Chemical composition of essential oil from Varronia curassavica Jacq. accessions in different seasons of the year

Varronia curassavica Jacq. is a native shrub species of the Atlantic Forest and is used as a phytomedicine in Brazilian folk medicine against inflammations, ulcers and arthritis and in commercial products as an anti-inflammatory drug. In this study, for the first time, the chemical profiles of the essential oils from three accessions of V. curassavica from different geographic origins in Brazil, namely, Bahia (BA), Sao Paulo (SP) and Rio de Janeiro (RJ), were evaluated according to their origin and season of the year. The yield of essential oil between accessions ranged from 0.44 to 2.74% (v/w) which the highest amount was found to BA and the lowest to SP. The substances with the highest relative proportions were alpha-pinene (RJ - 49.2% and SP - 32.6%) and (E)-caryophyllene (SP - 16.1% and RJ - 11.1%). For BA, the substance with the highest content wasamorpha-4,7(11)-diene (14.5%), followed by eudesm-7 (11)-en-4-ol (7.00%). Principal component analysis (PCA) revealed that the accession from Rio de Janeiro showed the most similarity to composition of its essential oil, whereas the accession from Bahia presented the most dissimilarity. Regardless of the differences within each population, the grouping of the samples occurred according to their origins, and no mixing occurred between the samples from the accessions. The difference in the chemical profiles found by the PCA analysis was corroborated by the hierarchical cluster analysis (HCA), which the samples from Sao Paulo were similar to those from Bahia, and those from Rio de Janeiro were the ones that differed most from the other accessions. Among the evaluated accessions, those from Rio de Janeiro (RJ) showed the highest content of alpha-humulene, with a higher production during the spring (2.89%), while SP had the highest (E)-caryophyllene content (16,12%) in all evaluated seasons, showing the potential of these accessions for cultivation of V. curassavica and consequently production of its essential oil for a phytomedicine application.