Limonoids from Trichilia lepidota seeds (Meliaceae)

Trichilia is one of the largest genera of Meliaceae family (also known as Mahogany), consists of 81 species distributed in tropical and subtropical areas. Characterized by the bioproduction of limonoids that present several biological activities. Trichilia lepidota is commonly known as cedrinho, the geographic distribution is predominantly in Brazil Coastal from Bahia and Minas Gerais to Rio Grande do Sul States. It was reported that the leaves provide a series of protolimonoids where some compounds exhibited significant cytotoxic activity against the MOLT-4 and U937 leukemic cell lines. To further investigate bioactive and novel compounds from the plant, was performed the phytochemical study of T. lepidota seeds. The plant material was collected in Reserva Natural Vale, Linhares City, Espírito Santo State, Brazil, in December 2018. The dried and powered seeds were extracted with MetOH three times at room temperature. MetOH extract was suspended in water and successively partitioned in ascending order of polarity (CH2Cl2, AcOEt and ButOH, respectively). For the isolation of the compounds present in the CH2Cl2 partition, classical chromatographic methods were used. The structures were elucidated by one- and two-dimensional Nuclear Magnetic Resonance (NMR 1H and 13C) and High Resolution Mass Spectrometry (HRESI-MS). The chemical investigation of T. lepidota seeds, partition CH2Cl2¬, resulted in the identification of four new limonoids: Lepidotrichilinin A (1), lepidotrichilinin B (2), Lepidotrichilinin C (3) and 12--hydroxynimonol (4), and one know limonoid Walsurin D (5).