Deamination of the Epimeric 3-Aminoandrost-5-en-17-ones and 6-Amino-3α,5α-cycloandrostan-17-ones

Tadanier, Jack; Cole, Wayne

doi:10.1021/jo01059a116

Cited by 4 publications

(2 citation statements)

References 4 publications

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“…Deamination of Ala2 in LPS from serotypes O6 and O57 led exclusively to racemic mixture of a O ‐nitroso‐lactic acid derivative as a result of the substitution of the diazo group with nitrite anion, rather then to lactic acid. A similar reaction was observed previously during deamination of steroids [13]. The stereochemistry of the lactic acid derivative influenced the spectra of Ala1 and 4‐aminoquinovose Q, which gave two sets of signals, whereas three other components S, L and M were insensitive to it.…”

Section: Resultssupporting

confidence: 74%

Structural analysis of the core region of lipopolysaccharides from Proteus mirabilis serotypes O6, O48 and O57

Vinogradov

Perry

2000

European Journal of Biochemistry

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The structure of lipid A core region of the lipopolysaccharides (LPS) from Proteus mirabilis serotypes O6, O57 and O48 was determined using NMR, MS and chemical analysis of the oligosaccharides, obtained by mild acid hydrolysis, alkaline deacylation, and deamination of LPS:Incomplete substitutions are indicated by bold italic type. All sugars are present in pyranose form, a-Hep is the residue of l-glycero-a-d-manno-Hep, a-dd-Hep is the residue of d-glycero-a-d-manno-Hep, l-Ara4N is 4-amino-4-deoxy-l-arabinose, Qui4NAlaAla is the residue of 4-N-(l-alanyl-l-alanyl)-4-amino-4,6-dideoxyglucose. All sugars except l-Ara4N have d-configuration. b-GalA* is partially present in the form of amide with 1,4-diaminobutane (putrescine)-HN(CH 2 ) 4 NH 2 or spermidine-HN(CH 2 ) 3 NH(CH 2 ) 4 NH 2 .Keywords: LPS; Proteus; Proteus mirabilis; core.Gram-negative bacteria of the genus Proteus are important pathogens causing nosocomial and urinary tract infections [1]. Lipopolysaccharides (LPS) have been identified as an important virulence factor of P. mirabilis [2]. O-Antigens (LPS) and H-antigens (flagellar) have been extensively investigated and so far 49 different O serogroups and 19 distinct H antigens have been recognized from Proteus mirabilis and P. vulgaris [3]. The structure of the core part of Proteus LPS is variable, all strains examined until now have had unique core structures. Recently the structures of the LPS cores from P. vulgaris serotype O2, P. mirabilis serotypes O3, O27, and P. penneri strains 16, 17, 18 were determined [4±6]. Structural analysis of several other strains revealed that LPS from three serotypes of P. mirabilis, O6, O48 and O57, give the same products after alkaline deacylation, which was the reason for the presentation of their structures in one publication. The structures of the O-specific polysaccharides from strains O57 and O6 were published [7,8]. E X P E R I M E N T A L P R O C E D U R E SBacterial strains and lipopolysaccharide isolation.P. mirabilis O6 (strain 2573, NRCC 4337, ATCC 49565), O48 (strain 9615, NRCC 4420) and O57 (strain 3735, NRCC 4417, ATCC 49995) were cultivated and LPS isolated as previously described [7].NMR spectroscopy and general methods 1 H and 13 C NMR spectra were recorded using a Varian Inova 500 spectrometer in D 2 O solutions at 25 8C with acetone standard (2.225 p.p.m. for 1 H and 31.5 p.p.m. for 13 C) using standard pulse sequences gDQCOSY, TNTOCSY (mixing time 120 ms), TNNOESY, TNROESY, gHSQC, gHMBC (optimized for 5 Hz coupling constant), gHSQC-TOCSY. NOESY (mixing time 200 ms) spectra were recorded for large oligosaccharides, ROESY (mixing time 250 ms) for compounds 4±6 (compounds in bold type refer to Scheme 1 throughout). 31 P and 1 H-31 P HMQC (optimized for 7 Hz coupling constant) spectra were recorded on Varian Inova 400 spectrometer. Spectra were assigned with the help of a pronto program [9]. Electrospray

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Section: Resultssupporting

confidence: 74%

Structural analysis of the core region of lipopolysaccharides from Proteus mirabilis serotypes O6, O48 and O57

Vinogradov

Perry

2000

European Journal of Biochemistry

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“…3 % (mol %). A small portion of the sample was evacuated (0.01 Torr) at ambient temperature for 10 hr and submitted for analysis.73 ívyí/zro-3-Pheny 1-2-butyl chloroformate (18) was prepared in 91 % yield from ery?Aro-3-phenyl-2-butanol and phosgene. A portion of the sample was passed over Florex AA-LVM 60-90 mesh in pentane and the resulting solution was concentrated with a nitrogen stream and held under vacuum at 0.01 Torr for 80 min to give eryrtro-3-phenyl-2-butyl chloroformate:73 ir (neat) 1774 cm-1 (C=0); nmr 7.17 (s, 5 ), 5.00 (doublet of quartets, J = 6.5 and 8 Hz, 1 H), 2.88 (broadened quintet, J = 7.3 Hz, 1 ), 1.32 (d, 7 = 7 Hz, 3 H), and 1.15 (d, J = 6.5 Hz, 3 H).…”

Section: Experimental Section69mentioning

confidence: 99%

Reaction of cis- and trans-4-tert-butylcyclohexyl and erythro- and threo-3-phenyl-2-butyl chloroformates and chlorides with silver hexafluoroantimonate in acetic acid. Comparison with deaminations and solvolyses

Beak¹,

Adams²,

Barron³

1974

J. Am. Chem. Soc.

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The acetate and olefin products from the reactions of cis-and rraní-4-rezt-butylcyclohexyl and erythroand r/zra>3-phenyl-2-butyl chloroformates and chlorides with silver hexafluoroantimonate in acetic acid are identified and found to be consistent with the hypothesis that the reactions of the chloroformates are similar to deaminations and are different from the reactions of the chlorides, which, in turn, resemble solvolyses. Deuterium labeled reactants are used to delineate the rearrangement reactions of both types of chloroformates. It is established by oxygen-18 labeling that the products from the 4-ren-butylcycIohexyl substrates do not arise from acetic (4-tertbutylcyclohexyl)carbonic anhydride. The acetates from the reaction of cis-and ?ra«j-Ar-(4-/e/-i-butylcyclohexyl)sulfinylamines with nitrosyl hexafluoroantimonate in acetic acid are found to be similar to those from the corresponding chloroformates. The results are interpreted in terms of silver assisted reactions of the chloroformates primarily by initial ionization (kc) to an ion pair in which the cation resembles the reactant and in terms of silver assisted reaction of the chlorides predominantly by classical nucleophilic participation by neighboring groups (kf) or solvent (ks). These proposals are in accord with previous suggestions for deaminations and solvolyses and are noted to provide an appealing mechanistic rationale for distinction between those reactions as well.similarity between the silver promoted dehalodecarboxylation of alkyl chloroformates and the

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Chretien‐Longi Reaction

2010

Comprehensive Organic Name Reactions and Reagents

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Deamination of the Epimeric 3-Aminoandrost-5-en-17-ones and 6-Amino-3α,5α-cycloandrostan-17-ones

Cited by 4 publications

References 4 publications

Structural analysis of the core region of lipopolysaccharides from Proteus mirabilis serotypes O6, O48 and O57

Structural analysis of the core region of lipopolysaccharides from Proteus mirabilis serotypes O6, O48 and O57

Reaction of cis- and trans-4-tert-butylcyclohexyl and erythro- and threo-3-phenyl-2-butyl chloroformates and chlorides with silver hexafluoroantimonate in acetic acid. Comparison with deaminations and solvolyses

Chretien‐Longi Reaction

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