Identification of Crepenynic Acid in the Seed Oil of Atractylodes lancea and A. macrocephala

Apiaceae Family an Important Source of Petroselinic Fatty Acid: Abundance, Biosynthesis, Chemistry, and Biological Proprieties

Petroselinic fatty acid (PeFA) is considered a rare fatty acid and one of the most important fatty acids in the Apiaceae family. Its content varies depending on plant species, geographical origin, extraction method, ripeness, etc. Indeed, reported levels of petroselinic fatty acid range from 10.4 to 75.6% (in anise seed oil), 1 to 81.9% (in coriander seed oil), 28.5 to 57.6% (in caraway seed oil), 49.4 to 75.6% (in celery seed oil), 41.3 to 61.8% (in caraway seed oil), 79.9 to 87.2% (in dill seed oil), 43.1 to 81.9% (in fennel seed oil), and 35 to 75.1% (parsley seed oil). In this review, we also show current knowledge about genes encoding biosynthesis, from the desaturation of 16:0-ACP to petroselinic acid stored in triacylglycerol in the seeds. Furthermore, petroselinic acid is not related to the synthesis of ABA. PeFA was successfully isolated from Apiaceae family plant seeds in order to study their reactivity and biological activities. Several investigations showed that this fatty acid has a wide range of biological potentials, including antidiabetic, antibacterial, and antifungal activities. In cosmetics, PeFA alone or in association with other active compounds has interesting applications as an anti-inflammatory agent for the treatment of skin, hair, and nail disorders.

Structural Characterization of Unusual Fatty Acid Methyl Esters with Double and Triple Bonds Using HPLC/APCI-MS2 with Acetonitrile In-Source Derivatization

Double and triple bonds have significant effects on the biological activities of lipids. Determining multiple bond positions in their molecules by mass spectrometry usually requires chemical derivatization. This work presents an HPLC/MS method for pinpointing the double and triple bonds in fatty acids. Fatty acid methyl esters were separated by reversed-phase HPLC with an acetonitrile mobile phase. In the APCI source, acetonitrile formed reactive species, which added to double and triple bonds to form [M + C₃H₅N]^+• ions. Their collisional activation in an ion trap provided fragments helpful in localizing the multiple bond positions. This approach was applied to fatty acids with isolated, cumulated, and conjugated double bonds and triple bonds. The fatty acids were isolated from the fat body of early-nesting bumblebee Bombus pratorum and seeds or seed oils of Punicum granatum, Marrubium vulgare, and Santalum album. Using the method, the presence of the known fatty acids was confirmed, and new ones were discovered.

Ectopic expression of cDNAs from larkspur (Consolida ajacis) for increased synthesis of gondoic acid (cis-11 eicosenoic acid) and its positional redistribution in seed triacylglycerol of Camelina sativa

A β-ketoacyl-ACP-synthase II (KAS2) like enzyme and a lysophosphatidic acid acyltransferase (LPAT2) from Consolida ajacis catalyze gondoic acid biosynthesis and incorporation into the sn-2 position of seed TAG in engineered Camelina sativa. Gondoic acid (cis-11 eicosenoic acid, 20:1∆11) is the predominant very-long-chain fatty acid (VLCFA) in camelina (Camelina sativa) seed oil accounting for 12-15% of total triacylglycerol fatty acids. To explore the feasibility of engineering increased levels of this fatty acid in camelina seed, oils from a range of plant species were analyzed to identify those producing 20-Carbon (C20) fatty acids as the only VLCFAs in their seed oil. Seeds of Consolida and Delphinium species (Ranunculaceae) were found to contain moderate levels (0.2% to 25.5%) of C20 fatty acids without accompanying longer chain fatty acids. The C20 fatty acids were abundant in both sn-2 and sn-1/3 positions of seed TAG in Consolida, but were largely absent from the sn-2 position in Delphinium seed TAG. Through generation of a developing seed transcriptome, sequences were identified and cDNAs amplified from Consolida ajacis encoding a β-ketoacyl-ACP-synthase II like protein (CaKAS2B) that lacked a predicted chloroplast transit peptide, and two homologues of Arabidopsis thaliana lysophosphatidic acid acyltransferase 2 (CaLPAT2a and CaLPAT2b). Expression of CaKAS2B in conventional (WT) camelina and a line previously engineered for high seed oleic acid content (HO) resulted in increased seed VLCFA content. Total VLCFA levels were raised from 24 to 35% and from 7 to 23% in T3 seed from representative transformants in the WT and HO backgrounds, respectively. Gondoic acid was the predominant VLCFA in transformed HO lines with low endogenous cytoplasmic fatty acid elongation activity, suggesting limited capacity of CaKAS2B to elongate beyond C20. Expression in camelina of CaLPAT2b resulted in significantly increased C20-VLCFA esterification at the sn-2 position of seed TAG with VLCFA levels of 33.8% in this position in one transformed line compared to 0.3% at sn-2 in the corresponding control line. Only small changes in total seed VLCFA content were observed in transformed lines implying that increased VLCFA esterification capacity in camelina results in positional redistribution of VLCFAs but does not significantly enhance flux through the fatty acid elongation pathway. The full potential of CaKAS2B and CaLPAT2a for the engineering of high gondoic acid levels in camelina remains to be determined. Seed fatty acid composition of Consolida and Delphinium also provides information that may be of value in the systematics of the Ranunculaceae.