Vanillic acids

Propanidid. Propanidid [1421-14-3] (Epontol), C gH2yNO, (7) a derivative of the propyl ester of homo vanillic acid, has been in clinical use in Europe for a number of years. Its main advantage is rapid onset of action and a fast recovery which, like etomidate, is because of rapid metaboHsm by esterases rather than redistribution (108). Excretion is rapid 75 to 90% of the dmg is eliminated as metaboUtes within two hours. Propanidid side effects include hypotension, tachycardia, and hyperventilation followed by apnea, as well as excitatory side effects such as tremor and involuntary muscle movement (109). 

On distillation at atmospheric pressure, vanillin undergoes partial decomposition with the formation of pyrocatechol. This reaction was one of the first to be studied and contributed to the elucidation of its stmcture. Exposure to air causes vanillin to oxidize slowly to vanillic acid. When vanillin is exposed to light in an alcohoHc solution, a slow dimerization takes place with the formation of dehydrodivanillin. This compound is also formed in other solvents. When fused with alkaU (eq. 3), vanillin (I) undergoes oxidation and/or demethylation, yielding vanillic acid [121 -34-6] (8) and/or protocatechaic acid (2). 

This type of cement has been further improved by the substitution of -hexyl van ill ate [84375-71-3] and similar esters of vanillic acid [121 -34-6] and/or syringic acid [530-57 ] for eugenol (93—95). These substituted cements are strong, resistant to dissolution, and, unlike ZOE and EBA cements, do not inhibit the polymerization of resin-base materials. Noneugenol cements based on the acid—base reaction of zinc and similar oxides with carboxyhc acids have been investigated, and several promising types have been developed based on dimer and trimer acids (82). 

Therapeutic Function Central and respiratory stimulant Chemical Name N,N-Diethyl-4-hydroxy-3-methoxybenzamide Common Name Vanillic acid diethylamide Structural Formula coxtc HjIj... 

Mobile phase front HomovanilUc acid Vanillic acid... 

Fig. II Fluorescence scan of a chromatogram track with SOO ng each of noradrenaline (1), adrenaline (2), serotonin (3), vanilmandelic add (4), 5-hydroxyindoleacetic add (6), homovanillic acid (7) and vanillic acid (8) together with 230 ng creatinine, all per chromatogram zone measurement at X(3,c = 313 nm and > 390 nm (cut off filter FI 39 (A)), X = 365 nm and Xj, >430 nm...

It is possible to replace the vanillin in the reagent by 4-dimethylaminobenzaldehyde, 4-hydroxybenzaldehyde, salicylaldehyde, /n-anisaldehyde, cinnamaldehyde, 4-hydioxy-benzoic acid or vanillic acid [3]. However, the range of colors obtained is not so broad. 

Studies by Hudson et al, (2000) have demonstrated the presence of eight polyphenols in rice bran by using high-pressure liquid chromatography. They are protocatechuic acid, p-coumaric acid, ferulic acid, sinapic aci vanillic acid, caffeic acid, which is a methoxycirmamic acid derivative, and tricin. The effect of these polyphenols on cell viability and on the colony-forming ability of human-derived MDA MB 468 and HBL 100 breast cells, colon-derived SW 480 and human colonic epithelial cells was assessed. These authors concluded that rice bran polyphenols have putative cancer chemopreventive properties. 

The total phenolic content in XRPP was 1.10%. The major components were found to be p-hydroxybenzoic acid (0.44%), vanillin (0.19%), syringic acid (0.13%), and syringaldehyde (0.13%). The contents of p-hydroybenzaldehyde, vanillic acid and ferulic acid were 0.032, 0.015 and 0.020%, respectively. Gallic acid, protocatechuic acid and cinnamic acid were detected in trace amounts. 

Pometto AL, JB Sutherland, DL Crawford (1981) Streptomyces setonii catabolism of vanillic acid viaguaiacol and catechol. Can J Microbiol 27 636-638. 

Taylor BE (1983) Aerobic and anaerobic catabolism of vanillic acid and some other methoxy-aromatic compounds by Pseudomonas sp. strain PN-1. Appl Environ Microbiol 46 1286-1292. 

Ander P, K-E Eriksson, H-S Yu (1983) Vanillic acid metabolism by Sporotrichium pulverulentum evidence for demethoxylation before ring-cleavage. Arc/ MicrobioZ 136 1-6. 

Chow KT, MK Pope, J Davies (1999) Characterization of a vanillic acid non-oxidative decarboxylation gene cluster from Streptomyces sp. D7. Microbiology (UK) 145 2393-2404. 

Civolani C, P Barghini, AR Roncetti, M Ruzzi, A Schiesser (2000) Bioconversion of ferulic acid into vanillic acid by means of a vanillate-negative mutant of Pseudomonas fluorescens strain BF13. Appl Environ Microbiol 66 2311-2317. 

All cements that contain eugenol inhibit the polymerization of acrylates, and those of EBA-eugenol are no exception. In order to remedy this and other defects, Brauer and his coworkers examined alternatives to eugenol (Figure 9.7). These included the esters of vanillic acid (3-methoxy-4-hydroxybenzoic acid, HV) and syringic acid (3,5-dimethoxy-4-hydroxy-benzoic acid). Both are 3-methoxy-4-hydroxy compounds and are thus chemically related to eugenol and guaiacol. Both are solids and have to be dissolved in EBA where they form satisfactory cements with EBA zinc oxide powder. The vanillate (EBA-HV) cements are the more important. 

Parthenin (19) has at a concentration of 50 ppm no effect on the germination of the bean Phaseolus vulgaris but inhibits the development of radicles and hypocotyls (41). Similar effects were observed by Kanchan for Parthenlum hysteropherus and Eleusine coracana coleoptiles (42) and it was shown that besides parthenin (19), caffeic acid, vanillic acid, ferulic acid, chlorogenic acid an3 anisic acid were major constituents in P. hysteropherus (43). 

Increased levels of nitrogen and phosphorous reduced the Inhibition of barley (Hordeum vulgare L.) growth caused by -coumaric and vanillic acids (8a). Although other explanations are possible, these effects of fertilizers suggest that Inhibition of mineral absorption was responsible for the observed Inhibition of growth. 

The short time periods (10 min to 4 hr) over which absorption was measured (Table 1) helps support the hypothesis that certain allelochemicals inhibit mineral absorption directly. Under acidic conditions (pH 4.0) salicylic acid inhibited K+ absorption within 1 min (32). The degree of inhibition remained constant over time when salicylic acid inhibited 1C " absorption (32) and when vanillic acid inhibited P0 absorption (28). Thus, at least phenolic acids appear to inhibit absorption rapidly and consistently. 

Einhellig and Rasmussen (17) reported that In addition to ferulic and p-coumaric acids, vanillic acid reduced chlorophyll content of soybean leaves but did not affect chlorophyll In grain sorghum fSorghum bicolor (L.) Moench.]. It Is not known whether these reported mechanisms are primary or secondary events In the Inhibition of plant growth by allelochemlcals. 

VII. Some New Esters of Vanillic Acid and Related Acids. J. Amer. chem. Soc. 71, 1066 (1949)-... 

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