title: Mangostanaxanthones III and IV: advanced glycation end-product inhibitors from the pericarp of Garcinia mangostana.
abstract: Advanced glycation end-products (AGEs) are associated with a non-enzymatic reaction between the amino group of a protein and the carbonyl group of a sugar during hyperglycemia. The precipitation of AGEs in different tissues leads to many complications, such as endothelial dysfunction, cardiovascular complications, atherosclerosis, retinopathy, neuropathy, and Alzheimer's disease. Garcinia mangostana L. (Clusiaceae) (GM) was selected owing to the ability of its polar and non-polar fractions to inhibit AGE formation. For the first time, the bioguided fractionation of its pericarp MeOH extract (GMT) gave rise to two new xanthones, namely, mangostanaxanthones III (1) and IV (3), in addition to six known compounds, β-mangostin (2), garcinone E (4), rubraxanthone (5), α-mangostin (6), garcinone C (7), and 9-hydroxycalabaxanthone (8), from the non-polar faction. Their structures were verified by various spectroscopic methods, including 1D and 2D NMR studies and high-resolution MS data. All of the isolated xanthones significantly inhibited both sugar (ribose) and dicarbonyl compound (methylglyoxal)-induced protein glycation in a dose-dependent manner. This is explained by the ability of the isolated xanthones to inhibit protein oxidation, as indicated by the decreases in dityrosine and N'-formylkynurenine formation.
authors.affiliation: Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia. hmafifi2013@gmail.com.|Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt. hmafifi2013@gmail.com.
authors.forename: Hossam M
authors.identifier: http://orcid.org/0000-0002-0234-7492
authors.initials: HM
authors.lastname: Abdallah
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.|Department of Pharmacology, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt.
authors.forename: Hany M
authors.initials: HM
authors.lastname: El-Bassossy
authors.affiliation: Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.|Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut, 71524, Egypt.
authors.forename: Gamal A
authors.initials: GA
authors.lastname: Mohamed
authors.affiliation: Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.|Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt.
authors.forename: Ali M
authors.initials: AM
authors.lastname: El-Halawany
authors.affiliation: Department of Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
authors.forename: Khalid Z
authors.initials: KZ
authors.lastname: Alshali
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
authors.forename: Zainy M
authors.initials: ZM
authors.lastname: Banjar
mesh_terms: D005638:Fruit / Q000737:chemistry*; D029762:Garcinia mangostana / Q000737:chemistry*; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D017127:Glycation End Products, Advanced; D010936:Plant Extracts
keywords: Clusiaceae; Diabetes; Garcinia mangostana; Glycation end-products; Mangostanaxanthone