Proton-decoupled 13C Research Articles

Hydrazone-flavonol based oxidovanadium(V) complexes: Synthesis, characterization and antihyperglycemic activity of chloro derivative in vivo

Wet synthesis approach afforded four new heteroleptic mononuclear neutral diamagnetic oxidovanadium(V) complexes, comprising salicylaldehyde-based 2-furoic acid hydrazones and a flavonol coligand of the general composition [VO(fla)(L-ONO)]. The complexes were comprehensively characterized, including chemical analysis, conductometry, infrared, electronic, and mass spectroscopy, as well as 1D 1H and proton-decoupled 13C(1H) NMR spectroscopy, alongside extensive 2D 1H1H COSY, 1H13C HMQC, and 1H13C HMBC NMR analyses. Additionally, the quantum chemical properties of the complexes were studied using Gaussian at the B3LYP, HF, and M062X levels on the 6–31++g(d,p) basis sets. The interaction of these hydrolytically inert vanadium complexes and the BSA was investigated through spectrofluorimetric titration, synchronous fluorimetry, and FRET analysis in a temperature-dependent manner, providing valuable thermodynamic insights into van der Waals interactions and hydrogen bonding. Molecular docking was conducted to gain further understanding of the specific binding sites of the complexes to BSA. Complex 2, featuring a 5-chloro-substituted salicylaldehyde component of the hydrazone, was extensively examined for its biological activity in vivo. The effects of complex administration on biochemical and hematological parameters were evaluated in both healthy and diabetic Wistar rats, revealing antihyperglycemic activity at millimolar concentration. Furthermore, histopathological analysis and bioaccumulation studies of the complex in the brain, kidneys, and livers of healthy and diabetic rats revealed the potential for further development of vanadium(V) hydrazone complexes as antidiabetic and insulin-mimetic agents.

The rate of lactate production from glucose in hearts is not altered by per-deuteration of glucose

This study was designed to determine whether perdeuterated glucose experiences a kinetic isotope effect (KIE) as glucose passes through glycolysis and is further oxidized in the tricarboxylic acid (TCA) cycle. Metabolism of deuterated glucose was investigated in two groups of perfused rat hearts. The control group was supplied with a 1:1 mixture of [U-13C6]glucose and [1,6-13C2]glucose, while the experimental group received [U-13C6,U-2H7]glucose and [1,6-13C2]glucose. Tissue extracts were analyzed by 1H, 2H and proton-decoupled 13C NMR spectroscopy. Extensive 2H-13C scalar coupling plus chemical shift isotope effects were observed in the proton-decoupled 13C NMR spectra of lactate, alanine and glutamate. A small but measureable (∼8%) difference in the rate of conversion of [U-13C6]glucose vs. [1,6-13C2]glucose to lactate, likely reflecting rates of CC bond breakage in the aldolase reaction, but conversion of [U-13C6]glucose versus [U-13C6,U-2H7]glucose to lactate did not differ. This shows that the presence of deuterium in glucose does not alter glycolytic flux. However, there were two distinct effects of deuteration on metabolism of glucose to alanine and oxidation of glucose in the TCA. First, alanine undergoes extensive exchange of methyl deuterons with solvent protons in the alanine amino transferase reaction. Second, there is a substantial kinetic isotope effect in metabolism of [U-13C6,U-2H7]glucose to alanine and glutamate. In the presence of [U-13C6,U-2H7]glucose, alanine and lactate are not in rapid exchange with the same pool of pyruvate. These studies indicate that the appearance of hyperpolarized 13C-lactate from hyperpolarized [U-13C6,U-2H7]glucose is not substantially influenced by a deuterium kinetic isotope effect.

Unusual effects in variable temperature powder NMR spectra of the methyl group protons in 9,10-dimethyltriptycene-d12

Variable temperature 1H wide line NMR spectra of polycrystalline 9,10-dimethyltriptycene-d12 deuterated in the aromatic positions were studied. The spectra show different patterns in an unrepeatable dependence on the way of preparation of the powdered samples. Simultaneously, no anomalies were seen in the MAS and CPMAS proton-decoupled room-temperature 13C spectra as well as in powder X-ray diffraction patterns. The effects observed in the 1H spectra are tentatively explained in terms of a phenomenological model. For one of the examined samples it afforded a consistent interpretation of the entire series of temperature dependent spectra in terms of structural non uniformity of the solid material studied. Quantum character of the stochastic dynamics of the methyl groups in the investigated compound was confirmed, although these dynamics are close to the classical limit where the familiar random jump model applies.

Quadrature transmit coil for breast imaging at 7 tesla using forced current excitation for improved homogeneity

To demonstrate the use of forced current excitation (FCE) to create homogeneous excitation of the breast at 7 tesla, insensitive to the effects of asymmetries in the electrical environment. FCE was implemented on two breast coils: one for quadrature (1) H imaging and one for proton-decoupled (13) C spectroscopy. Both were a Helmholtz-saddle combination, with the saddle tuned to 298 MHz for imaging and 75 MHz for spectroscopy. Bench measurements were acquired to demonstrate the ability to force equal currents on elements in the presence of asymmetric loading to improve homogeneity. Modeling and temperature measurements were conducted per safety protocol. B1 mapping, imaging, and proton-decoupled (13) C spectroscopy were demonstrated in vivo. Using FCE to ensure balanced currents on elements enabled straightforward tuning and maintaining of isolation between quadrature elements of the coil. Modeling and bench measurements confirmed homogeneity of the field, which resulted in images with excellent fat suppression and in broadband proton-decoupled carbon-13 spectra. FCE is a straightforward approach to ensure equal currents on multiple coil elements and a homogeneous excitation field, insensitive to the effects of asymmetries in the electrical environment. This enabled effective breast imaging and proton-decoupled carbon-13 spectroscopy at 7T.

Butyrate-rich Colonic Microenvironment Is a Relevant Selection Factor for Metabolically Adapted Tumor Cells

The short chain fatty acid (SCFA) butyrate is a product of colonic fermentation of dietary fibers. It is the main source of energy for normal colonocytes, but cannot be metabolized by most tumor cells. Butyrate also functions as a histone deacetylase (HDAC) inhibitor to control cell proliferation and apoptosis. In consequence, butyrate and its derived drugs are used in cancer therapy. Here we show that aggressive tumor cells that retain the capacity of metabolizing butyrate are positively selected in their microenvironment. In the mouse xenograft model, butyrate-preselected human colon cancer cells gave rise to subcutaneous tumors that grew faster and were more angiogenic than those derived from untreated cells. Similarly, butyrate-preselected cells demonstrated a significant increase in rates of homing to the lung after intravenous injection. Our data showed that butyrate regulates the expression of VEGF and its receptor KDR at the transcriptional level potentially through FoxM1, resulting in the generation of a functional VEGF:KDR autocrine growth loop. Cells selected by chronic exposure to butyrate express higher levels of MMP2, MMP9, α2 and α3 integrins, and lower levels of E-cadherin, a marker for epithelial to mesenchymal transition. The orthotopic model of colon cancer showed that cells preselected by butyrate are able to colonize the animals locally and at distant organs, whereas control cells can only generate a local tumor in the cecum. Together our data shows that a butyrate-rich microenvironment may select for tumor cells that are able to metabolize butyrate, which are also phenotypically more aggressive.

13C and 15N NMR evidence for peripheral intercalation of uniformly labeled fusogenic peptides incorporated in a biomimetic membrane

Membrane fusion requires drastic and transient changes of bilayer curvature and here we have studied the interaction of three de novo designed synthetic hydrophobic peptides with a biomimetic three-lipid mixture by solid state NMR. An experimental approach is presented for screening of peptide–lipid interactions and their aggregation, and their embedding in a biomimetic membrane system using established proton-decoupled 13C, 15N and proton spin diffusion heteronuclear 1H− 13C correlation NMR methods at high magnetic field. Experiments are presented for a set of de-novo designed fusion peptides in interaction with their lipid environment. The data provide additional support for the transmembrane model for the least fusogenic peptide, L16, while the peripheral intercalation model is preferred for the fusogenic peptides LV16 and LV16G8P9. This contributes to converging evidence that peripheral intercalation is both necessary and sufficient to trigger the fusion process for a lipid mixture close to a critical point for phase separation across the bilayer.

Characterisation of the 1H and 13C NMR spectra of methylcitric acid

Methylcitric acid (MCA) was synthesised in Reformatsky reaction (2 RS, 3 RS stereoisomers) and in the nucleophilic addition (2 RS, 3 SR stereoisomers). The stereoselectivity of these reactions was analysed. 1H and 13C NMR spectra of diastereoisomers of methylcitric acid were recorded and interpreted. The values of 1H chemical shifts and 1H– 1H coupling constants were analysed. Proton-decoupled high-resolution 13C NMR spectra of MCA diastereoisomers were measured in a series of dilute water solutions of various acidities. These data may provide a basis for unequivocal determination of the presence of MCA in the urine samples of patients’ suffering from propionic acidemia, methylmalonic aciduria, or holocarboxylase synthetase deficiency. NMR spectroscopy enables determination of MCA diastereoisomers in body fluids and can be a complementary and useful diagnostic tool.

Media phosphate and iron(II) supplementation affect Penicillium cell wall polymer structure

Our investigations focus on the effect of media nutrients, specifically phosphate and iron(II) on the composition of Penicillium fellutanum cell wall-derived polymers. In these studies we use four different media: high phosphate standard growth (HPSG), high phosphate high iron standard growth (HPSG Fe), low phosphate standard growth (LPSG), and low phosphate high iron standard growth (LPSG Fe). Mycelia obtained from these media are autoclaved in water to obtain heat-solubilized, cell wall-derived glycopeptides. Structures of heat-solubilized large (>14 kD) and small (<14 kD) mycelial glycopeptides have been characterized by GC/MS, NMR, and carbohydrate, phosphate, and protein analyses. We report that the phosphodiester composition in these polymers is a function of media phosphate and ferrous ion. Proton-decoupled 13C NMR spectra indicate that the large autoclaved mycelial polymers or LAMs resemble the 65 kD extracellular peptidophosphogalactomannans (pPGMs) in structure, however, they are very different from the small mycelial polymers or SAMs that consist primarily of glucose and peptides. Supported by NIH/NIGMS MBRS Grant# 2S06 GM008197.

A multinuclear ( 1H, 13C, 15N) NMR study of cis-halonitrosylbis(dithiocarbamato)iron(II) complexes: effect of replacement of S by Se

The 1H and proton-decoupled 13C NMR spectra of several cis-Fe(NO)(E 2CNR 2) 2X complexes (where R is an organic substituent, E=S and/or Se, and X=Cl −, Br − or I −) have been measured at room temperature in CDCl 3, as well as the 15N NMR spectrum (natural abundance) of cis-Fe(NO)(S 2CN(C 2H 5) 2) 2I. The two CE 2 signals observed between 190 and 206 ppm in the { 1H} 13C NMR spectra of these cis-Fe(NO)(E 2CNR 2) 2X complexes provide an indication of the structural rigidity of these compounds in solution. The multiple 13C NMR peaks observed for the four E 2CN( CH 2R) 2 α-carbons further support this rigidity. The 13C NMR signal of the α-C atoms of the ligand is dependent on the proximate chalcogen, the second chalcogen of the ligand and the ligand atoms to which each of these is trans. The 13C NMR spectra of the cis-Fe(NO)(E 2CNR 2) 2X complexes are comparable to the spectra of the structurally similar cis-Fe(S 2CNRR ′) 2(CO) 2 complexes and give insight into the interpretation of the 13C NMR spectra of the Co(SSeCNR 2) 3 series. The { 1H} 13C NMR spectrum of cis-Fe(SSeCN(C 2H 5) 2) 2(CO) 2 is included for comparison. The 1H NMR spectra are complex; the diethyl derivative exhibits a complex multiplet which is interpreted as four overlapping ABX 3 systems for the NC H 2(C H 3) protons. The 15N NMR spectrum of cis-Fe(NO)(S 2CN(C 2H 5) 2) 2I exhibits three peaks: 210.92, 209.09 and 29.28 ppm. This is interpreted as each dithiocarbamate ligand experiencing a different magnetic environment and the NO ligand. The 15N NMR spectrum is compared to tetraethylthiuram disulfide, Co(S 2CN(C 2H 5) 2) 3 and cis-Fe(S 2CN(C 2H 5) 2) 2(CO) 2 and is interpreted as indicating similar S 2C-NRR ′ rotational barriers.

A study of long range dipolar coupling constants in 4′-pentyloxy-4-biphenylcarbonitrile (5OCB)

It was shown previously that long range 2H-13 C dipolar coupling constants in liquid crystals could be obtained from the proton-decoupled 13C NMR spectrum of monodeuterated compounds. This approach has now been applied to the study of 4′-(1-deuteropentyloxy)-4-biphenylcarbonitrile (5OCB-d1). The 113C spectrum of this compound gives nine 2H- 13C dipolar coupling constants for carbon ranging from one to six bonds away from the dueterium nucleus. The 2 H NMR and 5OCB-d1 gives the deuterium quadrupole coupling constant and the 1H- 2H dipolar coupling constant for the α -CHD group. In addition, eleven 2-bond and two 3-bond 1H- 13C dipolar coupling constants have been obtained for 4′-pentyloxy-4-biphenylcarbonitrile (non-deuterated 5OCB) by using the 2D 13C method of proton-encoded local field spectroscopy.

Determination of Long-Range 13C−13C Dipolar Couplings Using a 13C Labeled Liquid Crystal

A liquid crystal labeled with a single 13C nucleus, 4‘-cyano-4-biphenyl hexanoate-1-13C, has been synthesized for the purpose of measuring long-range 13C−13C dipolar coupling constants. The proton-decoupled 13C spectrum of this compound gives eleven 13C−13C dipolar coupling constants for carbon nuclei ranging from one to seven bonds away from the labeled 13C position. In addition, although 1H−13C dipolar coupling constants for carboxyl carbons have never been determined from the 2D technique of proton encoded local field spectroscopy using naturally abundant liquid crystals, three such coupling constants were obtained using the 13C-enriched compound 4‘-cyano-4-biphenyl hexanoate-1-13C.

Characterisation of the 1H and 13C NMR spectra of N-acetylaspartylglutamate and its detection in urine from patients with Canavan disease

1H and 13C NMR spectra of N-acetylaspartylglutamate (NAAG) have been recorded and interpreted. The values of the 1H chemical shifts and 1H– 1H coupling constants at different pH were obtained by iterative computer fitting of 1-D 1H NMR spectra. This provided information on the solution conformation of the investigated molecule. Proton-decoupled high resolution 13C NMR spectra of NAAG have been measured in a series of dilute water solution of various acidity. These data have provided a basis for unequivocal determination of the presence of NAAG in the urine sample of a patient suffering from Canavan disease. NMR spectroscopy provides a possibility of detecting NAAG in body fluids.

Nematic ordering and crystal structure of liquid crystals containing a 4-chlorophenyldifluoroethylene unit

Partially fluorinated liquid crystals have many desirable properties such as high impedance and low viscosity. The compounds trans -1-(trans -4-alkylcyclohexyl)-2-(4-chlorophenyl)difluoroethylene have very low viscosities and reasonable nematic ranges, and are very suitable for electro-optic displays. The crystal structure of a compound in this homologous series has been determined by X-ray diffraction. The orientational ordering for this compound and for another homologue in their nematic phases has been studied by the use of one and two dimensional 13C NMR. The proton-decoupled 13C spectra are complex due to splittings from the two F-19 nuclei, but they have been analysed by combining chemical shift anisotropy and variable angle spinning studies. Carbon-proton and carbon-fluorine dipolar coupling constants were obtained, and the order parameters for the two conjugated molecular segments (the chlorophenyl ring and the difluoroethylenic link) were calculated from the dipolar coupling constants. The temperature dependences of the local order parameters of each fragment were studied.

Correlation of lipid content and composition with liposarcoma histology and grade.

The determination of sarcoma grade, histologic type, and differentiation is often pathologist dependent and requires considerable expertise. Lipid content and composition was analyzed in ex vivo fat, lipoma, and liposarcoma tissue samples using proton-decoupled 13C nuclear magnetic resonance (13C-NMR) spectroscopy and correlated with the histologic type and grade of liposarcoma. The well-differentiated liposarcomas were found to have threefold increases in fatty acyl chain content compared with benign lipomas. The fatty acyl chain content of the dedifferentiated and pleomorphic liposarcomas was 1% of that found in lipoma and < 0.2% of that found in well-differentiated liposarcoma. The 2.1- to 2.8-fold increase in the degree of polyunsaturation in the dedifferentiated and pleomorphic liposarcomas compared with well-differentiated liposarcoma could largely be accounted for by the 2.3-fold increase in the percentage of fatty acyl chains of lipid containing linoleic acid. The dedifferentiated and pleomorphic liposarcomas contained both free fatty acids and phospholipids that were not NMR detectable in normal fat, lipoma, and well-differentiated liposarcoma. Ex vivo 13C-NMR spectroscopy may be used to distinguish lipoma from well-differentiated, dedifferentiated, and pleomorphic liposarcoma based on changes in lipid and phospholipid metabolite profiles and may serve as adjunct to conventional light microscopy for the determination of liposarcoma histologic type and thus grade.

In Situ Solid-State NMR Observations of Photocatalytic Surface Chemistry: Degradation of Trichloroethylene

Environmental catalysts that can efficiently degrade hazardous chemicals are of growing importance. Among these, TiO2 photocatalysts show high potential for effective degradation of harmful species, particularly chlorine containing compounds, which are chemically persistent.1-3 TiO2 photocatalysts can display efficiencies (degradation rate/unit energy) that are 1-2 orders of magnitude higher than thermal catalysts, particularly for the low chlorocarbon concentrations often encountered.4 Gassurface experiments5-10 show that reactions occur both in the gas phase and/or on the surface of TiO2 catalysts and can involve the following radical initiators: O2, OH, and Cl. Although a number of studies have been carried out by means of GC,7-9 MS,6,8 and FT-IR,5-8,10 a detailed understanding of the reaction mechanisms remains elusive. In the present work, we report a new approach to the study of photocatalysis, namely in situ solid-state nuclear magnetic resonance (SSNMR) spectroscopy.11-13 SSNMR methods are advantageous because they allow a quantitative examination of the reactions on the catalyst surface as well as in the gas phase. We have characterized the reaction of trichloroethylene (TCE) over two types of TiO2 photocatalysts and have identified new intermediates in the complex surface chemistry. Figure 1 shows proton-decoupled 13C magic angle spinning (MAS) NMR spectra obtained from photooxidation of TCE in the presence of O2 and Degussa P-25 TiO2 powder.14 The NMR spectra show the degradation of TCE, the formation of dichloroacetyl chloride (Cl2CHCOCl, DCAC), CO, phosgene (CCl2O), and pentachloroethane (C2HCl5), and their conversion to the final product CO2. The narrow line widths of the peaks indicate that these species are very mobile and most likely exchange rapidly between the surface and the gas phase. Assignment of these intermediates are confirmed by comparing 13C NMR shifts for liquid samples reported in the literature15 or prepared in our lab and from proton coupled spectra during the photoreactions. Most of the intermediates identified above are in good agreement

Broad-spectrum analysis of a contaminated sediment: exemplification of a protocol

Chromatographic procedures have been outlined that enable isolation and analysis of structurally diverse groups of compounds from sediments. These methods have been exemplified using a contemporary sediment sample from a contaminated site in the Gulf of Bothnia that was examined for (a) selected di- and tri-terpenoids, β-sitosterol and aromatic hydrocarbons of biogenic origin and (b) chlorinated resin acids and chlorophenolic compounds. These were quantified together with the fully aromatic retene. A tetracyclic aromatic compound C 21H 22 was isolated and its structure deduced on the basis of its mass spectrum, high resolution MS and 1H NMR and proton-decoupled 13C spectra. It was identified as a des-A triterpenoid derived from lupane, or less likely as an aromatized steroid. Its concentration in segments of the sediment core was comparable to that of both lupeol and sitosterol.

Cell-wall polysaccharides from Australian red algae of the family Solieriaceae (Gigartinales, Rhodophyta): novel, highly pyruvated carrageenans from the genus Callophycus

Cell-wall polysaccharides from six species of red algae of the genus Callophycus were mainly galactans comprised predominantly of galactose (Gal) and 3,6-anhydrogalactose (AnGal), and were rich in pyruvate and sulfate. The Fourier Transform Infrared (FTIR) spectra of the polysaccharides superficially resembled that of α-carrageenan (composed of the repeating disaccharide carrabiose 2-sulfate), with major bands of absorption indicative of 4-linked AnGal, axial 2-sulfate on 4-linked AnGal, and unsulfated, 3-linked Gal. The FTIR spectra of solutions of Callophycus polysaccharides in D 2O-phosphate buffer displayed absorption, corresponding to the carboxylate anion of the pyruvate acetal substituent. Methylation analysis showed that 3,4,6-linked Gal p (interpreted as 4,6-pyruvated, 3-linked Gal p) and 2,4-linked AnGal p (interpreted as 4-linked AnGal p 2-sulfate) were the dominant linkages, together with significant quantities of 3-linked Gal p. Proton-decoupled 13C nuclear magnetic resonance (NMR) spectroscopy showed the polysaccharides to be composed predominantly of pyruvated carrageenans. The 13C NMR spectra were completely assigned by a J-modulated spin-echo pulse sequence and 2D experiments employing gradient Heteronuclear Multiple Bond Correlation (HMBC), 13C/ 1H Heteronuclear Multiple Quantum Coherence (HMQC), and HMQC Total Correlation Spectroscopy (HMQC-TOCSY). The Callophycus galactans thus consist predominantly of the novel repeating disaccharide 4′,6′- O-(1-carboxyethylidene)carrabiose 2-sulfate and minor amounts of the α-carrageenan repeating unit (carrabiose 2-sulfate), and other structural variations.

Direct determination of diastereomeric 13C-labeled ketoprofen glucuronides in human urine by nuclear magnetic resonance spectroscopy

A new method based on the 13C-labeling and nuclear magnetic resonance (NMR) spectroscopy was developed to study the human urinary excretion of diastereomeric acylglucuronides after the oral administration of 100 mg racemic [3- 13C]ketoprofen (KP). The urinary excretion of diastereomeric [3- 13C]KP glucuronides formed from [3- 13C]KP was followed by proton-decoupled 13C NMR spectroscopy (9.4 T, 10min accumulation time) without any separation procedures such as extraction and chromatography. The C3 resonances due to the diastereomers were satisfactorily separated from each other by the addition of methyl-β-cyclodextrin as an achiral shift reagent through the formation of inclusion complexes. The C3 resonances were detected with an acceptable signal-to-noise ratio over 8 h at a therapeutic dosage. The concentrations of [ 13C]KP glucuronides were calculated from the inverse gated decoupling and proton-decoupling experiments using [2- 13C]glycine as an internal standard. The urinary excretion of diastereomeric [3- 13C]KP glucuronides over 8 h amounted to 29% (downfield position) and 25% (upfield position) of the administered dose, respectively, and the former was presumed to have S-configuration. The elimination rate constants of both glucuronides were virtually the same ( K = 0.19 h −1). In addition, the susceptibility of the glucuronides to acyl migration as well as hydrolysis was suggested under the physiological conditions (37 °C, pH 7.3). The present direct approach is simple and convenient, and has the potential for wide application to the analysis of the labile acylglucuronides of 2-arylpropionic acids in biofluids.

Oxidation of acetate in rabbit skeletal muscle: detection by 13C NMR spectroscopy in vivo.

The results of a proton-decoupled and Overhauser-enhanced 13C NMR study of acetate metabolism in skeletal muscle are reported. [2-13C]Acetate was infused intravenously over 2 h into anesthetized rabbits, and skeletal muscle in the lateral thigh was monitored by 13C NMR spectroscopy at 4.7 T. Stable 13C enrichment in carbons 2, 3, and 4 of glutamate was observed at the end of the infusion, and the half-time for enrichment was 17 min for glutamate C4 and 50 min for glutamate C2 and C3. The contribution of exogenous acetate to acetylcoenzyme A was nearly equal in skeletal muscle and heart in vivo (83-87%, measured in tissue extracts), comparable with earlier perfused heart studies in which acetate was the sole available substrate. Although relative flux through the combined anaplerotic pathways (relative to citric acid cycle flux) was higher in quiescent skeletal muscle (28%) compared with hearts (3%) from the same animals, actual anaplerotic flux was estimated to be substantially higher in heart than in skeletal muscle after correcting for differences in citric acid cycle flux in the two tissues.

Fuels and chemicals from sewage sludge: 3. Hydrocarbon liquids from the catalytic pyrolysis of sewage sludge lipids over activated alumina

Toluene-extracted lipids (obtained by extraction with boiling toluene) from a dried raw Atlanta sewage sludge were pyrolysed over activated alumina at 450 °C and atmospheric pressure. Pyrolysis yielded low-viscosity liquids (10.7–67.5 wt%), non-condensable gases (12.1–15.6 wt%), semi-solids (only at higher weight-hourly space velocity) and water. The liquid products were hydrocarbon mixtures which contained predominantly alkanes. Infrared spectra, as well as proton-decoupled 13C nuclear magnetic resonance, confirmed the absence of carbonyl groups in the pyrolysed liquid products; showing that even the carboxylic acids, the major component of the separated lipid fraction, did not survive the pyrolysis reaction. Gas chromatography of the liquid products showed a uniform hydrocarbon distribution across the C6–C20 mass range. Non-condensable gases consisted of carbon dioxide, carbon monoxide, methane, ethane, ethene and C3–C5 compounds. This process resulted in rejection of both nitrogen and sulfur. The lipid extract only contained 1 wt% of the nitrogen and 16 wt% of the sulfur in the sludge. But these elements were reduced by a further 84% in the liquid product with respect to the lipid. The pyrolysed liquid contained 0.08 wt% nitrogen and 0.22 wt% sulfur. This liquid has a great potential to be used as diesel fuel, heating fuel and chemical feedstocks.