Abstract - Essential oil composition of some Centaurea sp. (Asteraceae) from different italian islands. The volatile constituents of leaves and flower heads of several Centaurea species from different islands of Ligurian and Tyrrhenian Sea were investigated for the first time. C.
veneris (Sommier) Bég. from Palmaria Island (Ligurian Sea), C. gym- nocarpa Moris & De Not. from Capraia Island, C. aetaliae (Somm.) Bég. and C. ilvensis (Sommier) Arrigoni from Elba Island (Northern Tyrrhenian Sea); C. aeolica Lojac. subsp. aeolica from Lipari, Aeolian Islands, C. busambarensis Guss., C. panormitana Lojac. subsp. ucriae (Lacaita) Greuter, C. panormitana Lojac. subsp. umbrosa (Fiori) Greu- ter, C. panormitana Lojac. subsp. todaroi (Lacaita) Greuter, C. panor- mitana Lojac. subsp. seguenzae (Lacaita) Greuter from different local- ities in Sicilia (southern Tyrrhenian Sea), were collected at flowering stage. All samples were extracted by steam distillation to obtain the volatile fraction with a yield ranging from 0.02-0.13% in leaves and 0.01-0.09% in flower heads (weight/fresh weight basis), respectively.
The oils were then analyzed by GC/FID and GC/MS methods and more than 100 compounds belonging to several chemical classes were identified and quantified in all the samples. Sesquiterpenes represent the most abundant class of compounds (22.35-61.67% and 35.16- 57.51% of the total volatiles in leaves and flower heads, respectively) of which germacrene D was the dominant constituent (10.03-42.65%
and 7.33-30.32% in leaves and flower heads, respectively). Aldehydes, hydrocarbons, ketones, monoterpenes, alcohols, acids, esters and mis- cellaneous compounds were also identified and quantified in different amount in the volatile oils from all the examined plant organs. Other compounds were also detected and they appear to be species-specific, as their presence was only detected in either one or the other Centau- rea species.
Key words - Centaurea aeolica; C. aetaliae; C. busambarensis; C. il- vensis; C. gymnocarpa; C. panormitana subsp. ucriae, subsp. umbrosa, subsp. todaroi and subsp. seguenzae; C. veneris; Asteraceae; essential oil composition; GC/MS; Ligurian and Thyrrenian sea Islands, Italy.
Riassunto - Composizione di oli essenziali di alcune specie del genere Centaurea raccolte in diverse isole italiane. Sono stati estratti per di- stillazione in corrente di vapore i costituenti volatili delle parti aeree (foglie e infiorescenze) di diverse specie appartenenti al genere Cen- taurea: C. veneris (Sommier) Bég, C. gymnocarpa Moris & De Not., C.
ilvensis (Sommier) Arrigoni e C. aetaliae (Somm.) Bég. da diverse isole del Mar Ligure e del Mar Tirreno Settentrionale; C. aeolica Lojac.
subsp. aeolica da Lipari, Isole Eolie; C. busambarensis Guss., C. panor- mitana Lojac. subsp. ucriae (Lacaita) Greuter, C. panormitana Lojac.
subsp. umbrosa (Fiori) Greuter, C. panormitana Lojac. subsp. todaroi (Lacaita) Greuter, C. panormitana Lojac. subsp. seguenzae (Lacaita) Greuter da diverse località della Sicilia. La resa in olio essenziale è risultata essere compresa tra 0.02 e 0.13% per le foglie e tra 0.01 e 0.09% per le infiorescenze, calcolata sul peso fresco. Gli estratti sono stati quindi analizzati mediante GC/FID e GC/MS e più di 100 com- posti appartenenti a diverse classi chimiche sono stati identificati e quantificati. I sesquiterpeni rappresentano la classe più abbondante di composti (valutati rispettivamente 22.35-61.67% e 35.16-57.51%
dei volatili totali in foglie ed infiorescenze), tra cui il germacrene D è risultato il composto dominante (valutato 10.03-42.65% dei volatili totali nelle foglie e 7.33-30.32% dei volatili totali nelle infiorescenze).
In tutti i campioni analizzati sono stati identificati anche: aldeidi, idrocarburi, chetoni, monoterpeni, alcoli, acidi ed esteri in quantità minore. Da queste indagini sono stati inoltre evidenziati alcuni com- posti specie-specifici che sembra possano avere anche un significato chemotassonomico.
Parole chiave - Centaurea aeolica; C. aetaliae; C. busambarensis; C. il- vensis; C. gymnocarpa; C. panormitana subsp. ucriae, subsp. umbrosa, subsp. todaroi e subsp. seguenzae; C. veneris; Asteraceae; composizio- ne di oli essenziali; GC/MS; Isole dei Mari Ligure e Tirrenico, Italia.
IntroductIon
The genus Centaurea (Cardueae tribe, Asteraceae) is represented by a very large number of species (400-700) with predominantly Old World distribu- tion (Hellwig, 2004; Bancheva & Greilhuber, 2006;
Greuter, 2006-09; Greuter 2008; Hilpod et al., 2011).
Several papers on secondary metabolites of Centau- rea species are available from literature (Baykan-Erel et al., 2010), and a number of them are on volatile constituents (Rosselli et al., 2009; Formisano et al., 2010, 2011; Tava et al., 2010; Viegi et al., 2010, 2011, 2013; Esmaeili & Khodadadi, 2012; Jemia et al., 2012;
Politeo et al., 2012; Demirtas & Sahin, 2012; Kilic, 2013). This taxon is very complex and could benefit from research using new cytological and chemical techniques.
The present study extends our work on Centaurea spe- LucIa VIegI (*), roberta VangeLIstI (**), roberto cecottI (***), aLdo taVa (***)
ESSENTIAL OIL COMPOSITION OF SOME CENTAUREA SP.
(ASTERACEAE) FROM DIFFERENT ITALIAN ISLANDS
(*) Dipartimento di Biologia, Unità di Botanica, University of Pisa, via L. Ghini 13, I-56126 Pisa, Italy; E-mail: lucia.viegi@unipi.it.
(**) SMA, University of Pisa, via L. Ghini 13, I-56126 Pisa, Italy.
(***) Consiglio per la ricerca in agricoltura e analisi dell’economia agraria, Centro di ricerca per le produzione foraggere e lattiero casearie, viale Piacenza 29, I-26900 Lodi, Italy.
cies in Italy and its aim was to investigate the essential oil composition of seven species from different Italian islands.
Four species were from Ligurian and Northern Thyr- renian Sea Islands:
C. veneris (Sommier) Bég. is an endemic perenni- al species that grows among the calcareous rocks of Portovenere and the nearby islands of Palmaria, Tino and Tinetto, in the Ligurian Sea. Chromosome number is 2n=18 (Viegi et al., 1972b, sub. C. cinerar- ia L. var. veneris (Somm) Bèg.). This taxon has not yet been assessed for the IUCN Red List, but it is in the Catalogue of Life (http://www.catalogueoflife.
org/);
C. gymnocarpa Moris & De Not is an endemic peren- nial species that inhabits among the acid rocks (vul- canites) of Capraia island (Tuscan Archipelago), in the northern Tyrrhenian Sea. Its localities have been described as “Habitat 8220” in the EC Habitats Di- rective. Chromosome number is 2n=18 (Guinochet
& Foissac, 1962; Viegi & Cela Renzoni, 1976). The species is considered endangered (EN), according to I.U.C.N. Red List criteria (Conti et al., 1997; Foggi, 2006);
C. aetaliae (Sommiér) Béguinot is an endemic pe- rennial species that grows on siliceous rocks of Mt Volterraio on Elba island, in the northern Tyrrhenian Sea. Chromosome number is 2n=18 (Viegi & Cela Renzoni, 1976; Signorini et al., 2001, sub C. aplolepa Moretti subsp. aetaliae (Sommier) Dostàl). This taxon has not yet been assessed for the IUCN Red List, but it is in the Catalogue of Life (http://www.catalogueof- life.org/);
C. ilvensis (Sommiér) Arrigoni is an endemic peren- nial species that inhabits among the acid rocks (gran- ites) of Mt Capanne on Elba island, in the northern Tyrrhenian Sea. Chromosome number is 2n=18 (Viegi
& Cela Renzoni, 1976, sub C. dissecta Ten. var. ilvensis Sommier). This species has not yet been assessed for the IUCN Red List, but it is in the Catalogue of Life (http://www.catalogueoflife.org/).
Three species were from Southern Thyrrenian Sea Is- lands and are all endemics:
C. aeolica Lojac. grows on volcanic rocks at Lipari (Ae- olian Islands). Chromosome number is 2n=18 (Viegi et al., 1972b, sub. C. aeolica Guss. in Lojac.). This taxon has not yet been assessed for the IUCN Red List, and also it is not in the Catalogue of Life;
C. busambarensis Guss. inhabits on calcareous rocks at Mt Busambra and Isnello (PA). Chromosome num- ber is 2n=18 (Tornadore et al., 1974; Cela Renzoni &
Viegi, 1982; Devesa et al., 1988). This taxon has not yet been assessed for the IUCN Red List, but it is in the Catalogue of Life;
C. panormitana Lojac., of which four subspecies were collected in different sicilian localities. This taxon has
not yet been assessed for the IUCN Red List, and also it is not in the Catalogue of Life;
7a - C. panormitana Lojac. subsp. ucriae (Lacaita) Greuter (= C. ucriae Lacaita) grows on arid rocks in front of the sea;
7b - C. panormitana Lojac. subsp. umbrosa (Fiori) Greuter (= C. umbrosa Lacaita) inhabits on shady rocks. Chromosome number is 2n=18 (Viegi et al., 1972b; Cela Renzoni & Viegi, 1982, sub. C. ucriae Lac.
subsp. umbrosa (Lac.) Cela Renzoni et Viegi);
7c - C. panormitana Lojac. subsp. todaroi (Lacaita) Greuter (= C. todaroi Lacaita) grows on arid rocks.
Chromosome number is 2n=18 (Brullo & Pavone, 1978, sub. C. todari Lacaita; Cela Renzoni & Viegi, 1982, sub. C. ucriae Lac. subsp. todari (Lac.) Cela Ren- zoni et Viegi);
7d - C. panormitana Lojac. subsp. seguenzae (Lacaita) Greuter (= C. todari Lacaita subsp. seguenzae (Lacaita) Giardina & Raimondo) grows on arid rocks in front of the sea. Chromosome number is 2n=18 (Viegi et al., 1972b, sub. C. todari Lacaita forma seguenzae Lacaita).
The nomenclature follows Greuter (2006).
C. gymnocarpa, C. veneris, C. aeolica, C. busambaren- sis, C. panormitana belong to the group known as the
“cineraria” group (Viegi et al., 1972a; Cela Renzoni
& Viegi, 1982; Bancheva et al., 2006; Hilpod et al., 2011). This group probably was once a single species when the land masses were united, but as islands were formed, new species evolved on each island (I.U.C.N., 2014)
MaterIaLsandMethods
Plant materials
The aerial parts (fresh and dry flower heads and leaves) of C. veneris from Palmaria, C. gymnocarpa from Capraia, as well as of C. ilvensis and C. aetali- ae from Elba island (Mt Capanne and Mt Volterraio, respectively), as well as of Sicilian species, C. aeolica subsp. aeolica from Lipari (Aeolian Islands), C. busam- barensis from Isnello (PA), C. panormitana. subsp.
ucriae from Sferracavallo (PA), C. panormitana subsp.
umbrosa from Mt Gallo and Mt Pellegrino, at Mon- dello (PA), C. panormitana. subsp. todaroi from Baghe- ria (PA) (along motorway), C. panormitana subsp. seg- uenzae from Capo Tindari (ME) were collected during their flowering period (April-July) in 2006 and 2007.
Voucher specimens of these plants are deposited in PI (Pisa University, Herbarium Horti Pisani). Num- bers as follows: PI - New acquisitions - 9476 Centaurea gymnocarpa/ 5; PI - New acquisitions - 9476 Centau- rea veneris/7; PI - New acquisitions - 9476 Centaurea aetaliae/ 3; PI - New acquisitions - 9476 Centaurea il- vensis/ 2; PI - New acquisitions -9476 C. aeolica subsp.
aeolica /4; PI - New acquisitions - 9476 C. busamba-
rensis/6 ; PI - New acquisitions - 9476 C. panormitana.
subsp. ucriae (sub. C. ucriae subsp. ucriae) from Sferra- cavallo/4; PI - New acquisitions - 9476 C. panormitana subsp. umbrosa (sub. C. ucriae subsp. umbrosa) from Mt Gallo /4 , PI - New acquisitions - 9476 C. panor- mitana subsp. umbrosa (sub C. ucriae) from Mondello (PA) /3; PI - New acquisitions - 9476 C. panormitana.
subsp. todaroi (sub C. todari) from Bagheria (PA) /2;
PI - New acquisitions - 9476 C. panormitana subsp.
seguenzae (sub C. todari subsp. seguenzae) /4.
For each population, a sample of 20 individuals was collected. Samples were stored in a corked glass bottle with 100 ml of CH2Cl2 as preservative and stored at 4°C until analysis.
Isolation of the essential oils
The tissue samples were steam distilled with odor-free water in a Clevenger-type apparatus to give 300 mL of distillate. This was saturated with NaCl, extracted with freshly distilled diethyl ether (3 × 100 mL), dried over anhydrous Na2SO4 and concentrated in a rotary evaporator to give a pale-yellow oil. The obtained es- sential oils were than analyzed by gaschromatographic methods.
Gas chromatography and gas chromatography-mass spec- trometry
GC/FID analyses were carried out using a Perkin Elmer model 8500 GC equipped with a 30 m × 0.32 mm Elite-5MS capillary column (0.5 mm film thick- ness). Samples (0.5 mL) were injected in the split mode (1:30) with a column temperature program of 40°C for 5 min, then increased to 280°C at 4°C/min and finally held at this last temperature for 10 min. Injector and detector were set at 250°C and 300°C, respectively;
the carrier gas was He with a head pressure of 12.0 psi.
GC/MS analyses were carried out using a Perkin El- mer Clarus 500 GC equipped with a Clarus 500 mass spectrometer using the same capillary column and chromatographic conditions as for the GC-FID anal- yses. Mass spectra were acquired over 40–500 amu range at 1 scan/s with ionizing electron energy 70 eV, ion source 200°C. Transfer line was set at 300°C, car- rier gas was He at 1.0 mL/min.
Identification and quantification of the essential oil com- ponents
The identification of the oil components was per- formed by their retention indices (RI), authentic ref- erence compounds, peak matching library search, as well as published mass spectra (NIST/EPA/NIH, 2000; Joulain & König, 1998; Adams, 2007). Retention indices (RI) were calculated using n-alkane series (C6- C32) under the same GC conditions as for the samples.
The relative amounts (RA) of individual components of the oil are expressed as percent peak area relative
to total peak area from the GC-FID analyses of the whole extracts. The amount of essential oil from leaves and flower heads of the examined Centaurea species ranged from 0.01 to 0.15% of fresh material.
resuLtsanddIscussIon
The volatile oil of the different Centaurea species under investigation contain several compounds belonging to different chemical classes, including sesquiterpenes, aldehydes, hydrocarbons, alcohols, monoterpenes, ketones, acids, esters and miscella- neous. The percentage composition of these classes of compounds in the volatile oils of leaves and flower heads of the Centaurea sp.pl. from different islands of Ligurian and Tyrrhenian Sea are listed in Table 1.
As shown in this table, the most abundant classes of compounds were sesquiterpenes, ranging from 22.35 to 61.67% of the total volatiles in leaves and from 35.16 to 57.51% of the total oil in flower heads. The other classes of detected compounds were: aldehydes (6.48-15.42% in leaves, 6.47-24.47% in flower heads), hydrocarbons (1.67-18.26% in leaves, 8.09-24.29% in flower heads), alcohols (1.76-21.83% in leaves, 0.55- 8.35% in flower heads), monoterpenes (1.24-2.74%
in leaves, 0.59-2.45% in flower heads), ketones (0.34- 11.85% in leaves, 0.71-3.51% in flower heads), acids (0.57-4.50% in leaves, 0.38-5.94% in flower heads), esters (0.75-4.67% in leaves, 0.05-1.45% in flower heads) and miscellaneous (0.09-7.72% in leaves, 0.24- 1.21% in flower heads).
Concerning the single oil constituent, the sesquiter- pene germacrene D is detected in all the analysed samples and represents one of the most abundant constituents. This compound is also reported as a constituent of the volatile fraction of other Centaurea sp.pl. from different countries (Binder et al., 1990;
Senatore et al., 2003; Beck et al., 2008; Rosselli et al., 2009; Formisano et al., 2010, 2011; Tava et al., 2010;
Viegi et al., 2010; 2011; 2013; Esmaeili et al., 2012;
Demirtas et al., 2012; Jamia et al., 2012; Politeo et al., 2012; Kilic, 2013).
Moreover, differences in the quantitative composition of the volatile fraction of the investigated Centaurea sp.pl. from Italian islands can be observed. In par- ticular, the five most abundant detected compounds - listed in terms of percentage amount - in the seven Centaurea species were:
from Ligurian and Northern Thyrrenian Sea Islands:
C. veneris: germacrene D (42.65% leaves - 30.32%
flower heads); E-caryophyllene (5.73% leaves, 5.80%
flower heads); phenylacetaldehyde (4.52% leaves, 3.23% flower heads); bicyclogermacrene (3.28%
leaves, 2.70% flower heads); a-ylangene (1.34% leaves, 4.31% flower heads);
C. aetaliaeC. ilvensis KIaCompoundsbleaves
flower heads
leaves
flower heads
leavesleavesleavesflower headsleaves
flower heads
leavesflower headsleavesflower headsleavesflower headsleavesflower headsleavesflower heads Alcohols1,761,012,530,555,647,357,666,1814,288,359,814,559,723,095,344,0721,836,608,995,35 6791-penten-3-ol0,120,070,07tr0,330,050,100,05tr0,060,050,030,060,150,34tr0,360,090,210,13 6823-penten-2-ol0,150,220,13tr0,230,050,150,24tr0,220,220,170,230,210,350,010,280,080,190,38 7233-methyl-3-buten-1-ol------0,060,060,470,06tr0,05trtr0,06tr0,240,060,08tr 7333-methyl-1-butanol0,060,060,060,210,060,220,242,451,090,200,270,350,240,610,380,321,111,880,230,32 7372-methyl-1-butanol0,050,450,050,020,040,070,140,980,560,460,731,870,190,370,320,230,361,130,211,29 7613,4-dimethyl pentanol------0,280,090,330,070,110,090,180,20tr0,350,070,300,040,26 766pentanol0,02tr0,05trtr--------------- 768cis-2-penten-1-ol0,120,080,07----------------- 7693-methyl-2-buten-1-ol------0,130,110,410,130,170,080,030,15-0,24tr0,020,130,21 855cis-3-hexen-1-ol1,130,121,12tr4,574,754,381,106,220,151,500,195,560,031,230,239,130,502,990,20 865trans-2-hexen-1-ol----0,01-0,150,070,150,090,120,080,090,140,100,260,090,040,450,21 869hexanol----0,050,100,210,260,740,230,470,450,340,280,190,281,230,800,061,09 8901-octen-3-ol-----0,010,220,040,030,020,040,100,070,120,000,150,080,100,200,05 1035benzyl alcohol0,110,010,980,320,140,660,370,202,950,353,900,431,430,401,320,125,510,642,730,47 1070octanol----0,050,030,380,060,170,100,450,100,230,120,000,040,340,260,250,16 11112-phenylethanol----0,161,410,140,161,160,811,780,411,020,280,940,242,940,701,220,44 1473dodecanol------0,01trtr3,01tr0,04-tr0,031,49--tr0,07 1678tetradecanol------0,700,31tr2,39tr0,110,050,030,080,110,09trtr0,07 Aldehydes8,2910,2210,296,476,487,3010,428,2411,9911,5915,4223,8310,1922,548,759,178,6518,4610,0424,47 6503-methylbutanal0,440,280,190,290,410,56--0,880,51-tr-0,04-0,87trtrtr4,34 6572-methylbutanal0,501,420,020,130,010,24tr0,381,811,772,235,790,410,281,500,350,241,380,824,59 699pentanal0,050,070,05--0,030,430,36tr0,120,410,040,270,070,111,050,190,380,340,03 7532-pentenal0,04tr0,04----------------- 802hexanal0,231,870,330,790,210,300,122,910,092,46tr5,790,043,920,211,780,334,280,094,50 831furfural-0,16-tr---------------- 853trans-2-hexenal0,630,180,34tr0,760,310,710,212,270,030,200,050,630,021,070,791,950,221,310,04 8882-ethenyl-2-butenal0,260,240,26tr---------------- 902heptanal0,030,190,060,150,070,220,150,710,080,640,000,830,200,370,130,020,130,120,010,88 9073-methylthyopropanal0,060,060,060,080,280,240,040,080,080,140,080,240,090,210,030,250,040,020,160,37 957trans-2-heptenal0,110,170,160,28---------------- 961benzaldehyde0,080,250,140,180,170,110,330,310,270,310,400,760,210,690,140,570,431,710,370,69 1002octanal0,030,250,250,13tr0,070,330,12tr0,220,230,36tr0,540,100,750,030,580,140,42 1008trans, trans-2,4-heptadienal----0,190,19-------------- 1043phenylacetaldehyde4,523,233,152,853,103,822,622,343,293,762,797,912,1612,731,291,402,028,152,305,02 1104nonanal0,420,621,540,570,640,602,780,181,280,764,090,712,061,431,240,901,381,072,281,33 1206decanal0,861,133,650,950,570,481,580,511,680,521,920,772,781,521,960,171,060,011,321,64 1262trans-2-decenal------1,160,020,11tr2,290,130,670,160,51tr0,570,190,570,24 1307undecanal0,030,100,050,07--tr0,030,090,060,30tr0,39tr0,270,010,15tr0,16tr 1364trans-2-undecenal------0,160,060,06tr0,48tr0,25tr0,15tr0,13tr0,17tr 1408dodecanal----0,070,13-------------- 1714hexadecanal------0,010,02tr0,29tr0,450,030,560,040,26tr0,35tr0,38 Monoterpenes1,781,191,170,592,202,212,111,922,740,791,242,452,302,061,381,881,471,161,731,07 932α−pinene0,020,030,030,330,080,080,020,021,980,360,110,580,680,330,290,310,020,060,640,62 972sabinene----0,09tr0,06tr0,140,010,240,030,26tr0,14-0,23-0,170,03 976β-pinene0,050,870,080,26tr-0,250,130,090,040,060,330,100,210,040,060,040,190,090,12 989β-myrcenetr0,04trtr-0,140,040,050,090,120,210,140,170,080,050,120,030,080,080,11 1031limonene----0,260,800,030,05tr0,080,22tr0,15-0,300,020,74tr0,43tr 1035(Z)-β-ocimene----trtr0,160,22trtr0,01trtr0,030,02trtrtrtrtr 1047(E)-β-ocimene1,670,250,16tr1,040,550,691,120,07trtr0,030,220,360,300,330,120,160,03tr 1092linalool oxide (furanoid)----0,140,09tr0,12tr0,060,050,650,030,070,02trtr0,47tr0,08 1099linalool0,03-0,70tr0,440,410,770,170,230,090,200,650,630,860,161,040,220,160,190,08 1195p-menth-1-en-8-ol----0,150,140,090,040,140,030,140,040,060,120,06tr0,070,040,100,03 1196a-terpineol0,01-0,20tr---------------- Sesquiterpenes61,6753,5234,3637,1149,8549,0430,9743,3048,7457,5122,3547,9332,3839,1755,4444,1935,3148,0549,4835,16 1337δ-elemene0,240,460,06tr0,190,03-tr-0,30tr0,08tr0,05trtr-0,12-0,03 1349α-cubebene------0,020,01trtr0,05tr0,15-tr-trtr0,09tr 1359α-longipinene------0,100,120,040,020,30tr0,11tr0,03trtr-0,04tr 1373α-ylangene1,344,310,09tr0,470,190,345,140,201,780,140,240,070,350,110,150,050,240,000,27 1379α-copaene0,691,460,640,720,530,500,992,540,710,891,690,620,880,570,990,301,000,661,000,47 1391β-elemene----0,270,400,751,680,260,291,020,260,592,440,330,820,260,270,410,47 1423(E)-caryophyllene5,735,804,884,498,969,795,7114,865,2217,791,948,142,677,574,9314,455,0311,334,529,97 1435(E)-a-bergamotene0,37tr2,045,96---------------- 1453(E)-β-farnesene0,530,580,042,740,462,240,230,391,412,320,000,610,640,130,30tr0,350,810,080,08 1459α-humulene1,181,430,530,000,890,910,811,841,222,600,631,281,741,011,331,341,051,171,211,06 1466alloaromadendrene------0,200,000,110,460,170,120,490,090,180,110,160,100,330,22 1478γ-muurolene----0,240,100,131,050,601,660,540,640,920,160,311,320,140,390,420,54 1485germacrene D42,6530,3213,8420,5316,9221,8310,037,3331,5617,6211,1127,8716,3020,9638,5216,8320,5923,7333,0115,21 1490(E,E)-α-farnesene----1,401,240,470,430,930,690,170,360,310,810,871,511,070,791,430,78 1491α-zingiberene1,17tr3,18tr--0,472,381,650,880,391,740,921,261,581,670,881,421,390,91 1499bicyclogermacrene3,282,700,620,731,572,06-------------- 1510β-bisabolene----0,440,240,430,830,150,310,460,980,540,790,300,520,330,270,010,36 C. panormitana subsp. todariC. panormitana subsp. ucriaeC. venerisC. gymnocarpa
Palmaria IslandCapraia Island C. aeolica
(Aeolian Island)IsnelloSferracavallo (Sicily) C. busambarensis
Table 1. Percentage composition of the most abundant chemical classes of compounds detected in Centaurea sp.pl. from Ligurian (Palmaria), Northern Tyrrhenian Sea Islands (Capraia and Elba) and from Southern Tyrrhenian Sea Islands (Lipari, Aeolian Island and Sicily).
Mt Pellegrino (Mondello)
(Sicily) C. panormitana subsp. umbrosa
Bagheria (Sicily)(Sicily)Elba IslandMt Gallo (Sicily)Capo Tindari (Sicily) C. panormitana subsp. seguenzaeC. panormitana subsp. umbrosa
Lipari
Table 1 - Percentage composition of the most abundant chemical classes of compounds detected in Centaurea species from Ligurian (Palmaria), Northern Tyrrhenian Sea Islands (Capraia and Elba) and from Southern Tyrrhenian Sea Islands (Lipari, Aeolian Island and Sicily).
