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Steryl esters in a cell suspension culture of celery ( Apium graveolens )
Author(s) -
Dyas Lynne,
Prescott Mark C.,
Evershed Richard P.,
Goad L. John
Publication year - 1991
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02536600
Subject(s) - stigmasterol , chemistry , cycloartenol , sterol , apium graveolens , campesterol , phytosterol , chromatography , hydrolysis , phytol , composition (language) , organic chemistry , biochemistry , cholesterol , botany , biology , linguistics , philosophy
Arange of analytical techniques was used to investigate the composition of the steryl fatty acyl esters in a cell suspension culture of celery ( Apium graveolens ). Gas chromatography (GC) and GC‐mass spectrometry (GC‐MS), using electron ionization (EI) and negative ion chemical ionization (NICI), were employed to characterize the intact steryl esters. Assignments were supported by analysis of the sterol and fatty acid moieties released from the intact molecular species by alkaline hydrolysis. A selectivity for sterol esterification was noted, with the major free sterol, stigmasterol, occurring only in a very small amount in the esterified form. Instead, the precursors to Δ 5 ‐phytosterols, particularly cycloartenol, predominated in the ester fraction. The pentacyclic triterpene, β‐amyrin, was also found as the palmitate and linoleate esters. Changes in composition and abundance of the steryl esters during the different growth phases of a celery cell suspension culture were investigated. The total amount of esterified sterols exceeded that of free sterols throughout the growth cycle. The changes observed during growth highlighted differences between the esters of precursor sterols and those of the 4‐desmethyl‐sterols, and it is postulated that the various steryl esters perform different functions in cell metabolism.