| 摘要: | 糖尿病為一代謝性疾病，隨著罹患時間的延長，可能會出現血管病變、心肌梗塞、腎功能衰竭等。然而臨床上的糖尿病治療藥物，除了降血糖外，還會造成肥胖的副作用，因此，尋找新的藥物來改善問題實是藥物開發中刻不容緩的任務。經由初步的活性篩選及文獻的整理，本實驗室發現寬筋藤萃取物及pentagalloylglucose (PGG) 皆具有降血糖之功效。
寬筋藤 (Tinospora crispa)為防巳科青牛膽屬 (Tinospora)植物，分布於雲南、廣東及廣西地帶。於馬來西亞，為治療糖尿病之民間用藥。本研究利用甲醇分別萃取寬筋藤 (Tinospora crispa)之莖、葉各部分，經由管柱層析與高效液相層析儀分離純化，共得到十二個化合物。經光譜分析及文獻比對後，確認其化學結構為 : β-sitosterol (5), stigmasterol (6), apigenin (7), makisteron C (8), N-formylanonaine (9), N-formylnornuciferine (10), N-acetylnornuciferine (11), N-acetylanonaine (12), cycloeucalenol (13), N-cis-feruloyltyramine (14), N-trans- feruloyltyramine (15), N-trans-caffeoyltyramine (16). 其中Makisteron C (8)、N-trans-caffeoyltyramine (16)、N-acetylnornuciferine (11)、N-acetylanonaine (12)、為首次自寬筋藤中所分離獲得。相關化合物活性則在進一步測試中。
化合物α-PGG及β-PGG具有降血糖及抑制脂肪細胞之效果，因此本研究進一步使用myo-inositol取代D-glucose，合成其類似物Hexa-O-gallyl-myo-inosit (HGI)，活性測試結果發現HGI對於前脂肪細胞具有選擇性抑制活性。
Diabetes mellitus (DM) is a chronic disease, which occurs due to the insufficient insulin excretion from the pancreas, or due to low-effective usage of the insulin in patient body. This leads to an increased concentration of glucose in the blood (hyperglycaemia), which become a serious health problem. Some of DM drugs are both hypoglycemic and weight-gain-promoting and finally make resistant for patients. Therefore, it is an emergent task to search new antidiabetic agents with side effects. According to preliminary bioactivity screening on the extract of traditional herb medicine and literature surveys, we found that the methanol extract of Tinospora crispa and pentagalloylglucose (PGG) show the effect to reduce the blood glucose level.
Tinospora crispa (Lour.) Merr. (Family Menispermaceae) is a folk medicine in Xishuangbanna, Yunnan, China. In the present study, the stems and leaves of Tinospora crispa were extracted with methanol, respectively. The extracts were further separated by column chromatography and HPLC. Twelve isolated compounds, including β-sitosterol (5), stigmasterol (6), apigenin (7), makisteron C (8), N-formylanonaine (9), N-formylnornuciferine (10), N-acetylnornuciferine (11), N-acetylanonaine (12), cycloeucalenol (13), N-cis-feruloyltyramine (14), N-trans- feruloyltyramine (15), N-trans-caffeoyltyramine (16), were isolated from the stem part. Among them, makisteron C (8), N-acetylanonaine (11), N-acetylnornuciferine (12), N-trans- caffeoyltyramine (16), were isolated from this plant for the first time. The bioactivity of these isolates is under investigation.
In addition, α- and β-PGG anomers can stimulate glucose transport in adipocytes and reduce blood glucose. We tried to make the analogue, hexa-O-gallyl-myo-inositol (HGI), of PGG by replacing glucose by myo-inositol. The bioassay data indicated that HGI exhibited significant inhibitory activity toward preadipocytes. |
