A-picolinic acid

Many alkaloids have been implicated in plant-animal chemical interactions but few have been associated with allelopathy (83). Several alkaloids were demonstrated by Evenari (73) to be strong inhibitors of seed germination. Little recent work has been done on alkaloids except for caffeine (78). a-Picolinic acid is a microbial alkaloid with toxic action on plants (82). One of the more active synthetic herbicides on the market, piclorariv(Dow s Tordon), is a chlorinated picolinic acid derivative. 

Clement and Paris [17] have devised a pair of methods for the determination of cobalt in steels, especially materials encountered in the nuclear industry. In the first technique, suitable for the analysis of solutions containing 8 to 160 mM cobalt(II), iron(III) is used to oxidize cobalt(II) in a picolinic acid medium, after which the resulting iron(II) is titrated po-tentiometrically with a standard solution of cerium(IV). An alternative procedure, for concentrations of cobalt(II) below 8 mM, involves a constant-current coulometric titration with electrogenerated cerium (IV) to measure the iron(II) that arises from the original reaction between cobalt(II) and iron(III). 

The pyridine ring is less reactive, and the benzene ring is oxidized to a-picolinic acid (a-NC,H4COOH). 

FIGURE 3.1 Schematic for the classi cation of polar and nonpolar portions of molecules, a Polar b Nonpolar, (a) Picolinic acid (b) Isopropyl alcohol. 

Iwahashi H, Kawamori H, Fukushima K. Quinolinic acid, a-picolinic acid, fusaric acid, and 2,6-pyridinedicarboxylic acid enhance the Fenton reaction in phosphate buffer. Chem-Biol Interact 1999 118 201-215. 

EPR parameters of Cu(II) ternary surface complexes at 77 K bpy, 2,2 -bipyridine pic, a-picolinic acid. 

Picloram is a picolinic acid derivative introduced by Dow Chemical in 1963 (Fig. 4). Picloram is highly active on most perennial broadleaf and woody species, and most grasses are resistant. 

Tryptophan and Zinc Absorption Boses of 4 mg Zn and 2 mg Cu were given in Trutol to subjects consuming a diet in which tryptophan was the limiting amino acid Absorption of Zn and Cu was also measured when they received the same diet plus a picolinic acid supplement Ficolinic acid is a metabolite of tryptophan which is thought to enhance zinc absorption (17) Picolonic acid was not present in the isotope dose The diets contained 0 8-l 2 mg Cu/day and 2 7-3 6 mg Zn/day (by analysis) Total tryptophan content of the diet was approximately 250 mg/day (calculated) Ficolinic acid supplementation was at a level of 10 mg/day ... 

Since the forward reaction in (29) is exothermic, the equilibrium is displaced to the left by increase in temperature this factor accounts in part for the anomalous temperature coefficient of reaction rate mentioned above. The apparent catalysis by propagating base is also explicable as acid catalysis since the carbamic acid is stoichiometrically derived from the base by reaction (29). That true base catalysis is not operative has been shown by the observation that addition of tertiary bases does not affect the reaction rate [17]. Further, the polymerization is catalysed by other weak acids such as hydrocinnamic [17] and a-picolinic acids [10, 17], which, if present in sufficient concentration under conditions of low CO2 pressure, reduce the order in initiating base to unity. Thus, under such conditions, with hydrocinnamic acid (HX) as catalyst the simple kinetic form (30) is achieved. 

In a few instances, not only methyl ketones but other alkyl ketones are degraded to shorter carboxylic acids resulting from halogenation of the methylene group adjacent to the carbonyl and subsequent hydrolysis [103, 160,1172]. The reaction between propiophenone and sodium hypobromite at 22-25 °C gives a 96% yield of benzoic acid [303]. Under similar conditions, 5-butyl-2-butyrylpyridine is converted into 5-butyl-a-picolinic acid in 79% yield [160]. Methyl 3-(a-pyridyl)propyl ketone yields not only the... 

Pb has been also determined by the FIA technique, after conversion in a picolinic acid complex which is then associated with Malachite Green [66],... 

Spcctrophotometric studies on technetium and rhenium were carried out with K4[b e(C N)f,], sulphosalicylic acid, and a-picolinic acid using pcrtechnetatc or perrhe-nate as starting compounds and bismuth amalgam, SnCl2 or ascorbic acid as reducing agents 78j. 

OSi= is for silica surface pic is for a-picolinic acid. Another batch of silica. 

CAS 55-22-1 EINECS/ELINCS 200-228-2 Synonyms 4-Carboxypyridine 4-Picolinic acid a-Picolinic acid 4-Pyridinecarboxylic acid Pyridine-4-carboxylic acid... 

Picoljnic acid a-Picolinic acid. See Isonicotinic acid... 

The rates of oxidation of pyridine (Py), quinoline (Qn), acridine (Ac), a-oxyquinoline (Oq), and a-picolinic acid (Pa) by peroxydecanoic acid (PDA) increase in the order Py < Qn < Ac. The rates of unsubstituted compounds are appreciably higher than for compounds bearing substituents positioned a to the reactive centre. 

C7H608N2 2-Carboxypyridine-3-carboxamide NaOBr j3-Amino-a-picolinic acid — 92... 

A specific inhibitor of sporulation, a-picolinic acid (Gollakota and Halvorson, i960) also inhibits polymyxin production (Paulus and Gray, unpublished). 

Gollakota, K. G., and H. O. Halvorson Biochemical changes during sporulation of Bacillus cereus. Inhibition of sporulation by a-picolinic acid. J. Bacteriol. 79, 1 (I960). 

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