- Bioinspired Diastereoconvergent Synthesis of the Tricyclic Core of Palodesangrens via Diels-Alder Reaction, LiAlH4-Mediated Isomerization, and Acid-Mediated Cyclization
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The cyclohexene moiety of the tricyclic 6,7-diaryl-tetrahydro-6H-benzo[c]chromene core of palodesangrens could be assembled in a biomimetic and step-economical fashion by the Diels-Alder reaction between the electron-rich (E)-1,3-butadienylarenes as the diene and the electron-deficient chalcones as the dienophile. During the reduction of ketone to the corresponding alcohol by LiAlH4, the mixture of endo and exo isomers underwent a novel diastereoconvergent LiAlH4-mediated isomerization to install the desired stereochemistry at C10a. Subsequent pyran ring closure under acidic conditions installed the stereochemistry at the remaining C6. Overall, the tricyclic core of palodesangrens could be prepared in three steps and up to 38% yield.
- Songthammawat, Poramate,Wangngae, Sirilak,Matsumoto, Koki,Duangkamol, Chuthamat,Ruchirawat, Somsak,Ploypradith, Poonsakdi
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p. 5225 - 5241
(2018/05/07)
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- Chalcones, inhibitors for topoisomerase i and cathepsin B and L, as potential anti-cancer agents
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In order to diversify the pharmacological activity of chalcones and extend the scaffold of topoisomerase and cathepsins B and L inhibitors, we have designed and synthesized total 18 chalcone compounds and tested their biological activity. In the topoisome
- Kim, Seok-Ho,Lee, Eunyoung,Baek, Kyung Hye,Kwon, Han Byeol,Woo, Hyunjung,Lee, Eung-Seok,Kwon, Youngjoo,Na, Younghwa
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p. 3320 - 3324
(2013/06/27)
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- Synthesis and topoisomerase II inhibitory and cytotoxic activity of oxiranylmethoxy- and thiiranylmethoxy-chalcone derivatives
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In order to find potential anticancer drug candidate targeting topoisomerases enzyme, we have designed and synthesized oxiranylmethoxy- and thiiranylmethoxy-retrochalcone derivatives and evaluated their pharmacological activity including topoisomerases inhibitory and cytotoxic activity. Of the compounds prepared compound 25 showed comparable or better cytotoxic activity against cancer cell lines tested. Compound 25 inhibited MCF7 (IC50: 0.49 ± 0.21 μM) and HCT15 (IC50: 0.23 ± 0.02 μM) carcinoma cell growth more efficiently than references. In the topoisomerases inhibition test, all the compounds were inactive to topoisomerase I but moderate inhibitors to topoisomerase II enzyme. Especially, compound 25 inhibited topoisomerase II activity with comparable extent to etoposide at 100 μM concentrations. Correlation between cytotoxicity and topoisomerase II inhibitory activity implies that compound 25 can be a possible lead compound for anticancer drug impeding the topoisomerase II function.
- Na, Younghwa,Nam, Jung-Min
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scheme or table
p. 211 - 214
(2011/02/25)
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- Biologically active 1,3-bis-aromatic-prop-2-en-1-ones, 1,3-bis-aromatic-propan-1-ones, and 1,3-bis-aromatic-prop-2-yn-1-ones
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The invention relates to the use of 1,3-bis-aromatic-prop-2-en-1-ones (chalcones), 1,3-bis-aromatic-propan-1-ones (dihydrochalcones), and 1,3-bis-aromatic-prop-2-yn-1-ones for the preparation of pharmaceutical compositions for the treatment or prophylaxis of a number of serious diseases including i) conditions relating to harmful effects of inflammatory cytokines, ii) conditions involving infection by Helicobacter species, iii) conditions involving infection by viruses, iv) neoplastic disorders, and v) conditions caused by microorganisms or parasites. The invention also relates to novel chalcones and dihydrochalcones (especially alkoxy substituted variants) having advantageous substitution patterns with respect to their effect as drug substances, and to methods of preparing them, as well as to pharmaceutical compositions comprising the novel chalcones. Moreover, the present invention relates to a method for the isolation of Leishmania fumarate reductase, QSAR methodologies for selecting potent compounds for the above-mentioned purposes.
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- FLAVONOID AND OTHER CONSTITUENTS OF BAUHINIA MANCA
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Phytochemical analysis of the stem of Bauhinia manca yielded 63 compounds, among them six new natural products.Major constituents were found to be 3-O-galloylepicatechin, gallic acid, cinnamic acid, β-sitosterol and its β-D-glucoside.The two new flavans possess significant antifungal activity.Key Word Index-Bauhinia manca; Leguminosae; 5,5-dimethoxylariciresinol; 4-O-methylisoliquiritigenin; 4'-O-methylliquiritigenin; 7,3'-dimethoxy-4-hydroxyflavan; 3',4'-dihydroxy-7-methoxyflavan; 2,4'-dihydroxy-4-methoxydihydrochalcone; antimicrobial activity.
- Achenbach, Hans,Stoecker, Markus,Constenla, Manuel A.
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p. 1835 - 1842
(2007/10/02)
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- Flavonoids from the cultured cells of Glycyrrhiza echinata
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Constituents of the cultured cells of Glycyrrhiza echinata have been investigated. Echinatin (4,4′-dihydroxy-2-methoxychalcone), a biosynthetically unique retrochalcone, and licodione (1-(2,4-dihydroxyphenyl)-3-(4-hydroxyphenyl)-1,3-propanedione), a dibezoylmethane derivative, which is the possible precursor of echinatin, were obtained. The structures were determined by spectroscopic methods and syntheses. 1H NMR of licodione revealed new features in chemical shifts of protons of diketonic and keto-enolic forms. 7,4′-Dihydroxyflavone, two of its prenyl derivatives and formononetin were also isolated. A discussion on retrochalcone biosynthesis is presented.
- Ayabe, Shin-Ichi,Kobayashi, Miyuki,Hikichi, Manabu,Matsumoto, Kazuo,Furuya, Tsutomu
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p. 2179 - 2183
(2007/10/02)
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