Study On Extracting Active Compound And Pharmacological Actions Of Guava(Psidium Guajava L.)

Psidium guajava L. is a kind of tropic fruit, which belongs to Psidium in the Myrtaceae. It is widely grown in the tropics and the semi-tropical areas, enriching the diet of hundreds of millions of people in the world. It has abundance of nutrition, especially high content in antiscorbutic vitamin. And the leaves of guava have a long history of medicinal uses that are still employed today, such as curing diarrhea, vomiting, stomach upsets, sore throats, bleeding gums, diabetes and so on. Therefore, more and more scientists and scholars find themselves much interest on guava. They set about to research it not only on the fruit, but also pay attention to the root, the stem, the bark and the leaves. Recently, people lucubrate on analysis of essential oil from the leaves of guava. In order to more broadly generalize, explore and utilize guava, the author will focus on studying some aspects about it as follow.1. Determining the nutrition components of guava, whose materials got from the variety in Chaoshan areas, including the content of water, protein, coarse fibre, crude fat, Vitamin C, Vitamin B₂ and total ash. The results were that the content of Vitamin C was 20⁶0mg, of water was 87.24g, of protein was 0.524g, of coarse fibre was 3.526g, of crude fat was 0.7g, and of Vitamin B₂ was 0.175mg, of total ash was 8.47g per 100g eatable fruit. We found that there had difference about the content of Vitamin C between former reports, which was, maybe, influenced with the varieties and the seasons.2. To ascertain the optimal condition of extracting the flavonoids from Psidium guajava leaves by ultrasonic method. The author designed a orthogonal experiment. Results indicated the optimum extracting condition of the ethanol digestion method being as follow, 40% ethanol as solvent, ratio of solid to liquid as 1 : 60, extracting time of 25h and ultrasonic extraction time of 50min. The extraction efficiency of flavonoids was as high as 9.9167%. And then we do the bacteriostatic activities experiments by the Oxford cup. The results showed that...