Chemical constituents from the stem bark of Tectona grandis L.f. (lamiaceae): chemophenetic significance and antifungal effect ☨

An extensive phytochemical investigation on the stem bark extract of Tectona grandis L.f. (Lamiaceae) led to the isolation of a new oxindole alkaloid named uncarine B (1), whose chemical structure and absolute configuration were determined here for the first time by single-crystal X-ray diffraction analysis, and a new ceramide named tectograndisamide (2). The structures were elucidated based on comprehensive spectroscopic analyses, particularly 1D and 2D-NMR, UV, IR, HR-MS and X ray as well as by comparison of the data with those reported in the literature. Quinovic acid derivatives and some isolated compounds (7–11) are reported for the first time from the Lamiaceae family. Compounds 3, 6, 7, 9 and 10 showed moderate activity, while quinovic acid (7) was the most active with MIC values of 125 and 62.5 μg/mL against C. albicans and C. krusei, respectively. Furthermore, the chemophenetic significance was discussed in detail.