New Flavan-3-ol Dimer from Green Tea Produced from <i>Camellia taliensis</i> in the Ai-Lao Mountains of Southwest China

Abstract

<i>Camellia taliensis</i> (W. W. Smith) Melchior, belonging to the genus <i>Camellia</i> sect. <i>Thea</i> (Theaceae), is an endemic species distributed from the west and southwest of Yunnan province, China, to the north of Myanmar. Known as a wild tea tree, its leaves have been used commonly for producing tea beverages by the local people of its growing area. One new flavan-3-ol dimer, talienbisflavan A (<b>1</b>), was isolated from green tea prepared from the leaves of <i>C. taliensis</i> collected from the east side of the Ai-Lao mountains, Yuanjiang county of Yunnan province, China. In addition, five hydrolyzable tannins (<b>2</b>–<b>6</b>), five flavonols and flavonol glycosides (<b>9</b>–<b>13</b>), three flavan-3-ols (<b>14</b>–<b>16</b>), nine simple phenolic compounds and glycosides (<b>7</b>, <b>8</b>, and <b>17</b>–<b>23</b>), and caffeine (<b>24</b>) were identified. Their structures were determined by detailed spectroscopic analysis. All of the isolated phenolic compounds were tested for their antioxidant activities by DPPH and ABTS⁺ radical scavenging assays. The contents of its main chemical compositions were also compared with those collected from the Lincang area of Yunnan province by high-performance liquid chromatography analysis