Para-amino benzoic

Dihydropteroic acid (85) is an intermediate to the formation of the folic acid necessary for intermediary metabolism in both bacteria and man. In bacteria this intermediate is produced by enzymatic condensation of the pteridine, 86, with para-amino-benzoic acid (87). It has been shown convincingly that sulfanilamide and its various derivatives act as a false substrate in place of the enzymatic reaction that is, the sulfonamide blocks the reaction by occupying the site intended for the benzoic acid. The lack of folic acid then results in the death of the microorganism. Mammals, on the other hand, cannot synthesize folic acid instead, this compound must be ingested preformed in the form of a vitamin. Inhibition of the reaction to form folic acid Ls thus without effect on these higher organisms. 

Para-amino benzoic acid (PABA) is considered to be in the B-complex vitamin family. The human body can make it from folic acid, since PABA forms the middle part of that vitamin ... 

In para-amino benzoic acid, there is another resonance structure right next to the six-sided ring. It is a carboxyl group, shown with a single bond between carbons, and a double bond between the carbon and the oxygen. This is also a place where the electron can bounce around between the three nuclei. 

You can learn more about molecules that absorb different colors in the section on para-amino benzoic acid (PABA). 

Benzocaine is an ester, a compound made from the organic acid PABA (para-amino benzoic acid) and the alcohol ethanol. 

PABA, 1,6-7, 11, 70. See also para-amino benzoic acid PABA esters, 6-7 padimate A, 7 padimate O, 7 pain relievers, 158,170-189 paints, 44, 70, 112, 129 acrylic, 234 latex, 232, 236, 237 oil, 94... 

PABA para-amino benzoic acid PAT paroxysmal atrial tachycardia pc after eating (Latin post cibum )... 

The compound sulfanilamide exhibits a structural similarity to para-amino benzoic acid (PABA). Woods and Fields proposed the theory that sulfonamides, being structurally similar to PABA, inhibit bacterial folate synthetase so that folic acid is not formed which is needed for a number of metabolic reactions. Folic acid derived from PABA is essential for bacterial metabolism. Sulfonamides inhibit the enzyme folic acid synthetase which is... 

Para-amino benzoic acid (PABA) can be measured by a diazotization reaction that yields a bright pink colour. The absorption is then measured at 510 nm. A series of standards yielded the results shown in Table 14.5. A graph of this data (Figure 14.11)... 

The discovery, isolation and final synthesis of a whole group of new compounds essential to health in a balanced diet was another triumph of the chemist. These compounds called vitamins A, Ba or G, C, D, E, K, and several others closely associated with vitamin Ba, such as niacin, pantothenic acid, inositol, para-amino benzoic acid, choline, pyndoxine (Be), biotin (H), folic acid and Bn, prevent deficiency diseases such as xerophthalmia (an eye disease), beriberi, pellagra, scurvy, rickets, sterility (in rats), excessive bleeding and so forth. Professors Elmer V. McCollum and Herbert M. Evans, and Joseph Goldberger were among the early American pioneers in this field of research. Drugs, anaesthetics, and medicines like procaine, cyclopropane, dramamme, ephedrine, aspirin, phenace-tin, urotropin, veronal, quinine, and strychnine have been synthesized to alleviate the pains of mankind. The essential... 

Meijer G, de Vries MS, Hunziker HE, Wendt HR (1990). Laser desorption jet-cooling spectroscopy of para-amino benzoic acid monomer, dimer, and clusters. J Chem Phys 92 7625-7635. 

Orthoform.— Another group of synthetic anesthetics are derivatives of para-amino benzoic acid or of amino hydroxy benzoic acids. Two of these are known as orthoform and new orthoform. 

Anesthesine. Novocaine.— Anesthesine, another member of this group, is simply the ethyl ester of para-amino benzoic acid. A recent very valuable synthetic anesthetic is related to anesthesine and also to. cocaine. It is known as novocaine and is the di-ethyl amine derivative of anesthesine. 

Procaine, on the other hand, is an ester-type local anesthetic when it is injected into the organism, it is transformed into N,N-diethylaminoethanol and para-amino-benzoic acid (PABA) when the ester link that binds these two components of procaine is broken. PABA is a well-known allergen. Methyl para-hydroxybenzoate, whose structure is similar to that of PABA, is also called PAB or methylparaben. It is a preservative that binds, like a hapten, to the immunoglobulin E (IgE) on the surface of mast cells and basophils and maybe the cause of the few cases of anaphylactic shock that have been described. Other patients may be allergic to metabisulfite conservative, found in preparations containing adrenaline (epinephrine). 

Fblicadd Teirahydrofolic acid Formyl group (I) Folic acid 00 Para-amino benzoic acid PenlcUllum spent mycelium Spinach Uver Cottonseed flour... 

Sulfa drugs do not kill bacteria, but stop them from reproducing. Bacteria need para amino benzoic acid (PABA) to reproduce. The sulfonamide drugs have a chemical structure similar to that of PABA, but they contain an S atom where PABA has a C atom. Bacteria cannot tell the difference and use the sulfa compound. The S atoms then stop one or more of the growth processes, and the bacteria cannot multiply. The body s defense kills the remaining bacteria. 

The sulfonamides are structurally similar to para-amino benzoic acid (PABA). Sulfonamides compete with PABA and prevent it from being incorporated into folate (Fig. 7.15). Trimethoprim on the other hand, prevents reduction of dihydrofolate (FAHp to tetrahydrofolate (FAH by binding to and inhibiting dihydrofolate reductase (Fig. 7.15). Human cells are spared from this reaction because trimethoprim has very low affinity for human dihydrofolate reductase. 

Pteridine + Para-amino benzoic acid (PABA)... 

Sulfadiazine Competes with PABA (para amino benzoic acid) for incorporation into folate. When sulfonamide becomes incorporated, it inhibits enzymes (Fig. 7.14). Susceptibie bacteria rely on self-produced folate, while human cells are able to utilize exogenous foiate. Broad spectrum covers both Gram-positives and Gram-negatives. Infrequently used for treatment of uncomplicated urinary tract infections, nocardiasis, chancroid, prophylaxis against rheumatic fever. 

NNRTI—non-nucleoside reverse transcriptase inhibitor NRTI—nucleoside reverse transcriptase inhibitor NSAID—non-steroidal anti-inflammatory drug PABA— para-amino benzoic acid PCP—Pneumocystis pneumonia... 

Meijer, G., de Vries, M.S., Hunziker, H.E., and Wendt, H.R., "Laser Desorption Jet-Cooling Spectroscopy of para-Amino Benzoic Acid Monomer, Dimer, and Clusters," Journal of Chemical Physics. 92 (12), 7625-7635,1990. 

Mathias CGT, Maibach HI (1978) Dermatotoxicology monographs I. Cutaneous irritation factors influencing the response to irritants. Clin Toxicol 13 333-346 Mathias CGT, Maibach HI, Epstein J (1978 a) Allergic contact photodermatitis to para-amino-benzoic acid. Arch Dermatol 114 1165-1666 Mathias CGT, Maibach HI, Ostler HB, Conant MA, Nelson W (1978 b) Delayed hypersensitivity to retrobulbar injections of methylprednisolone acetate. Am J Ophthalmol 86 816-819... 

FIGURE 8.3 Molecular structure of para-amino benzoic acid (PABA) highlighting the percentage contribution of each atom to the total lattice energy per molecule. The group contributions for CgH, COOH and NH groups are listed in Table 8.3. Source Adapted from Rosbottom et al. [37]. Reproduced with permission of Royal Society of Chemistry. 

Gas chromatography (GC) and GC-mass spectroscopy (GC-MS) methods often rely on the quantitative cleavage of folate to para-amino benzoic acid (pABA), in which molar concentration of HCl is used to hydrolyse folates to pABA, which is subsequently assayed by GC or GC-MS after derivatization (Dueker et al. 2000 Gregory et al. 2006 Lin et al. 2003) with an appropriate reagent. 

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