title: Investigation on the spectrum-effect relationships of EtOAc extract from Radix Isatidis based on HPLC fingerprints and microcalorimetry.
abstract: This work investigated the spectrum-effect relationships between HPLC fingerprints and the anti-bacterial activities of EtOAc extracts from Radix Isatidis. Fingerprints of EtOAc extracts of Radix Isatidis from various sources were established by a High-Performance Liquid Chromatography. The process of Escherichia coli (E. coli) growth affected by EtOAc extracts was monitored using a Thermal Activity Monitor (TAM) Air Isothermal Calorimeter by microcalorimetry. By analyzing the power-time curves, quantitative parameters, such as growth rate constant k, maximum heat-production rate P(m), appearance time t and total heat-production Q were obtained to characterize the interactions of E. coli and the EtOAc extracts from Radix Isatidis. The HPLC fingerprints were investigated using hierarchical clustering analysis. The main thermo-kinetic parameters from the power-time curves were analyzed using principal component analysis. The spectrum-effect relationships between the HPLC fingerprints and anti-bacterial activities were analyzed with multivariant correlation analysis. Close correlation existed between the spectrum-effect relationships of the EtOAc extracts. Salicylic acid in the HPLC fingerprints might be one of the anti-bacterial components. This work provides a general model of the combination of HPLC and microcalorimetry to study the spectrum-effect relationships of EtOAc extracts from Radix Isatidis, which can be used to search for principal components of Radix Isatidis on bioactivity.
authors.affiliation: Institute of Chinese Materia Medica, 302 Hospital of People's Liberation Army, Beijing, China.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Kong
authors.forename: Yan-Ling
authors.initials: YL
authors.lastname: Zhao
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Shan
authors.forename: Xiao-He
authors.initials: XH
authors.lastname: Xiao
authors.forename: Wei-Ying
authors.initials: WY
authors.lastname: Guo
mesh_terms: D000085:Acetates / Q000737:chemistry; D019607:Brassicaceae / Q000737:chemistry*; D002151:Calorimetry; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D015999:Multivariate Analysis; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*
chemical_list: D000085:Acetates; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; C007650:ethyl acetate