2315-05-1Relevant articles and documents
THE USE OF LIPOPHILIC BETA-LACTAM ANTIBIOTICS AND CARBOXYLATE ESTERS FOR THE TREATMENT OF BACTERIAL INFECTIONS WITHIN CITRUS AND OTHER PLANT SPECIES
-
Paragraph 0035-0036; 0037; 0048, (2020/08/05)
Disclosed is method for converting a beta-lactam antibiotic into a “masked” beta-lactam antibiotic to permit it to cross the waxy cuticle of a plant and then subsequently unmasking the beta-lactam and converting it into an active beta-lactam antibiotic in
Synthesis of new penicillin derivatives as drug-like molecules for biological screening
Liu, Chun-Jing,Dutta, Dinah,Mitscher, Lester
, p. 113 - 117 (2015/01/30)
Chemical modification of penicillin β-lactam ring was made. Six thiazolidine amides were produced through N4-C7 β-lactam ring opening of penicillin V methyl ester with various aliphatic, aromatic, and heterocyclic primary amines. Five 8-hydroxypenillic ac
CEPHALOSPORIN DERIVATIVES AND METHODS OF USE
-
Paragraph 0046; 0047; 00119, (2014/05/24)
This invention provides cephalosporin derivatives for killing or inhibiting the spread of microorganisms such as non-replicating Mycobacterium tuberculosis and in the treatment of infectious disease.
Alkylating polymers: Resin-released carbenium ions as versatile reactive intermediates in polymer-assisted solution-phase synthesis
Rademann, Jorg,Smerdka, Joachim,Jung, Gnther,Grosche, Philipp,Schmid, Dietmar
, p. 381 - 385 (2007/10/03)
Solid-supported diazoalkane analogues for the smooth and clean esterifications of carboxylic acids [Eq. (1)] as well as of complex compound mixtures: the alkylating polymers presented here were synthesized as solid-supported 3-alkyl-l-aryltriazenes and ar
Synthesis and decarboxylation of Δ2-cephem-4,4-dicarboxylic acids
Wolfe,Ro,Kim,Shi
, p. 1238 - 1258 (2007/10/03)
Penicillin V was converted in 14 steps into Δ2-cephems having hydrogen at C-3, hydrogen or methyl at C-2, and two methoxycarbonyl, two benzyloxycarbonyl, or one methoxycarbonyl and one benzyloxycarbonyl substituent at C-4. Deprotection of these Δ2-cephem-4,4-dicarboxylic acid esters by alkaline hydrolysis (in the case of methyl esters) or hydrogenolysis (in the case of benzyl esters) led in all cases to rapid decarboxylation of the Δ2-cephem-4,4-dicarboxylic acid or Δ2-cephem-4,4-dicarboxylic acid monoester. With hydrogen at C-2, hydrolysis of the dimethyl ester with 1 equiv of base produced a Δ2-cephem. With 2 equiv of base, and with all compounds having methyl at C-2, hydrolysis or hydrogenolysis afforded 4α-substituted-Δ2-cephems. In contrast, simpler benzyl or methyl acetamidomalonates could be deprotected without difficulty to afford stable malonic acids. Reasons for the differences in ease of decarboxylation were examined using semiempirical (AM1) and ab initio (3-21G) molecular orbital calculations. The decarboxylation barriers of unionized cephem or acetamido malonic acids were found to be high (35-40 kcal mol-1). Although the monoanion of acetamidomalonic acid retained a high barrier, the epimeric monoanions of a Δ2-cephem malonic acid decarboxylated with barriers of only 2 kcal mol-1.
Penicillin Biosynthesis: Direct Biosynthetic Formation of Penicillin V and Penicillin G
Baldwin, Jack E.,Abraham, Edward P.,Burge, Geoffrey L.,Ting, Hong-Hoi
, p. 1808 - 1809 (2007/10/02)
The enzyme isopenicillin N synthetase is able to convert directly the dipeptides, phenoxyacetylcysteinylvaline and phenylacetylcysteinylvaline into penicillin V and G respectively; these are however very slow compared with substrates of the α-aminoadipoyl or adipoylcysteinylvaline type.
Chemical ionization mass spectrometry of β lactam antibiotics
Mitscher,Hollis Showalter,Shirahata,Foltz
, p. 668 - 675 (2007/10/04)
Chemical ionization (CI) mass spectra are described for methyl esters of eight clinically significant penicillins and their breakdown products. These substances give spectra with very few fragment ions and contain easily discernible protonated molecule ions. The main cleavage reaction is postulated to involve a retro 2 + 2 Diels Alder type fragmentation of the β lactam ring liberating one fragment (m/e=174) that is characteristic of the penicillin nucleus and a second fragment that is molecule specific, as it contains the elements of the side chain. The other fragment ions, though interesting, are of minor intensity. The free acids, on the other hand, fragment more extensively because of their relative instability and lack of volatility. These spectra resemble electron impact spectra more closely and, though they encode more structural information, are less reproducible from run to run. The ease with which the esters can be made and the relative simplicity of their CI mass spectra make this method significant for the identification and characterization of β lactam antibiotics.
