蘭嶼肉桂在分類上屬於樟科,為臺灣的特有植物,其地理分布僅見於蘭嶼。近來,在免疫調節活性相關的預試驗中,發現蘭嶼肉桂的葉部萃出物對於人類周邊血管單核球細胞具顯著的抑制增生活性。鑑於此,遂以蘭嶼肉桂葉部為材料,針對其成分進行一系列的分析、分離、純化與構造解析,計分離、決定出十六個化合物,包括: 七個黃酮類 (1, 2, 5 – 9)、二個巨豆二烯酮化合物 (3, 4)、二個 gamma-內酯化合物 (12, 13)、一個二?類化合物 (14)、一個固醇類 (16) 和三個其他類 (10, 11, 15)。其結構分別利用各種光譜分析鑑定為: kaempferol 3-O-alpha-L-[2''-(Z)-p-coumaroyl-4''-(E)-p-coumaroyl] rhamnopyranoside (1)、kaempferol 3-O-alpha-L-[2'',4''-di-(E)-p-coumaroyl] rhamnopyranoside (2)、(6R,7E,9R)-megastigman-3-one-4-ene-9,13-diol (3)、(6R,7E,9S)-megastigman-3-one-4-ene-9,13-diol (4)、kaempferol 3-O-alpha-L-rhamnopyranoside (5)、rutin (6)、kaempferol 3-O-rutinoside (7)、quercitrin (8)、(-)-epi-catechin (9)、2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-glucopyranoside (10)、adenosine (11)、cinnakotolactone (12),isolinderanolide B (13)、trans-phytol (14)、alpha-tocopherol (15) 和 beta -sitosterol (16),其中,化合物1和12為新的化合物。此外,生物活性試驗的結果顯示化合物1和2對於植物血凝素活化後的人類周邊血管單核球細胞顯示具抑制增生的活性,其半抑制濃度 (IC50) 分別為5.5 M和6.1 M。
Cinnamomum kotoense (Lauraceae), an arbor indigenous to Taiwan, is found only in Lanyu Island. Recently, leaf extracts of C. kotoense were found to exhibit significant antiproliferation activity on peripheral blood human mononuclear cells (PBMC) in our preliminary studies. Therefore, we investigated the chemical constituents of the leaves of C. kotoense. Totally 16 compounds including seven flavanoids (1, 2, 5 – 9), two megastigmanes (3, 4), two gamma-lactones (12, 13), one diterpenoid (14), one steroid (16), and three others (10, 11, 15) were isolated and identified. Their structures were elucidated to be kaempferol 3-O-alpha-L-[2''-(Z)-p -coumaroyl-4''-(E)-p-coumaroyl] rhamnopyranoside (1), kaempferol 3-O-alpha-L-[2'',4''-di-(E)-p-coumaroyl] rhamnopyranoside (2), (6R,7E,9R) -megastigman-3-one-4-ene-9,13-diol (3), (6R,7E,9S)-megastigman-3-one -4-ene-9,13-diol (4), kaempferol 3-O-alpha-L-rhamnopyranoside (5), rutin (6), kaempferol 3-O-rutinoside (7), quercitrin (8), (-)-epi-catechin (9), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-glucopyranoside (10), adenosine (11), cinnakotolactone (12), isolinderanolide B (13), trans-phytol (14),alpha -tocopherol (15) and beta-sitosterol (16) on the basis of spectroscopic analysis. Of these compounds identified, 1 and 12 are new. In addition, results of biological tests indicated that 1 and 2 exhibited antiproliferation activities toward phytohemagglutinin-stimulated PBMC with an IC50 value of 5.5 M and 6.1?M, respectively.