- Isolation and Characterization of an Antibacterial Substance from Citrus Plant
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Citrus bacterial canker caused by Xanthomomas campestris pv. citri (Hasse 1915) Dye 1978, a gram-negative and rod-shape bacteria, is one of the destructive diseases of Citrus. There is marked diversity in resistance to the disease among Citrus plants. Calamondin, Citrus madurensis Lour. (Shiki-kitsu) is one of the highly resistant plants.1 In resistant plants bacterial multiplication is restrained by the embedding of electron dense materials in intercellular spaces.2 This suggests the presence of an antibacterial substance in resistant plants. The third author assayed the 85% ethanol extracts of Citrus leaves infected with bacterial canker for static activities to X. campestris. pv. citri. An active fraction was found in Calamondin. We further purified and characterized its ingredients on the basis of spectrometric analyses. Its structure was found to be identical with 3-hydroxy-5,6,7,8,3′,4′-hexamethoxyflavone (1) isolated from Citrus natsudaidai Hayata. However, its antibacterial activity is first reported by us.
- Ito, Chihiro,Fujiwara, Kazuko,Koizumi, Meisaku,Furukawa, Hiroshi
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- Synthesis of Citrus polymethoxyflavonoids and their antiproliferative activities on Hela cells
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Abstract: A series of polymethoxyflavonoids (3–16) were synthesized through dehydrogenation, O-methylation, glycoside hydrolysis, bromination, microwave-assisted aromatic nucleophilic substitution, dimethyldioxirane oxidation and regioselective demethylation, starting from abundant and inexpensive natural sources naringin and hesperidin. All the synthetic compounds were test for antiproliferative activities on human cervical carcinoma Hela cell line by the standard CCK-8 assay, the result showed that most of the target compounds exhibited moderate to potent antiproliferative activities on Hela cells comparable with the positive control cis-Platin. Among them, 5-hydroxypolymethoxy flavonoid 13 showed the strongest activity (IC50 0.791 μM). Graphical Abstract: [InlineMediaObject not available: see fulltext.].
- Nguyen, Van-Son,Li, Wei,Li, Yue,Wang, Qiuan
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p. 1585 - 1592
(2017/06/05)
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- Use of flavone and flavanone derivatives in preparation of sedative and hypnotic drugs
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Disclosed is a use of flavones derivatives and flavanone derivatives in preparation of sedative and hypnotic drugs.
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Page/Page column 37
(2017/07/01)
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- Semisynthesis of polymethoxyflavonoids from naringin and hesperidin
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Polymethoxyflavonoids (PMFs) possess important biological activities, notably as anticancer agents. Semisynthesis of a series of PMFs were performed by glycoside hydrolysis, dehydrogenation, bromination, aromatic nucleophilic substitution, O-methylation, dimethyldioxirane oxidation and regioselective demethylation, starting from abundant and inexpensive natural sources naringin and hesperidin. A new synthetic method for selective methylation using CuBr catalysed and microwave-assisted reaction was developed, and the dimethyl dioxirane oxidation of flavones to flavonols was much improved. The new semisynthetic route has the advantages of easy availability of starting materials, simple operation and good yields.
- Li, Yue,Cai, Shuanglian,He, Kailin,Wang, Qiuan
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p. 287 - 290
(2014/06/09)
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- Regioselective hydroxylation of 2-hydroxychalcones by dimethyldioxirane towards polymethoxylated flavonoids
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The flavone nucleus is part of a large number of natural products and medicinal compounds. In this presentation the novel regioselective hydroxylation of hydroxyarenes with DMD is described. The results showed further that flavonoids with 5-hydroxy group were selectively oxyfunctionalized at the para-position C8 carbon atom by DMD. Finally, according to this methodology, the naturally occurring isosinensetin, tangeretin, sinensetin, nobiletin, natsudaidain, gardenin B, 3,3′,4′,5,6,7,8- heptamethoxyflavone, quercetin and its derivatives were synthesized.
- Chu, Han-Wei,Wu, Huan-Ting,Lee, Yean-Jang
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p. 2647 - 2655
(2007/10/03)
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- Cytotoxic and anti-HIV-1 constituents of Gardenia obtusifolia and their modified compounds
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5α-Cycloart-24-ene-3,23-dione (1), 5α-cycloart-24-ene-3,16,23-trione (2) and methyl 3,4-seco-cycloart-4(28),24-diene-29-hydroxy-23-oxo-3-oate (3), together with five known flavones 5,7,4′-trihydroxy-3,8-dimethoxyflavone (4), 5,7,4′-trihydroxy-3,8,3′-tri-methoxyflavone (5), 5,7,4′-trihydroxy-3,6,8-trimethoxyflavone (6), 5,4′-dihydroxy-3,6,7,8-tetramethoxyflavone (7) and 5,3′-dihydroxy-3,6,7,8,4′-pentamethoxyflavone (8) have been isolated from the leaves and twigs of Gardenia obtusifolia. The structures were assigned on the basis of spectroscopic methods. Compounds 3-8 and some of the modified compounds showed significant cytotoxic activities in several mammalian cell lines, especially 8 and its diacetate 21 which exhibited potent cytotoxicities (compound 8: P-388 0.05μg/mL, KB 0.09μg/mL, BCA-1 0.63μg/mL, Lu-1 0.09μg/mL, ASK 0.70μg/mL; its diacetate: P-388 0.27μg/mL, KB 0.06μg/mL, BCA-1 0.53μg/mL, Lu-1 0.49μg/mL). It was also found that 5, 8 and 21 showed antimitotic acitivity in the ASK assay. Compounds 2, 4, 6, 7 and some of the modified compounds displayed interesting anti-HIV activity in the syncytium assay, but were inactive or exhibited weak activity in the HIV-1 RT assay; while compound 3 was found to be active in the HIV-1 RT assay (99.9 % inhibition at 200μg/mL), but cytotoxic in the syncytium assay.
- Tuchinda, Patoomratana,Pompimon, Wilart,Reutrakul, Vichai,Pohmakotr, Manat,Yoosook, Chalobon,Kongyai, Natedao,Sophasan, Samaisukh,Sujarit, Kulawee,Upathum, Suchart E,Santisuk, Thawatchai
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p. 8073 - 8086
(2007/10/03)
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- A new flavonol from Murraya paniculata var. omphalocarpa: 13C-NMR as a useful tool for structure elucidation of polyoxyflavones
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A highly oxygenated flavone was isolated from the leaves of Murraya paniculata var. omphalocarpa (Rutaceae). The spectroscopic analysis of this compound revealed the presence of an unusual para-diphenol moiety in the A ring and its structure was finally elucidated as 3',4',6,7-tetramethoxy- 3,5,8-trihydroxyflavone (1). The assignment of 13C resonances of nineteen polyoxyflavones was also made by use of 2D correlation spectroscopy and the usefulness of 13C NMR for identifying polyoxyflavones was discussed.
- Kinoshita, Takeshi
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p. 269 - 276
(2007/10/03)
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