Biflavonoids from the leaves and stem bark of Garcinia griffithii and their biological activities

Abstract

The phytochemical and biological activity of the leaves and stem barks of Garcinia griffithii have been investigated. Extraction and chromatographic purification of the leaves and stem barks extracts have successfully afforded five biflavonoids namely amento-4''-methylether (1), 3,8''-binaringenin (2), morelloflavone (3), 3,8''-binaringenin-7''-O-glucoside (4) and morelloflavone-7''-Oglucoside (5), together with squalene (6), canophyllol (7), friedelin (8) and β-amyrin (9) which were characterized spectroscopically.All extracts and phytochemicals were tested for antioxidant, antityrosinase and antibacterial activities. The antioxidant assay on DPPH radical scavenging showed that the n-hexane extract of the stem barks had the highest radical scavenging activity with IC 50 value of 96.4 μg/mL, while compound (3) was found to be the strongest antioxidant compound with IC 50 value of 57.6 μg/mL. The methanol extract of the leaves showed the highest total phenolic content with 444.1 mg/g of gallic acid equivalent (GAE/L) and 423.1 mg/g of cathechin equivalent (CE/L). The extracts and all compounds were found to have weak antityrosinase activity. The antimicrobial assays of all the extracts were carried out by minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The methanol extract of the leaves showed the most significant antimicrobial activity towards E. faecalis and K. pneumoniae with MIC and MBC value ranged between 225-450 μg/mL compared to the other extracts.

Phytochemicals and Tyrosinase Inhibitory Activity from Piper caninum and Piper magnibaccum

“…L-DOPA was used as the substrate and mushroom tyrosinase as the enzyme. [16][17] The assays were conducted in 96-well microtiter plate, and Epoch Biotek reader was used to measure the absorbance at 475 nm. Mushroom tyrosinase enzyme (MTE) was prepared from the stock solution to 480 units/ mL in PBS.…”

Bioactive properties and phytochemical assessment of Bacupari-anão (Garcinia brasiliensis Mart.) leaves native to Rondônia, Brazil

“…1) revealed the presence of twelve phenolic compounds, comprising five bioflavonoids, four flavones, two flavonols and one flavan-3-ol. The identification of the phenolic compounds was performed taking into account previous reports of chemical studies in Garcinia 6,25,26 and other plant species. 27 Bioflavonoids were the most abundant compounds present in G. brasiliensis.…”

“…leaf extract. 26 Due to the consistent presence of these compounds in these species, they are considered to be chemotaxonomic markers for the genus Garcinia. Compound 10 ([M − H] − at m/z 703) was identified as binaringenin-7″-O-glucoside, taking into account the findings presented by Salleh et al, 26 who studied the leaves and stem bark extracts from G. griffithii.…”

“…26 Due to the consistent presence of these compounds in these species, they are considered to be chemotaxonomic markers for the genus Garcinia. Compound 10 ([M − H] − at m/z 703) was identified as binaringenin-7″-O-glucoside, taking into account the findings presented by Salleh et al, 26 who studied the leaves and stem bark extracts from G. griffithii. Compound 11 ([M − H] − at m/z 701) was tentatively identified as volkensiflavone-7″-O-glucoside by examining its UV-VIS spectrum and mass fragmentation and it was previously described in the ethanol/water seed extract of G. madruno.…”

“…6 DPPH scavenging activity (108.1 ± 0.9 µg mL −1 ) was also reported for morelloflavone-7″-O-glucoside isolated from the leaves and stem bark of G. griffithii. 26 Morelloflavone-7″-O-glucoside and morelloflavone were isolated from the root bark of Allanblackia floribunda Oliv. and both the compounds were found to present broad spectrum antimicrobial activity against Gram-positive and Gramnegative bacteria and fungi with MICs values between 19.53 and 312.5 µg mL −1 .…”