gamma-linolenic and stearidonic acids from moroccan boraginaceae

José Luis Guil-Guerreroa

Juan Carlos López-Martíneza

Francisco Gómez-Mercadob

Pablo Campra-Madrida

a Departamento de IngenieríaQuímica,Universidad de Almería,Almería, Spain

b Departamento de BiologíaVegetal y Ecología,Universidad de Almería,Almería, Spain

Gamma-linolenic and stearidonic acids fromMoroccan Boraginaceae

Seeds from 20 species belonging to Boraginaceae, subfamilies Boraginoideae andHeliotropioideae, were surveyed in a search for new sources of g-linolenic acid (GLA)and stearidonic acid (SDA). Seed oil content ranged from 7.5% in Echium humile ssp.pycnanthum to 28.8% in Anchusa undulata. GLA ranged from 0.2% of total fatty acidsin Heliotropium undulatum to 20.2% in Lithodora maroccana. This last species may beconsidered as new source of GLA. GLA content was also tested in other Lithodoraspecies from the south east of Spain, to compare GLA percentages among relatedtaxa. GLA amounts in all Echium species reached approximately 12%, in good agree-ment with previous findings in other European Echium species. SDA ranged from anabsence in several Cynoglossum species to 16.2% in Echium humile ssp. pyc-nanthum, which may be considered as a new source of this fatty acid.

Keywords: Boraginaceae, g-linolenic acid, stearidonic acid, fatty acids.

1 Introduction

The fatty acid g-linolenic acid (GLA, 18:3 n-6) is a metab-olite of linoleic acid (LA, 18:2 n-6) and the first inter-mediate in the conversion of LA to arachidonic acid (AA,20:4 n-6) [1]. GLA has proved its therapeutic value in thetreatment of a wide variety of pathologies such as atopiceczema, diabetic neuropathy, rheumatoid arthritis, can-cer, viral infections, osteoporosis and alcoholism [1–3].

The fatty acid stearidonic acid (SDA, 18:4 n-3) is a metab-olite of a-linolenic acid (ALA, 18:3 n-3), and precursor oflong-chain polyunsaturated fatty acids (PUFA) such aseicosapentaenoic acid (EPA, 20:5 n-3) and docosahex-aenoic acid (DHA, 22:6 n-3). The use of SDA is increasing,due to its applications in several abnormalities and dis-eases, such as acne and prostate cancer, several cancertypes, skin drying, alcoholism, inflammation, thrombosisand rheumatoid arthritis, which have been recentlyreviewed [4]. The main commercial sources of GLA arethe seed oils from three plant species: Oenothera biennis,Borago officinalis, and Ribes nigrum [1, 3], while SDA isobtained from Echium species [4]. Taking into account thecommercial interest in GLA and SDA oils for human nutri-tion, and that they constitute a raw material to obtain pureGLA and/or SDA, new sources of these acids have beenrecently reported. Among these are MacaronesianEchium seed oils [5–7], new findings in species from sev-eral botanical families that are traditional sources of GLA[8, 9], and Caryophyllaceae seed oils [10]. These reports

have been added to the older literature included in theSOFA (seed oil fatty acids) database (http://www.bagkf.de/sofa), which contains more than 200 otheroccurrences for GLA in Boraginacae. This databaseshows also high levels of GLA in other families, mainly inAsteliaceae [11], Ranunculaceae [12] and Primulaceae[13]. In Boraginaceae, the highest GLA levels have beenreported in the seed oils of various Symphytum spp. [14].For SDA, Primula and Aleuritia spp. (Primulaceae), Hack-elia, Echium and Lappula spp. (Boraginaceae) are in thetop of the range [4].

In this work, the fatty acid composition of seed oils fromseveral Boraginaceae species collected from Morocco isreported.

2 Material and methods

Seeds were collected at maturity from their natural habi-tats in Morocco (Tab. 1). Just before analysis, seeds werefreeze-dried and ground to powder with a mortar at roomtemperature and then immediately analyzed.

2.1 Oil extraction and transesterification

Simultaneous oil extraction and transesterification wasmade according to the method of Lepage and Roy [15].Ground seeds (10 mg) were mixed with 1 mL of themethylation mixture (methanol/acetyl chloride 20 : 1, vol/vol) and 1 mL hexane, and heated at 100 7C for 30 min.After cooling to room temperature, 1 mL distilled waterwas added and the upper hexane layer was removed forGLC analysis.

Correspondence: José LuisGuil-Guerrero, Departamento deIngeniería Química, Universidad de Almería, E-04120 Almería,Spain. Phone: 134 950 015586, Fax: 134 950 015484, e-mail:[email protected]

Eur. J. Lipid Sci. Technol. 108 (2006) 43–47 DOI 10.1002/ejlt.200500251 43

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44 J. L. Guil-Guerrero et al. Eur. J. Lipid Sci. Technol. 108 (2006) 43–47

Tab. 1. Species location.

Species Locality Latitude[7N]

Longitude[7W]

Altitude[m]

Date

Subfam. Boraginoideae Arn.

Tribe Boragineae Rchb., Fl. Germ. Excurs.Anchusa azurea Miller Casablanca-Marrakech 32.30 7.93 240 10/03/2004Anchusa undulate L. Ifrane 33.52 5.09 1600 17/06/2004Anchusa undulate L. subsp. atlantica

(Ball) Braun-Blanq. & MaireFès-Ifrane road 33.75 5.01 1250 14/03/2004

Nonea vesicaria (L.) Reichenb. Fèz-Taza road 34.02 4.880 255 14/03/2004

Tribe Lithospermeae (DC.) GuerkeCerinthe gynnandra Gasparr. Ifrane-Fès road 33.77 5.00 1100 14/03/2004Echium arenarium Guss. Larache. Lixus. Loukos river 35.20 6.15 10 17/06/2004Echium flavum Desf. Tizi-n-Tretten 33.46 5.04 1900 17/06/2004Echium gaditanum Boiss Larache. Loukos 35.20 6.15 40 17/06/2004Echium horridum Batt 1 Marrakech-Tanaoute 31.21 8.19 776 15/03/2004Echium horridum Batt 2 Chichaoua-Imi-n-Tanoute 31.24 8.90 400 15/03/2004Echium horridum Batt 3 Ouarzazate-Zagora 30.77 6.68 60 12/03/2004Echium horridum Batt 4 Valle del Drâa (Zagora) 30.69 6.23 300 12/03/2004Echium horridum Batt 5 Valle del Drâa (Zagora) 30.71 6.25 360 12/03/2004Echium humile ssp. pycnanthum

(Pomel) Greuter & Burdet 1Kourkouda 33.46 5.04 1900 17/06/2004

Echium humile ssp. pycnanthum(Pomel) Greuter & Burdet 2

Taforalt. (Beni-Snassèn) 34.83 2.41 500 11/03/2004

Echium petiolatum Barratte Tamrhakht (near Agadir) 30.55 9.54 238 11/03/2004Echium plantagineum L. Ben Guerir 32.30 7.93 300 14/03/2004Echium sabulicola Pomel 1 Moulouya Valley 34.90 2.60 60 15/03/2004Echium sabulicola Pomel 2 Âït-Kamara 35.09 4.01 415 18/06/2004Lithodora maroccana I.M. Johnst. Beni-Snassèn 34.84 2.61 1300 16/06/2004

Tribe Cynoglosseae DC. In MeisnerCynoglossum cheirifolium L. 1 Aknoul (Rif) 34.64 3.86 1025 14/03/2004Cynoglossum cheirifolium L. 2 Taforalt (Beni-Snassèn) 34.84 2.43 252 15/03/2004Cynoglossum cheirifolium L. 3 Tizi-n-Tretten 33.46 5.04 1900 17/06/2004Cynoglossum creticum Miller Bab-Taza toBab-Berret road 35.02 5.01 260 18/06/2004Cynoglossum dioscoridis Vill. Bab-Berret 34.97 4.69 1520 18/06/2004Solenanthus lanatus L. Beni-Snassèn 34.84 2.96 320 15/03/2004

Tribe Trichodesmeae ZakTrichodesma calcarata Batt. Tamrhakht (near Agadir) 30.59 9.53 457 11/03/2004Subfam. Heliotropioideae GuerkeHeliotropium undulatum Vahl Agadir-Taroudannt 30.43 8.90 219 11/03/2004

2.2 Fatty acid analysis

An HP 5890 series II gas chromatograph (Hewlett Pack-ard, Palo Alto, CA, USA) equipped with an autoinjector(model HP 6890) and FID detector was used. The separa-tion was carried out in a Supelco Omega wax 250(30 m60.25 mm) fused silica capillary column (0.25 mm).The oven temperature profile was: 205 7C (10 min), 6 7C/min to 240 7C (9 min), with a total heating time of 25 min.Heptadecanoic acid (17:0) methyl ester was used as inter-nal standard for quantitative analyses. A chromatogram ofLithodora maroccana seed fatty acids is shown in Fig. 1.

All essays were performed at least in triplicate, and themean values of the different analyses are reported inTab. 2.

3 Results and discussion

Data about 28 populations belonging to 20 Boraginaceaetaxa, collected from Morocco, subfamilies Boraginoideaeand Heliotropioideae, are reported in Tab. 1. Tab. 2 showstheir fatty acid composition and total fatty acid content.Total fatty acids ranged from 7.5% in E. humile ssp. pyc-


Eur. J. Lipid Sci. Technol. 108 (2006) 43–47 GLA and SDA from Moroccan Boraginaceae 45

Tab. 2. Fatty acid composition of 28 populations of plant seeds from the Boraginaceae Juss.

Species Fatty acids§

Oil[wt-%]

16:0 18:0 18:1n-9

18:2n-6

18:3n-6

18:3n-3

18:4n-3

20:00 20:1n-9

22:1n-9

Subfam. Boraginoideae Arn.Tribe Boragineae Rchb.,

Fl. Germ. Excurs.Anchusa azurea Miller ˇ 21.5 12.2 2.2 32.6 38.5 8.0 0.3 – 0.3 3.5 –Anchusa undulate L. ˇ 28.8 15.3 2.0 31.0 18.0 1.0 9.9 4.2 – 3.7 2.7Anchusa undulata L. ssp. atlantica

(Ball) Braun-Blanq. & Maire26.9 13.8 2.2 30.6 18,0 10.3 9.5 3.9 – 4.6 4.7

Nonea vesicaria (L.) Reichenb. ˇ 18.1 10.6 3.5 28.3 31.3 11.6 5.3 1.9 0.3 3.4 –

Tribe Lithospermeae (DC.) GuerkeCerinthe gynnandra Gasparr 9.4 14.6 1.8 11.9 16.4 3.6 23.8 3.3 0.6 1.7 –Echium arenarium Guss. 10.7 6.4 3.7 18.6 19.7 11.2 25.2 11.3 – 1.3 –Echium flavum Desf. ˇ 21.6 6.4 2.9 9.5 17.6 10.6 41.6 10.8 – 1.6 –Echium gaditanum Boiss 9.4 6.9 3.6 20.4 20.9 12.4 24.4 10.1 – 1.3 –Echium horridum Batt 1 20.1 6.5 5.0 13.8 20.3 8.9 37.3 4.7 0.2 1.1 –Echium horridum Batt 2 19.4 8.6 12.1 13.0 19.2 6.9 34.5 5.0 0.2 0.3 –Echium horridum Batt 3 17.9 25.4 2.6 3.7 17.9 3.4 28.3 3.0 0.2 0.3 –Echium horridum Batt 4 18.6 8.3 5.3 30.4 23.3 6.2 19.9 2.0 0.3 1.3 –Echium horridum Batt 5 18.3 7.0 5.7 24.2 25.9 5.6 25.5 1.9 0.3 1.3 –Echium humile ssp. pycnanthum

(Pomel) Greuter & Burdet 110.3 5.5 2.1 12.8 18.3 10.9 35.2 14.0 – 1.1 –

Echium humile ssp. pycnanthum(Pomel) Greuter & Burdet 2

7.5 5.8 2.3 12.2 18.7 10.9 34.8 16.2 – 1.1 –

Echium petiolatum Barratte 25.8 5.7 3.6 10.1 18.2 12.5 36.0 10.8 0.2 1,0 –Echium plantagineum L. ˇ 24.6 8.4 2.9 12.2 14.7 10.1 34.2 13.0 0.2 0.9 –Echium sabulicola Pomel 1 ˇ 22.3 5.9 2.3 11.0 16.5 10.4 37.7 14.9 1.1 – –Echium sabulicola Pomel 2 ˇ 20.5 8.0 3.5 10.9 16.9 13.2 30.4 12.7 0.3 1.1 –Lithodora fruticosa (L.) Griseb. 17.2 12.9 2.9 23.4 24.5 13.3 18.3 4.5Lithodora maroccana I.M. Johnst. 16.5 10.8 3.2 15.0 18.4 20.2 23.2 8.2 – 1.0 –

Tribe Cynoglosseae DC. In MeisnerCynoglossum cheirifolium L. 1 ˇ 11.1 12.3 2.4 27.5 16.7 3.0 17.5 2.9 0.7 5.3 –Cynoglossum cheirifolium L. 2 ˇ 11.9 12.5 1.6 3.5 17.6 2.6 25.1 9.0 – 0.6 –Cynoglossum cheirifolium L. 3 ˇ 10.4 20.2 3.6 19.2 21.5 1.1 23.5 – – 3.6 4.4Cynoglossum creticum Miller ˇ 13.7 20.1 4.4 21.5 20.2 1.3 22.9 – – 2.9 4.9Cynoglossum dioscoridis Vill. 16.2 20.1 3.8 11.4 18.0 1.0 34.4 – – 2.4 3.3Solenanthus lanatus L. 12.5 14.5 2.9 25.5 24.6 5.2 11.3 2.3 0.7 4.6 –

Tribe Trichodesmeae ZakTrichodesma calcarata Batt. 18.8 8.4 7.2 34.4 20.7 1.5 23.0 1.9 0.7 0.7 –Subfam. Heliotropioideae GuerkeHeliotropium undulatum Vahl 15.3 10.6 4.1 17.4 5.0 0.2 5.0 1.6 0.4 0.3 –

§ Other fatty acids of undetermined structure account for 100% of the fatty acids.# Percentage based on total seed, determined by GC; serial numbers are used to distinguish different populations ana-

lyzed of the same species.ˇ Species for which previous reports about the fatty acid profile were available.


46 J. L. Guil-Guerrero et al. Eur. J. Lipid Sci. Technol. 108 (2006) 43–47

Fig. 1. GLC chromatogram ofLithodora maroccana seed fattyacids. For chromatographic condi-tions, see Material and methods.

nanthum to 28.8% in A. undulata. GLA was present in allthe accessions, while SDA was absent only in someCynoglossum species.

The amount of GLA in the seed oil ranged from 0.2% inH. undulatum to 20.2% in L. maroccana. The GLA con-tent exhibited by L. maroccana seed oil was within therange of B. officinalis (20–23%) and MacaronesianEchium (17–28%), which are placed among the bestsources of GLA found in nature until now. Such amountsof GLA (over 20%) have been found rarely in seed oils [3].On the other hand, several authors refer to L. maroccanataxa as L. fruticosa ssp. marocana, due to morphologicalsimilarities among both plants.Thus, to check similaritiesor divergences in the GLA content between so relatedtaxa, seeds of L. fruticosa (L.) Griseb. were collected fromthe south east of Spain, showing a GLA percentage in theseed oil of 13.5%, which considerably lower than for theother one.

The species analyzed in this work from the tribe Lithos-permeae (subfam. Boraginoideae) showed low(C. gynandra) and high (L .maroccana) GLA percentages,while SDA reached moderate amounts, ranging from3.3% (C. gynandra) to 16.2% (E. humile subsp. pyc-nanthum). It has been reported [2, 16] that the fatty acidprofiles of the seeds act as taxonomical markers in Bor-aginaceae; thus, similarities in the fatty acid content inrelated taxa might be expected. This rule works properlyfor the majority of the species analyzed here; never-theless, some exceptions appear. In this sense, E. flavumshows an SDA percentage higher than other E. flavumreported from the south east of Spain [8]. In addition, asexposed above, L. maroccana shows a GLA amount

considerably higher than L. fruticosa. These facts indicatethat the seed fatty acid profiles can differ strongly be-tween related species and/or among species popula-tions, reflecting minor genetic variations. Nevertheless,other factors could influence the fatty acid profiles of theseed oils, such as degree of ripeness, climate and dura-tion of sunshine, although these factors have only minorinfluence on Boraginaceae species [6].

On the other hand, GLA and SDA contents in all Echiumspecies analyzed in this work were in the range of otherEuropean and North African Echium species [3, 8].

Within the tribe Cynoglosseae, the lowest value of GLAwas found in C. dioscoridis (1.0%) and C. cheirifolium(1.1%), results in good agreement with previous reportsfrom plants of this genus [8]; thus, the present data con-firm that the GLA content in plants belonging to this taxonis low.

Species from subfamily Heliotropioideae have beencharacterized by low amounts of GLA [3]. The presentreport agrees with these previous findings, with the low-est amount of GLA being found in H. undulatum (0.2%).This fact could be an additional indicator supporting aseparate position of the Heliotropioideae, in agreementwith the Heliotropaceae family, as has previously beeninferred from ITS1 sequence data [17] .

Among the species surveyed in this report, L. maroccanaseems to be the best option to attempt an alternative cropto the current producers of GLA oils, while E. humilesubsp. pycnanthum constitutes the same option for SDAoils. Nevertheless, prior to a possible consumption ofthese oils, a possible presence of cyanogenic glycosides


Eur. J. Lipid Sci. Technol. 108 (2006) 43–47 GLA and SDA from Moroccan Boraginaceae 47

and cyanolipids should be excluded, taking into accountthat some species of Boraginaceae are described to beable to synthesize these toxic compounds [18].

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[3] J. L. Guil-Guerrero: Occurrence of gamma-linolenic acid. In:Recent Progress in Medicinal Plants. Vol. VIII. Eds. D. K.Majundar, J. N. Govil, V. K. Singh, Sci. Tech. Publishing LLC,Houston, TX (USA) 2002, pp. 467–487.

[4] J. L. Guil-Guerrero: Stearidonic acid (SA, 18:4n3): Metabo-lism, nutritional importance, medical uses, natural sources,isolation of pure SA and upgrading of SA oils. In: Omega-3Fatty Acids: New Research. Ed. F. Columbus, Nova SciencePublishers, Inc., Huntington, NY (USA) 2005.

[5] J. L. Guil-Guerrero, F. Gómez-Mercado, F. García-Maroto, P.Campra-Madrid: Occurrence and characterization of oils richin g-linolenic acid. Part I: Echium seeds from Macaronesia.Phytochemistry. 2000, 53, 451–456

[6] J. L. Guil-Guerrero, F. Gómez-Mercado, I. Rodríguez-García,P. Campra-Madrid, F. García-Maroto: Occurrence and char-acterization of oils rich in gamma-linolenic acid. III. The tax-onomical value of the fatty acids in Echium (Boraginaceae).Phytochemistry 2001, 58, 117–120.

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[10] J. L. Guil-Guerrero, J. C. López-Martínez, R. Navarro-Juárez, F. García-Maroto, P. Campra-Madrid: Gamma-lino-lenic acid from Caryophyllaceae seed oil. J Am Oil ChemSoc. 2004, 81, 659–661.

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[13] O. Sayanova, J. A. Napier, P. R. Shewry: 6-Unsaturated fattyacids in species and tissues of the Primulaceae. Phy-tochemistry. 1999, 52, 419–422.

[14] C. E. Hansen, P. S. Stoessel, P. Rossi: Distribution of g-lino-lenic acid in the Comfrey (Symphytum officinale) plant. J SciFood Agric. 1981, 54, 309–312.

[15] G. Lepage, C. Roy: Improved recovery of fatty acid throughdirect transesterification without prior extraction or purifica-tion. J Lipid Res. 1984, 25, 1391–139.

[16] L. Velasco, F. D. Goffman: Chemotaxonomic significance offatty acids and tocopherols in Boraginaceae. Phytochem-istry. 1999, 52, 423–426.

[17] N. Diane, H. H. Hilger, M. Weigend: Testing hypotheses ondisjunctions present in the primarily woody Boraginales:Ehretiaceae, Cordiaceae, and Heliotropaceae, inferred fromITS1 sequence data. Int J Plant Sci. 2004, 165, 123–135.

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[Received: July 1, 2005; accepted: November 21, 2005]


gamma-linolenic and stearidonic acids from moroccan boraginaceae

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