Antidiabetic and wound healing effects of smeathxanthone A

Wound healing is a natural and spontaneous phenomenon that takes place in three orderly and timely interactive phases: inflammation, proliferation, and remodelling. Normal wound healing cascade begins immediately following injury. Tissue damage and the activation of clotting factors during the vascular phase stimulate the release of inflammatory mediators, such as prostaglandins and histamine, from cells such as mast cells. The transition from the inflammatory to the proliferative phase, the stage characterized by the filling of the wound with new connective tissues, is orchestrated by macrophages. A decrease in wound size is achieved by a combination of the physiological processes of granulation, contraction, and epithelialization. Reepithelialization phase rebuilds the structure while the remodeling phase involves the final form. Surgery in diabetic patients is associated with slow wound healing process and hence requiring longer hospital stay, higher health care resource utilization, and greater perioperative mortality than nondiabetic subjects. The exact pathogenesis of the poor wound healing process in diabetic patients is not clearly understood, but evidence from studies involving both human and animal models reveal increased rate of infections and several abnormalities in the various phases of wound healing process. With the worldwide diabetes incidence now considered to be increasing in an epidemic proportion, there is a growing need to search for novel drugs to combat diabetes and the associated disorders, such as wound complications. Over 278 natural xanthones belonging to the plant families of Gentianaceae, Guttiferae, Moraceae, Clusiaceae, and Polygalaceae are known to occur. Most xanthones are polyphenols and hence regarded as powerful antioxidants that can offer beneficial health effect either by direct scavenging of reactive oxygen species or by acting as chain-breaking peroxyl radical scavengers. In addition to possessing antioxidant effects, xanthones have also been reported to be hepatoprotective, mutagenic, immunomodulatory, anticomplement, cardioprotective, antitumoral, antidiabetic, anti-inflammatory, antiulcer, and analgesic agents. Smeathxanthone A is a unique xanthone that combines a polyphenolic skeleton with four free hydroxyl groups and a terpenoid geranyl structural moiety. Although the compound has previously been isolated in our laboratories from Garcinia smeathmanii, it has never been investigated for its potential antidiabetic properties. In the present communication, the blood glucose lowering and wound healing effects of smeathxanthone A in diabetic mice are reported

Antioxidant benzophenones and xanthones from the root bark of Garcinia smeathmannii

A new geranylated xanthone (1) was isolated from the root bark extract of Garcinia smeathmannii Oliver along with known guttiferone I, isoxanthochymol, smeathxanthones A and B, and triacontanyl caffeate. The structures of these compounds were elucidated by spectral analysis and by comparison with the reported data. These compounds showed significant antioxidant DPPH radical scavenging activities.   KEY WORDS: Garcinia smeathmanii, Xanthone, Antioxidant  Bull. Chem. Soc. Ethiop. 2006, 20(2), 247-252

Polyanxanthone A, B and C, three xanthones from the wood trunk of Garcinia polyantha Oliv.

Three xanthones, polyanxanthone A (1), B (2) and C (3) have been isolated from the methanol extract of the wood trunk of Garcinia polyantha, along with five known xanthones: 1,3,5-trihydroxyxanthone (4); 1,5-dihydroxyxanthone (5); 1,3,6,7-tetrahydroxyxanthone (6); 1,6-dihydroxy-5-methoxyxanthone (7) and 1,3,5,6-tetrahydroxyxanthone (8). Their structures were determined by means of 1D- and 2D-NMR techniques. Some of the above compounds were screened for their anticholinesterase activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes.info:eu-repo/semantics/publishedVersio

Ovalifolone A and B: New friedelane derivatives from Garcinia ovalifolia

Lannang AM, Noudou BS, Sewald N. Ovalifolone A and B: New friedelane derivatives from Garcinia ovalifolia. Phytochemistry Letters. 2013;6(2):157-161.Two new friedelane type triterpenoids, ovalifolone A (1) and ovalifolone B (2), together with eight known compounds were isolated from the stem bark of Garcinia ovalifolia. Their structures were established on the basis of mass spectrometric, NMR data and by the comparison with literature data. Some of the isolated compounds were evaluated for their cytotoxicity and antibacterial activities and garcinane showed interesting activity against Artemia salina with LD50 value of 2.69 mu g/mL. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved

A Rapid Determination and Quantification of Three Biologically Active Polyisoprenylated Benzophenones using Liquid Chromatography-Tandem Mass Spectrometry (MRM) Method in Five Garcinia species from Cameroon

International audienceFollowing investigation of Garcinia genus, a sensitive, rapid and simple reversed-phase high performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for the identification and quantification of three polyisoprenylated benzophenones, garcinol (1), isogarcinol (2) and 7-epi-clusianone (3), in the extracts of five Garcinia species from Cameroon. The separation of those compounds was achieved on a RP-18 column using a solvent system consisting of a mixture of acetonitrile-water-formic acid as a mobile phase in a gradient elution mode. The identification of the three compounds was determined on a triple quadripole mass spectrometer with ESI interface operating in the negative mode. A multiple reaction monitoring (MRM) method was developed for the quantification of these polyisoprenylated benzophenones in the extracts of the Garcinia species. The method was validated through intra-and inter-day precision, with the relative standard deviation (RSD) less than 6%, limits of detection (LOD) and limits of quantification (LOQ) <1 ng. Overall recoveries ranged from 94% to 104%, with RSDs ranging from 0.8% to 4.5%. The results indicated that the fruits of G. preussii and the roots of G. brevipedicellata are good source of garcinol (1) and isogarcinol (2) respectively

Isolation and biological activity of compounds from Garcinia preussii

Plants of the genus Garcinia (Clusiaceae) are traditionally used to relieve stomachaches, toothaches, and as a chew stick

Cytotoxic Compounds from the Leaves of Garcinia polyantha

Lannang AM, Tatsimo SJN, Fouotsa H, Dzoyem JP, Saxena AK, Sewald N. Cytotoxic Compounds from the Leaves of Garcinia polyantha. Chemistry &amp; Biodiversity. 2014;11(6):975-981.A new compound, named banganxanthone C (=12-(1,1-dimethylprop-2-en-1-yl)-5,10-dihydroxy-9-methoxy-2-methyl-2-(4-methylpent-3-en-1-yl)-2H, 6H-pyrano[3,2-b]xanthen-6-one; 4), together with five known compounds, were isolated from the leaves of Garcinia polyantha. The structures of the compounds were elucidated on the basis of 1D- and 2D-NMR spectroscopy. Among the known compounds, two were xanthones, one was a pentacyclic triterpene, one sterol, and one benzophenone derivative. Isoxanthochymol (2) and 4-[(2E)-3,7-dimethylocta-2,6-dien-1-yl]-1,5,8-trihydroxy-3-methoxy-9H-xanthen-9-one (3) exhibited significant antiproliferative activity against the leukemia cell line TPH-1 with IC50 inhibition values of 1.5 and 2.8 mu g/ml, respectively. The cytotoxic activity was found to be related to apoptosis induction

Anti-inflammatory activity of benzophenone and xanthone derivatives isolated from Garcinia (Clusiaceae) species

Dzoyem JP, Lannang AM, Fouotsa H, et al. Anti-inflammatory activity of benzophenone and xanthone derivatives isolated from Garcinia (Clusiaceae) species. Phytochemistry Letters. 2015;14:153-158.Species of the genus Garcinia have been the source of many benzophenone and xanthone derivatives. Recent data regarding potent biological properties of natural compounds in Garcinia species led us to investigate the in vitro anti-inflammatory effect of three known xanthones, lichexanthone (1), 1,3,6,7-tetrahydroxyxanthone (2), 1,3,5,6-tetrahydroxyxanthone (3), two new xanthones 1-hydroxy-3,6,7-tri-O, O, O-triprenylxanthone (4), 1,6-dihydroxy-3,7-di-O, O-diprenylxanthone (5) and two benzophenones isoxanthochymol (6), guttiferone E (7), isolated from Garcinia nobilis and Garcinia punctata. The Griess assay was used for the measurement of nitric oxide (NO) production in RAW264.7 macrophages and the ferrous oxidation-xylenol orange assay was used to determine the 15-lipoxygenase (15-LOX) inhibitory activity. All the compounds had inhibitory effect on 15-LOX activity to different extents. Compound (7) had the highest anti-LOX activity with an IC50 value of 43.05 mu g/mL. At the highest studied concentration (25 mg/mL), compound (4) had the most potent inhibitory activity against NO release with a% of inhibition of 95.42% and less cytotoxic effect on RAW264.7 cells (% of cell viability of 81.40). The results presented here suggest that 1,3,5,6-tetrahydroxyxanthone (3) and guttiferone E (7) are promising inhibitors of NO production and 15-LOX activity. Further studies should be considered in order to elucidate the mechanism by which these compounds exert their inhibitory activities. (C) 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved

Lambertellin from Pycnoporus sanguineus MUCL 51321 and its anti-inflammatory effect via modulation of MAPK and NF-kappa B signaling pathways

Lambertellin (1) and ergosta-5,7,22-trien-3-ol (2) were isolated from the solid rice fermentation of the plant pathogenic fungus Pycnoporus sanguineus MUCL 51321. Their structures were elucidated using comprehensive spectroscopic methods. The isolated compounds were tested on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Lambertellin (1) exhibited promising inhibitory activity against nitric oxide (NO) production with IC50 value of 3.19 mu M, and it significantly inhibited the expression of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2). Lambertellin (1) also decreased the expression of pro-inflammatory cytokines IL-6 and IL-1 beta. The study of the mechanistic pathways revealed that lambertellin (1) exerts its anti-inflammatory effect in LPS-stimulated RAW 264.7 macrophage cells by modulating the activation of the mitogen activated protein kinase (MAPK) and nuclear factor kappa B (NF-kappa B) signaling pathways. Therefore, lambertellin (1) could be a promising lead compound for the development of new anti-inflammatory drugs