A new cytotoxic indole alkaloid from Tabernaemontana inconspicua stapf.

One new indole alkaloid derivative, 5,6-dioxo-11-hydroxy voacangine (1) together with four known compounds (2-5), were isolated from the fruits of Tabernaemontana inconspicua Stapf (Apocynaceae). Their structures were determined using 1D and 2D NMR, HRESI-MS, and a comparison with the literature. The new compound was found to be cytotoxic on human breast cancer MDA-MB 231 cells with IC50 values of 3.35 µM and 2.19 µM after 24 and 48 hours, respectively.

Secondary metabolites from Aspergillus japonicus CAM231, an endophytic fungus associated with Garcinia preussii.

Chemical investigation of Aspergillus japonicus CAM231, isolated from the leaf of Garcina preussii collected in Cameroon, yielded two new compounds; one pyrone derivative, hydroxy neovasinin (1) and one phenol derivative, asperolan (2), together with two known compounds neovasifurarone B (3) and variecolin (4). The structures of the two new compounds were established using intensive NMR spectroscopy and HRMS spectra in comparison with data found in literature. The structure of compound 1 was confirmed by single-crystal X-ray crystallographic analysis in combination with NOESY experiment. The new compounds were screened for their cytotoxic and antibacterial properties; however, the tested compounds displayed no significant activities.