Two unusual glycerophospholipids from a filamentous fungus, Absidia corymbifera.
The chloroform-methanol extractable lipids of the soil filamentous fungus Absidia corymbifera VKMF-965 account for about 20% by weight of dry cells and are composed of low-polarity constituents (about 75% of the total lipids), such as triacylglycerols (mainly), diacylglycerols, sterols and free fatty acids, as well as of glycolipids (about 3%) and phospholipids. The last consist largely of components common to the fungal lipids, namely, phosphatidylethanolamine (38% of the total phospholipids), phosphatidyl-myo-inositol (16%), diphosphatidylglycerol (12%), phosphatidylcholine (7%), phosphatidic acid (6%) and phosphatidylglycerol (3%), and two unusual phospholipids, PL1 (6%) and PL2 (9%). Based on the infrared (IR), (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectra along with the results of degradation experiment, these two phospholipids have been established to be 1,2-diacyl-sn-glycero-3-phospho(N-acetylethanolamine), or N-acetyl phosphatidylethanolamine, and 1,2-diacyl-sn-glycero-3-phospho(N-ethoxycarbonyl-ethanolamine), respectively. These structures have been confirmed by preparing similar phospholipids from the phosphatidylethanolamine isolated from the same fungus and correlating their chromatographic behaviour, IR and (1)H-NMR spectra with those of PL1 and PL2. So far N-acetyl phosphatidylethanolamine has been detected only in cattle and human brains and a human placenta but its structure was not rigorously proved. PL2 is a novel lipid; to our knowledge no natural phospholipid with an urethane group has yet been found. The main fatty acids of both the phospholipids are n-hexadecanoic, octadecanoic and octadecadienoic ones; PL2 contains in addition a considerable amount of octadecatrienoic acid with its greater portion located at the sn-1 position.
Batrakov
S G
SG
Research Centre Hydrobios of Ministry of Health, Moscow, Russia.
Konova
I V
IV
Sheichenko
V I
VI
Esipov
S E
SE
Galanina
L A
LA
D020095:Absidia / Q000737:chemistry* / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D020404:Glycerophospholipids / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010714:Phosphatidylethanolamines / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013055:Spectrophotometry, Infrared
D005227:Fatty Acids; D020404:Glycerophospholipids; D010714:Phosphatidylethanolamines