Erythromycins, chemical structure

XXIV) Structural formula of erythromycin. Chemical structure of the erythromycins... 

Structural Formula See Erythromycin for structure of base. Chemical Abstracts Registry No. 3847-29-8... 

Antibiotics may be classified by chemical structure. Erythromycin, chloramphenicol, ampicillin, cefpodoxime proxetil, and doxycycline hydrochloride are antibiotics whose primary structures differ from each other (Fig. 19). Figure 20 shows potential oscillation across the octanol membrane in the presence of erythromycin at various concentrations [23]. Due to the low solubility of antibiotics in water, 1% ethanol was added to phase wl in all cases. Antibiotics were noted to shift iiB,sDS lo more positive values. Other potentials were virtually unaffected by the antibiotics. On oscillatory and induction periods, there were antibiotic effects but reproducibility was poor. Detailed study was then made of iiB,sDS- Figure 21 (a)-(d) shows potential oscillation in the presence of chloramphenicol, ampicillin, cefpodoxime proxetil, and doxycycline hydrochloride [21,23]. Fb.sds differed according to the antibiotic in phase wl and shifted to more positive values with concentration. No clear relationship between activity and oscillation mode due to complexity of the antibacterium mechanism could be discovered but at least it was shown possible to recognize or determine antibiotics based on potential oscillation measurement. 

FIG. 19 Chemical structures of (a) erythromycin, (b) chloramphenicol, (c) ampicillin, (d) cefpo-doxime proxetil, and (e) doxycycline hydrochloride. 

Kosan Biosciences was formed almost 6 years ago, founded on an interest in polyketides, microbial metabolite-based drugs. Polyketides have many diverse chemical structures including erythromycin, which will be mentioned again later. These chemicals include fused-ring aromatic compounds, compounds decorated with sugars, and compounds with large stretches of double bonds. Each of these compounds has different biological activities and utilities, but they are all made in nature by very similar biochemistry. 

Modification of Chemical Structure of Drug The use of a Hammett linear free-energy relationship to investigate the effects of substituents on the rates of aromatic side-chain reactions such as hydrolysis of esters has been alluded to earlier vis-a-vis attainment of optimum stability [9,10]. Degradation of erythromycin under acidic pH conditions is inhibited by substituting a methoxy group for the C-6 hydroxyl as found for the acid stability of clathromycin, which is 340 times greater than that of erythromycin [70]. 

Tolman KG, Sannella JJ, Freston JW. Chemical structure of erythromycin and hepatotoxicity. Ann Intern Med 1974 81(l) 58-60. 

The commercial product is erythromycin A. which differs from its bio.syntlietic precursor, erythromycin B, in having a hydroxyl group at the 12 position of the aglycone. The chemical structure of erythromycin A was reported by Wiley et al. in I9.S7 and its stereochemistry by Celmer in 1965. An elegant synthesis of erythronolidc A, the aglycone pre.sent in erythromycin A. wa.s described by Corey and associates. ... 

Certain types of soil bacteria make the antibiotic erythromycin—a complicated chemical structure containing 37 atoms of carbon, 13 atoms of... 

Figure 11.17 (a) Chemical structures of macrolide antibiotics (note that erythromycin, ETM, was analyzed as its anhydro form shown, (ETM-H2O)), but tylosin (TLS) was analyzed as the intact protonated molecule. Spiromycin (SPM) was used as the internal standard, (b) Multiple reaction monitoring (MRM) chromatograms of macrolides, each spiked at a concentration of 300ng.L before extraction from 100 mL of influent wastewater from a water reclamation plant. The MRM transitions used for quantitation are shown in each case (the precursor ion for Spiromycin I was the (M+2H) + ion, the others were (M+H)+ ions), and the total ion current (TIC) chromatogram is simply the sum of the three MRM traces. Reproduced from Yang, Anal. Bioanal Chem. 385, 623 (2006), with permission from Springer Science and Business Media. 

FIGURE 5.4 Chemical structures of (a) (—)-erythromycin and (b) (—)-vancomycin hydrochloride. 

Ribosomal Protein Synthesis Inhibitors. Figure 5 Nucleotides at the binding sites of chloramphenicol, erythromycin and clindamycin at the peptidyl transferase center. The nucleotides that are within 4.4 A of the antibiotics chloramphenicol, erythromycin and clindamycin in 50S-antibiotic complexes are indicated with the letters C, E, and L, respectively, on the secondary structure of the peptidyl transferase loop region of 23S rRNA (the sequence shown is that of E. coll). The sites of drug resistance in one or more peptidyl transferase antibiotics due to base changes (solid circles) and lack of modification (solid square) are indicated. Nucleotides that display altered chemical reactivity in the presence of one or more peptidyl transferase antibiotics are boxed. 

Therapeutic Function Antibiotic Chemical Name Erythromycin, 6-O-methyl-Common Name Clarithromycin Structural Formula ... 

Therapeutic Function Antibacterial Chemical Name Erythromycin propionate lauryl sulfate Common Name -Structural Formula ... 

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