Tocotrienol monomers and dimers from the roots of Litchi chinensis with tyrosinase inhibition activity

Awat Wisetsai; Siwattra Choodej; Dina Nur Shinta; Sarawut Tontapha; Vittaya Amornkitbamrung; Paratchata Batsomboon; Khanitha Pudhom

doi:10.1016/j.phytochem.2023.113921

Tocotrienol monomers and dimers from the roots of Litchi chinensis with tyrosinase inhibition activity

Phytochemistry. 2024 Jan:217:113921. doi: 10.1016/j.phytochem.2023.113921. Epub 2023 Nov 10.

Authors

Awat Wisetsai¹, Siwattra Choodej¹, Dina Nur Shinta¹, Sarawut Tontapha², Vittaya Amornkitbamrung², Paratchata Batsomboon³, Khanitha Pudhom⁴

Affiliations

¹ Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
² Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
³ Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road Laksi, Bangkok, 10210, Thailand.
⁴ Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand. Electronic address: khanitha.p@chula.ac.th.

PMID: 37952709
DOI: 10.1016/j.phytochem.2023.113921

Abstract

Four undescribed modified tocotrienols, including two monomers, litchinols A (1) and B (2), and two walsurol dimers, δ,δ-walsurol (3) and γ,δ-bi-O-walsurol (4), as well as seven known compounds (5-11) were isolated from the roots of Litchi chinensis. The structures of the undescribed compounds were elucidated based on analyses of spectroscopic data and ECD spectra. All tocotrienol derivatives (1-6) were evaluated for their tyrosinase inhibition activity. Only monomers 1-2 and 5-6 displayed potent inhibitory activity and greater than kojic acid. Kinetic analysis revealed that the representative compound 2 was uncompetitive inhibitor with the inhibition constant value of 5.70 μM.

Keywords: Litchi; Litchi chinensis; Sapindaceae; Tocotrienols; Tyrosinase inhibition.

MeSH terms

Fruit / chemistry
Kinetics
Litchi* / chemistry
Monophenol Monooxygenase
Tocotrienols* / analysis
Tocotrienols* / pharmacology

Substances

Tocotrienols
Monophenol Monooxygenase