title: Avocado Proanthocyanidins as a Source of Tyrosinase Inhibitors: Structure Characterization, Inhibitory Activity, and Mechanism.
abstract: Proanthocyanidins were purified from avocado (Persea americana) fruit, and their structures were analyzed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and high-performance liquid chromatography-electrospray ionization-QTRAP mass spectrometry (HPLC-ESI-QTRAP MS) techniques. The results obtained from mass spectrometry (MS) analysis demonstrated that the proanthocyanidins were homo- and heteropolymers of procyanidins, prodelphinidins, propelargonidins, and procyanidin gallate. From the enzyme analysis, the results showed that they could inhibit the monophenolase and diphenolase activities of tyrosinase. The inhibition mechanism of the proanthocyanidins on the enzyme was further studied, and the results indicated that they were reversible and competitive inhibitors. Finally, the results acquired from molecular docking, fluorescence quenching, and copper ion interacting tests revealed that adjacent hydroxyl groups on the B ring of proanthocyanidins could chelate the dicopper catalytic center of the enzyme. In addtion, proanthocyanidins were proven to be an efficient quencher of substrates. This study would lay a scientific foundation for their use in agriculture, food, and nutrition industries.
authors.affiliation: College of Life Science, and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Chai
authors.affiliation: College of Life Science, and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
authors.forename: Man-Kun
authors.initials: MK
authors.lastname: Wei
authors.affiliation: College of Life Science, and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: College of Life Science, and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
authors.forename: Rong-Gen
authors.initials: RG
authors.lastname: Deng
authors.affiliation: College of Life Science, and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
authors.forename: Zheng-Rong
authors.initials: ZR
authors.lastname: Zou
authors.affiliation: College of Life Science, and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
authors.forename: Yi-Yuan
authors.initials: YY
authors.lastname: Peng
mesh_terms: D056148:Chromatography, Reverse-Phase / Q000379:methods; D003300:Copper / Q000737:chemistry; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D005453:Fluorescence; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D027421:Persea / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004791:Enzyme Inhibitors; D044945:Proanthocyanidins; D003300:Copper; D014442:Monophenol Monooxygenase
keywords: avocado; inhibitory mechanism; molecular docking; proanthocyanidins; structure; tyrosinase inhibitors