Morphinan alkaloids from the leaves of Alphonsea cylindrica and their antibacterial properties

• Main Authors: Cho, Kin-Hau, Tan, Siow-Ping, Tan, Hui-Yin, Liew, Sook Yee, Nafiah, Mohd Azlan
• Format: Article
• Published: Georg Thieme Verlag KG 2023
• Subjects: RM Therapeutics. Pharmacology; S Agriculture (General)
• Online Access: http://eprints.um.edu.my/38980/

A phytochemical study has been carried out on CH (2) Cl (2) extract of Alphonsea cylindrica leaves, resulting in the isolation of three new morphinan alkaloids. They are kinomenine ( 1 ), N -methylkinomenine ( 2 ), and hydroxymethylkinomenine ( 3 ). The structures of these compounds were elucidated by extensive spectroscopic analysis (1D and 2D NMR, IR, UV, HRESIMS) and comparison with the data reported in literature for similar alkaloids. Kinomenine ( 1 ) and N -methylkinomenine ( 2 ) showed weak inhibition against S. aureus (MIC values of 1 and 2 = 500 mu g/mL; pIC (50) values in 95% C. I. of: 1 = 2.9 to 3.0; 2 = 2.9 to 3.1), while kinomenine ( 1 ) also showed weak inhibition against E. coli (MIC values of 1 = 500 mu g/mL; pIC (50) value in 95% C. I. of: 1 = 2.9) by broth microdilution method. The results obtained can be used as future referencefor the discovery of morphinans and the potential of A. cylindrica as an antibacterial source.