紅花矮仙丹化學成份及其活性之研究

茜草科 (Rubiaceae)植物紅花矮仙丹(Ixora coccinea Linn.)，為常綠灌木植物，主要分布在亞洲及非洲熱帶地區。根據文獻及相關研究記載，仙丹花屬(Ixora.)，曾被報導含有 lupeol, ursolic acid, oleanolic acid具有抗癌及抗病毒活性等有效成份。此植物過去曾未有其化學成分以及其生物活性之研究，故採其地上部以甲醇萃取後，將其粗萃物進行液液分配畫分，並分為正己烷，氯仿及水等三層，並進行相關活性測試與成分分離，其中氯仿層對collagen (3 μg /ml)所誘導之血小板凝集具有77.91%的抑制作用及細胞毒殺性。至目前為止從此植物中分離得到三十個成份，包含八個三萜類化合物lupeol (1)、 3-acetyl-betulic acid (2)、betunolic acid (3)、 β-amyrin (4)、oleanonic acid (5)、α-amyrin(6)、ursolic acid(7)、3-acetyl ursolic acid (8), 四個固醇類化合物: 6β-hydroxystigmast-4-en-3-one (9)、 sitosteryl-3-O-β-D-glucoside (10)、β-sitosteroid (29) and stigmasteroid (30)；六個黃酮類化合物: kaempferol (11)、kaempferol- 7-O-α-L-rhamnoside (12)、kaempferitrin (13)、(-)-epi-catechin (14)、(-)- catechin(15)、luteolin (16)、epicatechin-(4β??8, 2β?袞??7) –ent-epicatechin (17)；三個香豆素類化合物scopletin(18), coumarin(19)、thero-1’, 2’-albiflorin (20)，二個雙萜類化合物16α-hydro-19-acetoxy-(-)-kauran-17-oic acid (21)、 16α-hydro-19-ol-(-)-kauran-17-oic acid (22)；二個quinone類化合物 XV 1,4-dihydroxy-3-methyl-anthraquninone (23)與α-tocopheryl quinone (26) 及二個胜肽類化合物ixoropeptide-I (24)*與ixoropeptide-II (25)*，此外還有一個三酸甘油酯2,3-dihydroxypropyl-eicosanoic ester (27)，一個脂肪酸oleic acid (28)，其中化合物24、25為新化合物，所有分離得之化合物都經由光譜及質譜等分析方法加以證明。在抗血小板凝集活性測試方面，黃酮類化合物11、14、15及16，在經由collagen所引導的血小板凝集上，均表現出不錯的對抗活性，其IC50均小於10 μg/ml。特別在其中，化合物11與16其IC50分別為3.55與2.56 μg/ml 。除此之外，我們更進一步進行抗發炎活性測試，結果發現新化合物25表現出非常好的活性，在抑制superoxide anion generation方面，其IC50為0.21 ± 0.01 μg/ml，抑制elastase release方面則為0.27 ± 0.03 μg/ml。

關鍵字

茜草科；抗血小板凝集活性；胜肽類化合物；三萜類化合物

並列摘要

Ixora coccinea Linn. (Rubiaceae) is an evergreen shrub, endemic in the tropics of Asia and Africa. Previously, the natural compounds from the genus Ixora such as lupeol, ursolic acid, and oleanolic acid were reported to show cytotoxicity and antiviral activity. The natural compounds and their bioactivity of this plant has not been studied yet. We collected the aerial part of Ixora coccinea and extracted with the material with MeOH. And the extract was partitioned to yeild n-hexane, CHCl3 and H2O- layers. The CHCl3 layer exhibited 77.91 % ( induced by collagen, 3 μg/ml ) antiplatelet aggregation activity and cytotoxicity .In this current study, we isolated 30 compounds from this species, including lupeol (1), 3-acetyl-betulic acid (2), betunolic acid (3), β-amyrin (4), oleanonic acid (5), α-amyrin (6), ursolic acid (7), 3-acetyl ursolic acid (8), 6β-hydroxystigmast-4-en-3-one (9), sitosteryl-3-O-β-D-glucoside (10), kaempferol (11), kaempferol- 7-O-α-L-rhamnoside (12), kaempferitrin (13), (-)-epi-catechin (14), (-)- catechin(15), luteolin (16), epicatechin-(4β??8, 2β?袞??7) – ent-epicatechin (17), scopoletin (18), coumarin (19), threo-1’,2’-albiflorin (20), 16α-hydro-19-acetoxy-(-)-kauran-17-oic acid (21), 16α-hydro-19-ol-(-) -kauran-17-oic acid (22), 1,4-dihydroxy-3-methyl-anthraquninone (23), ixoropeptide-I (24)*, ixoropeptide-II (25)*, α-tocopheryl quinone (26), 2,3-dihydroxypropyl-eicosanoic ester (27), oleic acid (28), β-sitosteroid XVII (29) and, stigmasteroid (30). Among them, compounds 24 and 25 are new compounds and the structures of these compounds were identified by spectroscopy data. In the anti-platelet aggregation assay, compounds 11、14、 15 and 16 showed mild anti-platelet aggregation activity induced by collagen (IC50< 10 μg/ml), especially, compounds 11 and 16 had significant result with IC50 3.55 and 2.56 μg/ml, respectively. In addition, the pure compounds were subjected to the anti-inflammatory assay. The result showed that compounds 25 had great inhibitory effects on superoxide anion generation with IC50 0.21 ± 0.01 μg/ml and elastase release 0.27 ± 0.03 μg/ml.