Crepenynic acid

Crepenynic acid 18 2 (9c, 12a) Accounts for 60% of the fatty acids in seeds of Crepis foetida, a member of the compositae family... 

Another alteration of unsaturated fatty acids is the formation of acetylenic groups (-OC-). This apparently occurs by dehydrogenation of -CH=CH- Examples of naturally occurring acetylenes are crepenynic acid (p. 381), alloxanthin (p. 1240), and the following remarkable hydrocarbon from the common cornflower Centaurea cyanusm ... 

These are average values from recent years crops bContains 89.2% ricinoleic and 1.4% dihydroxystearic acids Contains 59.8% crepenynic acid "Contains 78.0% licanic acid and 4.0% hydroxy acids eHigh-erucic-acid variety Contains 71.3% vemolic acid 6Contains 78.5% vemolic acid and 5.8% hydroxy fatty acids. 

Acetylenic Crepenynic acid 18 2AM2yne Crepis foetida Polymers -... 

Few recent studies have been made on alkyne biosynthesis. Crepenynic acid has been shown to be a precursor of C9 to C14 polyalkynes in fungal cultures, and was also demonstrated to be a precursor of falcarinol cf 4, falcarinone) in tissue cultures of Daucus car Ota (carrot). (14-Z)-14,15-didehydrocrepenynic acid (67, Figure 10) is predominately converted into 68 by fungi of Lepista spp whereas Caprinis spp yield 69. ... 

Crepenynic acid (18 2 9cl2a) is of special interest because it is recognized as an important biosynthetic intermediate between the more conventional Cig fatty acids and a large number of polyacetylenes of varying chain length but most commonly C9, C13 or C17. This acid, first recognized in Crepis foetida seed oil (35-60%), occurs in other Crepis species, in Saus-surea candicans seed oil (—33%) and in seed oils of the Afzelia species where it is sometimes accompanied by a more unsaturated compound (dehydro-crepenynic acid). 

Crambe abyssinica, 52, 65, 489 Crambe hispanicay 65 Crambe oil, 65 Crappie, fatty acids, 134 Crjanchiidae, wax esters, 147 Cream preparation, 224 Crepenynic acid, 13, 290 Crepis oils, 4,13,52,53 Criegee zwitterion, 463 Crude oils, 184,189,190,192,194 Crystallization, 171,179,214,368,470 Crystallization inhibitors, 214 Crystal structure, 321,325,327,343, 344-49, 370... 

Oleic and linoleic acids are precursors for acetylenes in microorganisms and plants (Fig. 3.1), but crepenynic and dehydrocrepenynic acids also are incorporated into most acetylenic compounds. Crepenynic acid (1) is the first acety-... 

A large series of compounds are derived by modification of crepenynic acid and related Cig acetylenic fatty acids. Whereas these acids may be accumulated in seed oils as components of triacylglycerols, modified derivatives usually are found in vegetative portions of plants. The biosynthesis of matricaria ester (4) and dehydromatricaria ester (5) (both with 10 carbon atoms in the acid portion of the molecule) (Fig. 3.1) is typical for this series of compounds. In this instance, fatty acids with chain lengths of less than 18 carbon atoms do not serve as precursors. 

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