Geissospermiculatine, a New Alkaloid from <i>Geissospermum reticulatum</i> Bark

• Main Authors: Joanna J. Sajkowska-Kozielewicz, Paweł Kozielewicz, Katerina Makarova, Marcin Stocki, Nicholas M. Barnes, Katarzyna Paradowska
• Format: Article
• Language: English
• Published: MDPI AG 2021-12-01
• Series: Molecules
• Subjects: <i>Geissospermum reticulatum</i>; Apocynaceae; NMR; alkaloids; cytotoxic effects; <i>Danio rerio</i>
• Online Access: https://www.mdpi.com/1420-3049/26/1/143
• ISSN: 1420-3049

A new alkaloid, geissospermiculatine was characterized in <i>Geissospermum reticulatum</i> A. H. Gentry bark (Apocynaceae). Here, following a simplified isolation protocol, the structure of the alkaloid was elucidated through GC-MS, LC-MS/MS, 1D, and 2D NMR (COSY, ROESY, HSQC, HMBC, ¹H-¹⁵N HMBC). Cytotoxic properties were evaluated in vitro on malignant THP-1 cells, and the results demonstrated that the cytotoxicity of the alkaloid (30  μg/mL) was comparable with staurosporine (10  μM). Additionally, the toxicity was tested on zebrafish (<i>Danio rerio</i>) embryos in vivo by monitoring their development (0–72 h); toxicity was not evident at 30  μg/mL.