Diterpene isopimaric acid

A number of diterpenes are known to be active against herbivores ( ). The diterpenes abietic, dehydroabietic, 12-methoxy-abietic, sandaracopimaric, and isopimaric acid serve as feeding deterrents for the larch sawfly, Pristiphora erichsonii in single needles from new shoots of tamarack (Larix laricina) (133). The larvae of this insect do eat tufted needles on short shoots of the same trees. 

Six pimarane diterpenes (297-302) were obtained from the rhizomes of an imnamed Kaempferia (Thai name jang-ngung) [270]. Rhizomes of K. pulchra were found to contain two pimarane diterpenes (303,304) [271], which were reported to possess anti-inflammatory action [272]. Isopimaric acid, a well-known pimarane derivative, was also isolated from the chloroform extract of the rhizomes oiKaempferia sp.[256]. 

Rosin contains mainly diterpene resin acids including abietic acid (22-50%), dehydroa-bietic acid (6-30%), palustric acid (10-25%), neoabietic acid (4-20%), isopimaric acid (10-17%), and pimaric acid (4- %). Others present include dehydropimaric acid, levopi-maric acid, and sandaracopimaric acid. It also contains small amounts of diterpene alcohols and aldehydes, sterols (mainly sitosterol), and phenolic compounds. ... 

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