Showing papers on "Acacetin published in 2004"

Inhibitory effects of active compounds isolated from safflower (Carthamus tinctorius L.) seeds for melanogenesis.

Abstract: In order to develop a new skin whitening agent, safflower (Carthamus tinctorius L.) seeds were evaluated for melanogenesis inhibitory activity and its active principles were identified following activity-guided isolation. The 80% aqueous methanol extract and ethyl acetate fraction from safflower seeds showed a significant inhibition for mushroom tyrosinase. Three active compounds, N-feruloylserotonin, N-(p-coumaroyl)serotonin, and acacetin, were isolated from the ethyl acetate fraction as the active principles. Compared with arbutin (IC50=0.223 mM), the IC50 values of these compounds were 0.023, 0.074, and 0.779 mM for N-feruloylserotonin, N-(p-coumaroyl)serotonin, and acacetin, respectively. It was also found that N-feruloylserotonin and N-(p-coumaroyl)serotonin strongly inhibited the melanin production of Streptomyces bikiniensis and B16 melanoma cells in comparison with a known melanogenesis inhibitor, arbutin.

Antimycobacterial activity and cytotoxicity of flavonoids from the flowers of Chromolaena odorata.

Abstract: From the flowers ofChromolaena odorata (Eupatorium odoratum) four flavanones, isosakuranetin (5,7-dihydroxy-4′-methoxyflavanone) (1), persicogenin (5,3′-dihydroxy-7,4′-dimethoxyflavanone) (2), 5,6,7,4′-tetramethoxyflavanone (3) and 4′-hydroxy-5,6,7-trimethoxyflavanone (4), two chalcones, 2′-hydroxy-4,4′,5′,6′-tetramethoxychalcone (5) and 4,2′-dihydroxy-4′, 5′,6′-trimethoxychalcone (6), and two flavones, acacetin (5,7-dihydroxy-4′-methoxyflavone) (7) and luteolin (5,7,3′,4′-tetrahydroxyflavone) (8) were isolated and identified. Compound 1 exhibited moderate antimycobacterial activity againstMycobacterium tuberculosis with the MIC value of 174.8 μM, whereas compounds4,7, and8 exhibited weak activity with the MIC values of 606.0, 704.2 and 699.3 μM respectively. Compound7 showed moderate cytotoxicity against human small cell lung cancer (NCI-H187) cells with the MIC value of 24.6 μM, whereas compound8 exhibited moderate toxicity against NCI-H187 cells and week toxicity against human breast cancer (BC) cells with the MIC values of 19.2 and 38.4 μM respectively.

Individual and interactive effects of apigenin analogs on G2/M cell-cycle arrest in human colon carcinoma cell lines.

Abstract: Apigenin has been previously shown to induce G2/M cell-cycle arrest in human colon cancer cell lines. The present study assessed the individual and interactive influence of seven apigenin analogs on cell cycle, cell number, and cell viability in human SW480 and Caco-2 colonic carcinoma cells. Cellular concentration of selected apigenin analogs was further assessed by high-performance liquid chromatography to assess cellular availability. The apigenin analogs studied were acacetin, chrysin, kampherol, luteolin, myricetin, naringenin, and quercetin. DNA flow cytometric analysis indicated that treatment with either chrysin or acacetin at 0 to 80 microM for 48 h resulted in cell-cycle arrest at the G2/M phase in a dose-dependent manner in the SW480 cells but not in the Caco-2 cells. The percentage of SW480 cells at G2/M also increased when cells were treated with kampherol, luteolin, or quercetin between 5 and 30 microM, but the percentage of cells in G2/M decreased at doses greater than 40 microM. Cell number was significantly decreased in a time- and dose-dependent manner following the treatments with each analog except for naringenin and myricetin. The interactive effects of these analogs with apigenin were further assessed by combining each analog at doses from 0 to 80 microM with apigenin at 20 microM, a dose at which apigenin was found to double the proportion of SW480 cells in G2/M. When either acacetin, chrysin, luteolin, kampherol, or quercetin at doses between 5 and 30 microM were combined with apigenin at 20 microM, there was an increase of 22% in the proportion of G2/M cells over that observed with 20 microM apigenin alone (P < 0.05). At doses higher than 40 microM, however, the interaction became antagonistic, and the proportion of cells in G2/M decreased below that observed with apigenin alone. Cell viability, as assessed by Trypan blue exclusion assay, significantly decreased by treatments with high doses of each agent or each agent combined with apigenin. Cellular concentration of apigenin, chrysin, or naringenin in SW480 cells significantly increased at doses of 40 microM or greater, but it was not correlated with their impact on G2/M cell-cycle arrest. The induction of cell-cycle arrest by five of seven tested apigenin analogs and the additive induction by the combination of flavonoids at low doses suggest that apigenin-related flavonoids may cooperatively protect against colorectal cancer through conjoint blocking of cell-cycle progression.

Semisynthesis of Linarin, Acacetin, and 6-Iodoapigenin Derivatives from Diosmin

Abstract: Semisynthesis of linarin and acacetin from the Citrus flavonoid diosmin was performed via, as first intermediate, the 3'-O-phenyltetrazolyl ether of diosmin. This paper relates also a semisynthetic access to 6-iodoapigenin derivatives, which are key compounds in the synthesis of some biflavonoids such as robustaflavone.

Phenolic Compounds from Carthamus tinctorius

Abstract: The contents of quercetin, luteolin, apigenin, isorhamnetin, umbelliferone, and daphnoretin in common safflower and of acacetin in the flowers were determined based on the physical and chemical properties of the isolated substances.

Chemical constituents from saussurea stella

Abstract: From the whole plant of Saussurea stella Maxim(Asteraceae),fifteen compounds were isolated and identified as 4-hydroxy-2-methoxy-benzaldehyde(1),3-(3-methoxy-phenyl)-propenal(2),(+)-pinoresinol-β-D-glucoside(3),daucosterol(4),luteolin(5),acacetin(6),apigenin(7),tilianin(8),chrysoeriol-7-O-β-glucoside(9),apigenin-7-O-β-glucoside(10),quercetin-3-O-α-L-rhamnoside(11),kaempferol-3-O-α-L-rhamnoside(12),quercetin-5-O-β-glucoside(13),quercetin 4′-methyl ether 5-O-β-glucoside(14)and 6-hydroxy-3-O-methyl-kaempferol 6-O-glucoside(15)on the basis of spectral evidence.Among them 1 ～ 5 ,9 ～ 10 and 13 ～ 15 were isolated from this medicine plant for the first time.