Chemical Composition, Larvicidal and Molluscicidal Activity of Essential Oils of Six Guava Cultivars Grown in Vietnam.

Diseases transmitted by mosquitoes and snails cause a large burden of disease in less developed countries, especially those with low-income levels. An approach to control vectors and intermediate hosts based on readily available essential oils, which are friendly to the environment and human health, may be an effective solution for disease control. Guava is a fruit tree grown on a large scale in many countries in the tropics, an area heavily affected by tropical diseases transmitted by mosquitoes and snails.

Three new iridoid glucoside salts from Hedyotis tenelliflora Growing in Vietnam.

Three new sodium salts of iridoid acids, deacetylasperulosidic acid sodium salt (1), teneoside D (2), and teneoside E (3) were isolated from the leaves of Hedyotis tenelliflora Blume (Rubiaceae), together with seven known iridoids, 6alpha-hydroxygeniposide (4), 6beta-hydroxygeniposide (5), 6-O-methyldeacetylasperulosidic acid methyl ester (6), 6-O-methylscandoside methyl ester (7), 6alpha-methoxygeniposidic acid (8), daphylloside (9), and mollugoside methyl ester (10). Their chemical structures were elucidated by 1D and 2D NMR spectroscopy, as well as HR-ESI-MS analysis.