کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2028223 1070402 2010 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Fatty acid composition of cholesteryl esters of human meibomian gland secretions
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Fatty acid composition of cholesteryl esters of human meibomian gland secretions
چکیده انگلیسی

Very long chain cholesteryl esters (CE) are a major group of lipids found in meibomian gland secretions (MGS, also called meibum). MGS are produced by the meibomian glands of human and animal eyelids. They are a critical part of the tear film which covers the exposed ocular surface and serves various physiological roles. The composition of CE of MGS is complex, and still remains poorly understood. Here, a liquid chromatography–ion trap mass spectrometry (LC–MS) procedure developed to analyze CE is described, and a detailed composition of human meibomian CE is reported.MGS were collected from donors, analyzed without any modifications by LC–MS in positive and negative ion modes (PIM and NIM), and quantified using lipid standards where available.CE comprised about 30% of human meibum by mass. More than 40 individual CE species were found and characterized. In PIM, CE were observed as spontaneously in-source generated product ions m/z 369. The signals of the proton adducts of intact CE (M+H)+ were of very low intensity. In NIM, all tested CE spontaneously fragmented in-source producing signals of their respective FA. By combining the LC and MS information, the most abundant CE were found to be based on FA ranging from C16 to at least C32 in the following order C26:0 > C25:0 > C24:0 > C27:0 > C24:1 = C18:1 = C20:0 > other CE.We conclude that the FA composition of CE can be successfully established in LC–MS experiments conducted in NIM. Meibomian CE have a large presence of both saturated and unsaturated FA with an average molar ratio of 4 to 1, respectively.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Steroids - Volume 75, Issue 10, October 2010, Pages 726–733
نویسندگان
,