大葉桃花心木 (Swietenia macrophylla King) 的果實,俗稱向天果,具有治療糖尿病、高血壓、高固醇、內分泌失調等民俗療效,相關藥理研究表明大葉桃花心木具抗氧化、降血糖、降血脂等功效。將乾燥之大葉桃花心木果殼以甲醇浸泡萃取得到粗萃物,再利用分配萃取得到乙酸乙酯層、正丁醇層及水層萃取物。將乙酸乙酯層萃取物進行分離純化,利用管柱層析分為五十八個分液,續以重複管柱層析、高效液相層析以及再結晶法得到純化合物,經由核磁共振光譜和質譜分析並利用文獻詳細比對確定化合物結構。目前共鑑定出九個已知化合物,四個固醇類:β-sitosterol (S1)、(3β, 7α)-7-methoxystigmast-5-en-3-ol (S2)、β-sitostenone (S3)、ergosterol peroxide (S4);一個芳香類:ethyl 4-hydroxybenzoate (A1);四個檸檬苦素類:swietenine (L1)、3-O-tigloylswietenolide (L2)、swietenine acetate (L3)、7-deacetoxy-7-oxogedunin (L4)。乙酸乙酯層萃取物在濃度為250 μg/mL對脂肪酶具有抑制作用,抑制率為44.44%,而標準品熊果酸的抑制率為16.40% (25 μg/mL)。乙酸乙酯層萃取物顯示出對血管收縮素轉化酶(ACE)具有抑制作用,其IC50為95.0 μg/mL,而標準品captopril的IC50值為0.02 pg/mL。總酚含量最高為正丁醇層萃取物(3.28±0.55 mg GAE/g DW),而三種抗氧化活性試驗結果皆為正丁醇層萃取物有良好的效果,透過皮爾森相關分析,得多酚含量影響抗氧化能力有密切相關。
Swietenia macrophylla King, known as sky fruit or big leaf mahogany, is used in traditional folk medicine to treat diabetes, hypertension, hypercholesterolemia, and endocrine disorders. Pharmacological studies have shown that the extracts of plant has antioxidant, hypoglycemic and hypolipidemic effects. The methanol extract of the pericarps was suspended in water and partitioned into ethyl acetate, n-butanol, and water-soluble fractions with ethyl acetate and n-butanol. The ethyl acetate layer was further purified by column chromatography and high performance liquid chromatography to give nine compounds. Their structures were identified by detailed comparison of their NMR and MS spectral data with literature values. The inhibitory activities of the plant on angiotensin-converting enzyme (ACE), α-glucosidase and lipase were investigated by in vitro methods. Nine known compounds were identified from the plant, including four sterols: β-sitosterol (S1), (3β, 7α)-7-methoxystigmast-5-en-3-ol (S2), β-sitostenone (S3), ergosterol peroxide (S4); one aromatic: ethyl 4-hydroxybenzoate (A1); four limonoids: swietenine (L1), 3-O-tigloylswietenolide (L2), swietenine acetate (L3), 7-deacetoxy-7-oxogedunin (L4). The ethyl acetate fraction showed inhibitory effects against lipase inhibitory percentage of 44.44% at concentration of 250 μg/mL while the standard ursolic acid had an inhibitory effect of 16.40% (25 μg/mL). The ethyl acetate fraction also exhibited inhibitory effect against ACE with an IC50 value of 95.0 μg/mL lower than the standard captopril with an IC50 value of 0.02 pg/mL. The highest total phenolic content was observed in the n-BuOH layer (3.28±0.55 mg GAE/g DW), and the n-BuOH layer also had the best antioxidant activity. The results showed that the phenolic content and the antioxidants activity have a correlation by Pearson’s correlation.