Diterpene acid

Fig. 7. Principal nionocarboxylic diterpene acids skeletons in rosins. Dotted line indicates that the chemical group is located below plane (see p. 266 in 118]).

The first sample, dating from the Ptolemaic period ( 300 BC), was found in a container from a tomb from Fayoum. The volatile compounds observed in this sample (see Table 10.1, column 11) were very similar to those of pine pitch. The two chromatograms are presented in Figure 10.21. The major compounds are guaiacol (11) and its para-n-alkyl derivatives (24, 35, 43) and the degradation products of diterpenic acids 19-norabieta-8,l 1,13-triene (95), 18-norabieta-8,11,13-triene (100), 10,18-bisnorabieta-5,7,9(10),ll,13-pentaene (102), retene (105) and methyldehydroabietate (106). The major compounds observed after... 

Many nonvolatile and thermally labile allelochemicals can be well separated by liquid chromatography (LC). Identification of the separated components on-line by mass spectrometry (MS) is of great value. Fused-silica LC columns of 0.22 mm ID packed with small-particle material are used in the described LC/MS system. The shape of the column end allows direct connection to a electron impact ion source of a magnetic sector mass spectrometer. Separations by LC are reported and LC/MS mass spectra are shown for monoterpenes, diterpene acids, phenolic acids and cardiac glycosides. The LC/MS system provides identification capability and high-efficiency chromatography with a universal detector. 

N.A. Aralia catechu L. A. nudicaulis L. A. racemosa L. Arctiin, tannins, diterpene acids, glucoside, volatile oil.99-102 Treat rheumatism, asthma, coughs. 

The diterpene acid, abietic acid, is a major constituent of rosin, which is obtained as a nonvolatile residue in the manufacture of turpentine by steam distillation of pine oleoresin or shredded pine stumps. Abietic acid is used extensively in varnishes and as its sodium salt in laundry soaps. 

All GAs are tetracyclic diterpene acids they can be divided into two types, the CpcrGAs and the C n-GAs (Figure 1). 

Pyrek, J. S. 1970. New pentacyclic diterpene acid trachyloban-19-oic acid from sunflower. Tetrahedron 26, 5029... 

Acetylphenylhydroquinone, 34, 1 5-Acetyl-k-valeric acid, 31, 3 Acid chlorides, synthesis of, 37, 69 Acid isomerization of diterpenic acids,... 

About 80% of the diterpene acids of the genus Finns have an abietane skeleton, with abietic acid (structure 3) as the predominant component. Other diterpene acids have a pimarane skeleton (structure 4). All compounds with the abietane skeleton are distinguished by the presence of an isopropyl group. 

Figure 6 Pathway of conifer diterpene resin acid biosynthesis. Bifunctional di-TPS convert geranylgeranyl diphosphate to various diterpenes, which are oxidized stepwise by multisubstrate and multifunctional cytochromes P450 to the corresponding diterpene acid. The oxidation of (-)-abietadiene to (-)-abietic acid is shown as an example.

The new natural product 765 (R = CHO) is reported to occur in juniper,but there is no information about stereochemistry or synthesis. The corresponding acid 765 (R = COOH) was said to occur in carrots. " Diterpene acid esters of sabinene hydrate (766) have been isolated from flowers of Helianthus annulus. 

Methyl ketones from acids [1, 688]. In the series of diterpene acids, Bory et a/.100... 

Both fatty and resin acids (diterpene acids) are obtained as a by-product of the pulping of wood for paper. The mixture is known as tall oil. The separated resin acids are known as rosin. Resin acids such as abietic acid (12.20) can also be obtained as exudates of pine trees. 

From another leguminous plant now classified in the Caesalpiniaceae, Erythrophleum chlorostachys, several alkaloids typified by norerythrostachamine (94) were isolated and their structures elucidated they occur as ethanolamine esters of diterpene acids, but readily rearrange to the corresponding amides [ 111J. These alkaloids are highly toxic and are responsible for cattle poisoning in the Darwin area. 

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