- Asymmetric oxidation of 1,3-propanediols to chiral hydroxyalkanoic acids by Rhodococcus sp. 2N
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Rhodococcus sp. 2N was found as a 1,3-propanediols-oxidizing strain from soil samples through enrichment culture using 2,2-diethyl-1,3-propanediol (DEPD) as the sole carbon source. The culture condition of the strain 2N was optimized, and the highest activity was observed when 0.3% (w/v) DEPD was added in the culture medium as an inducer. Chiral HPLC analysis of the hydroxyalkanoic acid converted from 2-ethyl-2-methyl-1,3-propanediol (EMPD) revealed that the strain 2N catalyzed the (R)-selective oxidation of EMPD. The reaction products and intermediates from DEPD and EMPD were identified by nuclear magnetic resonance analyses, and the results suggested that only one hydroxymethyl group of the propanediols was converted to carboxy group via two oxidation steps. Under optimized conditions and after a 72-h reaction time, the strain 2N produced 28 mM (4.1 g/L) of 2-(hydroxymethyl)-2-methylbutanoic acid from EMPD with a molar conversion yield of 47% and 65% ee (R).
- Kikukawa, Hiroshi,Koyasu, Rena,Yasohara, Yoshihiko,Ito, Noriyuki,Mitsukura, Koichi,Yoshida, Toyokazu
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p. 768 - 773
(2019/04/29)
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- A convenient one-pot synthesis of 2,2-dialkyl-2,3-dihydro-1H-naphtho[2,1-b] pyrans
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This work describes a convenient one-pot procedure for the synthesis of 2,2-disubstituted 2,3-dihydro-177-naphtho[2,1-b]pyrans {i.e. 2,2-disubstituted 1H-benzo[f]chromans} by the reaction of 2-tetralones and α,α- disubstituted β-hydroxy propionaldehydes under acidic conditions. Georg Thieme Verlag Stuttgart.
- Jha, Amitabh,Huang, Po-Jung Jimmy,Mukherjee, Chandrani,Paul, Nawal K.
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p. 3127 - 3130
(2008/09/19)
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- Discovery of potent, nonsystemic apical sodium-codependent bile acid transporter inhibitors (part 1)
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Elevated plasma levels of low-density lipoprotein (LDL) cholesterol are a major risk factor for atherosclerosis leading to coronary artery disease (CAD), which remains the main cause of mortality in Western society. We believe that by preventing the reabsorption of bile acids, a minimally absorbed apical sodium-codependent bile acid transporter (ASBT) inhibitor would lower the serum cholesterol without the potential systemic side effects of an absorbed drug. A series of novel benzothiepines (3R,3R′-2,3,4,5-tetrahydro-5-aryl-1- benzothiepin-4-ol 1,1-dioxides) were synthesized and tested for their ability to inhibit the apical sodium dependent bile acid transport (ASBT)-mediated uptake of [14C] taurocholate (TC) in H14 cells. A 3R,4R,5R/3S,4S,5S racemate was found to have greater potency than the other three possible racemates. Addition of electron-donating groups such as a dimethylamino substituent at the 7 position greatly enhanced potency, and incorporation of a long-chain quaternary ammonium substituent on the 5-phenyl ring was useful in minimizing systemic exposure of this locally active ASBT inhibitor while also increasing water solubility and maintaining potency. The reported results describe the synthesis and SAR development of this benzothiepine class of ASBT inhibitors resulting in an 6000-fold improvement in ASBT inhibition with desired minimal systemic exposure of this locally acting drug candidate.
- Tremont, Samuel J.,Lee, Len F.,Huang, Horng-Chih,Keller, Bradley T.,Banerjee, Shyamal C.,Both, Scott R.,Carpenter, Andrew J.,Wang, Ching-Cheng,Garland, Danny J.,Huang, Wei,Jones, Claude,Koeller, Kevin J.,Kolodziej, Steve A.,Li, James,Manning, Robert E.,Mahoney, Matthew W.,Miller, Raymond E.,Mischke, Deborah A.,Rath, Nigam P.,Fletcher, Theresa,Reinhard, Emily J.,Tollefson, Michael B.,Vernier, William F.,Wagner, Grace M.,Rapp, Steve R.,Beaudry, Judy,Glenn, Kevin,Regina, Karen,Schuh, Joe R.,Smith, Mark E.,Trivedi, Jay S.,Reitz, David B.
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p. 5837 - 5852
(2007/10/03)
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- A Novel Synthesis of 14-(Hydroxymethylalkyl) Derivatives of Dibenzoxanthenes and 3,3-Dimethyl-4-(2-hydroxy-1-naphthyl)benzochroman
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Several reactions of 2-naphthol with 2-alkyl-2-hydroxymethylaldehydes have been investigated.Novel synthesis of 14-(hydroxymethyl)alkyldibenzoxanthenes and 3,3-dimethyl-4-(2-hydroxy-1-naphthyl)benzochroman has been realized.
- Sirkecioglu, Okan,Tahnh, Naciye,Akar, Ahmet
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p. 456 - 460
(2007/10/03)
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