3 -Hydroxy dehydroabietic acid

Figure 8.4 Total ion current chromatograms of the (a) acidic and (b)neutral fractions of a sample collected from an amphora recovered in Fayum. DDA, didehydroabietic acid DA, dehydroabietic acid 70DA, 7 oxo dehydroabietic acid 70A, 7 oxo abietic acid 15Hy70DA, 15 hydroxy 7 oxo dehydroabietic acid 5HyDA, 15 hydroxy dehydroabietic acid R, retene MDA, methyl dehydroabietate. Slf internal standard, hexadecane IS2, internal standard, tridecanoic acid...

Diterpenoids with abietane structure (dehydroabietic acid, 7-oxo-dehydroabietic acid, 15-hydroxy-7-oxo-dehydroabietic acid, 15-hydroxy-dehydroabietic acid, retene, tetrahydroretene, norabietatriene, norabietatetraene, and methyldehydroabietate) 4-Hydroxy-benzaldehyde, vanillin, 3-hydroxy-benzoic acid, 4-hydroxy-benzoic acid, and vanillic acid... 

However, in many archaeological samples pimarane diterpenoids are often absent, and of the abietane compounds only dehydroabietic acid remains. In fact, dehydroabietic acid is present as a minor component in the fresh resins, but its abundance increases on ageing at the expense of the abietadienic acids since the latter undergo oxidative dehydrogenation to the more stable aromatic triene, dehydroabietic acid [2,18]. If oxygen is available, dehydroabietic acid can be oxidized to 7-oxodehydroabietic acid and 15-hydroxy-7-oxodehydroabietic acid. Since these diterpenoid compounds are often the dominant components in archaeological samples [95,97], they are considered characteristic for the presence of Pinaceae resins. 

Figure 8.14 Mass spectra of 15 hydroxy 7 oxo dehydroabietic acid after (a) methylation, (b) methylation followed by trimcthylsilylation and (c) trimcthylsilylation. Reproduced from K. J. van den Berg, J. J. Boon, I. Pastorova, L. F. M. Spetter, J. Mass Spectrom., 35, 512 533. Copyright 2000, with permission from John Wiley Sons, Ltd...

Figure 12.12 THM GC/MS curves of a Winsor Newton lemon alkyd paint (a) and of an alkyd sample taken from Fontana s work Concetto spaziale (1961) (b). Peak assignments 1, 1,3 dimethoxy 2 propanol 2, 1,2,3 trimethoxy propane 3, 3 methoxy 1,2 propandiol 4, 4 chloro benzenamine 5, 3 methoxy 2,2 bis(methoxymethyl) 1 propanol 6, 3 chloro N methyl benzenamine 7, 3 methoxy 2 methoxymethyl 1 propanol 8, 4 chloro N methyl benzenamine 9, phthalic anhydride 10, 3 chloro 4 methoxy benzenamine 11, suberic acid dimethyl ester 12, dimethyl phthalate 13, azelaic acid dimethyl ester 14, sebacic acid dimethyl ester 15, palmitic acid methyl ester 16, oleic acid methyl ester 17, stearic acid methyl ester 18, 12 hydroxy stearic acid methyl ester 19, 12 methoxy stearic acid methyl ester 20, styrene 21, 2 (2 methoxyethoxy) ethanol 22, 1,1 oxybis(2 methoxy ethane) 23, benzoic acid methyl ester 24, adipic acid dimethyl ester 25, hexadecenoic acid methyl ester 26, dihydroisopimaric acid methyl ester 27, dehydroabietic acid methyl ester 28, 4 epidehydroabietol...

Elforts have been made to characterize the nature and content of individual components that are present in the low-molecular-mass fraction of the total mill effluents, which include the spent chlorination and alkali extraction stage liquors [2,4]. Approximately 456 types of compounds have been detected in the conventional bleach effluents, of which 330 are chlorinated organic compounds [22]. The compounds may be lumped into three main groups, namely, acidic, phenolic, and neutral (Table 2). Acidic compounds are further divided into the five categories of acids fatty, resin, hydroxy, dibasic, and aromatic acids. The most important fatty acids are formic and acetic acids. The dominant resin acids are abietic and dehydroabietic acids. Among the hydroxy acids identified, glyceric acid predominates. Dibasic acids such as oxalic, malonic, succinic, and mafic acids are derived from the lignin and carbohydrate fraction... 

Reference Standards. Reference standards for TLC, GC, and MS were obtained as follows. Pure abietic acid (mp 172-173 °C) was used as received. Dehydroabietic acid was prepared by oxidation of abietic acid with selenium dioxide to hydroxy abietic acid and subsequent dehydration with glacial acetic acid (11). 7-Ketodehydroabietic acid was prepared by oxidation of dehydroabietic acid with potassium permanganate and isolation of the product by way of the Girard reagent T (12). Pyroabietic acid (a mixture of dehydro- and dihydroabietic acids) was prepared by heating abietic acid with 10% palladium on charcoal to 250 °C for 1 h (13). 

Diterpenoids (7-oxo-dehydroabietic and 15-hydroxy-7-oxo-dehydroabietic acid) triterpenoids (isomasticadienonic, masticadienonic, moronic and oleanonic acids) alkanes (C25-C33), wax esters (C o-Cso), hydroxy wax esters (C42-CS4) hydroxyaromatic acids fatty adds steranes and hopanes... 

Fig. 2. Chemical structures of identified oxidation products in colophony, a 15-hydroperoxyabietic acid, b i3,i4(a)-epoxyabietic acid, c i3,i4(p)-epoxyabietic acid, d di(dehydroabietic acid 15-yl) peroxide, e 15-hydroperoxydehydroabietic acid, f 7-oxodehydro-abietic acid, g 15-hydroxydehydroabietic acid, h 15-hydroxy-/-oxodehydroabietic acid, i i3(p), i4(p)-dihydroxyabietic acid, j 12-hydroxyabietic acid, k 8,i2-peroxo-7,8-dihydroabietic acid...

Within the GC detectable range, we identified the different composition of the liquid products from the various origins by using a GC-MS analysis. The liquid products from Kraft pine lignin contain mainly guaiacol and methyl dehydroabietate. The liquid products from oat hull, hardwood, and switchgrass contain acetic acid, 1-hydroxy-2-propanone, and/ or furfural, which are the products of hemicellulose and cellulose. This further confirms that these three materials contain hemicellulose and cellulose. The liquid products have only two to three component differences from one biomass species to another. But the composition distributions are quite different among species (Table 4). So the composition of liquid products depends on the type of raw materials. 

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