Abstract
Tyrosinase plays a key role in the production of melanin. A variety of industrial fields have shown interest in the development of tyrosinase inhibitors from plants. In this study, compounds 1–5 derived from Leonurus japonicas were evaluated to determine their ability to inhibit tyrosinase. Of these, 10-methoxy-leonurine (1) and leonurine (2) exhibited IC50 values of 7.4 ± 0.4 and 12.4 ± 0.8 μM, respectively, and acted as competitive inhibitors of tyrosinase, with Ki values in the micromolar range. In silico modeling revealed a guanidine group located in the inner cavity and a benzene ring docked within the active site of these compounds. These guanidine pseudoalkaloids show potential not only as tyrosinase inhibitors but also as lead compounds in new scaffolds for the development of novel inhibitors.
Highlights
Tyrosinase (EC 1.14.18.1), found in bacteria, fungi, plants, and mammals [1], is a copper-containing metalloenzyme with various catalytic functions, such as hydroxylation of monophenols and oxidation of diphenols, which are important for the production of melanin pigment [2]
Secondary metabolites isolated from natural products, such as aloe-emodin [4], broussoflavonol J, broussoflavonol H [7], and calycosin [8], have been evaluated as tyrosinase inhibitors because of their low toxicities
The guanidine group of (2) was hung on the cavity of three loops, and the aromatic ring docked within the active site or the other
Summary
Tyrosinase (EC 1.14.18.1), found in bacteria, fungi, plants, and mammals [1], is a copper-containing metalloenzyme with various catalytic functions, such as hydroxylation of monophenols and oxidation of diphenols, which are important for the production of melanin pigment [2]. Excessive accumulation of melanin is responsible for pigment disorders in human skin and enzymatic browning of fresh-cut fruits and vegetables [3]. It is important for cuticle formation in insects [4]. Tyrosinase inhibitors have been proposed as neuroprotective agents [6]. Secondary metabolites isolated from natural products, such as aloe-emodin [4], broussoflavonol J, broussoflavonol H [7], and calycosin [8], have been evaluated as tyrosinase inhibitors because of their low toxicities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
