Naphthoquinones and triterpenes from some asian Diospyros species

Zakaria, Mohd Idzwan; Jeffreys, J. A. D.; Waterman, Peter G.; Zhong, Shouming

doi:10.1016/s0031-9422(00)80490-2

Cited by 39 publications

(12 citation statements)

References 8 publications

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“…Its molecular formula was determined to be C 24 H 18 >CHCH 3 )) in 30. From the above results, compound 30 is a symmetric dimer of 20 linked by an ethylidene bridge.…”

Section: Structures Of Naphthoquinones Isolated From the Etoh Extractmentioning

confidence: 99%

“…The naphthoquinone derivatives isolated to date from the genus Diospyros are commonly assumed to be derived from a precursor equivalent to 4,5-dihydroxy-2-methylnaphthalene or a biogenetic analog. 3) 3-Methylplumbagin (3), 3-(2-hydroxyethyl) plumbagin (6), 6-(1-ethoxyethyl) plumbagin (7), methylene-3,3′-biplumbagin (15), ethylidene-3,3′-biplumbagin (16), ethylidene-3,6′-biplumbagin (17), and ethylidene-6,6′-biplumbagin (18) isolated from this plant contain an alkyl group that is not found in the naphthoquinone derivatives isolated from other Diospyros species. Because it is possible to isolate rare and novel quinones using different extraction solvents, we employed chloroform as the extraction solvent instead of ethanol to examine the naphthoquinone derivatives in the chloroform extract of the fresh fruits.…”

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confidence: 99%

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Naphthoquinone Derivatives from <i>Diospyros maritima</i>

Higa

Takashima

Yokaryo

et al. 2017

CHEMICAL & PHARMACEUTICAL BULLETIN

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From the chloroform extract of the fresh fruits of Diospyros maritima BLUME (Ebenaceae), five new naphthoquinone derivatives, 2,7′-dimethyl-2′,3-bijuglone (27), 2,7′-dimethyl-3,3′-bijuglone (28), 2,7′-dimethyl-6,8′-bijuglone (29), 7,7′-dimethyl-3,3′-ethylidenebijuglone (30), and 2′,7-dimethyl-3,6′-ethylidenebijuglone (31), were isolated, in addition to twenty-one known naphthoquinone derivatives: plumbagin (4), droserone (5), 2,3-epoxyplumbagin (8), 3,3′-biplumbagin (9), chitranone (10), 3,8′-biplumbagin (11), elliptinone (12), maritinone (13), isozeylanone (14), methylene-3,3′-biplumbagin (15), ethylidene-3,3′-biplumbagin (16), ethylidene-3,6′-biplumbagin (17), ethylidene-6,6′-biplumbagin (18), 7-methyl-β-dihydrojuglone (19), 7-methyljuglone ( Key words Diospyros maritima; Ebenaceae; naphthoquinone; bijuglone; ethylidenebijugloneDiospyros maritima BLUME (Ebenaceae) is a shrub that grows in Southeast Asia. We previously reported the isolation of eighteen naphthoquinone derivatives, 1-18, from the ethanol extract of the fruits of this plant 1,2) (Chart 1). The naphthoquinone derivatives isolated to date from the genus Diospyros are commonly assumed to be derived from a precursor equivalent to 4,5-dihydroxy-2-methylnaphthalene or a biogenetic analog.3) 3-Methylplumbagin (3), 3-(2-hydroxyethyl) plumbagin (6), 6-(1-ethoxyethyl) plumbagin (7), methylene-3,3′-biplumbagin (15), ethylidene-3,3′-biplumbagin (16), ethylidene-3,6′-biplumbagin (17), and ethylidene-6,6′-biplumbagin (18) isolated from this plant contain an alkyl group that is not found in the naphthoquinone derivatives isolated from other Diospyros species. Because it is possible to isolate rare and novel quinones using different extraction solvents, we employed chloroform as the extraction solvent instead of ethanol to examine the naphthoquinone derivatives in the chloroform extract of the fresh fruits. Here, we describe the isolation and structure elucidation of five new naphthoquinone derivatives, 27-31, from the chloroform extract; we also discuss the classification of naphthoquinone derivatives obtained only from the ethanol extract of the fresh fruits of this plant, only from the chloroform extract, and from both extracts. Results and DiscussionStructure Elucidation A chloroform extract of the fresh fruits of D. maritima afforded, after chromatographic separation, eight known naphthoquinone derivatives: 7-methyl-β-dihydrojuglone (19), 7-methyljuglone (20), 2,3-epoxy-7-methyljuglone (21), neodiospyrin (22), mamegakinone (23), ehretione (24), isoxylospyrin (25), β-dihydroplumbagin (26), and five new quinones (27 to 31) (Chart 2), in addition to quinones 4, 5, and 8-18, which were previously isolated from the ethanol extract.The new quinone 27 was obtained as red prisms with a melting point (mp) of 184-185°C. Its molecular formula was determined to be C [δ 7.28 (1H, dd, J=1.0, 8.0 Hz), 7.65 (1H, t, J=8.0 Hz), 7.71 (1H, dd, J=1.0, 7.5 Hz)], and another hydrogen-bonded hydroxyl (δ 11.75, (1H, s)) were attributed to the plumbagin moiety. From these resul...

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“…Its molecular formula was determined to be C 24 H 18 >CHCH 3 )) in 30. From the above results, compound 30 is a symmetric dimer of 20 linked by an ethylidene bridge.…”

Section: Structures Of Naphthoquinones Isolated From the Etoh Extractmentioning

confidence: 99%

mentioning

confidence: 99%

Naphthoquinone Derivatives from <i>Diospyros maritima</i>

Higa

Takashima

Yokaryo

et al. 2017

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…Compounds 3-8 were found to be 2-methyl anthraquinone (tectoquinone) (3), 24,25 maritinone (4), 26,27 elliptinone (5), 28,29 plumbagin (6), 27,30 (+)-cis-isoshinanolone (7), 26,31 and ethylidene-6,6′-biplumbagin (8) 32,33 by comparison of their NMR and MS data with those in the literature. The relative configuration of cis-isoshinanolone (7) was supported by the small coupling constant observed between H-3 and H-4 (J = 2.8 Hz); cis and trans isomers show significantly different coupling constants (cis: J = 2.5 Hz; trans: J = 7.5 Hz).…”

Section: Resultsmentioning

confidence: 97%

Synergistic trail sensitizers from Barleria alluaudii and Diospyros maritima

Whitson¹,

Hui²,

Thomas³

et al. 2012

Planta Med

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Barleria alluaudii and Diospyros maritima were both investigated as part of an ongoing search for synergistic TRAIL (tumor necrosis factor-α-related apoptosis-inducing ligand) sensitizers. As a result of this study, two naphthoquinone epoxides, 2,3-epoxy-2,3-dihydrolapachol (1) and 2,3-epoxy-2,3-dihydro-8-hydroxylapachol (2), both not previously isolated from natural sources, and the known 2-methyl anthraquinone (3) were identified from B. alluaudii. Time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra were utilized to establish the absolute configuration of 1 and 2. Additionally, five known naphthoquinone derivatives, maritinone (4), elliptinone (5), plumbagin (6), (+)-cis-isoshinanolone (7), and ethylidene-6,6′-biplumbagin (8) were isolated from D. maritima. Compounds 1, 2, and 4-6 showed varying levels of synergy with TRAIL. Maritinone (4) and elliptinone (5) showed the highest synergistic effect, with more than a three-fold increase in activity observed with TRAIL than with compound alone.Tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL/Apo2L) is a member of the tumor necrosis factor (TNF) family of apoptosis triggering proteins. 1 TRAIL promotes recruitment of the adaptor protein FADD (Fas associated death domain) upon binding to death domain-containing transmembrane receptors, death receptors 4 and 5 (DR4, DR5). FADD is responsible for recruiting procaspase-8 and procaspase-10, which results in the formation of a trimerized receptor-ligand complex called DISC (death-inducing signaling complex). The activated initiator caspase-8 then activates effector caspase-3, caspase-6, and caspase-7, which triggers the caspase cascade and subsequently results in apoptosis. 2,3 In type I cancer cells, caspase-8 can directly activate downstream effector caspases to promote apoptosis. However, in type II cancer cells, apoptosis proceeds through cross-talk between # Dedicated to Dr. Gordon M. Cragg, formerly of the National Cancer Institute, Frederick, Maryland, for his pioneering work on the development of natural product anticancer agents. * Corresponding Author: Tel: (301) 846-1943. Fax: (301) 846-6851. mckeeta@mail.nih.gov. ASSOCIATED CONTENT:Supporting Information: 1 H and 13 C NMR spectra for 1-2, chiral HPLC analysis of 1, Gaussian keywords, calculated excitation energies, oscillator strengths, and rotational strengths for 1-2, important dihedral angles of conformers 1a-1f and 2a-2f, conformational analysis of 1, calculated ORD values for 1-2, and coordinates of conformers 1a-1f and 2a-2f. This material is available free of charge via the Internet at http://pubs.acs.org. the extrinsic and intrinsic pathways and involves the participation of the mitochondria. 4 TRAIL is particularly important because it selectively induces apoptosis in cancer cells, while showing little to no effect in normal cells. 1,5 However, TRAIL resistance has been widely documented, 5-9 and there is evidence to suggest that combination chemotherapy regimens may b...

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“…Naphthoquinones are biologically active naturally occurring compounds found in various plant families, including Avicenniaceae, 7) Acanthaceae, [8][9][10][11] Balsaminaceae, Bignoniaceae, 12,13) Boraginaceae, 14) Droseraceae, 15,16) Ebenaceae, 17,18) Juglandaceae, 19) Lythraceae, Nepenthaceae 20) and Plumbagnaceae. 21,22) The common naphthoquinones found in these plant families are shown in Figs.…”

Section: Naphthoquinones Containing Plants In Thailandmentioning

confidence: 99%

Antidiabetic Naphthoquinones and Their Plant Resources in Thailand

Shah

Keach²,

Panichayupakaranant

2018

Chem. Pharm. Bull.

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Diabetes mellitus is the seventh leading cause of death globally. Ninety percent of the diabetic population suffers from type-2 diabetes, which still needs an effective, safe and economical oral hypoglycemic therapy. Plants are rich sources of various therapeutic molecules. More than 400 medicinal plants of interesting phytochemical diversity have been reported for their antidiabetic potential. Naphthoquinones are a group of phytochemicals, which have a wide range of pharmacological potential, including antidiabetic activity. Naphthoquinones exert their antidiabetic effects through various mechanisms such as the inhibition of α-glucosidase and protein tyrosine phosphatase 1B, increased glucose uptake in myocytes and adipocytes via glucose transporter type 4 (GLUT4) and GLUT2 translocations, enhanced peroxisome proliferator-activated receptor gamma (PPARγ) ligand activity, and by normalizing carbohydrate metabolizing enzymes in the liver. Moreover, naphthoquinone inhibits adipogenesis by both upstream and downstream regulation to control obesity, which is one of the important risk factors for diabetes. Naturally occurring naphthoquinones, as well as their plant sources, are therefore of interest for exploring their antidiabetic potential. The present review aims to overview the antidiabetic potential of naphthoquinones and their plant resources in Thailand.

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Naphthoquinones and triterpenes from some asian Diospyros species

Cited by 39 publications

References 8 publications

Naphthoquinone Derivatives from <i>Diospyros maritima</i>

Naphthoquinone Derivatives from <i>Diospyros maritima</i>

Synergistic trail sensitizers from Barleria alluaudii and Diospyros maritima

Antidiabetic Naphthoquinones and Their Plant Resources in Thailand

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