Isolation of Pheophytin A and β-amyrin from Newbouldia laevis (P. Beauv) Leaf Extract

Anotace: Pulverized leaves samples of Newbouldia laevis were extracted by cold maceration using methanol. The extract was concentrated in vacuo to yield a reddish brown solid of 120.191 g. The crude methanol extract was partitioned into n-hexane 0.1 g, dichloromethane 2.5 g, ethyl acetate 4.6 g, and methanol 10.0 g, fractions via coarse chromatography. Methanol fraction gave the highest yield and was subjected to further purification using repeated column chromatography to yield pure components, namely NLM24 (Rf 0.48), EAc:n-hex:MeOH (4:5:1) and NLM19 (Rf0.47), EAc:n-hex:MeOH, respectively. These pure fractions were subjected to 1H NMR, 13C, COSY, HSQC and HMBC spectroscopy. Pheophytin A and β-amyrin were proposed as the structures of the isolated compounds. Even though the pure fractions were not used for the analgesic activity, the literature reveals that pheophytin A & β-amyrin are potent analgesics.