Polyneurines A-H, iboga alkaloids from Tabernaemontana polyneura

Sin-Yee Tang; Chun-Hoe Tan; Kae-Shin Sim; Kien-Thai Yong; Kuan-Hon Lim; Yun-Yee Low; Siew-Huah Lim

doi:10.1016/j.phytochem.2023.113587

Polyneurines A-H, iboga alkaloids from Tabernaemontana polyneura

Phytochemistry. 2023 Apr:208:113587. doi: 10.1016/j.phytochem.2023.113587. Epub 2023 Jan 14.

Authors

Sin-Yee Tang¹, Chun-Hoe Tan², Kae-Shin Sim³, Kien-Thai Yong³, Kuan-Hon Lim⁴, Yun-Yee Low⁵, Siew-Huah Lim⁶

Affiliations

¹ Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
² Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia; Department of Biotechnology, Faculty of Applied Science, Lincoln University, 47301, Petaling Jaya, Selangor, Malaysia.
³ Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
⁴ School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor, Malaysia.
⁵ Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia. Electronic address: yylow@um.edu.my.
⁶ Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia. Electronic address: shlim80@um.edu.my.

PMID: 36646163
DOI: 10.1016/j.phytochem.2023.113587

Abstract

Eight undescribed iboga alkaloids, polyneurines A-H, were isolated from the bark of Tabernaemontana polyneura. The structures of these alkaloids were established by interpretation of the MS and NMR data, while the configurations were determined using GIAO NMR calculations and DP4+ probability analysis, TDDFT-ECD method, or X-ray diffraction analysis. Polyneurine A possesses a γ-lactone unit embedded within the iboga skeleton, while polyneurines D and E incorporate a formylmethyl moiety at C-3 of the iboga skeleton. Biosynthetic pathways towards the formation of polyneurines A, C, D, and E were proposed.

Keywords: Alkaloids; Apocynaceae; DP4+; ECD; Iboga; Tabernaemontana polyneura; X-ray diffraction.

MeSH terms

Alkaloids* / chemistry
Crystallography, X-Ray
Indole Alkaloids / chemistry
Molecular Structure
Tabernaemontana* / chemistry

Substances

Indole Alkaloids
Alkaloids