Pot Aloe vera gel – a natural source of antioxidants

Abstract

Aloe vera (Aloe barbadensis Miller) is widely spread around the world and it is used in the food and cosmetic industry and traditional medicine due to its high content in bioactive compounds. Thus, this article investigated the phenolic compounds of Romanian Aloe vera gel and its antioxidant capacity. The gel was extracted using 4 different solvents: methanol, ethanol, water, and acetone. Total phenolics were measured by the Folin-Ciocalteu method, total flavonoids by aluminium chloride reaction, and the antioxidant capacity by DPPH radical-scavenging activity. The profile of the phenolic compound was determined using Fourier transform infrared spectroscopy and Liquid Chromatography-Diode Array Detection–Electro-Spray Ionization Mass Spectrometry. The methanolic extract had a significantly higher antioxidant activity, followed by ethanolic, water, and acetone extracts. The methanolic extract had also the highest total polyphenol content, while ethanolic extract had the highest total flavonoid content. The extracts contained 14 compounds identified as 7 chromones (Aloesin, Neoaloesin, Aloinoside A, Aloinoside E, Aloe-emodin-glucoside, Isoaloeresin D, Methoxycoumaroyl-aloresin) 2 flavones (Luteolin-glucoside, Apigenin-glucoside), one hydroxycinnamic acid (Caffeic acid) and 4 to anthrones (Aloin A, Aloin B, Emodin, Aloe-emodin). The LC-MS results showed important quantities of Aloesin, Neoaloesin, Aloeresin E, and Aloe-emodin-glucoside while FTIR analysis showed the presence of polysaccharides, pectins, anthraquinones, and saponins.

Keywords

• antioxidant activity
• phenolic compounds
• infrared spectroscopy