Chemical Analysis Of The Original Plants And Tissue Cultures Of Vaccinium Dunalianum

Vaccinium dunalianum Wight(Ericaceae) is an evergreen shrub mainly distributed in the Southwest of China, with its leaves used as a folk medicine for the treatment of articular rheumatism. The dried leaf buds have also been used for preparing a traditional folk herbal tea. Previous phytochemical study found that arbutin(1), chlorogenic acid(2) and 6’-O-caffeoylarbutin(3) are rich in the leaf buds of the title plant. Compound 3 was also found to suppress the melanogenesis in a live zebrafish model, in which it has a stronger anti-melanin activity in a dose-dependent manner with about a two-fold over that of 1. Interestingly, the unusual accumulation of 3, up to 22% by yield from the dried leaf buds, was suggestive of its unknown important physiological role in this plant tissue, and whether 3 presents in the other parts of the title plant with a higher content. Through the first time studies on the chemical constituents, nutrition contents, tissue culture and rapid propagation of V. dunalianum, we expect to make a certain contribution to develop and use of V. dunalianum. The results were as follows:1. A reliable, reproducible and accurate method for simultaneous and quantitative determination of 1-3 is developed by RP-HPLC analysis. This method should be appropriate for the quality assurance of unprocessed and processed materials of V. dunalianum. The contents of 1-3 in different parts of V. dunalianum from different origins were analyzed. The content of 3 was much higher than those of 1 and 2, accounting for up to 31.76% in the dried leaf buds. Moreover, the leaf buds, flower buds and leaves showed a tendency towards higher contents of 1-3 than the other plant parts.2. Taking the healthy tender stem segments of wild V. dunalianum as an explant, the media for axillary bud induction, subculture and rooting culture were selected. The results showed that the optimal medium for initial culture with an induction rate of 83.33% was WPM+6-BA 3.0 mg·L-1+NAA 0.2 mg·L-1, and the optimal medium for subculture was WPM+ZT 2.0 mg·L-1 with darkness cultured for 7d. The optimal rooting medium was WPM+IBA 0.2 mg·L-1, which has a rooting rate of 86.67%.3. Using the phytochemical method to study the chemical constituents from the dried fruits of V. dunalianum. The fruits were extracted with 80% methanol, and then extracted with petroleum ether, and ethyl acetate, successively. Nineteen compounds were isolated from the aqueous layer by Diaion HP20, silica gle, MCI gel, Sephadex LH-20 and CG161 column chromatographies. On the basis of the ESI-MS, 1H and 13 C NMR spectroscopic analyses, the chemical structures of four compounds were elucidated as 6’-O-caffeoylarbutin(1), monotropein methyl ester(2), dihydroxy monotropein methyl ester(3), and arbutin(4), respectively. Compounds 2 and 3 were isolated from the genus Vaccinium for the first time, and the structural elucidation of the other isolated compounds are in progress.4. The fruit matter nutrition contents of V. dunalianum was determined. The results showed that the content of cellulose was 36.3%. The V. dunalianum was hydrolyzed into 16 kinds of amino acid and in rich of tasty amino acids; The V. dunalianum was in rich of mineral elements. The contents of quantity elements from rich to low was as follows: K>Ca>Mg>P>Na, and the contents of K in V. dunalianum was much higher than Na. V. dunalianum is high in nutrition value.