Stearolic Acid Research Articles

LC-MS-based serum metabolomics analysis and potential biomarkers for oxaliplatin induced neurotoxicity in colorectal cancer

Oxapliplatin-induced peripheral neuropathy (OIPN) is a significant adverse effect encountered in patients with colorectal cancer undergoing oxaliplatin therapy. However, the pathogenesis of OIPN remains unclear. This study aimed to identify potential diagnostic biomarkers for OIPN and discover the metabolic pathways associated with the disease. Serum samples were collected from 218 subjects, including patients with OIPN and control (CONT). The metabolite profiles were analyzed using nontargeted liquid chromatography-mass spectrometry (LC-MS) serum metabolomics method. Subsequently, differentially altered metabolites were identified and evaluated through multivariate statistical analyses. In this study, patients with OIPN and CONT were distinguished by ten significant metabolites. The levels of racemethionine, O-acetylcarnitine, stearolic acid, aminoadipic acid, iminoarginine, galactaric acid, and all-trans-retinoic acid were increased, whereas the levels of 3-methyl-L-tyrosine, 5-aminopentanoic acid, and erythritol compared were found to be diminished in patients with OIPN when compared to the CONT. Through receiver operating characteristic (ROC) curve analysis, racemethionine, stearolic acid, 5-aminopentanoic acid, erythritol, aminoadipic acid, and all-trans-retinoic acid were pinpointed as promising biomarkers for OIPN. Significantly altered pathways included amino acids (arginine biosynthesis, beta-alanine metabolism, arginine and proline metabolism, alanine, aspartate and glutamate metabolism, lysine degradation, and phenylalanine, tyrosine and tryptophan biosynthesis), lipid (linoleic acid metabolism and the biosynthesis of unsaturated fatty acids), and energy metabolism. This study, by identifying serum biomarkers and dissecting metabolic pathways, offers a groundbreaking perspective on the susceptibility mechanisms underlying OIPN. It stands as an invaluable resource for the adjunctive diagnosis of OIPN, with the potential to diminish the incidence of adverse reactions and to enhance the objectivity and reliability of clinical diagnoses of OIPN.

Hepatic Metabolomic Responses to Low-Temperature Stress in the Invasive Turtle, Trachemys scripta elegans.

Investigating the physiological and biochemical changes of ectothermic species before entering hibernation would contribute to the understanding of how they adapt to low-temperature environments. Here, red-eared slider turtle (Trachemys scripta elegans) hatchlings were maintained under different thermal treatments (24 °C, slowly decreasing temperatures from 24 °C to 14 °C, and to 4 °C). Hepatic metabolite alterations were measured to assess the metabolic impacts of low-temperature stress in this species. Of these differentially changed metabolites, some (e.g., raffinose, spermidine, allocholic acid, taurohyocholate, 2-ketobutyric acid, acetylcysteine) were shown to decrease, while others (e.g., stearolic acid, D-mannose) increased in low-temperature treatments. Our results indicated that short-term low-temperature stress might have limited impacts on lipid and energy metabolism in this species. The changes in other metabolites (e.g., allocholic acid, taurohyocholate, spermine, acetylcysteine) might be associated with a low food intake (and thus reduced digestive performance) and weakened immune ability of low-temperature-exposed animals.

Metabolomic profiling to identify early urinary biomarkers and metabolic pathway alterations in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the formation of numerous fluid-filled cysts that lead to progressive loss of functional nephrons. Currently, there is an unmet need for diagnostic and prognostic indicators of early stages of the disease. Metabolites were extracted from the urine of patients with early-stage ADPKD (n = 48 study participants) and age- and sex-matched normal controls (n = 47) and analyzed by liquid chromatography-mass spectrometry. Orthogonal partial least squares-discriminant analysis was used to generate a global metabolomic profile of early ADPKD for the identification of metabolic pathway alterations and discriminatory metabolites as candidates of diagnostic and prognostic biomarkers. The global metabolomic profile exhibited alterations in steroid hormone biosynthesis and metabolism, fatty acid metabolism, pyruvate metabolism, amino acid metabolism, and the urea cycle. A panel of 46 metabolite features was identified as candidate diagnostic biomarkers. Notable putative identities of candidate diagnostic biomarkers for early detection include creatinine, cAMP, deoxycytidine monophosphate, various androgens (testosterone; 5-α-androstane-3,17,dione; trans-dehydroandrosterone), betaine aldehyde, phosphoric acid, choline, 18-hydroxycorticosterone, and cortisol. Metabolic pathways associated with variable rates of disease progression included steroid hormone biosynthesis and metabolism, vitamin D3 metabolism, fatty acid metabolism, the pentose phosphate pathway, tricarboxylic acid cycle, amino acid metabolism, sialic acid metabolism, and chondroitin sulfate and heparin sulfate degradation. A panel of 41 metabolite features was identified as candidate prognostic biomarkers. Notable putative identities of candidate prognostic biomarkers include ethanolamine, C20:4 anandamide phosphate, progesterone, various androgens (5-α-dihydrotestosterone, androsterone, etiocholanolone, and epiandrosterone), betaine aldehyde, inflammatory lipids (eicosapentaenoic acid, linoleic acid, and stearolic acid), and choline. Our exploratory data support metabolic reprogramming in early ADPKD and demonstrate the ability of liquid chromatography-mass spectrometry-based global metabolomic profiling to detect metabolic pathway alterations as new therapeutic targets and biomarkers for early diagnosis and tracking disease progression of ADPKD.NEW & NOTEWORTHY To our knowledge, this study is the first to generate urinary global metabolomic profiles from individuals with early-stage ADPKD with preserved renal function for biomarker discovery. The exploratory dataset reveals metabolic pathway alterations that may be responsible for early cystogenesis and rapid disease progression and may be potential therapeutic targets and pathway sources for candidate biomarkers. From these results, we generated a panel of candidate diagnostic and prognostic biomarkers of early-stage ADPKD for future validation.

Physiochemical properties and phytochemical characteristics of bottle gourd (Lagenaria siceraria) seed oil

The physicochemical properties and phytochemical constituents of an extracted oil are important indicators for determining its compositional performance. In the current study, to assess the compositional quality of bottle gourd seed oil, physiochemical properties such as percentage yield, color, boiling point, specific gravity, acid value, peroxide value, saponification value, ester value and free fatty acid were estimated. In addition, GC-MS analysis was performed to identify the chemical components of bottle gourd seed oil. Physicochemical analysis revealed oil yield percentage of 47.22%, oil color is dark yellow, boiling point of 1420C, specific gravity of 0.77, acid value of 10.77 ± 0.06 (mg/g), peroxide value 0.55 ± 0.04 (mEq/kg), saponification value 71.52 ± 0.03 (mg/g), ester value 60.75 ± 0.03 (mg/g) and free fatty acid 2.23 ± 0.04 (mg/g). GC-MS fragment spectral analysis showed many fatty acids, including palmitic acid, stearolic acid, erucic acid (an omega-9 fatty acid), stearic acid and other active ingredients. According to these findings bottle gourd seed oil can be useful in nutritional approaches and has excellent purity, storage quality and a wide range of health benefits.

DECAY RESISTANCE, DIMENSIONAL STABILITY AND MECHANICAL STRENGTH OF POPLAR WOOD MODIFIED WITH PLANT-DERIVED COMPOUNDS

The cinnamaldehyde, salicylic acid, stearolic acid and citric acid were plant-derived organic compounds that can be activated to fungi, that could degrade the wood in long term. The compounds with concentrations of 3%, 5% and 7% assisted by different dispersants were impregnated into poplar (Populus nigra L.) specimens by the vacuum-pressure method. After that, weight percentage gain (WPG), decay resistance against white-rot fungi (Trametes versicolor) and brown-rot fungi (Gloeophyllum trabeum), color change, dimensional stability and mechanical properties including modulus of elasticity (MOE) and modulus of rupture (MOR) were measured. The results indicated that cinnamaldehyde impregnated poplar showed antifungi activity against both G. trabeumand T. versicolor, and citric acid impregnated poplar showed antifungi activity against G. trabeum. The color of poplar specimens before and after impregnated cinnamaldehyde and citric acid had a little change, dimensional stability had been improved and mechanical properties especially for MOR increased significantly.

Acetylenic fatty acids from Porcelia macrocarpa (Annonaceae) against trypomastigotes of Trypanosoma cruzi: Effect of octadec-9-ynoic acid in plasma membrane electric potential

Porcelia macrocarpa (Warm.) R. E. Fries (Annonaceae) is an endemic plant in Brazil where its tasty pulp has been eaten fresh. The hexane extract from its flowers was subjected to chromatographic procedures to afford four acetylene derivatives identified as octadec-9-ynoic (stearolic acid – 1), (11E)-octadec-11-en-9-ynoic (santalbic acid – 2), 8-hydroxyoctadec-9,11-diynoic (3) and 8-hydroxyoctadec-17-en-9,11-diynoic (isanolic acid – 4) acids by NMR and HRESIMS. Among tested compounds against trypomastigote forms of T. cruzi, octadec-9-ynoic acid (1) displayed higher potential with IC50 = 27.6 µM and a selectivity index (SI) higher than 7. Compounds 2 and 3 showed IC50 of approximately 60 µM while compound 4 was inactive. The lethal action of the compound 1 was investigated using spectrofluorometric techniques to detect ROS content, plasma membrane permeability and plasma membrane potential by flow cytometry. Compound 1 showed no alteration in the production of ROS of treated trypomastigotes and no alteration of the plasma membrane permeability was observed as detected by the fluorescent probe SYTOX-green after 120 min of incubation. However, by using the potential-sensitive fluorescent probe DiSBAC2(3), compound 1 caused depolarization of the plasma membrane potential when compared to untreated parasites. Our results demonstrated the anti-T. cruzi effects of compounds 1–3 isolated from flowers of P. macrocarpa and indicated that the lethal effect of compound 1 in T. cruzi could be associated to the plasma membrane disturbance of the parasite.

Effect of the fluorination degree of hydrophobic chains on the monolayer behavior of unsaturated diacylphosphatidylcholines bearing partially fluorinated 9-octadecynoyl (stearoloyl) groups at the air–water interface

The effect of the fluorination degree of hydrophobic chains on the monolayer behavior of unsaturated diacylphosphatidylcholines (PCs) was examined by employing a series of PCs bearing partially fluorinated 9-octadecynoyl (stearoloyl) groups (DFnStPCs, n: the number of fluorinated carbon atoms in a stearoloyl group; n=1, 2, 4, 8), including their hydrophobic parts – partially fluorinated stearolic acids (FnStAs) – at the air–water interface. π–A isotherm measurements and Brewster angle microscope observations revealed: (i) all DFnStPCs including FnStAs form monolayers of liquid character at 25°C; (ii) they form more expanded monolayers than their non-fluorinated counterparts, distearoloyl-PC (DStPC) and stearolic acid, while the monolayer stability increases with n; (iii) compared with DStPC and DF8StPC, DFnStPCs (n=1, 2, 4) in the low-π region tend to show a weakening in their self-aggregation property and an increase in the work required for monolayer compression; (iv) although DF8StPC forms the most expanded monolayer, the behavior of DF8StPC resembles that of DStPC rather than that of DFnStPCs (n=1, 2, 4). The monolayer behavior of DFnStPCs (n=1, 2, 4) is explained by postulating a flatly-lying conformation of hydrophobic chains, in which three polar parts (ester group, triple bond, CF2CH2 linkage) in chains are immersed in the subphase at large areas. DStPC and DF8StPC lacking a CF2CH2 linkage, however, do not likely adopt such a conformation.

Diversity of Δ12 Fatty Acid Desaturases in Santalaceae and Their Role in Production of Seed Oil Acetylenic Fatty Acids

Plants in the Santalaceae family, including the native cherry Exocarpos cupressiformis and sweet quandong Santalum acuminatum, accumulate ximenynic acid (trans-11-octadecen-9-ynoic acid) in their seed oil and conjugated polyacetylenic fatty acids in root tissue. Twelve full-length genes coding for microsomal Δ12 fatty acid desaturases (FADs) from the two Santalaceae species were identified by degenerate PCR. Phylogenetic analysis of the predicted amino acid sequences placed five Santalaceae FADs with Δ12 FADs, which include Arabidopsis thaliana FAD2. When expressed in yeast, the major activity of these genes was Δ12 desaturation of oleic acid, but unusual activities were also observed: i.e. Δ15 desaturation of linoleic acid as well as trans-Δ12 and trans-Δ11 desaturations of stearolic acid (9-octadecynoic acid). The trans-12-octadecen-9-ynoic acid product was also detected in quandong seed oil. The two other FAD groups (FADX and FADY) were present in both species; in a phylogenetic tree of microsomal FAD enzymes, FADX and FADY formed a unique clade, suggesting that are highly divergent. The FADX group enzymes had no detectable Δ12 FAD activity but instead catalyzed cis-Δ13 desaturation of stearolic acid when expressed in yeast. No products were detected for the FADY group when expressed recombinantly. Quantitative PCR analysis showed that the FADY genes were expressed in leaf rather than developing seed of the native cherry. FADs with promiscuous and unique activities have been identified in Santalaceae and explain the origin of some of the unusual lipids found in this plant family.

Synergistic effect of inhibitors of fatty acid desaturases on Trypanosoma parasites.

The pathway for unsaturated fatty acid biosynthesis is essential in trypanosomatid parasites and has been a key target in our work on the discovery and analysis of several inhibitory compounds. Here, we show the effect of novel inhibitors of stearoyl-CoA desaturase (SCD) and oleate desaturase (OD), alone and in combination, on the growth rate of parasite cultures. GS-456332, an inhibitor of human Δ9 desaturase, efficiently inhibited growth of both Trypanosoma cruzi epimastigotes and Trypanosoma brucei bloodstream form cells, with EC50 values of 136.9 ± 24.2 and 9.4 ± 3.1 nM, respectively. This effect was specific for SCD. Stearolic acid (9-octadecynoic acid) was also able to arrest T. cruzi and T. brucei growth by specific inhibition of their OD, with EC50 values of 1.0 ± 0.2μM and 0.1 ± 0.01μM, respectively. When these compounds were administered simultaneously, a clearly synergistic effect was observed for both Trypanosoma species, with EC50 values in the low nanomolar range. These results demonstrate the feasibility of using combinations of drugs, inhibiting different enzymes on the same metabolic pathway, for the development of more efficient chemotherapeutic strategies against neglected diseases caused by these parasites.

Pentadecyl ferulate, a potent antioxidant and antiproliferative agent from the halophyte Salicornia herbacea

An investigation of the chemical constituents of Salicornia herbacea has led to the isolation of one new natural product, pentadecyl ferulate (6), together with 11 known compounds, including phytol (1), stearolic acid (2), γ-linolenic acid (3), (3Z,6Z,9Z)-tricosa-3,6,9-triene (4), linoleic acid (5), stigmasterol (7), ergosterol (8), dioctyl phthalate (9), dibutyl phthalate (10), vanillic aldehyde (11), and scopoletin (12). The chemical structures of these materials were elucidated mainly by spectroscopic analysis. This work represents the first recorded example of the isolation of compounds 1, 2, 3, 4, 9, 10, and 11 from S. herbacea. The antioxidant experiments revealed that compound 6 possessed strong hydroxy radical and superoxide anion scavenging activities and was the principle antioxidant ingredient in the ethyl acetate extract. The antiproliferative results exhibited that compound 1 selectively inhibited HepG2 cells, whereas compounds 3 and 6 showed potent antiproliferative activities against HepG2 and A549 cells.

Effect of Polyunsaturated Fatty Acids on Homocysteine Metabolism through Regulating the Gene Expressions Involved in Methionine Metabolism

The objective was to investigate the regulatory effect of polyunsaturated fatty acids (PUFAs) on mRNA expression of key genes involved in homocysteine (Hcy) metabolism. Eighty male Sprague Dawley rats were randomly divided into eight groups. The oils were orally administered daily for 8 weeks. Plasma Hcy, phospholipids fatty acids, and mRNA expression were determined. Compared with the control group, plasma Hcy was significantly decreased in the 22:6n-3 and conjugated linoleic acid (CLA) groups; mRNA expression of Mthfr was significantly upregulated in the 22:6n-3, 20:5n-3, and 18:3n-3 groups and downregulated in the 18:2n-6 and stearolic acid (SO) groups. Mat1a was upregulated in the 22:6n-3, 20:5n-3, 18:3n-3, and CLA groups. In addition, Cbs was upregulated in the 22:6n-3, 20:5n-3, 18:3n-3 and CLA groups while downregulated in 18:2n-6 and SO groups. Dietary 22:6n-3 and CLA decrease the plasma concentration of Hcy. mRNA expression of Mthfr, Mat1a, Cbs and Pemt, Gnmt, Mtrr, and Bad is upregulated by n-3 PUFA and downregulated by n-6 PUFA. CLA upregulates mRNA expression of Mat1a and Cbs.

Santaluminsulare Acetylenic Fatty Acid Seed Oils: Comparison within the Santalum Genus

AbstractThe sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E‐11‐octadecen‐9‐oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry (GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The content in stearolic acid, octadec‐9‐ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content.

Synthesis and characterization of partially fluorinated stearolic acid analogs: Effect of their fluorine content on the monolayer at the air–water interface

Novel stearolic acid analogs (i.e., 9-octadecynoic acid analogs: 1a– d) containing the shorter perfluoroalkyl groups, CF 3, C 2F 5, n-C 3F 7 or n-C 4F 9 group were synthesized. Equilibrium spreading pressures ( π es) of their monolayers at the air–water interface were measured in order to demonstrate how the fluorine content has an effect on the stability of the fatty acid monolayers. As the fluorine content in stearolic acid molecule increased, its melting points was lowered indicating the solid bulk phase of stearolic acid became thermally unstable, while its monolayer stability evaluated by π e at 25 °C, dramatically increased and subsequently leveled off above a certain fluorine content. Under this condition, the replacement of at least five hydrogen atoms at the terminal hydrophobic segment in stearolic acid molecule by fluorine atoms (CF 3CF 2 group) was required to alter the bulk property of stearolic acid and exhibit the stabilization of monolayers, whereas further fluorination of stearolic acid had a minor effect on the monolayer stability. This behavior suggests the terminal fluorinated hydrophobic segment exclusively controls the interfacial stability of fatty acid monolayers.

Identification of nine acetylenic fatty acids, 9‐hydroxystearic acid and 9,10‐epoxystearic acid in the seed oil ofJodina rhombifolia hook et arn. (Santalaceae)

AbstractIn addition to some usual fatty acids, the seed oil ofJodina rhombifolia (Santalaceae) contains nine acetylenic fatty acids [9‐octadecynoic acid (stearolic acid) (1.1%),trans‐10‐heptadecen‐8‐ynoic acid (pyrulic acid) (20.1%), 7‐hydroxy‐trans‐10‐heptadecen‐8‐ynoic acid (2.3%),trans‐10,16‐heptadecadien‐8‐ynoic acid (0.7%), 7‐hydroxy‐trans‐10,16‐heptadecadien‐8‐ynoic acid (0.1%),trans‐11‐octadecen‐9‐ynoic acid (ximenynic acid) (20.3%), 8‐hydroxy‐trans‐11‐octadecen‐9‐ynoic acid (12.2%),trans‐11,17‐octadecadien‐9‐ynoic acid (1.5%), 8‐hydroxy‐trans‐11,17‐octadecadien‐9‐ynoic acid (1.3%), 9‐hydroxystearic acid (<0.1%) and 9,10‐epoxystearic acid (0.7%)]. The fatty acids have been analyzed by gas chromatography/mass spectrometry of their methyl ester and 4,4‐dimethyloxazoline derivatives. The hydroxy fatty acid methyl esters have been examined also as trimethyl‐silyl ethers. Furthermore, the fatty acid methyl esters (FAME) have been fractionated according to their polarity (FAME‐A: nonhydroxy; FAME‐B: hydroxy fatty acids) and to their degree of unsaturation (FAME‐A1/A2; FAME‐B1/B2) by preparative thin‐layer chromatography and argentation chromatography, respectively. All of these fractions have been analyzed by ultraviolet and infrared spectroscopy, and the fractions FAME‐A and FAME‐B have been analyzed further by nuclear magnetic resonance (1H,13C, 2D H/C, attached proton test) spectroscopy and gas chromatography/mass spectrometry.

Facile dehydrobromination ofvic‐dibromo fatty acids: A one‐vessel bromination‐dehydrobromination of oleic acid to stearolic acid

AbstractThe effects of time and temperature on the dehydrobromination by alcoholic KOH of 9,10‐dibromostearic acid to 9(10)‐bromo‐9‐octadecenoic and stearolic acid (9‐octadecynoic acid) have been studied. Dimethylsulfoxide (DMSO) in n‐propanol‐KOH solution has been found to be an effective cosolvent‐catalyst. In the absence of DMSO, the first monodehydrobromination step to the ethenylene bromide is quantitative in 5 min at 60 C and the second dehydrobromination step to the acetylenic acid is complete in about 6 hr at 100 C. In the presence of DMSO, the dehydrobromination to stearolic acid is quantitative at 100 C in 1–2 hr. A 1‐vessel oleic acid bromination‐dehydrobromination has been devised to give stearolic acid in 98% yield and purity.

Gas chromatography of free fatty acids after treatment with iodine and iodine trichloride solution.

A modified gas chromatographic procedure is described for the separation of mixtures of saturated and unsaturated higher fatty acids having the same carbon number. On a 2% OV-17 column, the chromatogram of mixtures of stearic acid (18:0) and oleic acid (18:1) treated with iodine and iodine trichloride (I2-ICl3) in acetic acid at 20°C for 1 h showed better separation than that of those non-treated acids. The reaction product of oleic acid and I2-ICl3 solution was identified as stearolic acid by gas-liquid chromatography and mass spectrometry. The proposed method was also applied to the separation of palmitic (16:0) and palmitoleic acid (16:1).

Syntheses with stable isotopes: Oleic‐1‐13C acid and triolein‐1′,1″, 1″′‐13C3

AbstractA synthesis of oleic‐1‐13C acid and its conversion to triolein‐1′,1″,1″′‐13C3 are described. 9‐Octadecynenitrile‐1‐13C was prepared from 1‐bromo‐8‐heptadecyne and sodium cyanide‐13C. Hydrolysis afforded stearolic‐1‐13C acid, which was reduced to oleic‐1‐13C acid by the action of disiamylborane on methyl stearolate‐1‐13C. Hydrogenation of stearolic acid in the presence of Lindlar's catalyst was also investigated. Condensation of glycerol and oleic‐1‐13C acid to give triolein‐1′,1″,1″′‐13C3 was effected with dicyclohexylcarbodiimide and 4‐dimethylaminopyridine. The overall yield of triolein‐13C3 from sodium cyanide‐13C was 40%.

The effect of fluidity of membrane lipids on freeze-thaw survival of yeast

One approach to studying the importance of membranes in freeze-thaw damage is to modify their composition and study the effect of this modification on survival after freeze-thaw damage. Fatty acid desaturase auxotrophs of yeast cells were enriched with two fatty acids having substantially different physical properties thus resulting in cells whose membranes had very different physical properties. The fatty acids were stearolic acid (mp = +45 °C) and linolenic acid (mp = −10 °C). Electron-spin resonance studies showed that membranes containing the latter fatty acid were more fluid than those containing stearolic acid. The yeast were grown under either anaerobic or aerobic conditions. In the former case, the mitochondria appear as membraneous shells with little, if any, internal membrane structure; thus, the plasma and tonoplast membranes are the primary membranes. Yeast cells grown under these conditions survived freezethaw damage (−196 °C) significantly better when the fatty acid composition was mainly stearolic acid rather than linolenic acid. The absolute survival depended on the freezing rate and the differences in survival became small at fast rates. With yeast cells grown under aerobic conditions, when functional mitochondria are formed, the pattern in freeze-thaw survival reversed; cells with γ-linolenic acid in their membranes survived significantly better than cells containing stearolic acid.

Der Stoffwechsel von Verbindungen mit Dreifachbindung. VII. Verteilung und Abbau der 9‐Octadecinsäure bei Ratten, ein Beitrag zur α‐Oxydation der C‐Kette

Distribution and Metabolism of Octadec‐9‐ynoic acid in RatsOctadec‐9‐ynoic acid (stearolic acid) fed to rats leads to the metabolic excretion of six dicarboxylic acids with retained triple bond. The main metabolic steps are ω‐, β‐, and presumably α‐oxidation. Feeding of 14C‐stearolic acid proves that the α‐oxidative steps involves the methyl end of the original acid. It could further be shown that this acid is incorporated partially in the body lipids. To a substantial degree it is totally oxidized and expired as 14CCO2.

Synthesis and Characterization of 9(10)‐Bromo‐9‐octadecenoic Acids

Abstract9(10)‐Bromo‐cis‐9‐octadecenoic acid, m. p. 36.7° C, was prepared by dehydrobromination of threo‐9,10‐dibromo‐stearic acid with bases and by polar addition of hydrogen bromide to stearolic acid. The trans isomer, m. p. 6°–8° C, was obtained from the corresponding erythro‐dibromide. Both compounds were characterized by IR and NMR spectroscopies and a reaction scheme for their formation by dehydrobromination is suggested.