Secondary Metabolic Profile as a Tool for Distinction and Characterization of Cultivars of Black Pepper (Piper nigrum L.) Cultivated in Para State, Brazil

This study evaluated the chemical compositions of the leaves and fruits of eight black pepper cultivars cultivated in Para State (Amazon, Brazil). Hydrodistillation and gas chromatography-mass spectrometry were employed to extract and analyze the volatile compounds, respectively. Sesquiterpene hydrocarbons were predominant (58.5-90.9%) in the cultivars "Cingapura", "Equador", "Guajarina", "Iacara", and "Kottanadan", and "Bragantina", "Clonada", and "Uthirankota" displayed oxygenated sesquiterpenoids (50.6-75.0%). The multivariate statistical analysis applied using volatile composition grouped the samples into four groups: gamma-Elemene, curzerene, and delta-elemene ("Equador"/"Guajarina", I); delta-elemene ("Iacara"/"Kottanadan"/"Cingapura", II); elemol ("Clonada"/"Uthirankota", III) and alpha-muurolol, bicyclogermacrene, and cubebol ("Bragantina", IV). The major compounds in all fruit samples were monoterpene hydrocarbons such as alpha-pinene, beta-pinene, and limonene. Among the cultivar leaves, phenolics content (44.75-140.53 mg GAE center dot g(-1) FW), the enzymatic activity of phenylalanine-ammonia lyase (20.19-57.22 mu U center dot mL(-1)), and carotenoids (0.21-2.31 mu g center dot mL(-1)) displayed significant variations. Due to black pepper's susceptibility to Fusarium infection, a molecular docking analysis was carried out on Fusarium protein targets using each cultivar's volatile components. F. oxysporum endoglucanase was identified as the preferential protein target of the compounds. These results can be used to identify chemical markers related to the susceptibility degree of black pepper cultivars to plant diseases prevalent in Para State.