Bioassay-guided Separation and Identification of Pharmacodynamic Constituents with Nitrite-scavenging Effect in &lt;em&gt;Aquilaria sinensis&lt;/em&gt; Leaves

Yang Maoxun,Zhao Bin,Huang Yongfang,Chen Heru

doi:10.19026/ajfst.11.2652

Abstract

To explore the pharmacodynamic constituents with nitrite-scavenging effect in Aquilaria sinensis leaves, a new food raw material, applying bioassay-guided method by using UV spectrophotometry, scavenging rates of crude extracts of wild and cultivated A. leaves with different solvents, each polar fraction of the crude extracts and each cut fractions from the n-butanol fraction were tested. It is disclosed that scavenging effect of the crude extract from wild A. leaves was better than that from cultivated. n-Butanol fraction of the crude extract from wild A. with 70% acetone displayed the best scavenging effect among all the counterparts. Mangiferin (1) and 2-O-α-Lrhamnopyranosyl- 4, 6, 4'-trihydroxybenzophenone (2) were identified as the two most active compounds with scavenging rate up to 29.4±0.7% and 24.6±0.8%, at the conditions of pH 3.0, 37°C and 30 min treatment, respectively.

Highlights

Sodium nitrite, which is widely used in food and drug industries as a preservative, is omnipresent in the environment and can be formed from nitrogenous compounds by microorganisms present in the soil, water, saliva and the gastrointestinal tract (Chow and Hong, 2002; Omar and Webb, 2014)
Silica gel (100-200, 200-300 mesh) was purchased from Qingdao Ocean Chemical Co. (Qing-dao, China); and pre-coated silica gel HSGF254 Thin Layer Chromatography (TLC) plates were obtained from Jiangyou Silica Gel Development Co. (Yantai, China)
Scavenging rates of crude extracts of wild and cultivated Aquilaria sinensis leaves with different where, the Acontrol is the absorbance of solution without the addition of sample solution

Summary

Introduction

Sodium nitrite, which is widely used in food and drug industries as a preservative, is omnipresent in the environment and can be formed from nitrogenous compounds by microorganisms present in the soil, water, saliva and the gastrointestinal tract (Chow and Hong, 2002; Omar and Webb, 2014). When human body ingests nitrite, endogenous nitrosation may form N-nitrosocompounds (NOCs) that have been reported to induce tumors of the kidney in animals. Our previous study indicated that the extract from A. sinensis leaves was confirmed to have nitrite scavenging activities, which pharmacodynamic material basis remain further investigation (Yang et al, 2012). Bioassay-guided method is a frequently-used and efficient separation method in natural product research (Wu, 2008), αglucosidase inhibitors from the leaves of A. sinensis were isolated by activity-directed fractionation and purification processes in Feng’s study (Feng et al, 2011). Pharmacodynamic constituents of A. sinensis leaves with nitrite-scavenging effect were separated and identificated by bioassay-guided method in this study, to establish the scientific basis for further development and use of A. sinensis leaves

Methods

Results

Conclusion