Xian-li Zhou (School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan,China.)
Further investigation of the chemical constituents of Huajiao, the pericarps of the fruits of Zanthoxylum bungeanum Maxim. (Rutacease) has led to the isolation of two new unsaturated alkylamides, (2E, 7E, 9E)-N-(2-hydroxy-2-methylpropyl)-6, 11-dioxo-2, 7,9-dodecatrienamide (1) and (2E, 6E, 8E)-N-(2-hydroxy-2-methylpropyl)-10-oxo-2, 6, 8-decatrienamide (2), along with seven known compounds. Their structures were elucidated on the basis of extensive spectroscopic analysis, including MS, IR, 1D and 2D NMR experiments. Compound 2 is the first natural unsaturated alkylamide possessing an aldehyde group from the Z. bungeanum. The backbone of compound 1 contains two ketonic carbons rarely seen in the natural unsaturated alkylamides. Hydroxy-β-sanshool were isolated and purified with chromatographic methods, and the purities of Hydroxy-β-sanshool was higher than 99%. The process has the advantages of short preparation period, low production cost, simple operation, good product quality, high yield.
- Synthesis analogue of spicy constituents of Zanthoxylum bungeanum
Spicy taste is the main character of its flavor as well as the most important quality indicator. The standardized method of evaluating pungency has not been established at present. The pungency of Zanthorylum bungeanum is closely associated with the chemistry compositions and the structure of the pungent principles. We have synthesized 25 compounds, by using DCC (Dicyclohexylcarbodiimide) dehydration condensation reaction synthesis of amides and using the special catalyst (C18H28F6N6OP) synthesis of amides selectively.
- Quantitative prediction of pungency in Zanthoxylum bungeanum using electronic tongue based
on differential degree
Pungency is a kind of sensory attributes which stimulate strong and is easy to let evaluators feel fatigue. It is very important to establish an electronic evaluation method to replace sensory method for quickly evaluating pungent intensity in batch. In order to carry out pungency evaluation by electronic tongue, there are two questions should be solved. First, electronic tongue should be capable to response for different pungent concentrations quantitatively. Second, the specific relationship between pungent concentrations and pungent intensity should be existed. In order to explore prediction model for pungent concentration by electronic tongue, the extract of dry Zanthoxylum bungeanum sample was used as the research object, methods and principles of difference test for sensory evaluation were adopted, samples were detected using parallel measurement, and Euclidean Distance was used to present differential degree between fixed reference and unknown samples. Results showed that the differential degree could well response to variances in series concentration samples, especially the variances could be represented by linear mathematical model. Using this model to predict unknown samples showed that the relative standard deviation between predicted value and actual value was less than 20%, which satisfied with requirements of sensory evaluation for quantitative. It was a breakthrough in predicting pungent concentration, and also it laid a solid foundation for quantitative prediction of pungent intensity, for which provided a method for semi-quantitative and quantitative determination.
