Selective Cleavage of Boc-acylamides. A Novel Approach to Deacylation of Carboxamides.

Grehn, Leif; Gunnarsson, Kerstin; Ragnarsson, Ulf; Cheung, Kwai-Ming J.; Utley, James H. P.

doi:10.3891/acta.chem.scand.41b-0018

Cited by 36 publications

(26 citation statements)

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“…Because of its highly crystalline nature, one recrystallization of 3 f (89:11 er) afforded enantiopure 3 f (99:1 er). The Ac group of 3 f was converted into the Boc group of 3 a by treating with Boc 2 O and DMAP, and subsequently with K 2 CO 3 and MeOH 18. Acid‐promoted deprotection of 3 a gave rise to the free amine 7 .…”

Section: Methodsmentioning

confidence: 99%

Engineering stress tolerance of Escherichia coli by stress‐induced mutagenesis (SIM)‐based adaptive evolution

Zhu

Zhang

et al. 2013

Biotechnology Journal

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Microbial tolerance to toxic products and biomass hydrolysates is a challenge for the production of fuels and chemicals from renewable resources. To improve cellular tolerance to these environmental stresses, a novel adaptive evolutionary strategy based on stress-induced mutagenesis (SIM) was developed using non-dividing cells. The concept of this method was proved using Escherichia coli FC40 as a model strain, which was used to quantitatively evaluate the rate of SIM. By deleting either the mutL or mutS gene to disturb the mismatch repair activity of the host cells, the SIM rate under stressful conditions increased by 92- and 57-fold, respectively. A periodic SIMbased adaptive evolution procedure, which synchronized the mutagenesis and the selection process in a single plate-incubation step, was then developed using the mutL-deleted mutant. E. coli mutants tolerant to high concentrations of butanol (13 g/L), NaCl (95 g/L), and high temperature (50°C) were obtained. These results indicate that stress-induced adaptive evolution in non-dividing cells is an effective approach that can improve microbial tolerance against various stresses and generate robust microbial strains suitable for production of fuels and chemicals.

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Section: Methodsmentioning

confidence: 99%

Engineering stress tolerance of Escherichia coli by stress‐induced mutagenesis (SIM)‐based adaptive evolution

Zhu

Zhang

et al. 2013

Biotechnology Journal

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“…One-pot replacement of the 4-methoxy-3-hydroxypicolinamide with a Boc carbamate provided a more robust intermediate (1) able to withstand a variety of reaction conditions. 12,19 The phenyl ring of 1 was reduced to cyclohexyl (14) using catalytic 5% Rh on carbon. Alternatively, oxidative cleavage of the phenyl ring using catalytic ruthenium trichloride and excess sodium periodate cleanly gave the carboxylic acid 2.…”

Section: Synthesis Of Title Compoundsmentioning

confidence: 99%

Synthesis and biological activity of analogs of the antifungal antibiotic UK‐2A. II. Impact of modifications to the macrocycle benzyl position

Owen

Meyer

Slanec

et al. 2019

Pest Management Science

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BACKGROUND: UK-2A is an antifungal antibiotic produced by Streptomyces sp. 517-02. Derivatization of its picolinamide OH to form the isobutyryl acetal led to the discovery of fenpicoxamid (InatreqTM active), which is currently under development as a fungicide by Dow AgroSciences LLC. This paper documents efforts to achieve additional efficacy enhancements through semi-synthetic modification of the benzyl substituent of the UK-2A macrocycle.RESULTS: Of 34 analogs prepared, the most active had mitochondrial electron transport IC 50 values 1.5-to 3.7-fold higher than UK-2A (IC 50 0.86 nM). The cyclohexyl analog (38, IC 50 1.23 nM) was the most intrinsically active derivative, and inhibited in vitro growth of Zymoseptoria tritici (EC 50 2.8 ppb) and Leptosphaeria nodorum (EC 50 6.2 ppb) more strongly than UK-2A (EC 50 5.3 and 11.3 ppb for Z. tritici and L. nodorum, respectively). Heterocyclic ring systems and polar linker functionalities resulted in substantial activity loss . Several analogs (20, 22, 23, 24, 36 and 38) translated Z. tritici in vitro growth inhibition activity to in planta disease control more effectively than did UK-2A, with log D being a key factor in this regard. CONCLUSIONS: UK-2A is amenable to further modification at the benzyl position on the macrocycle, which provides opportunities for manipulation of physical properties while retaining strong intrinsic and antifungal activity.

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“…The colored substrate 17c (62 mg, 0.11 mmol) was treated with DEAEA (62 ϫ 10 Ϫ3 mL, 0.44 mmol) for two days according to the procedure of Grehn [25] et al The product was chromatographed with diethyl ether/hexane (2:8) as the eluent to give ester 18c (16 mg, 50%) as an oil. TLC (chloroform/methanol, 5.8:0.2): R f ϭ 0.90.…”

Section: N-{3-[(nn-dimethylaminophenyl)-4ј-diazenyl]phenylacetyl}-n-mentioning

confidence: 99%

Chromophoric Azo Reagents for Amino Acid and Peptide Labelling

et al. 2004

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Selective Cleavage of Boc-acylamides. A Novel Approach to Deacylation of Carboxamides.

Cited by 36 publications

References 0 publications

Engineering stress tolerance of Escherichia coli by stress‐induced mutagenesis (SIM)‐based adaptive evolution

Engineering stress tolerance of Escherichia coli by stress‐induced mutagenesis (SIM)‐based adaptive evolution

Synthesis and biological activity of analogs of the antifungal antibiotic UK‐2A. II. Impact of modifications to the macrocycle benzyl position

Chromophoric Azo Reagents for Amino Acid and Peptide Labelling

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