Gas chromatography–mass spectrometry analysis of phenolic compounds from Carica papaya L. leaf

Phenolic compounds are important components in vegetable foods, infusions and teas for their beneficial effects on human health. The presence of such compounds, evidenced for the first time in Carica papaya leaves, could partially explain the pharmacological properties of this plant and demonstrates its importance in alimentation and daily intake. C. papaya leaves were extracted with methanol in a Soxhlet apparatus and later with a liquid–liquid extraction (LLE) with the aim of identifying and quantifying secondary metabolites from this plant, using gas chromatography–mass spectrometry (GC–MS) in the selected ion-monitoring (SIM) mode. Derivatization procedure of the extract was necessary to analyze the polar compounds in GC–MS. 5,7-Dimethoxycoumarin and polar molecules such as protocatechuic acid, p-coumaric acid, caffeic acid, chlorogenic acid, kaempferol and quercetin were detected and identified in qualitative analysis. The quantitative analysis has shown the presence of phenolic acids as the main compound, while chlorogenic acid was found in trace amounts, compared to the flavonoids and coumarin compounds. The quantities detected were 0.25 mg/g (dry leaf) for caffeic acid, 0.33 mg/g for p-coumaric acid and 0.11 mg/g for protocatechuic acid. Kaempferol and quercetin were 0.03 and 0.04 mg/g, respectively, while that for 5,7-dimethoxycoumarin was 0.14 mg/g.