Entity

Time filter

Source Type


Wu M.,Chengdu University of Traditional Chinese Medicine | Wu M.,China Military Institute of Chinese Medicine | Qu F.,Clinical Examination Center | Zhao Y.,Chengdu University of Traditional Chinese Medicine | And 13 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2015

As a healthcare-associated pathogen with the resistance to anti-bacterial agent, P. aeruginosa has caused prevalent public burden and should not be ignored. Facing the realistic situation, developing novel anti-P. aeruginosa agents is urgent. Leaves of Dracontomelon dao were extensively used in southern China to treat various infectious diseases 1000 years ago. And in the study, the heat flow power–time (HFP–time) curves generated by P. aeruginosa which were disturbed by the five fractions (PE, CHCl3, EtOAc, n-BuOH and Vestiges fraction) from them were investigated through microcalorimetry, and then, some thermal kinetic parameters were obtained from the curves to characterize the metabolism of P. aeruginosa. The parameters were analyzed by principal component analysis (PCA), and the anti-P. aeruginosa activities of the five fractions were systematically compared and evaluated. The results showed that five fractions all expressed respective anti-P. aeruginosa effects in a dose-dependent manner and especially the performance of EtOAc fraction with half-inhibitory concentration (IC50) of 18.06 μg mL−1. Simultaneously, the prospective performance of EtOAc fraction was confirmed by turbidimetry. Based on the promising anti-P. aeruginosa activities of EtOAc fraction, it could be developed as a novel anti-bacterial agent used in practice for treating certain infectious diseases. © 2015 Akadémiai Kiadó, Budapest, Hungary Source


Wu M.,Chengdu University of Traditional Chinese Medicine | Wu M.,China Military Institute of Chinese Medicine | Qu F.,Clinical Examination Center | Zhao Y.,Chengdu University of Traditional Chinese Medicine | And 12 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2016

As a healthcare-associated pathogen with the resistance to anti-bacterial agent, P. aeruginosa has caused prevalent public burden and should not be ignored. Facing the realistic situation, developing novel anti-P. aeruginosa agents is urgent. Leaves of Dracontomelon dao were extensively used in southern China to treat various infectious diseases 1000 years ago. And in the study, the heat flow power-time (HFP-time) curves generated by P. aeruginosa which were disturbed by the five fractions (PE, CHCl3, EtOAc, n-BuOH and Vestiges fraction) from them were investigated through microcalorimetry, and then, some thermal kinetic parameters were obtained from the curves to characterize the metabolism of P. aeruginosa. The parameters were analyzed by principal component analysis (PCA), and the anti-P. aeruginosa activities of the five fractions were systematically compared and evaluated. The results showed that five fractions all expressed respective anti-P. aeruginosa effects in a dose-dependent manner and especially the performance of EtOAc fraction with half-inhibitory concentration (IC50) of 18.06 μg mL-1. Simultaneously, the prospective performance of EtOAc fraction was confirmed by turbidimetry. Based on the promising anti-P. aeruginosa activities of EtOAc fraction, it could be developed as a novel anti-bacterial agent used in practice for treating certain infectious diseases. © 2015 Akadémiai Kiadó, Budapest, Hungary. Source


Chen C.,Chengdu University of Traditional Chinese Medicine | Qu F.,Clinical Examination Center | Wang J.,Chengdu University of Traditional Chinese Medicine | Xia X.,Hunan University | And 13 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2015

The root of Wikstroemia indica has been widely used in China as folk medicine for the treatment for arthritis, whooping cough, cancer, and bacillosis. However, the constituents which have antibacterial activity were not clarified yet. In this study, the antibacterial effect of five extracts from W. indica on Escherichia coli was evaluated by microcalorimetry coupled with agar dilution method. The ethanol extract of W. indica was isolated with organic solvents of different polarities including petroleum (P.E.) extract, chloroform (CHCl3) extract, ethyl acetate (EtOAc) extract, n-butylalcohol (nBuOH) extract, and residue extract. The metabolic profiles of E. coli growth at 37 °C were measured by microcalorimetry. According to the principal component analysis, k1, k2, and P1 were obtained from heat flow power–time (HFP–time) curve. The agar dilution method was performed to verify the results of thermodynamics. The results of microcalorimetric experiment indicated that EtOAc fraction demonstrated the strongest antibacterial activity with half-inhibitory concentration of 92.4 μg mL−1. Meanwhile, similar results were gained from the common method of agar diffusion, which suggested that EtOAc extract could be further developed as antibacterial bioactive fraction of W. indica. Altogether, microcalorimetry is a useful technique to provide sufficient quantitative information and evaluate the antimicrobial effect with its sensitive. © 2015 Akadémiai Kiadó, Budapest, Hungary Source


Chen C.,Chengdu University of Traditional Chinese Medicine | Qu F.,Clinical Examination Center | Wang J.,Chengdu University of Traditional Chinese Medicine | Xia X.,Hunan University | And 13 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2016

The root of Wikstroemia indica has been widely used in China as folk medicine for the treatment for arthritis, whooping cough, cancer, and bacillosis. However, the constituents which have antibacterial activity were not clarified yet. In this study, the antibacterial effect of five extracts from W. indica on Escherichia coli was evaluated by microcalorimetry coupled with agar dilution method. The ethanol extract of W. indica was isolated with organic solvents of different polarities including petroleum (P.E.) extract, chloroform (CHCl3) extract, ethyl acetate (EtOAc) extract, n-butylalcohol (nBuOH) extract, and residue extract. The metabolic profiles of E. coli growth at 37°C were measured by microcalorimetry. According to the principal component analysis, k 1, k 2, and P 1 were obtained from heat flow power-time (HFP-time) curve. The agar dilution method was performed to verify the results of thermodynamics. The results of microcalorimetric experiment indicated that EtOAc fraction demonstrated the strongest antibacterial activity with half-inhibitory concentration of 92.4 μg mL-1. Meanwhile, similar results were gained from the common method of agar diffusion, which suggested that EtOAc extract could be further developed as antibacterial bioactive fraction of W. indica. Altogether, microcalorimetry is a useful technique to provide sufficient quantitative information and evaluate the antimicrobial effect with its sensitive. © 2015 Akadémiai Kiadó, Budapest, Hungary. Source


Zhao Y.,Chinese Peoples Liberation Army | Liu S.,Chinese Peoples Liberation Army | Qu F.,Clinical Examination Center | Wang J.,Chinese Peoples Liberation Army | And 8 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2015

With the prevalence resistance of Staphylococcus aureus to antibacterial agents, developing novel antibacterial agents is urgent. Recently, plant extracts have got more focus. In this study, the power-time curves produced by S. aureus under the action of the four extracted fractions (PE, CHCl3, EtOAc, and n-BuOH fractions) from the leaves of Dracontomelon dao were determined by microcalorimetry, and then some quantitative parameters, such as growth rate constant k, total heat output Q t, maximum heat-output power Pm, and the appearance time tm were obtained. By analyzing the parameters using principal component analysis, the anti-S. aureus effects of the four fractions were systematically evaluated and compared. Meanwhile, the total flavonoid contents in these fractions were analyzed. The results have evidenced that different fractions using various extraction solvents expressed various anti-S. aureus effects, and the inhibitory effects were presented in a flavonoid content-dependent manner. The EtOAc fraction with the highest total flavonoid content (41.86 %) expressed the strongest anti-S. aureus effect with half-inhibitory concentration (IC50) of 83.93 μg mL-1, which might be applied as a novel antibacterial agent in practice for some infectious diseases. In addition, the microcalorimetric method should be strongly suggested in screening for novel antibacterial agents for fighting against pathogenic bacteria. © 2014 Akadémiai Kiadó. Source

Discover hidden collaborations