RESUMO
Objective: To explore the structure and reaction sites of the reaction products of chlorogenic acid and sodium sulfite,and the chemical changes of chlorogenic acid in Lonicerae Japonicae Flos after sulfur fumigating. Method: Chlorogenic acid was reacted with sodium sulfite under mild conditions. Liquid chromatography-mass spectrometry-ion trap-time-of-flight (LC-MS-IT-TOF) and 1H nuclear magnetic resonance spectroscopy (1H-NMR) detection techniques were used to detect the reaction products,and the sulfur-fumigated and unsulfurized Lonicerae Japonicae Flos water extract was detected by LC-MS-IT-TOF. Result: After analyzing the mass spectrometry data of fragment ion,molecular cleavage and accurate molecular weight,according to the results of nuclear magnetic signals of chemical shift,peak intensity and peak splitting, the products of chlorogenic acid and sodium sulfite were preliminarily identified as chlorogenic acid α,β-unsaturated carbonyl addition product:3-((3-(3,4-dihydroxyphenyl)-2-sulfopropyl)oxy)-1,4,5-trihydroxycyclohexane-1-carboxylic acid or 3-((3-(3,4-dihy droxyphenyl)-3-sulfopropyl)oxy)-1,4,5-trihydroxycyclohexane-1-carboxylic acid,and the same characteristic fragments were detected as the addition product in the sulfur fumigated Lonicerae Japonicae Flos,but not found in the unsulfurized. Conclusion: It is the first time to demonstrate the structure and reaction sites of chlorogenic acid and sulfurous acid reaction products,and detect the chlorogenic acid sulfite addition product in sulfur-fumigated Lonicerae Japonicae Flos. Although it is still unclear how the sulfite addition compound produced by sulphur Lonicerae Japonicae Flos affects the efficacy and toxicological activity of Lonicerae Japonicae Flos,we shall still pay attention to the changes of active ingredients in sulphuric medicinal materials. Besides,this study can also provide reference for the studies of chemical composition changes after sulfuration of traditional Chinese medicine containing α,β-unsaturated carbonyl structure.
RESUMO
Panax notoginseng is a commonly used traditional Chinese medicine with blood activating effect while has continuous cropping obstacle problem in planting process. In present study, a semimicroextraction method with water-saturated n-butanol on 0.1 g notoginseng sample was established with good repeatability (RSD<2.5%) and 9.6%-20.6% higher extraction efficiency of seven saponins than the conventional method. A total of 16 characteristic peaks were identified by LC-MS-IT-TOF, including eight 20(S)-protopanaxatriol (PPT) type saponins and eight 20(S)-protopanaxadiol (PPD) type saponins. The established method was utilized to evaluate the quality of notoginseng samples cultivated by manual intervened methods to overcome continuous cropping obstacles.As a result, HPLC fingerprint similarity, content of Fa and ratio of notoginsenoside K and notoginsenoside Fa (N-K/Fa) were found out to be as valuatable markers of the quality of samples in continuous cropping obstacle research, of which N-K/Fa could also be applied to the analysis of notoginseng samples with different growth years.Notoginseng samples with continuous cropping obstacle had HPLC fingerprint similarity lower than 0.87, in consistent with normal sample, and had significant lower content of notoginsenoside Fa and significant higher N-K/Fa (2.35-4.74) than normal group (0.45-1.33). All samples in the first group with manual intervention showed high similarity with normal group (>0.87), similar content of common peaks and N-K/Fa (0.42-2.06). The content of notoginsenoside K in the second group with manual intervention was higher than normal group. All samples except two displayed similarity higher than 0.87 and possessed content of 16 saponins close to normal group. The result showed that notoginseng samples with continuous cropping obstacle had lower quality than normal sample. And manual intervened methods could improve their quality in different levels.The method established in this study was simple, fast and accurate, and the markers may provide new guides for quality control in continuous cropping obstacle research of notoginseng.