天然抗氧化劑可以保護人體免受自由基傷害並減緩許多慢性疾病惡化。楝樹在印度是一種廣為人知的多用途藥用植物且具有廣泛的生物活性。
此研究主要的目的為從印尼種楝樹的葉子中分離及定性抗氧化劑化合物。乾燥的楝樹葉在搖床上用80%(v/v)的甲醇在30°C萃取24小時。接著萃取物進行過濾和用迴轉蒸發濃縮機濃縮。以水溶解乾燥的萃取物後，使用己烷、乙酸乙酯和正丁醇使其分相。乙酸乙酯相有最高的抗氧化性，被用來做進一步的純化和測定。使用矽膠管柱層析法進行酚類化合物的分離和純化，薄層層析法矽膠60 GF254被用來決定最佳的展開劑。使用高效能液相層析儀和紫外光/可見光光譜儀對純化後的化合物進行測定。
高效能液相層析儀測定的結果顯示，四種次要的化合物為阿魏酸、楊梅黃素、山奈酚和槲皮素。經由紫外光/可見光光譜儀測定的結果顯示，木犀草素-7-O-β-D-葡萄糖苷為主要化合物的其中一種。

Natural antioxidants can protect human body from free radicals and retard the progress of many chronic diseases. Neem (Azadirachta indica A. Juss) is well known in India as one of the most versatile medicinal plants having a wide spectrum of biological activity.
The aim of this study was to isolate and characterize antioxidant compounds from leaf of neem of species of Indonesia. The dried neem leaves were extracted using 80% (v/v) methanol at 30°C for 24 h on a shaker. The extract was filtered and concentrated in vacuo in a rotary evaporator. The dried extract was dissolved in water and partitioned with hexane, ethyl acetate, and butanol. Ethyl acetate fraction showed the highest antioxidant activity and was subjected to further purification and identification. Isolation and purification of phenolic compounds were done using silica gel column chromatography. Elution solvent was selected using TLC silica gel 60 GF254. The purified compounds were identified using HPLC and UV-Vis spectroscopy.
The four minor compounds identified by HPLC are ferulic acid, myricetin, kaempferol and quercetin. One of the major compounds was identified using UV-Vis spectroscopy as luteolin-7-O-β-D-glucopyranoside.

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