Salicornia ramosissima W. A. Clarke & E. S. Marshall
Creators: name: Maciel, Elisabete
name: Lillebø, Ana
name: Domingues, Pedro
name: Costa, Elisabete da
name: Calado, Ricardo
name: Domingues, M. Rosário M.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Amaranthaceae
Salicornia
Salicornia ramosissima

description: 2.1. Lipid profile of Salicornia ramosissima   
 Seventeen different fatty acids (FAs) were identified in the lipid extracts of S. ramosissima (Table 1). Results obtained indicate that S. ramosissima had a high content of long chain FA, with a length between 16 and 18 carbons and a high level of unsaturation (e.g., polyunsaturated fatty acids (PUFA)) up to 61.3%. PUFA included mainly n -3 and n -6 FA. The most abundant FAs were α -linolenic acid (C18:3 n -3, ALA), which correspond to with nearly 40% of the total pool of FAs, followed by linoleic acid (C18:2 n -6, LA), which contributed with 20% of the total pool. Saturated fatty acids (SFA) were the second most abundant group of FAs, whose content was estimated to be ∼30% of total FAs present in S. ramosissima. The main saturated FA was palmitic acid (C16:0, PA) (22.1% of the total pool of FAs). Monounsaturated fatty acids (MUFA) were less abundant than PUFA and SFA, only accounting for approximately 6% of the total pool of FA. Oleic acid (C18:1 n -9) was the most abundant MUFA, although it only accounted for 5% of the total pool of FAs.   
 The polar lipidome was determined in crude lipid extracts using HILIC coupled to a high resolution and accurate mass spectrometer. Over 200 molecular species were identified in S. ramosissima lipid extracts, distributed by five different classes of PL, three classes of glycolipids and one glycosphingolipid, as described above. The MS profiles are shown in supplementary information (Figs. S1 and S2).   
 MS/MS data allowed the identification of 62 PC, 43 PE, 30 PA, 15 PG and 9 PI molecular species, with different fatty acyl moieties ranging from 15 to 24 carbon atoms and containing from 0 to 6 double bonds. FA distribution was found to be class dependent (Table 2). The main PC molecular species were found at m/z 756.551 (PC 16:0/18:3), m/z 758.567 (PC 16:0/18:2), m/z 780.550 (PC 18:2/18:3), m/z 782.566 (PC 18:2/18:2 and PC 18:1/18:3) and m/z 870.666 (PC 18:2/ 24:0). The PC profile of S. ramosissima was characterized by the presence of polyunsaturated PC species, odd-chain FA and very long FA, such as C24:0. These FA were also detected using GC-MS analysis (Table 1). In the case of PE class, the molecular species were composed of a combination of acyl groups ranging from 15 to 24 carbon atoms containing 0 to 3 double bonds (Table 2). The most abundant PE molecular species was found at m/z 714.490, corresponding to PE 16:0/ 18:2, followed by PE 18:2/18:2 at m/z 738.505. Similar to the PC class, some species with very long chain FAs, such as 24:0 were identified in PE class, namely at m/z 824.614, m/z 826.630, m/z 858.584 and m/z 872.600. PE molecular species esterified with odd-chain FA were also found such as the FA C15:0, C19:2 and C21:0. PA class included molecular species carrying fatty acyl groups ranging from 16 to 19 carbon atoms and the major PA molecular species were identified at m/z 669.448 (PA 16:0/18:3 and PA 16:1/18:2), m/z 671.464 (PA 16:0/ 18:2), m/z 693.448 (PA 18:2/18:3) and m/z 695.463 (PA 18:2/18:2 and PA 18:1/18:3. Species with odd-chain fatty acids (C19:0, C19:1, C19:2, C19:3, C17:0 and C21:0) were also identified. In the case of PG class, the most abundant molecular species were found at m/z 719.484 and m/z 745.499 (Fig. S 1 in the supplementary information) corresponding to PG 16:0/16:1 and PG 16:0/18:2, respectively. The acyl composition of PG ranged from 16 to 20 carbon atoms. The molecular species identified in the case of PI class included only the fatty acyl chains of C16:0, C18:0, C18:1, C18:2 and C18:3. The most abundant PI molecular specie was found at m/z 833.515 and was assigned to PI 16:0/18:2.   
 Table 2 Phospholipid molecular species identified by HILIC− Q− Exactive− MS from total lipid extract of Salicornia ramosissima.   
 The analysis and interpretation of LC− MS/MS data allowed to identify 13 molecular species of SQDG, 21 MGDG, 10 DGDG and 5 HexCer. The acyl composition of GL ranged from 16 to 22 carbon atoms and 0 to 3 double bonds (Table 3). The main SQDG molecular species was SQDG 18:3/16:0 at m/z 815.496, followed by SQDG 16:0/ 16:0 at m/z 793.511 and SQDG 18:3/18:3 at m/z 837.479. For MGDG, the major molecular specie was MGDG 18:3/18:3 at m/z 792.56. Some MGDG molecular species with odd-chain FA were observed, namely with FA C17:0, C19:1, C19:2, C19:3 and C21:0. The fatty acyl chains of DGDG ranged from 16 to 21 carbon atoms. The main molecular specie of DGDG class was the DGDG 18:3/18:3 at m/z 954.612. Two DGDG molecular species were identified with odd-chain FA: DGDG 19:2/18:3 and DGDG 21:0/18:3 at m/z 970.607 and 1002.596 respectively.   
 The glycosphingolipids HexCer were also identified and included molecular species with both di- and trihydroxy long-chain bases. The sphingoid bases identified in the present work were C18, while the length of the identified hydroxylated fatty acids varied between 16 and 24 carbon atoms. The most abundant molecular species was HexCer t 18:1/h24:0 detected at m/z 844.684 with a trihydroxy long chain base. The HexCer d 18:1/16:1, at m/z 714.549, displayed a dihydroxy long chain base moiety.
description: Published as part of Maciel, Elisabete, Lillebø, Ana, Domingues, Pedro, Costa, Elisabete da, Calado, Ricardo & Domingues, M. Rosário M., 2018, Polar lipidome profiling of Salicornia ramosissima and Halimione portulacoides and the relevance of lipidomics for the valorization of halophytes, pp. 94-101 in Phytochemistry 153 on pages 95-96, DOI: 10.1016/j.phytochem.2018.05.015, http://zenodo.org/record/10483880