids; Cells, Cultured; Chlorogenic Acid; HIV Integrase; HIV-1; Lactuca; Plant Leaves; Quinic Acid; Succinates

The dicaffeoylquinic acids (DCQAs) and dicaffeoyltartaric acids (DCTAs) are potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) integrase. They also inhibit HIV-1 replication at nontoxic concentrations. Since integrase is an excellent target for anti-HIV therapy, structure-activity relationships were employed to synthesize compounds with: (1) improved potency against HIV-1 integrase, (2) improved anti-HIV effect in tissue culture, and (3) increased selectivity as indicated by low cellular toxicity. Thirty-four analogues of the DCTAs and DCQAs were synthesized and tested for cell toxicity, anti-HIV activity, and inhibition of HIV-1 integrase. Seventeen of the 34 analogues had potent activity against HIV-1 integrase ranging from 0. 07 to >10 microM. Seventeen analogues that were synthesized or purchased had no inhibitory activity against integrase at concentrations of 25 microM. Of the biologically active analogues, 7 of the 17 inhibited HIV replication at nontoxic concentrations. The most potent compounds were D-chicoric acid, meso-chicoric acid, bis(3,4-dihydroxydihydrocinnamoyl)-L-tartaric acid, digalloyl-L-tartaric acid, bis(3,4-dihydroxybenzoyl)-L-tartaric acid, dicaffeoylglyceric acid, and bis(3, 4-dihydroxyphenylacetyl)-L-tartaric acid. Anti-HIV activity of the active compounds in tissue culture ranged from 35 to 0.66 microM. Structure-activity relationships demonstrated that biscatechol moieties were absolutely required for inhibition of integrase, while at least one free carboxyl group was required for anti-HIV activity. These data demonstrate that analogues of the DCTAs and the DCQAs can be synthesized which have improved activity against HIV integrase.

Topics: Anti-HIV Agents; Base Sequence; Caffeic Acids; Cell Line; Cell Survival; Chlorogenic Acid; Cloning, Molecular; DNA Primers; Drug Resistance, Microbial; HIV Integrase Inhibitors; HIV-1; Humans; Magnetic Resonance Spectroscopy; Structure-Activity Relationship; Succinates; Tartrates; Virus Replication