Extraction of phytochemicals with health benefit from Peperomia pellucida (L.) Kunth through liquid-liquid partitioning

• Main Authors: Ho, Keat Lam, Tan, Chung Ghuan, Yong, Phaik Har, Wang, Chee Woon, Lim, Siew Huah, Kuppusamy, Umah Rani, Ngo, Chek Tung, Massawe, Festo, Ng, Zhi Xiang
• Format: Article
• Published: Elsevier 2022
• Subjects: QD Chemistry; R Medicine (General)
• Online Access: http://eprints.um.edu.my/41537/

Peperomia pellucida (L.) Kunth has been traditionally used as food and medicine in both Eastern and Western countries. Owing to the vast variety of bioactive compounds, there is no definite extraction system or formula to efficiently extract the bioactive compounds with commercial value. This study aimed to evaluate the bioactive compounds in P. pellucida with liquid-liquid partitioning method and compare their anti-glycaemic, anti-in-flammatory, antioxidant, and anti-glycation potential in different solvent fractions. The dried plant powder was macerated with methanol and successively partitioned with five solvents of different polarity. Five classes of bioactive compounds, four categories of biological activities and in vivo toxicity were evaluated with quanti-tative bioassays. This study found that the plant extraction yield varied with solvent polarity. The chloroform, ethyl acetate and n-butanol plant fractions were rich in phenolics, tannin, saponin and alkaloid despite their low extraction yields. Plant phenolics and saponin were positively correlated (p < 0.01) with antioxidant, anti-inflammatory and anti-glycation activities. The non-polar hexane fraction displayed high anti-inflammatory potential while ethyl acetate, aqueous and hexane fractions showed relatively strong anti-glycation effect. The anti-alpha-glucosidase and anti-alpha-amylase activities in all plant fractions except the non-toxic aqueous fraction were stronger than standard acarbose drug. Four main bioactive compounds, including the dillapiole, 2,4,5-trimethox-ystyrene, 9-octadecenoic acid methyl ester and pheophorbide-a methyl ester have been characterized through nuclear magnetic resonance and electrospray ionization mass spectrometry. Principal component analysis confirmed that both solvent polarity and plant extraction yield contributed to 63% of biological activity variation in P. pellucida. This study has demonstrated that the liquid-liquid partitioning method could be optimized to extract bioactive compounds from P. pellucida with potent antioxidant, anti-diabetic, anti-inflammatory and anti-glycation activities.