Pimarane

Source Erythroxylon monogynum Mol. formula 2011 2 Mol. wt. 272 Solvent CDCL 

Kitajima, T. Komori and T. Kawasaki, Chem. Pharm. Bull., (Tokyo), 30(11), 3912 (1982). 

Source Vellozia nanuzae L.B. Smith and Ayensu Mol. formula C2QH2QO2 Mol. wt. 302 Solvent CDCL 

Source Vellozia aompaota Martius ex Schultes Mol. formula C2qH 30 2 Mol. wt. 302 Solvent CDClo 

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With very few exceptions, the pine resin acids belong to four basic skeletal classes abietane, pimarane, isopimarane, and labdane (Fig. 7). The acids of the abietane, pimarane and isopimarane series have a isopropyl or methyl/ethyl group in the carbon-13 position and a single carboxyl group in the carbon-18 position, and differ only in the number and location of the carbon-carbon double bonds (the most common have two carbon-carbon double bonds). The acids of labdane series are less common and contain one carboxyl group in the carbon-19 position. 

Fig. 9. Common acids of the pimarane and isopimarane skeletal class (pimaric-type acids) (see p. 269 in [18 ).

The common pine resin acids based on the pimarane and isopimarane skeletal (pimaric-type acids) are shown in Fig. 9. The pimarane and isopimarane acids series differ only in the methyl group position in the carbon-13 position. Isopimaric and sandaracopimaric acids differ in the location of the carbon-carbon double bond. 

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. 

These two examples demonstrate clearly the usefulness of SPME to detect volatile compounds in complex mixtures. Among the few sesquiterpenes identified in the SPME extract for the two samples, longifolene can be considered as a biomarker of a substance originating from a conifer tree. The absence of abietane or pimarane diterpenoids is indicative of the use of parts of the tree with low resin content. 

Mono-, sesqui-, and some diterpenoids are found in marine and terrestrial flora. They are, therefore, not always unambiguous tracers for higher plant sources. However, diterpenoids with the abietane and pimarane (Fig. 1), and less common phyllocladane and kaurane, skeletons are predominant constituents in resins and supportive tissue of coniferous vegetation (Coniferae), which evolved in the late Paleozoic (200—300 million years ago). Diterpenoid biomarkers have been characterized in... 

Shibuya H. Bohgaki, T. Ohashi, K. (1999) Two novel migrated pimarane-type diterpaies from the leaves of Orthosiphon aristatus. Chem. Pharm. Bull., 47,911-2. 

Diterpene phytotoxins sphaeropsidins A—F, tri- and tetracyclic unrearranged pimarane skeleton, are isolated from Sphaeropsis sapinea, a fungus that causes a canker disease of Italian cypress. Sphaeropsidin A is the major toxic substance showing nonhost-selective phytotoxic activity326 (Figure 36). 

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. 

Organomercuiial intermediates have aiso been utilized in the biotnimetic conversion of communic acids to the pimarane system, during which the radical involved in the NaBH4-demercuration step was captured by oxygen. Treatment of rrnns-communic acid with Hg(OAc)2 (2 equiv.), followed by reduction, led to (44) and (45) and other products. These results are consistent with the intervention of the radical formed fh)m the dimercurial (46) and, indeed, separate reduction in the presence of oxygen provided the peroxy compound (45) directly (Scheme 36). 

Pimarane diterpenes with an antipodal backbone have been isolated from Cleistanthus schlechteri. These included ent-3)8-hydroxypimara-8,l5-diene, ent-3)3,12 -dihydroxypimara-8,l 5-diene (16), and the corresponding C-12 ketone. The location of the carbonyl group at C-12 was inferred from bromination and dehydrobromination and from the multiplicity of the C—H resonance of the C-12 alcohol. Macarangonol (17) has been isolated from Macaranga tanarius. 

We ve classified more than 550 diteipenoids (listed in Table 3 whith corresponding sources) from all the reported Salvia species which we ve divided into 2 categories. The first one contains the monocyclic and bicyclic diterpenoids including labdanes and clerodanes and related diterpenes. The second category concerns tricyclic and tetracyclic diterpenes including pimaranes and abietanes and related diterpenes. The clerodane type diterpenes are mainly represented by american species while abietane type are found in european and asian species. 

Tricyclic diterpenoids were found in numerous species. They may be divided into 2 categories, pimaranes and abietanes. 

Epipimaranes (156-157) were respectively isolated from S. heldrichiana [114] and S. ceratophylla [119]. A pimarane with a C6-C-7-C-5-ring system (158) has been found in S. parryi [38] while the seco-pimarane (159), which exhibited in vitro nonspecific spasmomytic activity, was reported from S. cinnabarina [37],... 

Pimaranes.—Sandaracopimaradien-19-ol is found in Dacrydium colensoi. The heartwood of D. biforme contains isopimara-7,15-diene and 18-... 

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