(–)-β-Homoarginine anhydride, a new antioxidant and tyrosinase inhibitor, and further active components from Trichosanthes truncata

Abstract

One new amino acid derivative, (–)-β-homoarginine anhydride 1, as well as nine known compounds were isolated from Trichosanthes truncata. The structures of the isolates were elucidated by spectroscopic methods. Among them, compounds 5 and 11 could notably dose-dependently inhibit ROS productions in HaCaT keratinocyte cells without cytotoxicity in the concentration range of 0.2–20 μM. In cell-free mushroom tyrosinase assay, compounds 1–5, 10 and 11 had more potential anti-tyrosinase activities with IC₅₀ values of 106.9–255.6 μM than arbutin that were similar to predicted values of binding affinity calculated by molecule docking. The most active 2 had hydrogen bonds (Ser77, Glu309, Phe454) and electrostatic charges (Glu309, Glu248) interactions with mushroom tyrosinase, respectively. Our data manifested that T. truncata and its components are potentially to be developed as anti-aging and whitening agents for skin disorders.

Graphical Abstract

Keywords:

• Trichosanthes truncata
• Cucurbitaceae
• Antioxidant
• Tyrosinase inhibition

Acknowledgements

This work was financially supported by the “Chinese Medicine Research Center, China Medical University” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan (CMRC-CHM-2) and China Medical University (CMU105-S-27), Taiwan.

Disclosure statement

No potential conflict of interest was reported by the authors.