Structural Determination of Lysosphingomyelin-509 and Discovery of Novel Class Lipids from Patients with Niemann-Pick Disease Type C

Niemann-Pick disease type C (NPC) is an autosomal recessive disorder caused by the mutation of cholesterol-transporting proteins. In addition, early treatment is important for good prognosis of this disease because of the progressive neurodegeneration. However, the diagnosis of this disease is difficult due to a variety of clinical spectrum. Lysosphingomyelin-509, which is one of the most useful biomarkers for NPC, was applied for the rapid and easy detection of NPC. The fact that its chemical structure was unknown until recently implicates the unrevealed pathophysiology and molecular mechanisms of NPC. In this study, we aimed to elucidate the structure of lysosphingomyelin-509 by various mass spectrometric techniques. As our identification strategy, we adopted analytical and organic chemistry approaches to the serum of patients with NPC. Chemical derivatization and hydrogen abstraction dissociation-tandem mass spectrometry were used for the determination of function groups and partial structure, respectively. As a result, we revealed the exact structure of lysosphingomyelin-509 as N-acylated and O-phosphocholine adducted serine. Additionally, we found that a group of metabolites with N-acyl groups were increased considerably in the serum/plasma of patients with NPC as compared to that of other groups using targeted lipidomics analysis. Our techniques were useful for the identification of lysosphingomyelin-509.

Lyso-sphingomyelin is elevated in dried blood spots of Niemann-Pick B patients

Niemann-Pick disease type B (NPD-B) is caused by a partial deficiency of acid sphingomyelinase activity and results in the accumulation of lysosomal sphingomyelin (SPM) predominantly in macrophages. Notably, SPM is not significantly elevated in the plasma, whole blood, or urine of NPD-B patients. Here, we show that the de-acylated form of sphingomyelin, lyso-SPM, is elevated approximately 5-fold in dried blood spots (DBS) from NPD-B patients and has no overlap with normal controls, making it a potentially useful biomarker.

A new antifungal macrolide, eushearilide, isolated from Eupenicillium shearii

In screening for antifungal substances, a new macrolide, eushearilide (1), was isolated from Eupenicillium shearii IFM54447. The structure of 1 was established to be 24-membered macrolide having a non-conjugated diene and a choline phosphate ester moetiy on the basis of detailed investigation of NMR, UV, IR and MS spectral data. Compound 1 showed antifungal activity against various fungi and yeasts, including human pathogens Aspergillus fumigatus, Trichophyton spp. and Candida spp.

Endocannabinoid Metabolism in the Absence of Fatty Acid Amide Hydrolase (FAAH): Discovery of Phosphorylcholine Derivatives ofN-Acyl Ethanolamines†

Lipid transmitters are tightly regulated by a balance of biosynthetic and degradative enzymes. Termination of the activity of the N-acyl ethanolamine (NAE) class of lipid-signaling molecules, including the endocannabinoid anandamide (AEA), is principally mediated by the integral membrane enzyme fatty acid amide hydrolase (FAAH) in vivo. FAAH(-/-) mice are highly sensitized to the pharmacological effects of AEA; however, these animals eventually recover from AEA treatment, implying the existence of alternative routes for NAE metabolism. Here, we have pursued the characterization of these pathways by profiling the metabolome of FAAH(-/-) mice treated with AEA. Multiple AEA-induced metabolites were observed in brains from FAAH(-/-) mice, including a major product with a mass shift of +165 Da (m/z 513). The structure of this product was determined to be O-phosphorylcholine (PC)-AEA. Analysis of untreated mice identified PC-NAEs as endogenous constituents of the central nervous system (CNS) that were highly elevated in FAAH(-/-) animals. PC-NAEs were very poor substrates for FAAH; however, a vanadate-sensitive enzymatic activity was detected in brain membranes that converted PC-NAEs back to their parent NAEs. The choline-specific phosphodiesterase NPP6 was identified as a candidate enzyme responsible for this activity. These data indicate the presence of a complete metabolic pathway for the production and degradation of PC-NAEs in the CNS that constitutes an alternative route for endocannabinoid metabolism.

Separation and quantification of alkylphosphocholines by reversed phase high performance liquid chromatography

Alkylphosphocholines represent a new class of drugs with remarkable antineoplastic and antiprotozoal activity. For instance, hexadecylphosphocholine has been approved for the topical treatment of skin metastasis. In addition, it was successfully studied in India for the treatment of leishmaniasis. Different phase-I and phase-II-trials resulted in cure rates of more than 97%. To optimize antitumor or antiprotozoal activity, we have prepared alkylphosphocholines differing in chain length and unsaturation. For the qualitative and quantitative analysis of these longer chain analogues, we have used isocratic high performance liquid chromatography. The separation of the alkylphosphocholines with different chain lengths in this reversed phase HPLC system was achieved on a YMC-TMS column with a mobile phase consisting of methanol-water (85:15; v/v) at a flow rate of 1.0 ml/min. Furthermore the cis-/trans-isomers such as oleylphosphocholine and elaidylphosphocholine were clearly separated on a YMC-C8 column with a methanol-water mixture (80:20; v/v) as mobile phase. In the described reversed phase HPLC systems simple refractive index detection and UV detection allow the sensitive and quantitative determination of alkylphosphocholines. These methods are very important for reproducible identification and quantitative determination of saturated and mono-unsaturated alkylphosphocholines with alkyl residues containing up to 25 carbon atoms.

Synthetic analogues of irlbacholine: a novel antifungal plant metabolite isolated from Irlbachia alata

Irlbacholine and a series of related analogues were synthesized and their antifungal activities against Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus were assessed. The natural bisphosphocholine, irlbacholine, was the most potent compound, its 22-carbon chain length appearing to be optimal.

Structure of a novel phosphocholine-containing aminoglycoglycerolipid of Mycoplasma fermentans

Mycoplasma fermentans is thought to be a pathogen of rheumatoid arthritis or a cofactor of AIDS (acquired immunodeficiency syndrome). To elucidate the possible involvement of membrane constituents in the pathogenesis of these diseases, we studied its lipid components. Several alkali labile glycophospholipids were detected and named glycoglycerophospholipids (GGPLs). Previously, we purified and determined the structure of one of them as 6'-O-phosphocholine-alpha-glucopyranosyl-(1'-3)-1,2-diacyl-sn-glycerol (GGPL-I). The present paper describes the purification and structural characterization of GGPL-III, the major GGPL of M. fermentans using 1H-, 13C- and 31P-nuclear magnetic resonance spectroscopy, and mass-spectroscopy as 1"-phosphocholine,2"-amino dihydroxypropane-3"-phospho-6'-alpha-glucopyranosyl-(1'-3)-1,2-dia cyl-glycerol.

Preparation of a naturally occurring D-erythro-(2S, 3R)-sphingosylphosphocholine using Shewanella alga NS-589

Sphingosylphosphocholine, an N-deacylated derivative of sphingomyelin, has been found to be involved in many cellular events. This paper describes a new method for preparation of a D-erythro-sphingosylphosphocholine, which is naturally occurring but difficult to prepare by chemical methods, using marine bacteria as a biocatalyst. When cultured with Shewanella alga NS-589 in synthetic medium, sphingomyelin was found to be efficiently converted by sphingomyelin deacylase to sphingosylphosphocholine. Sphingosylphosphocholine was purified with a high yield from the culture supernatant and identified to be a D-erythro-(2S,3R)-isomer containing d18:1 sphingenine as a long-chain base by fast atom bombardment mass spectrometry and NMR analyses.

[Proton magnetic resonance spectroscopy of excised pig liver]

After evaluating ex vivo pig liver by 1H magnetic resonance spectroscopy (1H-MRS) using a 1.5 Tesla super-conducting unit, the assignment of peaks was reevaluated in vitro using a 9.4 Tesla superconducting unit. The portal vein was cannulated and perfused by cooled Euro-Collins solution, and pig liver was removed and preserved in the solution. Five to 8 g of the liver was excised before and after preservation, then extracted by perchloric acid (PCA). In 1H-MRS of PCA extracted pig liver, large peaks of fatty acid disappeared, while peaks of the choline group from 3.2-3.3 ppm were clearly observed. Using high performance liquid chromatography (HPLC) and 31P (phosphorus)-MRS, the 3.23 ppm peak was determined as glycerophosphorylcholine (GPC), which diminished after preservation. The chronological change of GPC in PCA extracted pig liver was able to be observed by 1H-MRS. GPC peak may play a role as an indicator in evaluating preserved liver by 1H-MRS.

Isolation and identification of a choline-linked mannobiose in the glycoproteins of Fusarium sp. M7-1

An unidentified oligosaccharide was isolated from an oligomer mixture derived by alkaline borohydride treatment from glycoproteins of Fusarium sp. M7-1. The isolated compound was identified as O-alpha-D-Mannopyranosyl (1-->2)-D-Mannitol-6-phosphocholine by NMR and Ms spectrometry.

Phosphocholine-bonded galactosylceramides having a tri-unsaturated long-chain base from the clam worm, Marphysa sanguinea

Seven glycosphingolipids were obtained in the pure state from the clam worm, Marphysa sanguinea, by preparative HPLC with a reversed-phase column in a recycling mode. Their structures were elucidated based on detailed analyses of 1H- and 13C-NMR spectra of the intact compounds. The position and the geometry of double bonds in the long-chain base (LCB) were determined by the two-dimensional NMR (COSY, NOESY, and HMBC) analyses. All compounds are phosphocholine-bonded monogalactosylceramides and two of them have tri-unsaturated long-chain bases.

Identification of a naturally occurring methyl-ester of phosphate, methyl-phosphorylcholine (methyl-2-(N,N,N trimethylamino) ethyl phosphate), in the eggs of the sea urchin S. purpuratus

A novel metabolite of choline, phosphorylcholine methyl ester, has been identified in the eggs of S. purpuratus wherein it is present at approximately 1 mM concentration. To the best of our knowledge, this is the first instance of a phosphoryl-methyl-ester to be observed in nature. The compound appears to be species specific, since it has not been observed in other species such as L. pictus and P. depressus. In S. purpuratus its distribution is confined to the ovary, eggs and embryos, and is absent from young animals following metamorphosis.

Analysis of the water-soluble products of phosphatidylcholine breakdown by ion-exchange chromatography. Bombesin and TPA (12-O-tetradecanoylphorbol 13-acetate) stimulate choline generation in Swiss 3T3 cells by a common mechanism

A method for the rapid and quantitative separation of glycerophosphocholine, choline phosphate and choline upon ion-exchange columns is described. The method has been utilized to examine the stimulation of phosphatidylcholine breakdown in quiescent Swiss 3T3 cells in response to bombesin and 12-O-tetradecanoylphorbol 13-acetate (TPA). The stimulated generation of choline is shown to precede that of choline phosphate, with no effect upon glycerophosphocholine levels; but was attenuated in cells in which protein kinase C activity was down-regulated. The results thus suggest that stimulation of the cells with either bombesin or TPA activates phospholipase D-catalysed phosphatidylcholine breakdown by a common mechanism involving the activation of protein kinase C.

Partial synthesis and properties of a series of N-acyl sphingomyelins

A series of sphingomyelins (SM) with different chain length fatty acids (C14:0, C16:0, C18:0, C20:0, C22:0, and C24:0) N-linked to the primary amino group of sphingosine have been synthesized starting with bovine brain SM. Two different acid hydrolysis procedures, butanolic HCl (H. Kaller, 1961. Biochem. Z. 334: 451-456) and methanolic HCl (R.C. Gaver and C.C. Sweeley. 1965. J. Am. Oil Chem. Soc. 42: 294-298), were used and the resultant sphingosylphosphocholine (SPC) was converted to SM using two acylation methods: using fatty acid imidazolide to yield the O-acyl, N-acyl SPC, followed by mild alkaline hydrolysis for selective deacylation at the O-acyl linkage, and selective acylation at the amino group of SPC using the free fatty acid in the presence of dicyclohexylcarbodimide. Following chromatographic purification, N-acyl SM were obtained in high yield (80-90%), and were characterized by a combination of thin-layer chromatography, high performance liquid chromatography, chemical analysis, optical rotation, circular dichroism, infrared spectroscopy, 13C NMR, and sphingosine base analysis. The N-acyl SM were chemically homogeneous with respect to fatty acid composition and the sphingosine base composition resembled that of the starting bovine brain SM. However, as a consequence of the epimerization at C-3 of SPC in both acid hydrolysis procedures, the resulting N-acyl SM consisted of mixtures of D-erythro and L-threo sphingomyelins. By differential scanning calorimetry hydrated C14:0 to C24:0 SM exhibited gel-liquid crystal transitions in the range 30-50 degrees C but the chain length dependence was complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of complement in C-reactive protein positive sera by phosphorylcholine-bearing component isolated from parasite extract

Phosphorylcholine-bearing component levels in extracts of various parasites were determined by a capillary precipitin test using anti-phosphorylcholine Ig A myeloma protein. TEPC-15. Phosphorylcholine was demonstrated as a structural component not only in nematodes but also in trematodes and cestodes. The phosphorylcholine-bearing component was isolated from an extract of Toxocara canis larvae using a TEPC-15-Sepharose 4B column. The component reacted with C-reactive protein in sera to form one precipitin line in immunoelectrophoresis. The component provided two Brilliant Coomassie Blue positive bands in SDS-polyacrylamide gel electrophoresis. It reacted with C-reactive protein to activate complement in serum.

Isolation of a phosphorylcholine-containing component from the turbot tapeworm, Bothriocephalus scorpii (Müller), and its reaction with C-reactive protein

A fraction isolated by electrofocusing (pI 4.2) from a saline extract of the turbot parasite, Bothriocephalus scorpii, contained choline and precipitated with a teleost C-reactive protein (CRP) and a phosphorylcholine-binding Balb/c mouse myeloma protein, TEPC-15. Non-dialysable products released from cultured tapeworms also precipitated with the phosphorylcholine-specific precipitins. Ca2+ was required for precipitation with CRP and immunodiffusion lines were confluent with pneumococcal C-polysaccharide and a fungal C substance. Intradermal injection of the phosphorylcholine-containing fraction caused an immediate erythema reaction in all mature turbot tested. The skin reaction is though to be related to the amount of circulating CRP and this protein was present in sera fro all nature turbot giving a positive skin response. There is no evidence for CRP being toxic to the tapeworms and the possibility is discussed that the worms exploit the host CRP for their own survival.

[Effect of injection of a phosphorylcholine-containing compound from Nippostrongylus brasiliensis on the infestation of the rat by this parasite]

Rats were injected intradermally with the purified phosphorycholine bearing component of the nematode Nippostrongylus brasiliensis. Eight days later they were experimentally infected with 1 X 10(3) infective larvae of the parasite. Compared to the non injected controls we showed a significant decrease in the number of adult worms able to be established in the small intestine. This protective effect seems to be due at least partly to a phenomenom being located between the skin and the lungs of the rats.