- Plant growth regulators and Axl and immune checkpoint inhibitors from the edible mushroom Leucopaxillus giganteus
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A novel compound, (R)-4-ethoxy-2-hydroxy-4-oxobutanoic acid (1), and six known compounds (2–7) were isolated from the fruiting bodies of the wild edible mushroom Leucopaxillus giganteus. The planar structure of 1 was determined by the interpretation of spectroscopic data analysis. The absolute configuration of 1 was determined by comparing specific rotation of the synthetic compounds. In the plant regulatory assay, the isolated compounds (1–7) and the chemically prepared compounds (8–10) were evaluated their biological activity against the lettuce (Lactuca sativa) growth. Compounds 1 and 3–10 showed the significant regulatory activity of lettuce growth. 1 showed the strongest inhibition activity among the all the compounds tested. In the lung cancer assay, all the compounds were assessed the mRNA expression of Axl and immune checkpoints (PD-L1, PD-L2) in the human A549 alveolar epithelial cell line by RT-PCR. Compounds 1–10 showed significant inhibition activity against Axl and/or immune checkpoint.
- Choi, Jae-Hoon,D’Alessandro-Gabazza, Corina N.,Gabazza, Esteban C.,Harada, Etsuko,Hirai, Hirofumi,Kawagishi, Hirokazu,Malya, Irine Yunhafita,Toda, Masaaki,Wu, Jing,Yasuma, Taro
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p. 1332 - 1338
(2020/03/31)
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- A one-pot combination of amine and heterocyclic carbene catalysis: direct asymmetric synthesis of β-hydroxy and β-malonate esters from α,β-unsaturated aldehydes
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The one-pot combination of amine and heterocyclic carbene catalysis (AHCC) enabled the synthesis of β-hydroxy, β-malonate and β-amino esters from α,β-unsaturated aldehydes with high enantioselectivity (91-97% ee).
- Zhao, Gui-Ling,Córdova, Armando
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p. 5976 - 5980
(2008/02/10)
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- Enantiomerically pure tetrahydro-5-oxo-2-furancarboxylic esters from dialkyl 2-oxoglutarates
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Enantiomerically pure tetrahydro-5-oxo-2-furancarboxylic esters can be prepared either by enzymatic resolution of the racemic γ-lactones themselves or by bioreduction with baker's yeast of dialkyl 2-oxoglutarates and subsequent cyclization of the resulting dialkyl 2-hydroxyglutarates. The best results were obtained by the former route, by which the desired compounds were isolated in high enantiomeric excess. Bioreductions were less satisfactory. In fact the hydroxyester intermediates were initially formed as racemic mixtures and their final enantiomeric enrichment was reached by asymmetric destruction, occurring in the bioreaction medium, however at the same time large amounts of alkyl 4-hydroxybutanoates were formed as side products.
- Drioli, Sara,Nitti, Patrizia,Pitacco, Giuliana,Tossut, Laura,Valentin, Ennio
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p. 2713 - 2728
(2007/10/03)
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- A Biocatalytic Approach to the Enantioselective Synthesis of (R)- and (S)-Malic Acid
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(S)-Diethyl malate 1a was prepared (70-80percent yield; >98percent optical purity) by an enantioselective reduction of sodium diethyl oxalacetate 2 by fermenting baker's yeast (Saccharomyces cerevisiae).Other microorganisms were tested for their capability of reducing 2.Most of them afforded (S)-1a with ee from 8 to 94percent and only Candida utilis, Aspergillus niger and Lactobacillus fermentum ILC G18D preferentially reduced compound 2 to (R)-1a. (R)-Dimethyl malate 1b was obtained from (R,S)-malate 1b by hydrolysis with pig liver esterase (PLE), the highest ee (93percent) being realized at 0 deg C in 20percent aqueous methanol.Enzymatic hydrolyses of protected malates 1d and 1e did not lead to improvement of the ee.
- Santaniello, Enzo,Ferraboschi, Patrizia,Grisenti, Paride,Aragozzini, Fabrizio,Maconi, Elisabetta
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p. 601 - 605
(2007/10/02)
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