γ-Linolenic and stearidonic acids in Mongolian Boraginaceae

Chemotaxonomic perspectives of the Paracaryum (Cynoglosseae, Boraginaceae) taxa based on fruit fatty acid composition

Paracaryum is a medium sized genus in Cynoglosseae. This study represents the most comprehensive phytochemical investigation of Paracaryum to date. The fatty acid compositions of the fruits of ten Paracaryum taxa belonging to three different subgenera were investigated for chemotaxonomic allocation using gas chromatography. The fatty acid profiles of seven Paracaryum taxa, five of which are endemic to Turkey, were recorded for the first time. Among the twenty-two analysed fatty acids, oleic, linoleic and α-linolenic acids were the major fatty acids represented. The oleic acid content ranged from 22.1% in P. hirsutum to 51.7% in P. lithospermifolium subsp. cariense var. erectum; linolenic acid content ranged from 8.6% in P. lithospermifolium subsp. cariense var. erectum to 20.7% in P. erysimifolium; α-linolenic acid content ranged from 7.5% in P. lithospermifolium subsp. cariense var. erectum to 13.5% in P. cristatum subsp. cristatum; gamma linolenic acid content ranged from 2.8% in P. erysimifolium to 6.0% in P. hirsutum. Additional fatty acids also displayed varying levels in different species; palmitic acid content accounted for 17.7% in P. erysimifolium, erucic acid content was 8.73% in P. strictum, eicosenoic acid content was 6.0% in P. cristatum subsp. cristatum, eicosadienoic acid content was 4.4% in P. hirsutum, and stearic acid content was 4.3% in P. erysimifolium. The classification of the tribe Cynoglosseae remains controversial despite the many intensive morphological and phylogenetic investigations that have been carried out. Our fatty acid data from Paracaryum were analysed together with previously recorded fatty acid data from Cynoglosseae s.l. taxa to examine the chemotaxonomic contribution to the classification among taxa in Cynoglosseae by multivariate methods, including the unweighted pair group method with arithmetic mean and principal component analysis. An assessment of these chemometrics data supported the chemotaxonomic position of the genus Paracaryum in the tribe Cynoglosseae. While the principal component graphic did not depict clear separation of the three subgenera of Paracaryum, the principal component analysis revealed the chemotaxonomic significance of palmitic, linoleic, capric, and oleic acids.

Searching for health beneficial n-3 and n-6 fatty acids in plant seeds

Various plant seeds have received little attention in fatty acid research. Seeds from 30 species mainly of Boraginaceae and Primulaceae were analysed in order to identify potential new sources of the n-3 PUFA α-linolenic acid (ALA) and stearidonic acid (SDA) and of the n-6 PUFA γ-linolenic acid (GLA). The fatty acid distribution differed enormously between genera of the same family. Echium species (Boraginaceae) contained the highest amount of total n-3 PUFA (47.1%), predominantly ALA (36.6%) and SDA (10.5%) combined with high GLA (10.2%). Further species of Boraginaceae rich in both SDA and GLA were Omphalodes linifolia (8.4, 17.2%, resp.), Cerinthe minor (7.5, 9.9%, resp.) and Buglossoides purpureocaerulea (6.1, 16.6%, resp.). Alkanna species belonging to Boraginaceae had comparable amounts of ALA (37.3%) and GLA (11.4%) like Echium but lower SDA contents (3.7%). Different genera of Primulaceae (Dodecatheon and Primula) had varying ALA (14.8, 28.8%, resp.) and GLA portions (4.1, 1.5%, resp.), but similar amounts of SDA (4.9, 4.5%, resp.). Cannabis sativa cultivars (Cannabaceae) were rich in linoleic acid (57.1%), but poor in SDA and GLA (0.8, 2.7%, resp.). In conclusion, several of the presented plant seeds contain considerable amounts of n-3 PUFA and GLA, which could be relevant for nutritional purposes due to their biological function as precursors for eicosanoid synthesis.

Comparative study of lipids in mature seeds of six Cordia species (family boraginaceae) collected in different regions of Brazil

The oil content, FA, and lipid class composition of the mature seeds of six Cordia species were analyzed. Mature seeds of each species were collected in their natural habitat from 2002 to 2004. The total lipid content varied from 1.9% to 13.2%, there being significant differences between the results found in different years for each species and between the species analyzed. The contents of FFA varied from 2.0% to 7.9% of total lipids. Neutral lipids (NL) were the largest class, making up between 89.6% and 96.4% of the total lipids; the phospholipids (PL) were the second largest class (3.0% to 8.9% of the total lipids), and the glycolipids (GL) were the smallest class (0.6 to 3.4%). The presence of GLA was determined in each class of lipids; it is predominant in the NL. Levels of GLA ranged from 1.2% to 6.8% of total seed FA. This is, to our knowledge the first study of lipid composition in seeds of species of Cordia from Brazil.

Geranium sanguineum (Geraniaceae) seed oil: A new source of petroselinic and vernolic acid

The occurrence of petroselinic acid (18:1delta6cis) in seed oils was believed to be limited to the Umbelliferae or Apiaceae, and a few other members of the Umbelliflorae. A major occurrence of petroselinic acid outside the Umbelliflorae must therefore be regarded as highly unusual and surprising. The seed oil of Geranium sanguineum, a member of the family Geraniaceae, has now been found to contain petroselinic and vernolic acids as major FA in its seed oil TAG. These unusual FA have not been reported previously as constituents of Geraniaceae seed oils. The structure and composition of the seed oil FA from G. sanguineum were determined by combined use of chromatographic (TLC, capillary GLC) and spectroscopic (IR, GC-MS) techniques. The double-bond position in petroselinic acid was located unambiguously by the characteristic mass fragmentation of its dimethyldisulfide (DMDS) adduct. The epoxy FA was identified as vernolic acid by co-chromatography and by the mass fragments formed during GC-MS of the products of the epoxy ring-opening reaction with BF3 in methanol.

Lipids of the hexane extract from the roots of medicinal boraginaceous species

The chemical compositions of hexane extracts of the lipid fraction of the roots of the medicinal Boraginaceous species Alkanna tinctoria, Onosma heterophylla, Macrotomia densiflora and Onosma hispidium are presented and their phytochemical relevance evaluated. The predominating fatty acids in all of the root lipids were stearic, palmitic, oleic, linoleic and gamma-linolenic acids, while the latter and stearidonic acid predominated in the seeds and leaves of various Boraginaceous species. The indigenous presence of methyl, ethyl and isopropyl esters of fatty acids, reported for the first time in the roots of higher plants, is considered to be of particular importance in the biosynthesis of fatty substances. The results suggest the use of fatty acids as chemotaxonomic markers for Boraginaceous species and the utilisation of Boraginaceous species as new commercial sources for fatty acids with valuable medicinal and nutritional properties.

Occurrence and characterization of oils rich in gamma-linolenic acid (III): the taxonomical value of the fatty acids in Echium (Boraginaceae)

Fourteen species of the genus Echium (Fam. Boraginaceae) collected in the Macaronesia were surveyed in a search for high levels of gamma-linolenic acid (GLA, 18:3omega6) in the seed oil. High amounts of this fatty acid were found in all of them, ranging from 18.85% (E. pitardii var. pitardii) to 27.42% (E. gentianoides) on total seed fatty acids. The GLA content related to total seed weight was also significant, ranging from 1.26% (E. handiense) to 8.22% (E. gentianoides). In addition, considerable amounts of stearidonic acid (SA, 18:4omega3) were detected, ranging from 3.78% (E. bonnetii var. bonnetii) to 8.81% (E. pininana) on total fatty acids. Besides all the perennial species, the four herbaceous Echium taxa endemic to the Macaronesia also showed high GLA percentages. This is in contrast to the low GLA level found in continental Echium species, all of them bearing an herbaceous habit. These results are in good agreement with the available genetic data and show the ability of GLA to discriminate between Macaronesian and continental Echium species. The analysis of five other Macaronesian species belonging to plant families rich in GLA are also reported.

Occurrence and characterization of oils rich in gamma-linolenic acid Part I: Echium seeds from Macaronesia

Nineteen species of the genus Echium (Fam. Boraginaceae) collected in Macaronesia were surveyed in a search for new sources of gamma-linolenic acid (GLA, 18:3omega6). High amounts of this acid were found in all of them, ranging from 9.15% (E. plantagineum) to 26.31% (E. callithyrsum) of total seed fatty acids. The amounts of GLA related to total seed weight were also significant, ranging from 1.77% (E. sventenii) to 5.02% (E. nervosum). In addition, considerable amounts of stearidonic acid (SA, 18:4omega3) were detected, ranging from 3.03% (E. auberianum) to 12.94% (E. plantagineum) of total fatty acids. These data allow us to consider tile members of the genus Echium from Macaronesia as one of the richest sources of gamma-linolenic acid found so far in nature. The results obtained from multivariable data analysis and the taxonomic relationships among the species is discussed.

Occurrence of gamma-linolenic acid in compositae: a study of Youngia tenuicaulis seed oil

Seeds of Youngia tenuicaulis and other species from the plant family Compositae (Asteraceae) were studied for their oil content and fatty acid composition. The seed oil of Y. tenuicaulis growing in Mongolia was found to contain 5.6% gamma-linolenic acid (18:3delta6cis,9cis,12cis) in addition to common fatty acids. The oil was analyzed using chromatographic [capillary gas-liquid chromatography (GLC), thin-layer chromatography] and spectroscopic (infrared, gas chromatography-mass spectrometry) techniques. Seed oil fatty acids of Saussurea amara (containing gamma-linolenic acid) and of Arctium minus (containing 18:3delta3trans,9cis,12cis), as well as delta5cis- and delta5trans-18:3 were used as GLC reference substances. The evolution in this plant family of a large number of different 18:3 acids as well as the corresponding evolution of unusual desaturases should be investigated. On the other hand, the delta6cis-desaturase required for the biosynthesis of gamma-linolenic acid may have evolved independently several times in unrelated families of the plant kingdom.

Tanacetum (Chrysanthemum) corymbosum seed oil--a rich source of a novel conjugated acetylenic acid

A new conjugated trans,trans-diunsaturated acetylenic acid (17%), found for the first time in nature as a main component of the seed oil of Tanacetum (Chrysanthemum) corymbosum, was shown to be octadeca-8t,10t-dien-12-ynoic acid. Another already known naturally occurring acetylenic acid, crepenynic acid (10%), was found also in the seed oil. The structure of this new unusual fatty acid was confirmed by chromatographic (thin-layer chromatography, gas chromatography, high-performance liquid chromatography) and spectroscopic (infrared, ultraviolet, mass spectrometry) methods by using different chemical derivatizations (deuteration, preparation of picolinyl ester, dimethyloxazoline, and maleic anhydride adduct).