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Prenylated flavones from Artocarpus altilis

Shamaun SS, Rahmani M, Hashim NM, Ismail HB, Sukari MA, Lian GE, et al.

J Nat Med, 2010 Oct;64(4):478-81.
PMID: 20526745 DOI: 10.1007/s11418-010-0427-4

Six prenylated flavones, including one new compound, were isolated and identified from the stem bark extracts of Artocarpus altilis. The new prenylated flavone hydroxyartocarpin (1) was characterized as 3-(gamma,gamma-dimethylallyl)-6-isopentenyl-5,8,2',4'-tetrahydroxy-7-methoxyflavone and the known compounds were artocarpin (2), morusin (3), cycloartobiloxanthone (4), cycloartocarpin A (5) and artoindonesianin V (6). The structures of the compounds were determined by spectroscopic methods (IR, MS, (1)H-NMR and (13)C-NMR) and comparison with published data for the known compounds.

Matched MeSH terms: Prenylation*
Fulltext Enhancing flavonoid production by promiscuous activity of prenyltransferase, BrPT2 from Boesenbergia rotunda

Liew YJM, Lee YK, Khalid N, Rahman NA, Tan BC

PeerJ, 2020;8:e9094.
PMID: 32391211 DOI: 10.7717/peerj.9094

Flavonoids and prenylated flavonoids are active components in medicinal plant extracts which exhibit beneficial effects on human health. Prenylated flavonoids consist of a flavonoid core with a prenyl group attached to it. This prenylation process is catalyzed by prenyltranferases (PTs). At present, only a few flavonoid-related PT genes have been identified. In this study, we aimed to investigate the roles of PT in flavonoid production. We isolated a putative PT gene (designated as BrPT2) from a medicinal ginger, Boesenbergia rotunda. The deduced protein sequence shared highest gene sequence homology (81%) with the predicted homogentisate phytyltransferase 2 chloroplastic isoform X1 from Musa acuminata subsp. Malaccensis. We then cloned the BrPT2 into pRI vector and expressed in B. rotunda cell suspension cultures via Agrobacterium-mediated transformation. The BrPT2-expressing cells were fed with substrate, pinostrobin chalcone, and their products were analyzed by liquid chromatography mass spectrometry. We found that the amount of flavonoids, namely alpinetin, pinostrobin, naringenin and pinocembrin, in BrPT2-expressing cells was higher than those obtained from the wild type cells. However, we were unable to detect any targeted prenylated flavonoids. Further in-vitro assay revealed that the reaction containing the BrPT2 protein produced the highest accumulation of pinostrobin from the substrate pinostrobin chalcone compared to the reaction without BrPT2 protein, suggesting that BrPT2 was able to accelerate the enzymatic reaction. The finding of this study implied that the isolated BrPT2 may not be involved in the prenylation of pinostrobin chalcone but resulted in high yield and production of other flavonoids, which is likely related to enzyme promiscuous activities.

Matched MeSH terms: Prenylation
Prenylated xanthones from mangosteen as promising cholinesterase inhibitors and their molecular docking studies

Khaw KY, Choi SB, Tan SC, Wahab HA, Chan KL, Murugaiyah V

Phytomedicine, 2014 Sep 25;21(11):1303-9.
PMID: 25172794 DOI: 10.1016/j.phymed.2014.06.017

Garcinia mangostana is a well-known tropical plant found mostly in South East Asia. The present study investigated acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of G. mangostana extract and its chemical constituents using Ellman's colorimetric method. Cholinesterase inhibitory-guided approach led to identification of six bioactive prenylated xanthones showing moderate to potent cholinesterases inhibition with IC50 values of lower than 20.5 μM. The most potent inhibitor of AChE was garcinone C while γ-mangostin was the most potent inhibitor of BChE with IC50 values of 1.24 and 1.78 μM, respectively. Among the xanthones, mangostanol, 3-isomangostin, garcinone C and α-mangostin are AChE selective inhibitors, 8-deoxygartanin is a BChE selective inhibitor while γ-mangostin is a dual inhibitor. Preliminary structure-activity relationship suggests the importance of the C-8 prenyl and C-7 hydroxy groups for good AChE and BChE inhibitory activities. The enzyme kinetic studies indicate that both α-mangostin and garcinone C are mixed-mode inhibitors, while γ-mangostin is a non-competitive inhibitor of AChE. In contrast, both γ-mangostin and garcinone C are uncompetitive inhibitors, while α-mangostin is a mixed-mode inhibitor of BChE. Molecular docking studies revealed that α-mangostin, γ-mangostin and garcinone C interacts differently with the five important regions of AChE and BChE. The nature of protein-ligand interactions is mainly hydrophobic and hydrogen bonding. These bioactive prenylated xanthones are worthy for further investigations.

Matched MeSH terms: Prenylation
Prenylated flavanones and flavanonols as chemical markers in Glycosmis species (Rutaceae)

Lukaseder B, Vajrodaya S, Hehenberger T, Seger C, Nagl M, Lutz-Kutschera G, et al.

Phytochemistry, 2009 May;70(8):1030-7.
PMID: 19535116 DOI: 10.1016/j.phytochem.2009.05.007

Fifteen prenylated or geranylated flavanones and flavanonols were isolated from the leaf extracts of different Glycosmis species collected in Thailand and Malaysia. All structures were elucidated by spectroscopic methods, especially 1D and 2D NMR. Six compounds were described for the first time and two were only known so far as synthetic products. The chemotaxonomic significance of flavanoid accumulation within the genus Glycosmis is highlighted.

Matched MeSH terms: Prenylation
Cytotoxic caged-polyprenylated xanthonoids and a xanthone from Garcinia cantleyana

Shadid KA, Shaari K, Abas F, Israf DA, Hamzah AS, Syakroni N, et al.

Phytochemistry, 2007 Oct;68(20):2537-44.
PMID: 17602714

Phytochemical studies on the leaves and trunk bark of Garcinia cantleyana yielded five caged-xanthonoids including one tetra- and four tri-prenylated xanthones, cantleyanone A (1), 7-hydroxyforbesione (2) and cantleyanones B-D (4-6), as well as a simple xanthone, 4-(1,1-dimethylprop-2-enyl)-1,3,5,8-tetrahydroxyxanthone (3). Eight other known compounds, deoxygaudichaudione A, gaudichaudione H, friedelin, garbogiol, macranthol, glutin-5-en-3beta-ol, and a mixture of sitosterol and stigmasterol were also isolated. Their structures were elucidated by means of spectroscopic data and comparison of their NMR data with literature values. Significant cytotoxicity against MDA-MB-231, CaOV-3, MCF-7 and HeLa cancer cell-lines was demonstrated by cantleyanones B-D, 7-hydroxyforbesione, deoxygaudichaudione A and macranthol, with IC(50) values ranging from 0.22 to 17.17 microg/ml.

Matched MeSH terms: Prenylation
Discovery of gamma-mangostin from Garcinia mangostana as a potent and selective natural SIRT2 inhibitor

Yeong KY, Khaw KY, Takahashi Y, Itoh Y, Murugaiyah V, Suzuki T

Bioorg Chem, 2020 01;94:103403.
PMID: 31711765 DOI: 10.1016/j.bioorg.2019.103403

Studies have suggested that sirtuin inhibition may have beneficial effects on several age-related diseases such as neurodegenerative disorders and cancer. Garcinia mangostana is a well-known tropical plant found mostly in South East Asia with several positive health effects. Some of its phytochemicals such as α-mangostin was found to be able to modulate sirtuin activity in mice and was implicated with inflammation, diabetes and obesity. However, comprehensive studies on sirtuin activity by the prenylated xanthones extracted from Garcinia mangostana have yet to be reported. The present study led to the discovery and identification of γ-mangostin as a potent and selective SIRT2 inhibitor. It was demonstrated that γ-mangostin was able to increase the α-tubulin acetylation in MDA-MD-231 and MCF-7 breast cancer cells. It was also found to possess potent antiproliferative activity against both cell lines. In addition, it was able to induce neurite outgrowth in the N2a cells.

Matched MeSH terms: Prenylation
Identifying Potential Therapeutics for Osteoporosis by Exploiting the Relationship between Mevalonate Pathway and Bone Metabolism

Hasan WNW, Chin KY, Jolly JJ, Ghafar NA, Soelaiman IN

Endocr Metab Immune Disord Drug Targets, 2018;18(5):450-457.
PMID: 29683099 DOI: 10.2174/1871530318666180423122409

BACKGROUND: Osteoporosis is a silent skeletal disease characterized by low bone mass and destruction of skeletal microarchitecture, leading to an increased fracture risk. This occurs due to an imbalance in bone remodelling, whereby the rate of bone resorption is greater than bone formation. Mevalonate pathway, previously known to involve in cholesterol synthesis, is an important regulatory pathway for bone remodelling.
OBJECTIVE: This review aimed to provide an overview of the relationship between mevalonate pathway and bone metabolism, as well as agents which act through this pathway to achieve their therapeutic potential.
DISCUSSION: Mevalonate pathway produces farnesyl pyrophosphate and geranylgeranyl pyrophosphate essential in protein prenylation. An increase in protein prenylation favours bone resorption over bone formation. Non-nitrogen containing bisphosphonates inhibit farnesyl diphosphate synthase which produces farnesyl pyrophosphate. They are used as the first line therapy for osteoporosis. Statins, a well-known class of cholesterol-lowering agents, inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, the rate-determining enzyme in the mevalonate pathway. It was shown to increase bone mineral density and prevent fracture in humans. Tocotrienol is a group of vitamin E commonly found in palm oil, rice bran and annatto bean. It causes degradation of HMG-CoA reductase. Many studies demonstrated that tocotrienol prevented bone loss in animal studies but its efficacy has not been tested in humans.
CONCLUSION: Mevalonate pathway can be exploited to develop effective antiosteoporosis agents.

Matched MeSH terms: Protein Prenylation/drug effects
Flemingin-Type Prenylated Chalcones from the Sarawak Rainforest Plant Desmodium congestum

Rees KA, Bermudez C, Edwards DJ, Elliott AG, Ripen JE, Seta C, et al.

J Nat Prod, 2015 Aug 28;78(8):2141-4.
PMID: 26284978 DOI: 10.1021/acs.jnatprod.5b00410

In an ongoing program to identify new anti-infective leads, an extract derived from whole plant material of Desmodium congestum collected in the Sarawak rainforest was found to have anti-MRSA activity. Bioassay-guided isolation led to the isolation of two new prenylated chalcones, 5'-O-methyl-3-hydroxyflemingin A (1) and 5'-O-methylflemingin C (2), which were closely related to the flemingins previously isolated from various Flemingia species. Chalcones 1 and 2, which were determined to be 4:6 enantiomeric mixtures by chiral HPLC, exhibited moderate activity against a panel of Gram-positive bacteria and were also cytotoxic to the HEK293 human embryonic kidney cell line.

Matched MeSH terms: Prenylation
Molecular Characterization of a Geranyl Diphosphate-Specific Prenyltransferase Catalyzing Stilbenoid Prenylation from Morus alba

Zhong Z, Zhu W, Liu S, Guan Q, Chen X, Huang W, et al.

Plant Cell Physiol, 2018 Nov 01;59(11):2214-2227.
PMID: 30020500 DOI: 10.1093/pcp/pcy138

Pharmaceutically active compounds from medical plants are attractive as a major source for new drug development. Prenylated stilbenoids with increased lipophilicity are valuable secondary metabolites which possess a wide range of biological activities. So far, many prenylated stilbenoids have been isolated from Morus alba but the enzyme responsible for the crucial prenyl modification remains unknown. In the present study, a stilbenoid-specific prenyltransferase (PT), termed Morus alba oxyresveratrol geranyltransferase (MaOGT), was identified and functionally characterized in vitro. MaOGT recognized oxyresveratrol and geranyl diphosphate (GPP) as natural substrates, and catalyzed oxyresveratrol prenylation. Our results indicated that MaOGT shared common features with other aromatic PTs, e.g. multiple transmembrane regions, conserved functional domains and targeting to plant plastids. This distinct PT represents the first stilbenoid-specific PT accepting GPP as a natural prenyl donor, and could help identify additional functionally varied PTs in moraceous plants. Furthermore, MaOGT might be applied for high-efficiency and large-scale prenylation of oxyresveratrol to produce bioactive compounds for potential therapeutic applications.

Matched MeSH terms: Prenylation
O-prenylated flavonoid, an antidiabetes constituent in Melicope lunu-ankenda

George S, Ajikumaran Nair S, Johnson AJ, Venkataraman R, Baby S

J Ethnopharmacol, 2015 Jun 20;168:158-63.
PMID: 25858510 DOI: 10.1016/j.jep.2015.03.060

Melicope lunu-ankenda leaves are used to treat diabetes in folklore medicinal practices in India and Malaysia. Here we report the isolation of an O-prenylated flavonoid (3,5,4'-trihydroxy-8,3'-dimethoxy-7-(3-methylbut-2-enoxy)flavone; OPF) from the leaves of M. lunu-ankenda and its antidiabetes activity against type-2 diabetes mellitus (T2DM).

Matched MeSH terms: Prenylation
Fulltext Targeting MHC Regulation Using Polycyclic Polyprenylated Acylphloroglucinols Isolated from Garcinia bancana

Coste C, Gérard N, Dinh CP, Bruguière A, Rouger C, Leong ST, et al.

Biomolecules, 2020 09 02;10(9).
PMID: 32887413 DOI: 10.3390/biom10091266

Modulation of major histocompatibility complex (MHC) expression using drugs has been proposed to control immunity. Phytochemical investigations on Garcinia species have allowed the isolation of bioactive compounds such as polycyclic polyprenylated acylphloroglucinols (PPAPs). PPAPs such as guttiferone J (1), display anti-inflammatory and immunoregulatory activities while garcinol (4) is a histone acetyltransferases (HAT) p300 inhibitor. This study reports on the isolation, identification and biological characterization of two other PPAPs, i.e., xanthochymol (2) and guttiferone F (3) from Garcinia bancana, sharing structural analogy with guttiferone J (1) and garcinol (4). We show that PPAPs 1-4 efficiently downregulated the expression of several MHC molecules (HLA-class I, -class II, MICA/B and HLA-E) at the surface of human primary endothelial cells upon inflammation. Mechanistically, PPAPs 1-4 reduce MHC proteins by decreasing the expression and phosphorylation of the transcription factor STAT1 involved in MHC upregulation mediated by IFN-γ. Loss of STAT1 activity results from inhibition of HAT CBP/p300 activity reflected by a hypoacetylation state. The binding interactions to p300 were confirmed through molecular docking. Loss of STAT1 impairs the expression of CIITA and GATA2 but also TAP1 and Tapasin required for peptide loading and transport of MHC. Overall, we identified new PPAPs issued from Garcinia bancana with potential immunoregulatory properties.

Matched MeSH terms: Prenylation