Vanillyl phenols

The other axis of this property/property plot is the C/V lignin ratio (Fig. 15.15b), which is the weight ratio of total cinnamyl phenols to total vanillyl phenols. This tracer is based on the general relationship that cinnamyl phenols are obtained from the CuO oxidation of nonwoody plant tissues, whereas vanillyl phenols are produced by all vascular plant tissues, including woods. Phytoplankton do not produce either cinnamyl or vanillyl phenols, and hence have no effect on C/V ratios. Woods produce only trace amounts of cinnamyl... 

Figure 4 Variations in of total OC (left axis %o, open circles) and the abundance of lignin-derived syringyl and vanillyl phenols (right axis A, mg per 100 mg OC, triangles) in surface sediments from various water depths of the Gulf of Mexico in the vicinity of the outflow from the Mississippi River system (after Goni et aL, 1997 Also shown are average values for the same parameters determined on suspended particulate matter from the upper and lower reaches of the Mississippi River (extreme left column, error bars = 1 SD data from Onstad et ai, 2000). In addition, values are indicated for one lignin phenol (syringic acid filled circles), for selected shelf and slope...

Vanillyl phenols Syringyl phenols Cinnamyl phenols p-Hydroxyl phenols Sum of phenols ( Lig/g organic carbon) % phenol carbon totd organic carbon ... 

Cinnamyl/vanillyl ratio (CA ) The C/V ratio is calculated as the sum of p-coumaric acid plus ferulic acid concentrations divided by the sum of the three vanillyl phenols. It is a measure of the relative contributions of woody and non-woody land-plant tissues to the organic matter in a sediment sample... 

Vanillyl phenols A group of degradation products released from the alkaline oxidation of lignin that includes vanillin, acetovanillone, and vanillic acid. The vanillyl components are diagnostic of vascular-plant organic matter. 

Fraaije MW, WJH van Berkel (1997) Catalytic mechanism of the oxidative demethylation of 4-(methoxymethyl)phenol by vanillyl-alcohol oxidase. Evidence for formation of a /7-quinone intermediate. /Sio/ Chem 272 18111-18116. 

Kondo R, H Yamagami, K Sakai (1993) Xylosation of phenolic hydroxyl groups of the monomeric lignin model compounds 4-methylgnaiacol and vanillyl alcohol by Coriolus versicolor. Appl Environ Microbiol 59 438-441. 

Aryl alcohol oxidase from the ligninolytic fungus Pleurotus eryngii had a strong preference for benzylic and allylic alcohols, showing activity on phenyl-substituted benzyl, cinnamyl, naphthyl and 2,4-hexadien-l-ol [103,104]. Another aryl alcohol oxidase, vanillyl alcohol oxidase (VAO) from the ascomycete Penicillium simplicissimum catalyzed the oxidation of vanillyl alcohol and the demethylation of 4-(methoxymethyl)phenol to vanillin and 4-hydro-xybenzaldehyde. In addition, VAO also catalyzed deamination of vanillyl amine to vanillin, and hydroxylation and dehydrogenation of 4-alkylphenols. For the oxidation of 4-alkylphenol, the ratio between the alcohol and alkene product depended on the length and bulkiness of the alkyl side-chain [105,106]. 4-Ethylphenol and 4-propylphenol, were mainly converted to (R)-l-(4 -hydroxyphenyl) alcohols, whereas medium-chain 4-alkylphenols such as 4-butylphenol were converted to l-(4 -hydroxyphenyl)alkenes. 

Benzoic aldehydes mainly cover syringaldehyde and vanillin. Natural vanilla is prepared from the seeds (beans) of Vanilla planifolia, which may contain about 21 mg/ 100 g FW total phenols, including the major components vanillin (19.4 mg/100 g FW), 4-hydroxybenzaldehyde (1 mg/100 g FW), and vanillic acid (0.4 mg/100 g FW) (Clifford 2000b). In mango, vanillin has been found as free as well as vanillyl glu-coside (Sakho and others 1997). It has also been found in lychees (Ong and Acree 1998) and wines (Moreno and others 2007). For analysis of both brandy and wine aged in oak barrels, the limits of detection were found to be 27.5, 14.25, 14.75, and... 

In flavin-dependent monooxygenases, a flavin-oxygen intermediate reacts with the substrate, also producing water in a second step, and requiring cofactors for regeneration of the flavin moiety. The unusual flavoprotein vanillyl-alcohol oxidase (EC 1.1.3.38), in which the flavin moiety is covalently bound, catalyzes the oxidation of p-substituted phenols as well as deamination, hydroxylation and dehydrogenation reactions [10]. 

Aromatic Ring Cleavage of Phenolic 0-0-4 Substructure Model Compounds by Laccase. When vanillyl alcohol was used as a substrate, only biphenyl formation (C5-C5 linked) occurred and no evidence for the formation of any ring-opened products was obtained (26). Hence, we also examined the effect of laccase on the sterically hindered 4,6-di-<-butylguaiacol substrate 50, as it would be unlikely to undergo such free-radical coupling reactions... 

Properties. Vanillin is a colorless crystalline solid mp 82-83 °C) with a typical vanilla odor. Because it possesses aldehyde and hydroxyl substituents, it undergoes many reactions. Additional reactions are possible due to the reactivity of the aromatic nucleus. Vanillyl alcohol and 2-methoxy-4-methylphenol are obtained by catalytic hydrogenation vanillic acid derivatives are formed after oxidation and protection of the phenolic hydroxyl group. Since vanillin is a phenol aldehyde, it is stable to autoxidation and does not undergo the Cannizzarro reaction. Numerous derivatives can be prepared by etherification or esterification of the hydroxyl group and by aldol condensation at the aldehyde group. Several of these derivatives are intermediates, for example, in the synthesis of pharmaceuticals. 

Vanilla flavour is not only determined and characterised by the vanillin molecule, but also by many more phenolic compounds and vanillin derivatives. Two examples of molecules that recently obtained FEMA-GRAS status are vanillyl ethyl ether and vanillin 2,3-butanediol acetal (Scheme 13.11). Vanillin can be hydrogenated to form vanillyl alcohol, which is also used in vanilla flavours. Vanillyl alcohol can be reacted with ethanol to form vanillyl ethyl ether. Vanillin can also form an acetal with 2,3-butanediol (obtained by fermentation of sugars) catalysed byp-toluene sulfonic acid in toluene. 

Figure 2. The reaction of vanillyl alcohol (4) with a reactive phenol (5)-...

Figure 9.45 Eleven dominant phenolic monomers, yielded from the oxidation of lignin using the CuO oxidation method these compounds can be separated into four families p-hydroxyl, vanillyl (V), syringyl (S), and cinnamyl (C) phenols. (Modified from Hedges...

Figure 9.47 Concentrations of acid aldehyde ratios in vanillyl (Ad/Al)v and syringyl (Ad/Al phenols during the subaqueous decay of lignin in vascular plants in a 4-year laboratory incubation study. (Modified from Opsahl and Benner, 1995.)...

Figure 9.48 Lignin-phenol concentrations in (a) water column POC and (b) the syringyl-to-vanillyl (S/V) and cinnamyl-to-vanillyl (C/V) ratios of POC at stations in the Baltic Sea from Lulealven River (Lu) to Baltic proper (Bp)—situated from the head (north) to the mouth (south) of the estuary. Other stations are An = Angermanalven BB = Bothnian Bay BSN = Bothnian Sea north BSS = Bothnian Sea south. (Modified from Bianchi et al., 1997.)...

Capsaicin (= tams-8-Methyl-N- [(4-hydroxy-3-methoxyphenyl)methyl] -6-nonenamide toz.v-8-Methyl-jV-vanillyl-6-nonenamide) (vanilloid phenolic) Daidzein (= 4, 7-Dihydroxyisoflavone) (isoflavone)... 

W-vanillyl-G-nonenamide) (vanilloid phenolic) Inositol hexaphosphate Widespread esp. in seeds of irritant, tachykinin release, topical analgesic] V-K+ CH (plant stomatal... 

Olvanil (= A-(Vanillyl)-9-oleamide] (vanilloid phenolic) Cholecystokinin receptor Synthetic (cf. Capsaicin) Anandamide transport inhibition [14] (VR agonist) 5.8D... 

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