γ-Mangostin

A series of new C-4- and C-4/C-5-aminomethyl derivatives were synthesized on the basis of α- and γ-mangostins. A comparative evaluation of their chelating ability, radical scavenging activity and hemolytic activity, as well as antioxidant and membrane-protective properties, was carried out on the model of H;2;O;2;-induced hemolysis of mammalian red blood cells. It was shown that γ-mangostin and its C-4/C-5-derivatives were superior to α-mangostin and its derivatives in all the investigated parameters characterizing the antioxidant activity in the test systems used. Most of the synthesized Mannich bases at low concentrations were superior to the original α- and γ-mangostins in the ability to protect mammalian red blood cells under H;2;O;2;-induced oxidative stress conditions.

Bioassay-guided fractionation of an ethanol extract of the pericarps of Garcinia mangostana led to the isolation of two new prenylated xanthones, named 1,3,7-trihydroxy-2-(3-methyl-2-butenyl)-8-(3-hydroxy-3-methylbutyl)-xanthone (1) and 1,3,8-trihydroxy-2-(3-methyl-2-butenyl)-4-(3-hydroxy-3-methylbutanoyl)-xanthone (2), together with the five known compounds garcinones C (3) and D (4), gartanin (5), xanthone I (6), and γ-mangostin (7). Their structures were elucidated primarily based on MS and NMR data. Compounds 1-7 showed significant cytotoxic activities against various human cancer cell lines.

Herbal or botanical dietary supplements are an ever increasingly popular category of products in the United States and around the world. In vitro data can provide meaningful insight into the potential target and mechanism of action for a proposed active compound but may also be misused to promote a supplement to consumers with unverified health claims. In vitro data need to be considered alongside pharmacokinetic and pharmacodynamic data in preclinical animal and clinical human trials. While considerable activity of compounds and extracts in vitro may lead to further testing in vivo, in many instances, concentrations tested in cell lines or isolated targets are not achievable at the target site in vivo. Thus, whether the in vitro data are relevant to humans after oral administration is questionable. This review will discuss this discrepancy using in vitro and in vivo data of resveratrol, xanthones (α-mangostin and γ-mangostin) and xanthohumol.