Isolation and Structure Determination of Antioxidants Active Compounds from Ethyl Acetate Extract of Heartwood Namnam (Cynometra cauliflora L.)

Abstract

Active compounds with antioxidant activity were isolated from ethyl acetate extract of namnam stem (C. cauliflora L.) that had undergone maceration and fractionation by gravity column chromatography. The compounds were later identified by by using UV-Vis Spectrophotometry, FTIR, LCMS and 1H-NMR. Ethyl acetate extract of namnam stem showed considerably high antioxidant activity (IC50 value 4.68 ± 0.035 ppm). The results of analysis by UV-Vis and FTIR showed carbonyl group conjugated with an aromatic ring at band I (λmax 330.22 nm), chromophore group of alkene (C=C) at band II (λmax 268.67 nm) and functional groups such as O−H (3343.91 cm-1), C=O (1729.23 cm-1), C=C (1652.64 and 1611.99 cm-1), C−O (1269.89) and C−H ortho (738.23 cm-1). LCMS (m/z 270.9246) and 1H-NMR data showed seven proton signals on the aromatic ring at carbon position C-3 at δH 6.86 ppm (1H, s), C-6 at δH 5.95 ppm (1H, d, J=1.95 Hz), C-8 at δH 6.25 ppm (1H, d, J= 1.95 Hz), C-2’ and C-6’ at δH 7.03 ppm (2H, d, J=7.87 Hz), C-3’ and C-5’ at δH 6.87 ppm (2H, d, J= 7.87 Hz) so that the structure was identified as a flavonoid which was 4 ', 5,7-trihydroxy-flavones or known as apigenin. The isolated apigenin had very strong antioxidant activity, as shown by IC50 value of 5.18 ± 0.014 ppm.

The Genus Cynometra: A Review of Ethnomedicine, Chemical, and Biological Data

“…The stem ethyl acetate and methanol extracts showed, strong antioxidant and anticholinesterase activities (>80% inhibition), respectively [53,68]. The leaf and fruit of C. cauliflora were the most biologically tested plant parts of this species:…”

“…The stem ethyl acetate and methanol extracts showed, strong antioxidant and anticholinesterase activities (>80% inhibition), respectively [53,68].…”

“…The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/plants11243504/s1, Table S1: In vitro and in vivo biological studies reported from the genus Cynometra [15,17,19,[33][34][35]40,[46][47][48][49][50][51][52][53].…”

The effect of different sweeteners on the free radical scavenging activities, alcohol contents, sugar reductions, and hedonic properties of green tea kombucha

“…As presented in Table 2, kombucha had very strong activity. Sukandar et al stated that very strong antioxidant activity if IC50 less than 50 ppm, and strong if IC50 50-100 ppm 25 . Kombucha with the highest free radical scavenging activity used stevia with an IC50 value of 33.44 ppm.…”

Formulasi serta Uji Aktivitas Antioksidan dan Tabir Surya Krim Ekstrak Aseton Biji Buah Alpukat

“…Hasil ini berbeda dengan penelitian Arukwe dkk. 23 Nilai IC50 ekstrak aseton biji alpukat dan krim ekstrak aseton biji alpukat Formula 1, Formula 2 dan Formula 3 <50 ppm dan masuk kategori memiliki aktivitas antioksidan sangat kuat 31 . Aktivitas antioksidan ekstrak aseton biji alpukat dan krim…”