Structure, carboxyl group

Other centrosymmetric structures can be drawn these have the two hydrogen atoms out of the plane of the carboxyl groups, however, and are less likely to occur, in view of the known planarity of carboxyl groups. Structures in which the carbonyl groups are syn to each other do not have a center of symmetry. 

Leenheer, J.A., Wershaw, R.L. and Reddy, M.M. (1995a) Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 1. Minor structures. Environ. Sci. Technol, 29, 393-398. 

Fig. 8-15. Possible carboxyl group structures formed in cellulose during chlorine and hypochlorite stages. 1, Arabinonic acid 2, erythronic acid 3, glucuronic acid 4, dicarboxylic acid.

Ochratoxin A (OTA) is dangerous to human health, and its legal limits in grape and wine are fixed. The molecule consists of an isocoumarin derivative linked to phenylalanine through a carboxyl group (structure reported in Fig. 8.1). 

The structural features of the carboxyl group are most apparent m formic acid Formic acid IS planar with one of its carbon-oxygen bonds shorter than the other and with bond angles at carbon close to 120°... 

Hydrolysis of cinenn I gives an optically active carboxylic acid (+) chrysanthemic acid Ozonolysis of (+) chrysanthemic acid followed by oxidation gives acetone and an optically active dicarboxyhc acid (—) caronic acid (C7H10O4) What is the struc ture of (—) caronic acid" Are the two carboxyl groups cis or trans to each other What does this information tell you about the structure of (+) chrysanthemic acid" ... 

Muzolimine (710), a 1-substituted 2-pyrazolin-5-one derivative, is a highly active diuretic, differing from the structures of other diuretics since it contains neither a sulfonamide nor a carboxyl group. It has a saluretic effect similar to furosemide and acts in the proximal tubule and in the medullary portion of the ascending limb of the loop of Henle. Pharmacokinetic studies in dogs, healthy volunteers and in patients with renal insufficiency show that the compound is readily absorbed after oral administration (B-80MI40406). 

The structures and abbreviations for the 20 amino acids commonly found in proteins are shown in Figure 4.3. All the amino acids except proline have both free a-amino and free a-carboxyl groups (Figure 4.1). There are several ways to classify the common amino acids. The most useful of these classifications is based on the polarity of the side chains. Thus, the structures shown in Figure 4.3 are grouped into the following categories (I) nonpolar or hydrophobic... 

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