We have disclosed our effort to develop caffeic acid derivatives as potent and non-toxic inhibitors of α-MSH-stimulated melanogenesis to treat pigmentation disorders and skin medication including a cosmetic skin-whitening agent. The SAR studies revealed that cyclohexyl ester and secondary amide derivatives of caffeic acid showed significant inhibitory activities.
Five 5-lipoxygenase inhibitors, chlorogenic acid (1), 6''-p-coumaroyl genipin gentiobioside (2), 3, 4-di-O-caffeoylquinic acid (3), 3-O-caffeoyl-4-O-sinapoylquinic acid (4) and 3, 5-di-O-caffeoyl-4-O-(3-hydroxy-3-methyl)glutaroylquinic acid (5), were isolated from Gardeniae Fructus. The structures of the new compounds (2, 4 and 5) were elucidated on the basis of spectral data and chemical evidence. These hydroxycinnamic acid derivatives inhibit 5-lipoxygenase activity, and 3 was the most potent inhibitor. The inhibitory effects were enhanced on methylation of the carboxyl group(s) of 1, 3, 4 and 5, and the ID<50> values of the methyl esters of 3, 4 and 5 were of the order of 10<-8>M.
Synthesis of 1-<i>O</i>-Methylchlorogenic Acid: Reassignment of Structure for MCGA3 Isolated from Bamboo (<i>Phyllostachys edulis</i>) Leaves
作者:Wayne E. Zeller
DOI:10.1021/jf4042112
日期:2014.2.26
coincide with those reported for the original isolation from bamboo (Phyllostachys edulis) leaves of the compound designated MCGA3. Comparison of the published spectroscopic data reported for MCGA3, with both reported literature values and spectroscopic data obtained from an authentic sample, leads to the conclusion that the compound isolated from bamboo (Phyllostachys edulis) leaves is instead methyl
A screening of the natural product chlorogenic acid, isolated from the Brazilian medicinal plant Hypericum brasiliense, caffeic acid, cinnamic acid, and p-methoxycinnamic acid, and derivatives of caffeoylquinic, caffeoyl, and cinnamoyl against the enzymes prolyl oligopeptidase and dipeptidyl peptidase IV was carried out. Caffeoylquinic, caffeoyl, and cinnamoyl derivatives were prepared using simple derivatization procedures and through coupling reactions with the amino acid proline. The dipeptidyl peptidase IV assay showed inhibitory activity of the tested compounds at a high concentration (500 mu M) in the range of 81.5-7.2%. In contrast, the derivatives methyl ester and 1,7-acetonide obtained from chlorogenic acid, and caffeic acid and its methyl ester derivative showed selectivity and activity as prolyl oligopeptidase inhibitors, with IC50 values of 3 to 14mM.
Chlorogenic Acid and Synthetic Chlorogenic Acid Derivatives: Novel Inhibitors of Hepatic Glucose-6-phosphate Translocase
作者:Horst Hemmerle、Hans-Joerg Burger、Peter Below、Gerrit Schubert、Robert Rippel、Peter W. Schindler、Erich Paulus、Andreas W. Herling
DOI:10.1021/jm9607360
日期:1997.1.1
The enzyme system glucose-6-phosphatase (EC 3.1.3.9) plays a major role in the homeostatic regulation of blood glucose. It is responsible for the formation of endogenous glucose originating from gluconeogenesis and glycogenolysis. Recently, chlorogenic acid was identified as a specific inhibitor of the glucose-6-phosphate translocase component (G1-6-P translocase) of this enzyme system in microsomes of rat liver. Glucose B-phosphate hydrolysis was determined in the presence of chlorogenic acid or of new synthesized derivatives in intact rat liver microsomes in order to assess the inhibitory potency of the compounds on the translocase component. Variation in the 3-position of chlorogenic acid had only poor effects on inhibitory potency. Introduction of lipohilic side chain in the 1-position led to 100-fold more potent inhibitors. Functional assays on isolated perfused rat liver with compound 29i, a representative of the more potent derivatives, showed a dose-dependent inhibition of gluconeogenesis and glycogenolyosis, suggesting glucose-6-phosphatase as the locus of interference of the compound for inhibition of hepatic glucose production also in the isolated organ model. G1-6-P translocase inhibitors may be useful for the reduction of inappropriately high rates of hepatic glucose output often found in non-insulin-dependent diabetes.