一、Retrojusticidin B在大鼠中的藥物動力學及代謝研究 二、串聯式LC-SPE-NMR技術的應用 1.分析及確認錫蘭葉下珠及葉下珠所含之木脂素成份 2.TM-1在大鼠及豬中的藥物動力學及代謝研究

Abstract

中文摘要 一、Retrojusticidin B在大鼠中的藥物動力學及代謝研究 Retrojusticin B分離自錫蘭葉下珠（Phyllanthus myrtifolius），在活性篩選的過程中，發現retrojusticidin B對於抑制人類免疫缺陷病毒-1型的反轉錄酶（HIV-1 reverse transcriptase）有很高的選擇性，故本實驗擬利用大鼠進行其藥物動力學及代謝的研究，以釐清其開發之潛力。先建立一簡易的分離步驟及經由Solvolysis、

I. Pharmacokinetic and Metabolic Studies of Retrojusticidin B in Rats The pharmacokinetics and metabolism of retrojusticidin B, an anti-HIV reverse transcriptase agent isolated from Phyllanthus myritifolius, were studied in rats. The phase II conjugated metabolites were characterized after solvolysis and enzymatic hydrolysis. The oral bioavailabilities of retrojusticidin B, suspended in Tween 80 and in corn oil, were found to be 22.1% and 33.1%, respectively. The elimination half-lives (T1/2) were 22.9 and 36.2 minutes, respectively. The T1/2, clearance, and the volume of distribution (Vz) of retrojusticidin B estimated from i.v. were 24.5 min, 2.6 ± 0.4 L/min, and 90.6 ± 6.4 L, respectively. 9,9'-Secoretrojusticidin B was proved to be phase I metabolite. II. Application of LC-SPE-NMR Hyphenated Technique i. Analysis and Identification of Lignans in Phyllanthus myrtifolius and P. urinaria Application of LC-SPE-NMR hyphenated technique in analyzing lignans of great structural similarity, present in Phyllanthus urinaria L. and P. myrtifolius Moon, was undertaken. An LC system, composed of a C8 column, eluted with THF-H2O/ MeCN and detected at 225 nm, with good resolution for 7 lignans isolated from P. urinaria was developed. An LC system, composed of a C18 column, eluted with H2O/ MeCN and detected at 280 nm, also had good resolution for 7 pure lignans from P. myrtifolius. Hyphenation of this system to SPE-NMR provided very clean 1H NMR spectra for 9 and 7 lignans present in a partially purified and lignan rich fraction of P. urinaria and P. myrtifolius, respectively. The result demonstrates that LC-SPE-NMR is a very efficient and powerful tool in thorough structural identification of natural products, at least for those known, using a minute amount of plant materials. ii. Pharmacokinetic and Metabolic Studies of TM-1 in Rats and Pigs. A study on the metabolism of TM-1 /tartaric acid IV bolus in rats showed that, within 4 hours, laurolitsine, norglaucine, glaucinone, and TM-1-1 were the major metabolites in the blood of rats, and TM-1-1-like metabolites were also detected. Analysis of the extract of urine and feces of rats, collected within 2 days after iv injection of TM-1/tartaric acid, showed that both TM-1 and its metabolites probably were eliminated through hepatic-bile duct. Pharmacokinetic study of TM-1/tartaric acid in rats IV bolus showed that its blood concentration decayed with time; and both norglaucine and TM-1-1 were the major metabolites. Tissue distribution study indicated that the highest concentration of TM-1 was observed in kidney, followed by liver and heart, and decreased with time. Pharmacokinetics of TM-1 in the domestic pig via ear vein injection, with doses of 1.28 g/ 65kg, 0.45 g/ 67 kg, and 0.14 g/ 65 kg was studied. The blood samples were picked up from jugular vein at 5, 15, 30, 60, 120, 240 and 360 (480) min sharp after injection. HPLC analysis indicated that the concentration of TM-1 in the first 5 min was much lower than that expected, and TM-1 was still detectable after 6 hours’ injection. The metabolites, however, were not detected in this study.