Botanical origin of mei-gui hua (petal of a Rosa species).

Mei-gui hua has been used as a crude drug in traditional medicine and as herbal tea in China. The scientific name of Mei-gui is Rosa rugosa thunb. However, the morphological characteristics and botanical ecology of Mei-gui were different from those of R. rugosa. Since the botanical origins of Mei-gui cultivated in China have not yet been clarified, we compared Mei-gui and R. rugosa in terms of their morphological characteristics, phylogenetic analysis, and phytochemical studies. Our research suggested that Mei-gui cultivated around Tarim Basin in Xinjiang Province showed homology to Rosa gallica, while those cultivated in the northeastern parts of China are considered to be hybrids of R. rugosa.

Simultaneous determination of hydrolysable tannins in the petals of Rosa rugosa and allied plants.

The petals of Rosa rugosa and allied plants for medicinal use contain abundant hydrolysable tannins, and they show remarkable biological activities. The activities are dependent on the structures of the hydrolysable tannins, so their contents and compositions are essential for evaluation of medicinal potency. Therefore, we optimized the simultaneous quantitative determination of the hydrolysable tannins using ultra-performance liquid chromatography. A column of ethylene bridged hybrid (BEH) phenyl (C(6) alkyl phenyl group as solid-phase modification) was shown to be most effective for the separation of hydrolysable tannins isolated from R. rugosa and related compounds when the column temperature was kept under 25 degrees C. The efficacy of the BEH phenyl column might be due to the interaction between solid phase and phenolic ester groups of hydrolysable tannins such as galloyl, hexahydroxydiphenoyl and valoneoyl groups. The relation between the retention times on the BEH phenyl column and the column temperature was demonstrated to depend on the structural characteristics of hydrolysable tannins.