γ-dodecalactone化學結構與生物活性作用之研究

Abstract

牛樟芝在台灣是一種傳統的中國草藥，已經被利用來治療多種疾病。不過，牛樟芝香氣成分的免疫活化功能目前還未有相關的研究。本研究的目的在於分離及鑑定牛樟芝精油的主要香氣成分及探討此成分的化學結構及生物功能之間的關連性。利用氣相層析/質譜 (GC/MS) 分析鑑定出牛樟芝精油主要的香氣成份為gamma-dodecalactone (gamma-DDL)。透過氣相層析和流式細胞儀分析 (flow cytomertry)，發現gamma-DDL可以進入細胞並誘導臍帶血單核球細胞表徵改變及活化自然殺手細胞(NK cells)。同時我們也發現gamma-DDL可以轉變成開環形式的4-hydroxydodecanoic acid後進而活化自然殺手細胞。利用對掌性衍生劑 (chiral derivatising agents) 及高壓液體層析 (HPLC) 分離具有活性結構的gamma-DDL。結果只有R結構的gamma-DDL具有活化自然殺手細胞的能力。此外，也鑑定出存在於牛樟芝中的gamma-DDL是屬於R結構的。最後，我們觀察到在自然殺手細胞中gamma-DDL可以快速的活化介白素-2 (interferon-2) 基因的表現並且透過介白素-2自體分泌循環機制 (autocrine) 活化自然殺手細胞。除了自然殺手細胞外，gamma-DDL也可能透過不同的活化機制去誘導T細胞、B細胞、單核球細胞、樹突狀細胞的活化。

In Taiwan, Antrodia camphorata (A. camphorata) is a traditional Chinese medicine and it has been utilized to treat a wide variety of diseases. However, the immuno-activating function of the flavor components from A. camphorata had not yet been investigated. In the present work, the volatile oil of A. camphorata was analyzed with the aim of isolating and identifying the major flavor compound and investigating the relationship between the chemical structure and biological functions of compound. The major component of A. camphorata volatile oil was identified as gamma-dodecalactone (gamma-DDL) by GC/MS analysis. By GC and flow cytomertry analysis, suggested that gamma-DDL entered the cells for the induction of human umbilical cord blood mononuclear cells (hUCB-MNCs) phenotypic changes and activation of NK cells. gamma-DDL was found to convert its open ring form: 4-hydroxydodecanoic acid for the activation of NK cells. The active configuration of gamma-DDL was deduced with the help of chiral derivatising agents (CDAs) and HPLC analysis. Only the R-configurated form of gamma-DDL was able to mediate NK cell activation. Furthermore, the configuration of gamma-DDL was identified in A. camphorata also as R-form. Finally, gamma-DDL induced rapid activation of interferon-2 (IL-2) gene in NK cells and the IL-2 autocrine system to activate NK cells. gamma-DDL also induced the activation of T cells, B cells, monocytes and DCs, but there might be different mechanisms of activation.