苦瓜與福木之抗氧化及抗癌成分與甘草次酸衍生物之 設計、合成、及抗癌活性之評估

The Antioxidant and Anticancer Constituents of Momordica charantia and Garcinia subelliptica, and Design, Synthesis, and Anticancer Evaluation of 18β-Glycyrrhetinic Acid Derivatives

林凱偉(Kai-Wei Lin)

指導教授 ： 楊世群

高雄醫學大學/藥學院/藥學研究所/博士(2013年)

https://doi.org/10.6832/KMU.2013.00116

摘要

從苦瓜 (Momordica charantia L.，Cucurbitaceae) 莖分離得到1 個新的
cucurbitane 型三萜類配醣體 (triterpene glycoside)，taiwacin A (1)、1 個新的
cucurbitane 型triterpene，taiwacin B (2)與已知的steroid glycoside (4)。從苦
瓜果實分離得到已知的cucurbitane 型triterpene glycoside (3)。從福木
(Garcinia subelliptica Merr.，Guttiferae) 種子分離得到1 個新骨骼間苯三酚
(phloroglucinol) 衍生化合物，garcinielliptone R (5) 與1 個新的
triterpenoid，garcinielliptone S (6)。在合成方面，以甘草次酸
(18??-glycyrrhetinic acid，GA) (11) 為原料合成得12-37，其中包含12 種新
化合物，分別為20、21、23?{27、與31?{35。新化合物經由各種化學鑑定方
式來決定其構造。
從苦瓜得到的 1?{4 具2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid)
(ABTS) 自由基清除活性，其中1 與3 具黄嘌呤氧化酶 (xanthine oxidase，
XO) 抑制活性，2?{4 對XO 催化作用所生的O2
?{?h具清除活性，relative oxygen
radical absorbance capacity (ORAC) 值測定以2 表現最佳，1 對人類膀胱癌
細胞 (NTUB1) 細胞毒表現最佳。由以上結果可知，1?{4 可能成為抗氧化
劑，而1 亦有成為抗癌藥潛力。
從福木得到的已知 phloroglucinol (7) 對NTUB1 有細胞毒，但是與
cisplatin 共同培養時會顯著的減少其細胞毒，且在活性氧 (reactive oxygen
2
species，ROS) 實驗中，7 與cisplatin 共同與NTUB1 培養24 小時後所產生
的ROS 量比cisplatin 單獨作用者顯著的減少，可推知7 在此濃度時可藉著
減少ROS 量來降低cisplatin 的細胞毒性以保護細胞。除以上之活性外，從
福木得到的另外3 個已知的phloroglucinols，8?{10，具有ABTS 自由基清除
活性，而8 對XO 也有抑制活性，可知8?{10 可能作為抗氧化劑。
Seco-compounds 19、35、與37 對NTUB1 具顯著細胞毒，以35 培養
於NTUB1 24 小時後ROS 量增加，於Flow cytometry 實驗，35 對NTUB1
會經由細胞凋亡與粒腺體膜電位降低而造成細胞死亡。以Western blot 分
析，35 使p-p53 表現增加，而與N-acetylcysteine (NAC) 共同培養卻會降低
p-p53 之活化。可知35 會經由誘發ROS，增加p-p53 表現，進而調控粒腺
體使膜電位下降，引發細胞經由凋亡而死亡。

關鍵字

苦瓜屬 ； 葫蘆烷三萜類配醣體 ； 抗氧化 ； 類固醇配醣體 ； 合成 ； 甘草次酸衍生物 ； 細胞毒 ； 三萜類 ； 間苯三酚 ； 福木

並列摘要

A new cucurbitane-type triterpene glycoside taiwacin A (1), a new
23,24,25,26,27-pentanorcucurbitane, taiwacin B (2), and a known steroid
glycoside (4), were isolated from the stems of Momordica charantia,
respectively. A known cucurbitane-type triterpene glycoside (3) was isolated
from the fruits of M. charantia. A new phloroglucinol possessing an
unprecedented skeleton, garcinielliptone R (5), and a new triterpenoid
garcinielliptone S (6), were isolated from the seed of Garcinia subelliptica.
Twenty six 18??-glycyrrhetinic acid (11) derivatives 12?{37 including twelve
new GA derivatives 20, 21, 23?{27, 31?{35 were synthesized. The structures of
new compounds were elucidated by spectroscopic methods. 1?{4 revealed
ABTS?h?y scavenging activity. Compounds 1 and 3 displayed an inhibitory effect
on xanthine oxidase (XO) activity. Compounds 2?{4 significantly displayed O2
?h?{
scavenging activity. Compounds 2 and 3 showed the effects of relative oxygen
radical absorbance capacity (ORAC). These findings showed that 1?{4 may be
used as antioxidants. Compound 1 exhibited the significant inhibiting effect for
NTUB1 (human bladder cancer cell lines). Phloroglucinol, garcinielliptone FC
(7) from this plant exhibited a significant increase of antiproliferative effect,
while 7 combined with cisplatin significantly caused decrease of cell inhibition induced by cisplatin in NTUB1 and decreased the amount of reactive oxygen
species (ROS) than that of the total amount generated by 7 and cisplatin. These
results suggested that 7 could protect the cisplatin toxicity through reduction of
ROS in NTUB1. Phloroglucinols, garcinielliptones, A (8) and F (10), and
garsubelline A (9), from this plant, revealed ABTS radical cation scavenging
activity and 8 displayed an inhibitory effect on XO. seco-Compounds 19, 35,
and 37 showed significant cytotoxicities against NTUB1. Exposure of NTUB1
to 35 for 24 h significantly increased the production of ROS. Flow cytometric
analysis exhibited that treatment of NTUB1 with 35 induced an increase of
apoptotic cell death and mitochondrial membrane potential (MMP) decreased in
a dose-dependant manner after 24 h. Western blot analysis shows that NTUB1
cells treated with 35 increased the level of p-p53 in a dose-dependant manner.
Further, NAC treatment prevented p53 phosphorylation stimulated by 35. These
results suggested that 35 induced a mitochondrial-mediated apoptosis in
NTUB1 cells through activation of p53, which are mainly mediated ROS
generated by 35.

並列關鍵字

Momordica ； Cucurbitane-type triterpene glycoside ； Antioxidant ； Steroid glycoside ； Synthesis ； 18β-Glycyrrhetinic acid derivatives ； Cytotoxicity ； p53 ； Triterpenoid ； Phloroglucinol ； Garcinia subelliptica

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