第一部份

第一部份 : 黑星櫻成份之研究 第二部份 : 黑星櫻成份 , 苯駢 塞井酮類及類似 物對黃嘌呤氧化脢之抑制作用

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科植物 . 據文獻記載 , 梅屬植物有潤肺化痰 , 潤燥 , 利水 , 固精 , 收歛及治療良 性前列腺增殖等效用 . 故本實驗分離純化黑星櫻之成份 , 與同屬已知成份做 一對照比較 , 以期能發現新的有效成份 . 經由各種管柱層析 , 由黑星櫻氯仿 層分離出七個化合物 . 利用光譜測定及化學方法分析 , 目前鑑定出三個化合 物為 beta- 香樹脂醇 (1), 蒲公英賽醇 (2),beta- 穀茲醇 -3-O-beta-D- 葡萄糖 甘 (3). 第二部份 : 黑星櫻成份 , 本駢塞井酮類及類似物對黃嘌呤氧化脢之 抑制作用 根據文獻 , 黃嘌呤氧化脢與痛風 , 缺血後組織再灌流傷害 , 腦瘤 , 急性胰臟炎及肝炎等疾病有關 . 故本實驗探討黑星櫻成份 , 塞侳類與本駢塞 井酮類化合物對黃嘌呤氧化氧化脢之抑制作用 . 如測試抑制百分比 , 抑制百 分之五十濃度 (IC50), 抑制型態及抑制常數 (Ki), 以其對治療或預防黃嘌呤 氧化脢相關疾病有所幫助 . 次黃嘌呤受黃嘌呤氧化脢的催化作用轉變成黃 嘌呤 , 然後此脢在催化黃嘌呤變尿酸 , 而尿酸在紫外線波長 295nm 處有最大 吸收 . 故利用紫外線光譜測定尿酸的吸光值變化速率 , 做為黃嘌呤氧化脢之 活性指標 . 抑制型態及抑制常數依據 Line-weaver-Burk plot 公式求得 . 結 果顯示 , 黑星櫻成份對黃嘌呤氧化脢抑制作用非常微弱 . 苯駢塞井酮類化合 物中 , 則以 2-amino-4H-1,3-benzothiazin-4-one(IC50=5.54uM,Ki=5.12

uM) 及 2-guanidino-4H-1,3-benzothiazin-4-one(IC50=5.60uM,Ki=19.47

uM) 較具活性 , 抑制型態分別屬於不競爭型與混合型 ( 不競爭型 - 非競爭型 ) 抑制劑 . 而塞侳類化合物中只有 rhodan-ine(IC50=121.40uM,Ki=206.23uM) 具微弱的抑制效果 , 抑制型態屬混合型 ( 不競爭 - 非競爭型 ) 抑制劑 .

Part I:Studies on the Constituents of Prunus phaeosticta (HANCE) MA XIM. Part II:Inhibition of Xanthine Oxidase by the Constituents of Prunu

s phaeosticta (HANCE) MAXIM. and Benthiazinone Analogues.

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Part I. The Constituents of Prunus phaeosticta (HANCE) MAXIM.

Prunus phaeosticta (HANCE) MAXIM. is a novel Prunus plant of Rosaceae in Taiwan. Prunus plants have been used as nourish the lung, resalve sputum, for treatment of dryness-syndrome, also as diuretic, tonic, astringent and for treatment of benign prostate hyperplasia. In this study, the constituents of the plant were isolated, and compared with the constituents of other Prunus spp. By variaus column chromatography, seven compounds were isolated from the chloroform soluble fraction. Three compounds, beta-amyrin(1), taraxerol(2) and beta-sitosterol-3-O-beta-D- glucoside(3) were characterized by spectroscopic data and chemicalmethods, and four constituents remain to be analyzed.

Part II. Inhibition of Xanthine Oxidase by the Constituents of

Prunus phaeosticta (HANCE) MAXIM. and Benzothiazinone Analogues.

According to the literature, xanthine oxidaseis related to several diseases such as gout, tissue reperusion iniuries, brain tumors, acute pancreatitis and hepatitis. In this study, the

constituents of Prunus phaeosticta (HANCE) MAXIM., thiazoles and benzothiazinones have been tested for their inhibitory, effects on xanthine oxidase:determination of percent inhibition, IC50, mode of inhibition and the apparent inhibition constant (Ki). It is expected that xanthine oxidase inhibitors are useful for the treatment or prevention of these diseases mentioned as above.

The enzyme, xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and of xanthine to uric acid which has wavelength of 295 nm. Uric acid was thus forming basis for a spectrophotometric assay of the activity of xanthineoxidase.

According to the Lineweaver-Burk plot equation, mode of inhibition andthe apparent inhibition constants (Ki) were estimated. The results showed that the constituents of Prunus phaeosticta (HANCE) MAXIM. showed very weak inhibitory effect on xanthine oxidase. On the other hand, benzothiazinone analogues, 2-amino-4H-1,3-benzothiazin-4-one (IC50-5.54uM, Ki=5.12uM) and 2-guanidino-4H-1,3-benzothiazin-4-one (IC50=5.60uM, Ki=19.47uM) displayed potent activities on xanthine oxidase inhibition. They induced noncompetitive and mixed (non-competi tive-uncompective) type inhibitions respectively, with respect to the substrate

xanthine. Rhodanine (IC50=121.40uM, Ki=206.23uM) also showed

moderate effects on xanthine oxidase inhibition, and induced

mixed (non-compective-uncompetitive) type inhibition of the

enzyme with respect to the substrate xanthine.