Category:LBSB


Upper classes: LB LBS

Long-chain base

Long-chain base (LCB or sphingoid base) is a 2-aminoalkane (or alkene) 1,3-diol with 2R, 3R stereochemistry (D-erythro for dihydroxy LCB and D-ribo for trihydroxy LCB). Major types are listed in the following Table. Animals usually contain LCB of length 18 (d18:1) and a little amount of d20:1. In yeast (S. cerevisiae), the predominant LCB is 4-hydroxysphinganine (t18:0)[1]. In higher plants, six LCB are major( (8E/Z)-d18:1, (8E/Z)-t18:1, (4E,8E/Z)-d18:2) with little d18:0, t18:0, and (4E)-d18:1. This means (4Z)-d18:1 is absent in plants. Insects contain LCB of shorter chains, e.g. d14:1 and d16:1.

長鎖塩基(またはスフィンゴイド塩基)は 2-アミノアルカン(またはアルケン) 1,3-ジオールを指す(立体化学はジヒドロキシLCBがD-エリスロ、トリヒドロキシLCBがD-リボ型)。代表的なものは以下のとおり。動物は通常、鎖長18のLCBを持ち (d18:1)、少量の d20:1 がある。イースト(パン酵母)で主要なLCBは t18:0 になる。高等植物では 6 種の LCB、(8E/Z)-d18:1, (8E/Z)-t18:1, (4E,8E/Z)-d18:2 が多く、少量の d18:0, t18:0, (4E)-d18:1、も見られる。(4Z)-d18:1 は見られない。昆虫は短い炭素鎖のスフィンゴイド塩基、例えば d14:1, d16:1 を持つ。

Notation

d18:1  h, d or t stands for single, double, or triple hydroxy groups, respectively.
18 is the carbon chain length.
1 is the number of unsaturated bonds (double bonds).

Major Sphingoid

Name Symbol Abbreviation Note
sphingosine = (4E)-sphingenine
(4E)-2-amino-octadec-4-ene-1,3-diol
d18:1 So Major in mammals
sphinganine = dihydrosphingosine
2-amino-octadecane-1,3-diol
d18:0 Sa or DHSo Lacking the trans-double bond of sphingosine
4-hydroxysphinganine = phytosphingosine
2-amino-octadecane-1,3,4-triol
t18:0 Phyto Major in yeast (S. cerevisiae)
6-hydroxysphingosine
(4E)-2-amino-octadec-4-ene-1,3,6-triol
6-t18:1 Found in skin


  1. Yeast is an exceptional case. Many fungi contain a (4,8)-diunsaturated, 9-methyl-branched LCB.

Ceramides

The word ceramide (Cer) basically refers to all N-acyl-sphingoid bases, but most representative one is N-acylsphingosines. The conjugated fatty acids are often 16 to 26 carbon chains.

In mammalian skin, free ceramides comprise 55% of the intercellular lipid layer and exhibit barrier function. The ceramides may contain >30 carbon chains. Atopic dermatitis (and dry skin) is associated with a decrease and compositional change of such ceramides.

In industry, ceramides are extracted from vegetable-oil cakes from corn, rice, wheat, soybean, and others.

セラミドという言葉は基本的に N-アシルスフィンゴイド塩基を指すが、最も代表的なものは N-アシルスフィンゴシンである。結合する脂肪酸の炭素長は16から26である。

動物の皮膚における角質細胞間脂質では遊離のセラミドが55S%を占め、バリア機能を持つ。セラミドの長さも30以上に及ぶ。アトピー性皮膚炎や乾燥肌ではセラミド量が減少し、組成も変化していることが知られる。

工業的には、セラミドはトウモロコシ、コメ、コムギ、ダイズ等からの植物油滓から精製する。

Notation

Cer d18:1Δ8E/20:0  The first part indicates the LCB part and the second, fatty acid.
In this page we do not use superscripts or subscripts for readability.
Also we do not italicize E (or trans) and Z (or cis) for the same reason.


Composition

Species Glycosylceramide Glycosyl inositol phosphoceramide (GIPC)
Fatty acid Long chain base References Fatty acid Long chain base References
Plants h16:0 - h26:0
h16:1 - h26:1
h16:0
VLCFA
d18:2Δ4E8E/Z
d18:2Δ4E8E/Z
d18:1Δ8E/Z
t18:1Δ8E/Z
[1][2]
[1][2]
[1]
[1][2]
hVLCFA
h14:0 - h26:0
h20:1 - h26:1
t18:1Δ8E/Z
t18:1Δ8E/Z, t18:0
t18:1Δ8E/Z, t18:0
[1]
[3]
[1][3]
Fungi h16:0 - h18:0
h16:1 - h18:1
9-methyl d18:2Δ4E,8E
9-methyl d18:2Δ4E,8E
[4][2]
[4][2]
h24:0 - h26:0
h24:1 - h26:1
h16:0 - h26:0
t18:0
t18:0
t18:0, t20:0
[4]
[2]
[2][3]
  1. 1.0 1.1 1.2 1.3 1.4 1.5 Markham JE, Lynch DV, Napier JA, Dunn TM, Cahoon EB. Plant sphingolipids: function follows form. Curr Opin Plant Biol. 2013 16: 350-7. doi: 10.1016/j.pbi.2013.02.009.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Warnecke D, Heinz E..Recently discovered functions of glucosylceramides in plants and fungi. Cell Mol Life Sci. 2003 60:919-41.doi: 10.1007/s00018-003-2243-4.
  3. 3.0 3.1 3.2 Buré C, Cacas JL, Mongrand S, Schmitter JM. Characterization of glycosyl inositol phosphoryl ceramides from plants and fungi by mass spectrometry. Anal Bioanal Chem. 2013 doi: 10.1007/s00216-013-7130-8.
  4. 4.0 4.1 4.2 Nimrichter L, Rodrigues ML. Fungal glucosylceramides: from structural components to biologically active targets of new antimicrobials. Front Microbiol. 2011 2:212. doi: 10.3389/fmicb.2011.00212.

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