Two New Polymethoxylated Flavones, a Class of Compounds with Potential Anticancer Activity, Isolated from Cold Pressed Dancy Tangerine Peel Oil Solids

Chen, Jie; Montanari, and Antonio M.; Widmer, Wilbur W.

doi:10.1021/jf960110i

Cited by 129 publications

(93 citation statements)

References 18 publications

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“…1 H and 13 C NMR spectral data of the polymethoxylated flavonoids 1 and 2, recorded in CDCl 3 (See Experimental), are in good agreement with those described in the literature (Calvert et al 1979, Chen et al 1997.…”

Section: Resultssupporting

confidence: 85%

“…Flavonoids constitute one of the most important classes of naturally occurring phenols with interesting properties, to the plants as protective agents and human health (Ezeonu et al 2001, Del Río et al 1998, Bohm 1998, Chen et al 1997, Harborne et al 1975, Mayer 1998. Many analytical procedures have been developed for flavonoids analysis in mixture, although the most successful are based on chromatographic techniques such as high-performance liquid chromatography (HPLC) and Gas Chromatography (GC) (Oliveira et al 2001, Branco et al 1998, Stremple 1998.…”

Section: Introductionmentioning

confidence: 99%

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Complete ¹H and 13C NMR assignments and anti fungal activity of two 8-hydroxy flavonoids in mixture

Johann

Smânia-Jr

Pizzolatti

et al. 2007

An. Acad. Bras. Ciênc.

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A mixture of the two new flavonols 8-hydroxy-3,4',5,6,7-pentamethoxyflavone (1) and 8-hydroxy-3,3',4',5,6,7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one-( 1 HNMR, { 1 H}-13 C NMR, and APT-13 C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the structural elucidation and the complete 1 H and 13 C chemical shift assignments of these natural compounds. In addition, the antifungal activity of these compounds against phytopathogenic and human pathogenic fungi was investigated.

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Section: Resultssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Complete ¹H and 13C NMR assignments and anti fungal activity of two 8-hydroxy flavonoids in mixture

Johann

Smânia-Jr

Pizzolatti

et al. 2007

An. Acad. Bras. Ciênc.

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“…Therefore, nobiletin exhibited more potency compared with kojic acid, by approximately two-fold. Nobiletin is a polymethoxyflavonoid occurring exclusively in Citrus fruits, 10) and has been reported to induce the differentiation of mice myeloid leukemia cells, 12) to exhibit antiproliferative activity toward a human squamous cell carcinoma cell line, 13) to exert anti-mutagenic activity, 14) and to suppress the induction of matrix metalloproteinase-9 and prostaglandin E 2 release. 15) In addition, nobiletin inhibits the combined endotoxin and cytokine-induced expression of nitric oxide synthesis and cyclooxygenase-2 proteins, and suppresses the formation of tumor promoter-induced edema 16) and papilloma 17) in mice.…”

Section: Resultsmentioning

confidence: 99%

Nobiletin as a Tyrosinase Inhibitor from the Peel of Citrus Fruit.

Sasaki

Yoshizaki

2002

Biological & Pharmaceutical Bulletin

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Tyrosinase catalyzes the oxidation of tyrosine and certain diphenolic intermediate products to quinines, which polymerize to give rise to melanin. 1) Tyrosinase inhibitors are used in depigmentation drugs and whitening cosmetics, 2,3) whereas compounds that increase melanogenesis may protect human skin from ultraviolet irradiation damage.4) The tyrosinase metabolic pathway also seems to be involved in the antimelanoma effects of some tyrosinase analogues.2) These substances are oxidated by tyrosinase, generating reactive oquinone with cytotoxic potential.2,5) Therefore, tyrosinase may be a useful target in the fields of hyperpigmentation and cosmetic materials. 6)Flavonoids and hydroxycinnamates, major constituents of the human diet, are powerful electron-donating anti-oxidants, the catechol moiety being one of the main structural features responsible for their antioxidant activities.7,8) Several flavonoids, stilbenes and related 4-substituted resorcinols, were tested for their inhibitory activity against tyrosinase to clarify the structure-activity relationship.9)The present study was under-taken to search for tyrosinase inhibitors in the peel of Citrus fruit. It has been used not only in traditional Chinese medicines but also as a skin whitening and skin-moisturized agent in Japanese folk medicines. Citrus fruit contains several biologically active components, e.g., limonoids and their glycosides, glyceroglycolipids, alkaloids such as synephrine, and several flavonoids in a large amount. Thus, the components of the peel of Citrus fruit are expected to provide valuable material to prevent skin pigmentation. MATERIALS AND METHODS Chemicals and General MaterialsMushroom tyrosinase, l-dopa, was purchase from Nakalai Tesque (Kyoto), and kojic acid from Tokyo Kasei Co. (Tokyo). Silica gels (Wakogel C-200) were purchased from Wako Chemical, Inc., Ltd. (Kyoto). Plant materials were purchased from Uchida Wakanyaku Co. (Niigata, from China).General Procedures Melting point was determined on a Yanagimoto micromelting point apparatus and is uncorrected. A Perkin Elmer 1600 series FTIR spectrophotometer was used for the measurement of IR spectrum. Mass spectrum (MS) was taken on a JEOL DX-303 mass spectrometer. Proton nuclear magnetic resonance (NMR) spectrum was recorded with JEOL EX-270 spectrometer, and chemical shifts are given in d (ppm) with tetramethylsilane as an internal standard (s: singlet, d: doublet, dd: double doublet).Extraction and Isolation The peel of Citrus fruit (3.5 kg) was extracted twice with methanol (8 l) at room temperature. Removal of solvent in vacuo gave 952.2 g of methanol extract. The extract was dissolved in water and distributed three times between chloroform (1 l), giving a chloroform extract (31.6 g). The water-soluble residue was partitioned three times between ethyl acetate (1 l) and H 2 O (1 l). After removal of the solvent in vacuo, the ethyl acetate extract (27.3 g) was column chromatographed on silica gel (Wakogel C-200) using n-hexane and n-hexane-acetone, giving colorless needles,...

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“…The five compounds are reported for the first time in plants from Bombacaceae family. Compound 1 is structurally similar to flavones with citotoxic 5,6 and insect antifeedant properties. 7 The structure elucidation of the isolated compounds was performed by spectroscopic analysis and comparison with literature data.…”

Section: Introductionmentioning

confidence: 99%

Chemical Constituents from Bombacopsis glabra (Pasq.) A. Robyns: Complete ¹H and 13C NMR Assignments and X Ray Structure of 5-Hydroxy-3,6,7,8,4'-pentamethoxyflavone

Paula

Barbosa

Errington

et al. 2002

J. Braz. Chem. Soc.

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Do extrato hexânico da casca do caule de Bombacopsis glabra (Bombacaceae) foram isolados a flavona 5-hidroxi-3,6,7,8,4'-pentametoxiflavona (1) e os triterpenos lupenona, 9,19-ciclolanost-23-eno-3β,25-diol (2), (24R)-9,19-ciclolanost-25-eno-3β,24-diol (3) e (24S)-9,19-ciclolanost-25-eno-3β,24-diol (4). As estruturas foram determinadas por espectroscopia de RMN de 13 C e de 1 H (1D e 2D) e EM, e ainda, por comparação com dados da literatura para os triterpenos. A confirmação inequívoca da estrutura da flavona 1 foi realizada por um estudo de difração de raios X. As cinco substâncias foram isoladas pela primeira vez de espécies de Bombacaceae.The flavone 5-hydroxy-3,6,7,8,4'-pentamethoxyflavone (1) and the triterpenes lupenone, 9,19-cyclolanost-23-ene-3β,25-diol (2), (24R)-9,19-cyclolanost-25-ene-3β,24-diol (3) and (24S)-9,19-cyclolanost-25-ene-3β,24-diol (4) were isolated from the hexane extract of the stem bark of Bombacopsis glabra (Bombacaceae). The structures were determined by 13 C and 1 H NMR (1D and 2D) and mass spectrometry, and by comparison with literature data for triterpenes. The structure of the flavone 1 was unambiguously confirmed by a X-ray diffraction study. The five substances were isolated for the first time from Bombacaceae species.

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Two New Polymethoxylated Flavones, a Class of Compounds with Potential Anticancer Activity, Isolated from Cold Pressed Dancy Tangerine Peel Oil Solids

Abstract: Ten polymethoxylated flavonoids were isolated and characterized from cold pressed tangerine oil solids; they are 5,6,7,3′,4′-pentamethoxyflavone (sinensetin) (

Cited by 129 publications

References 18 publications

Complete ¹H and 13C NMR assignments and anti fungal activity of two 8-hydroxy flavonoids in mixture

Complete ¹H and 13C NMR assignments and anti fungal activity of two 8-hydroxy flavonoids in mixture

Nobiletin as a Tyrosinase Inhibitor from the Peel of Citrus Fruit.

Chemical Constituents from Bombacopsis glabra (Pasq.) A. Robyns: Complete ¹H and 13C NMR Assignments and X Ray Structure of 5-Hydroxy-3,6,7,8,4'-pentamethoxyflavone

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