Cytotoxic monoterpenoid indole alkaloids from Tabernaemontana bovina.

Chemical investigation of the native medicinal plant Tabernaemontana bovina led to the isolation of five previously unreported monoterpenoid indole alkaloids tabernovinaines A-E (1-5) together with twenty-seven known analogs (6-32), including a bisindole alkaloid 1 with the (E)-4-aminobut-3-en-2-one fragment, as well as a unique cage skeleton 2 containing 6/5/8/6/6 ring system. The chemical structures of these unreported compounds were elucidated using mass spectrometry, NMR spectroscopy, circular dichroism, density functional theory calculations, and derivatizations. The activity evaluation shows that the bisindole alkaloid 1 revealed a potential cytotoxic effect by inducing HepG2 cell apoptosis and damaging clonal sphere expansion.

New and Antifungal Diterpenoids of Sunflower against Gray Mold.

Sunflower ( L.) is cultivated around the world as an oil crop, and its receptacle is the byproduct and is usually deemed to be an agro-industrial waste. Then, phytochemical constituents and antifungal bioactivity of the sunflower receptacle against phytopathogenic fungi were investigated.

Monoterpene indole N-oxide alkaloids from Tabernaemontana corymbosa and their antimicrobial activity.

Tabernaemontana corymbosa is a traditional folk medicine. In our research, six monoterpene indole N-oxide alkaloids and their parent alkaloids were obtained from the stem bark of T. corymbosa, including seven new alkaloids (1-7) and five known alkaloids (8-12).

Tabernaecorymine A, an 18-normonoterpenoid indole alkaloid with antibacterial activity from Tabernaemontana corymbosa.

Tabernaecorymine A, an 18-normonoterpenoid indole alkaloid with conjugated (E)-3-aminoacrylaldehyde fragment was obtained from the stem bark of Tabernaemontana corymbosa. Its structure was elucidated by extensive spectroscopic data analyses, and further verified by ACD/structure elucidator, electronic circular dichroism (ECD) analyses and density functional theory (DFT) chemical shift predictions. The compound exhibited significant antibacterial bioactivity against Streptococcus dysgalactiae with an MIC value of 3.