Evaluation of anti-oxidant properties in essential oil and solvent extracts from Tagetes minuta

Abstract

Synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are toxic and carcinogenic, thus they induce DNA damage. This calls for the need to find alternative antioxidants from natural products. Tagetes minuta (Asteraceae) is an annual herb that belongs to the Asteraceae family. It is used in common medicine and grows in temperate regions of South America, some parts of Africa and Asia. Essential oil from T. minuta was obtained by hydrodistillation while solvent extracts were obtained using ethyl acetate and methanol. Antioxidative compounds of T. minuta were isolated both from the Ethyl acetate extract and the essential oil. It was done by determining the scavenging activity using 2,2-diphenyl-1-picrylhaydrazyl free radical (DPPH) using thin layer chromatography (TLC). The active compounds were tested quantitatively for their radical scavenging activity using the U-1100 UV-VIS Spectrophotometer. The active fractions were isolated using TLC and High performance liquid chromatography (HPLC) and later detected using both Gas chromatography mass spectrometry (GC-MS) and Nuclear magnetic resonance (NMR). One pure active compound was obtained from the ethylacetate extract (neophytadene) by a combintion of GC-MS and NMR. The essential oil contained a number of compounds among which are trans-ocimen 15.90%, I-verbanone 15% of limonene 8.02%, tegetone 3.56%, and 2-pinen-4-one 7.84%.              Key words: Antioxidant activity, essential oil, 2,2-diphenyl-1-picrylhaydrazyl free radical (DPPH), Tagetes minuta.