Phytochemical Analysis and Antimicrobial, Antinociceptive, and Anti-Inflammatory Activities of Two Chemotypes of Pimenta pseudocaryophyllus (Myrtaceae).

Preparations from Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae) have been widely used in Brazilian folk medicine. This study aims to evaluate the antimicrobial activity of the crude ethanol extracts, fractions, semipurified substances, and essential oils obtained from leaves of two chemotypes of P. pseudocaryophyllus and to perform the antinociceptive and anti-inflammatory screening. The ethanol extracts were purified by column chromatography and main compounds were spectrally characterised (1D and 2D (1)H and (13)C NMR). The essential oils constituents were identified by GC/MS. The broth microdilution method was used for testing the antimicrobial activity. The abdominal contortions induced by acetic acid and the ear oedema induced by croton oil were used for screening of antinociceptive and anti-inflammatory activities, respectively. The phytochemical analysis resulted in the isolation of pentacyclic triterpenes, flavonoids, and phenol acids. The oleanolic acid showed the best profile of antibacterial activity for Gram-positive bacteria (31.2-125 µg mL(-1)), followed by the essential oil of the citral chemotype (62.5-250 µg mL(-1)). Among the semipurified substances, Ppm5, which contained gallic acid, was the most active for Candida spp. (31.2 µg mL(-1)) and Cryptococcus spp. (3.9-15.6 µg mL(-1)). The crude ethanol extract and fractions from citral chemotype showed antinociceptive and anti-inflammatory effects.

Essential oils in aerial parts of Myrcia tomentosa: composition and variability

Species in the Myrtaceae family are used in folk medicine to treat gastrointestinal disorders, infectious diseases and hemorrhagic conditions and are known for their essential oil contents. Gas chromatography coupled with mass spectrometry (GC-MS) was used to characterize the chemical composition of essential oils of the leaves, stem bark and flowers of Myrcia tomentosa (Aubl.) DC., as well as to assess the chemical variability in the constituents of the essential oils of the leaf. Soil and foliar analyses were also performed to determine the mineral compositions. Principal component analysis (PCA) was used to examine the interrelationships between the obtained data. The most abundant component in the essential oils of the flowers was (2E,6E)-methyl farnesoate, whereas hexadecanoic acid was the most abundant essential oil component in the stem bark. The leaf essential oils showed seasonal variation in their chemical composition, with bicyclogermacrene and (2E,6E)-methyl farnesoate as the major chemical components. Forty-four constituents were identified, and only nine compounds were found in all of the samples. Sesquiterpenes were mainly produced in the flowers and leaves. The PCA showed a positive correlation between the oxygenated sesquiterpenes and the foliar nutrients Cu and P. Significant statistical correlations were verified between the climatic data, foliar nutrients and essential oil compositions.