The Nematicide Components From Dendrobium Sinense (Orchidaceae)

Dendrobium is one of the largest genus of Orchidaceae, which has many varieties, and there are about 1400 species widely distributed in the tropics, the subtropics of Asia and the Oceania. Dendrobium is not only of high value on horticulture, but also one of the famous traditional Chinese medicines. The main medicinal components of Dendrobium are dendrobine, bibenzyls, phenanthrenes and polysaccharide, and its medicinal value and healthy function are demonstrated in the following aspects: the treatment for deficiency of yin in stomach, the unfaded deficiency-heat after illness, the dim eyes, diabetes mellitus and so on. At the same time, it is proved by the modern pharmacological experiments that Dendrobium has remarkable curative effect on inhibiting the growth of tumor cells, and has obvious effect on enhancing human immunity, anti-oxidation and anti-aging, so that is widely focused by the domestic and overseas scholars. Dendrobium sinense is endemic to Hainan, and the chemical composition and biological activity of this plant was further studied in this paper, and provided the theoretical basis for the development of Dendrobium resources.In order to study the chemical constituents of Dendrobium sinense, twenty six compounds were isolated from whole herb by column chromatography. On the basis of spectral data, their structures were identified as chrysotobibenzyl (1), dendrosinen C (2),dendrosinen A (3), aloifol (4), 3,3',4'-trihydroxy-4,5-dimethoxybibenzyl (5),3,3'-dihydroxy-4,5-dimethoxybibenzyl (6), crepidatin (7),2',4'-dihydroxy chalcone (8),2,7-dihydroxy-3,4,6-trimethoxy-9,10-dihydrophenanthrene (9), 2,5-dihydroxy-3,4-dimethoxy-9,10-dihydrophenanthrene (10), marylaurencinols A (11), 4,7-dihydroxy-2,3-dimethoxy-9,10-dihydrophenanthrene (12), erianthridin (13), 2,5,7,Trihydroxy,4-methoxy-9,10-dihydrophenanthrene (14), medioresinol (15), lasiodiplodin (16),trans-p-hydroxylethyl cinnamate (17), ferulic acid (18), (Z)-coniferyl aldehyde (19),P-hydroxyphenylpropionic methyl ester (20),P-hydroxyphenylpropionic acid (21),4-Methoxy-phenylethanol (22), syringaldehyde (23), vanillic acid (24), 4-hydroxybenzoic acid (25), 3,9-dihydroxy-megastigma-5-ene (26). Among them, compound 1-25 were phenolic compounds, compounds 1-7 were belonged to bibenzyl, compounds 8-14 were belonged to phenanthrene, compound 1, 5, 7-18, 20-21 and 23-26 were isolated from D.sinense for the first time.The bioactivity of compounds 1-26 against Panagrellus redivivus inhibitory were tested by direct contact method. The results indicated that 8 compounds included 1, 4, 5, 8,17, 19,20 and 22 had the marginal toxicities against Panagrellus redivivus. The activity of compounds 1-26 acetylcholinesterase (AChE) inhibitory were tested by Ellman's method.The results indicated that 8 compounds included 8, 9,11,16, 18, 19, 22 and 26 exhibited AChE inhibitory activity.In this paper, according to the analysis of the chemical constiuents of Dendrobium,the Dendrobium sinense was proved to have the characteristic components of medicinal Dendribium-the bibenzyl compounds and phenanthrene compounds. In addition, further research was done from the biological-activity perspective, and the nematicida-activity test was done based on the previous research, and the active nematicidal ingredients was found in this test, the result provides scientific basis for nematode control and the search for new insecticide resources. At the same time, the active components of acetylcholinesterase inhibitor was screened out, which provides the scientific basis for the nerve protection, the prevention and treatment for neurodogenerative dementia.