Anthranilic acid fluorescence

Inspect the paper in ultraviolet light—conveniently in front on a Hanovia ultraviolet strip light—in a dark room. The acids show up as intense blue fluorescent spots. Mark with a pencil the positions of all spots. The position of the two spots arising from solution (C) should be compared with the single spots arising from solutions (A) and (B). It is probable that the solution (B) of pure N-methylan-thranilic acid may also reveal a faint spot corresponding to anthranilic acid still present in minute traces in the methylated acid cf. p. 223). 

Bigge, J.C., Patel, T.P., Bruce, J.A., Goulding, P.N., Charles, S.M., and Parekh, R.B. (1995) Nonselective and efficient fluorescent labeling of glycans using 2-amino benzamide and anthranilic acid. Anal. Biochem. 230, 229-238. 

C8H9NO2, Mr 151.16, bp2w 135.5 °C, df 1.1682, ng 1.5815, occurs in a large number of blossom essential oils (e.g., neroli, ylang-ylang, and jasmin oils), grapes, and citrus oils. It occurs as white crystals mp 24-25 °C), or a yellowish liquid, that show blue fluorescence and have an orange blossom odor. Methyl anthranilate is prepared by esterification of anthranilic acid with methanol or by reaction of isatoic anhydride with methanol [163]. 

Elkana et al. [138] made a careful study of the transfer of energy from excited naphthalene donor molecules to anthranilic acid acceptor molecules by observing the acceptor and donor fluorescence intensities when the donor was excited with continuous radiation (A = 272nm). The solvents were changed from glycerol to increasingly more and more... 

Most of the older methods of fluorimetric analysis of pesticides involved hydrolysis to form fluorescent anions. Co-ral (coumaphos) [147] was hydrolyzed in alkali to the hydroxybenzopyran, which was subsequently determined by means of its fluorescence. Guthion (azinphosmethyl) was hydrolyzed to anthranilic acid for fluorimetric analysis [148,149]. A method was developed [150] for Maretin (N-hydroxynaphthalimide diethyl phosphate) in fat and meat which involved hydrolysis in 0.5 M methanolic sodium hydroxide followed by determination of the fluorescence of the liberated naphthalimide moiety. Carbaryl (1-naphthyl N-methylcarbamate) and its metabolites have been determined by a number of workers using base hydrolysis and the fluorescence of the resulting naphtholate anion [151-153]. Nanogram quantities of the naphtholate anion could be detected. Zectran (4-dimethylamino-3,5-xylyl N-methylcarbamate) has been determined by the fluorescence of its hydrolysis product [154]. The fluorescence behaviour of other carbamate insecticides in neutral and basic media has been reported [155]. Gibberellin spray used on cherries has been determined fluorimetrically after treatment with strong acid [156]. Benomyl (methyl N-[l-(butylcarbamoyl)-2-benzimidazolyl]carbamate) has been analyzed by fluorimetry after hydrolysis to 2-aminobenzimidazole [157]. 

Ioannou et al. [41] reported the use of terbium sensitized fluorescence to develop a sensitive and simple fluorimetric method for the determination of the anthranilic acid derivative, mefenamic acid. The method makes use of radiative energy transfer from anthranilate to Tb(III) in alkaline methanolic solutions. Optimum conditions for the formation of the anthranilate-Tb(III) complex were investigated. Under optimized conditions, the detection limit was 1.4 x 10-8 mol/L, and the range of application was 2.5 x 10 8 to 5.0 x 10 5 mol/L. The method was successfully applied to the determination of mefenamic acid in serum after extraction of the sample with ethyl acetate, evaporation of the organic layer under a stream of nitrogen at 40°C, and reconstitution of the residue with alkaline methanolic terbium solution prior to instrumental measurement. The mean recovery from serum samples spiked with mefenamic acid (3.0 x 10-6, 9.0 x 10-6, 3.0 x 10-5 mol/L) was 101 5%. The within-run precision (RSD) for the method for the two serum samples varied from 2 to 8%, and the day-to-day precision for two concentration levels varied from 2 to 13%. 

Kynureninase is involved in the oxidative metabolism of tryptophan. It catalyzes the conversion of L-kynurenine to anthranilic acid. The enzyme also converts L-3-hydroxykyneurenine to 3-hydroxyanthranilic acid. The latter compound has a high fluorescence, which is the basis for detection in this assay. 

The resistance of oats Avena sativa, Poaceae) to the take-all fungus Ophiobolus graminis is due to a fluorescent wot tip glycoside. This resistance factor, avenacin, has proven to be a mixture of four pentacyclic triterpene glycosides (5-8). Compounds (5 and 7), which possess anthranilic acid residues as a part of the molecule, have the greatest fungicidal properties (Fig. 24.3) (Harbome, 1986). 

SEHiER et al. [110] describe a direct quantitative determination of anthranilic acid and some indole derivatives, without elution. Layers on 5 X 20 cm plates were chromatographed using solvent XIV, Table 89, sprayed with the Prochazka reagent (No. 123, Table 88), illuminated with UV light of wave-length 365 nm and the fluorescence measured with a slightly modifled Zeiss-Spektralphotometer PMQ II (Firm 155). The surface areas under the lines registered with a recorder were found to be directly proportional to the amount of material between 10 and 2000 ng. A TLC-attachment for the Zeiss Spektralphotometer has been developed with which direct routine qualitative and quantitative measurements on normal TLC-plates have become possible [41, 42]. 

Definition Aq. sol n. of the odoriferous principles of the flowers of the orange. Citrus aurantium var. dulcis] constituents are limonene, l-linalool, geraniol, linalyl acetate (7-18%), some methyl anthranilate, nerol, neroli camphor Properties YIsh. fluorescent liq. turns brown on exposure to light very intense, pleasant odor sol. in DMSO, 95% ethanol, acetone sol. < 1 mg/ml in water sp.gr. 0.86-0.88 flash pt. > 93.3 C ref. index 1.475 (20 C) pH neutral or si. acid to litmus volatile... 

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