Antioxidant and cytotoxicity activities of δ-tocotrienol from the seeds of Allophylus africanus

Abstract

Chemical investigation of Allophylus africanus P. Beauv fruits led to the isolation of a new δ-tocotrienol, 3α-hydroxy-δ-tocotrienol (1) together with eight known compounds (2-9). Compound (1) was allylated (1a) and prenylated (1 b and 1c) to give three new semi-synthesized derivatives which were fully characterized as: 6-O-allyl-3α-hydroxy-δ-tocotrienol (1a), 6-O-prenyl-3α-hydroxy-δ-tocotrienol (1 b) and 6-O,5-C-diprenyl-3α-hydroxy-δ-tocotrienol (1c). The structures of compounds were established using comprehensive spectroscopic analysis including UV, MS, 1 D NMR, 2 D NMR and by comparison with the corresponding literature data. Compound (1) and its semi-synthetic derivatives (1a-c) were tested for their antioxydant activity using DPPH radical scavenging assay and also for their cytotoxicity using human cervix carcinoma KB-3-1 cell lines. The results showed that compound (1) exhibited antioxidant activity with an IC₅₀ value of 0.25 μM compared to the reference control trolox (26 µM); and good cytotoxic activity with IC₅₀ values of 97 μM compared to the reference (+)-griseofulvin (IC₅₀ between17-21 μM).

Graphical Abstract

KEYWORDS:

• Allophylus africanus
• tocotrienol
• antioxidant
• cytotoxicty

Acknowledgements

The authors acknowledge the DAAD through the Yaoundé-Bielefeld Graduate School (YaBiNaPA Project N^o 57316173), and the Alango Foundation (Reference Hospital of African Medicine, Dschang, Cameroon).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by German Academic Exchange Service.