Fast chromatography of pulse triacylglycerols

A short 10-min ultra high performance liquid chromatography (UHPLC) method was used for separation and lipidomic analysis of triacylglycerols (TAGs) in 10 pulses: baby lima beans, black beans, black-eyed peas, butter beans, cranberry beans, garbanzo beans, green split peas, lentils, navy beans, and pinto beans. The lipids extracted using chloroform/methanol averaged 1.9–2.7% across all pulses except garbanzo beans, which gave 6.2% lipids. TAGs were analyzed using dual parallel mass spectrometry (LC1MS2), areas were integrated using LipidSearch 4.2 software, and percent relative TAG compositions were calculated. Fatty acid response factors were calculated by comparison to calibrated GC-FID, which were used to calculate response-factor adjusted TAG compositions. Principal component analysis revealed that the pulses separated into three clusters, which were further highlighted using hierarchical cluster analysis. A subset of TAGs was quantified using calibration curves made from alternating sets of regioisomers in the non-linear high concentration range (~2.5 nMol/ml to ~300 nMol/ml). A linear calibration curve for the sum of tocopherols detected by fluorescence was constructed with a coefficient of determination, r², >0.99 for low concentrations (0.50–50 μg/ml), but tocopherols in pulses appeared to be inefficiently extracted. TAG regioisomers were quantified based on a Critical Ratio (CR), [AA]⁺/[AB]⁺, interpolated between the CRs of two pure regioisomer standards taken from alternating calibration standards. TAG mole percent relative compositions are reported for the first time for most pulses and the compositions are given with more detail and specificity than previously reported.     

Effect of cationization reagents on the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrum of Chinese gallotannins

In this study, Chinese gallotannins were characterized by MALDI‐TOF MS, and effects of cationization reagents on the quality of spectra were investigated. The trideca‐ and tetradeca‐galloyl glucoses were observed in Chinese gallotannins, which could not be detected in earlier studies. When Cs⁺ was used as the cationization reagent, Chinese gallotannins gave a relatively simple MALDI‐TOF spectrum, three series of quasimolecular ions [M + Cs]⁺, [M + 2Cs–H]⁺, and [M + 3Cs–2H]⁺ and a series of metastable ion peaks with minimum abundance were detected. Selection of Na⁺ as the cationization reagent, additional three series of ion peaks including two patterns from the fragmentation and complex 2M adducts [2M + Na]⁺ can be distinguished. In the case of no deionization or addition of cationization reagent to the analyte/matrix, naturally abundant Na⁺ and K⁺ as the cationization reagent, [M + Na]⁺ and [M + K]⁺ molecular ions both appeared in the complicated spectrum. Therefore, we conclude that cationization reagents affect the MALDI‐TOF MS spectrum of Chinese gallotannins significantly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Analysis of triacylglycerols in refined edible oils by isocratic HPLC‐ESI‐MS

A simple, fast and reproducible reversed‐phase high performance liquid chromatography (HPLC) method coupled to electrospray ionization mass spectrometry (ESI‐MS) for the analysis of triacylglycerols (TAGs) species in the commercial edible oils has been developed. The TAGs species were separated using isocratic 18% isopropanol in methanol and a Phenomenex C18 column. The ESI‐MS conditions were optimized using flow injection analysis of standard TAG. Fifteen, fourteen, and sixteen TAGs were separated and identified in corn oil, rapeseed oil, and sunflower oil, respectively. The presence of intense protonated molecular (M + H⁺), ammonium (M + ${\rm NH}_{4}^{ + } $ ), and sodium (M + Na⁺) adducts ions and their respective diacylglycerols ions in the ESI‐MS spectra showed correct identification of TAGs. Some minor potassium adducts (M + K⁺) were also found. In addition, the identity of the fatty acid, position of each fatty acid, and the location of the double bond in the fatty acid moiety were explained. It was found that this isocratic method is useful for fast screening and identification of triacylglycerols in lipids.     

The bottom-up solution to the triacylglycerol lipidome using atmospheric pressure chemical ionization mass spectrometry

Presented here is an approach to representing the data from atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) of triacylglycerols (TAG) using a set of one, two, or three Critical Ratios. These Critical Rations may be used directly to provide structural information concerning the regioisomeric composition of the triacylglycerols (TAG), and about the degree of unsaturation in the TAG. An AAA-type, or Typel, TAG has only one Critical Ratio, the ratio of the protonated molecule, [M+H]⁺, to the DAG fragment ion, [AA]⁺. The Critical Ratio for a Type I TAG is [MH]⁺/Σ[DAG]⁺, and the mass spectrum of a Type I TAG can be reproduced from only this one ratio. An ABA/AAB/BAA, or Type II, TAG has two Critical Ratios, the [MH]⁺/Σ[DAG]⁺ ratio and the [AA]⁺/[AB]⁺ ratio. The [AA]⁺/[AB]⁺ ratio for a single TAG or TAG mixture can be compared with the [AA]⁺/[AB]⁺ ratios of pure regioisomeric standards, and the percentage of each regioisomer can be estimated. The abundance of the protonated molecule and the abundances of the two [DAG]⁺ fragment ions can be calculated from the two Critical Ratios for a Type II TAG. To calculate the abundances, the Critical Ratios are processed through the Bottom-Up Solution to the TAG lipidome. First, Critical Limits are calculated from the Critical Ratios, and then the Critical Ratios are classified into Cases by comparison with the Critical Limits. Once the Case classification is known, the equation for the abundance of each ion in the mass spectrum is given by the Bottom-Up Solution. A Type III TAG has three different FA and three Critical Ratios. The [MH]⁺/Σ/[DAG]⁺ ratio is the first Critical Ratio, the [AC]⁺/([AB]⁺+[BC]⁺) ratio is the second Critical Ratio, and the [BC]⁺/[AB]⁺ ratio is the third Critical Ratio. The second critical ratio for a Type III TAG can be compared with regioisomeric standards to provide an estimate of the percentage composition of the regioisomers. The three Critical Ratios for a Type III TAG can be processed through the Bottom-Up Solution to calculate the four ion abundances that make up the APCI-MS mass spectrum. The Critical Ratios constitute a reduced data set that provides more information in fewer values than the raw abundances.     

Analysis of the seed oil of Heisteria silvanii (Olacaceae)—A rich source of a novel C18 acetylenic fatty acid

Besides some usual fatty acids (FA), two conjugated ene-yne acetylenic FA [trans-10-heptadecen-8-ynoic acid (pyrulic acid) (7.4%), and trans-11-octadecen-9-ynoic acid (ximenynic acid) (3.5%)], a novel ene-yne-ene acetylenic FA [cis-7, trans-11-octadecadiene-9-ynoic acid (heisteric acid) (22.6%)], and 9,10-epoxystearic acid (0.6%) could be identified in the seed oil of Heisteria silvanii (Olacaceae). Two further conjugated acetylenic FA [9,11-octadecadiynoic acid (0.1%) and 13-octadecene-9,11-diynoic acid (0.4%)] were identified tentatively by their mass spectra. The FA mixture has been analyzed by gas chromatography/mass spectrometry (GC/MS) of their methyl ester and 4,4-dimethyloxazoline derivatives. The structure of heisteric acid was elucidated after isolation via preparative silver ion thin-layer chromatography and by various spectroscopic methods [ultraviolet; infrared; ¹H, ¹³C nuclear magnetic resonance (NMR); ¹H−¹H and ¹H−¹³C correlation spectroscopy]. To determine the position of the conjugated ene-yne-ene system, the NMR spectra were also measured after addition of the lanthanide shift reagent Resolve-Al EuFOD^TM. Furthermore, the triyglyceride mixture was analyzed by high-temperature GC and high-temperature GC coupled with negative chemical ionization MS. A glass capillary column coated with a methoxy-terminated 50%-diphenyl-50%-dimethylpolysiloxane was used for the separation of the triacylglycerol (TAG) species. No evidence of decomposition of the TAG species containing conjugated ene-yne-ene FA was observed. Twenty-six species of the separated TAG were identified by means of their abundant quasi molecular ion [M−H]⁻ and their corresponding carboxylate anions [RCOO]⁻ of the fatty acids, respectively. The major molecular species of the TAG were found to be 16:0/18:1/18:1, 16:0/18:1/18:3 (heisteric acid), 17:2 (pyrulic acid)/18:1/18:1, 18:1/18:1/18:3 (heisteric acid). The TAG containing acetylenic FA showed an unexpected increase of the retention time in comparison to the TAG containing usual FA, thus making the prediction of the elution order of lipid samples containing acetylenic FA difficult.     

Comparative analysis of triacylglycerols from Olea europaea L. fruits using HPLC and MALDI‐TOFMS

MALDI‐TOFMS and HPLC are two analytical methods that were used to characterize triacylglycerols (TAG) of the Meski, Sayali, and Picholine Tunisian olive varieties. The HPLC chromatograms of the oils showed the presence of 15 TAG species, among which triolein (OOO) was the most abundant (21–48%). In the Sayali cultivar, OOO was the predominant TAG species followed by POO and LOO. However, the minor TAG molecules were represented by LnLO and LnLP. MALDI mass spectra produced sodiated ([M + Na]⁺) and potassiated ([M + K]⁺) TAG molecules; only the major TAG were potassiated [OOO + K] ([OOO + K]⁺, [POO + K]⁺, and [LOO + K]⁺). In contrast to the HPLC chromatograms, the MALDI mass spectra showed 13 peaks of TAG. The major peak was detected at m/z 907, which corresponds to OOO with an Na⁺ adduct. The results from both HPLC and MALDI techniques predict the fatty acid composition and their percentages for each olive variety. Practical applications: TAG are the main components in vegetable oils. These biomolecules determine the physical, chemical, and nutritional properties of the oils. The nutritional benefits of TAG are related to DAG (moderate plasma lipid level) and esterified FA, which are intermediate biosynthetic molecules of TAG. TAG analysis is necessary to discriminate between oils of different origin, since some oils have similar FA profiles. Olive products, oils, and table olives, are the main diet sources of TAG in the Mediterranean countries. In this work, chromatographic and spectrometric methods were used for TAG analysis and characterization of Tunisian olive varieties.     

The Updated Bottom Up Solution Applied to Atmospheric Pressure Photoionization and Electrospray Ionization Mass Spectrometry

The Updated Bottom Up Solution (UBUS) was recently applied to atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) of triacylglycerols (TAG). This report demonstrates that the UBUS applies equally well to atmospheric pressure photoionization (APPI) MS and to electrospray ionization (ESI) MS. Critical Ratio 1 (CR1), the [MH]⁺/Σ[DAG]⁺ or [MNH₄]⁺/Σ[DAG]⁺ ratio, does not exhibit the same strongly sigmoidal shape as it does by APCI‐MS. CR1 varies more widely for APPI‐MS than by APCI‐MS, having a maximum value of 11.8, indicating a much greater effect of unsaturation on ion ratios in APPI‐MS than APCI‐MS. Critical Ratio 2, the [AA]⁺/[AB]⁺ ratio for Type II TAG or [AC]⁺/([AB]⁺+[BC]⁺) ratio for Type III TAG, allows quantification of regioisomers of TAG, and shows good agreement for APPI‐MS to regioisomer quantification determined by APCI‐MS. Critical Ratio 3, the [BC]⁺/[AB]⁺ ratio for Type III TAG, reveals new trends relating the degree of unsaturation by APPI‐MS, and shows that structural assignments made by ESI‐MS are in good agreement to APCI‐MS data. In addition to providing valuable structural information, the Critical Ratios also constitute a reduced data set that allows APPI‐MS or ESI‐MS mass spectra to be reconstructed when processed through the UBUS. Quantification by APPI‐MS of vitamin D in the gelcaps gave values of 42.90 ± 0.83 μg, or 1716 ± 33 international units, in good agreement with APCI‐MS.     

Characterization of triacylglycerols in madeira laurel oil by HPLC-atmospheric pressure chemical ionization-MS

Madeira laurel oil was fractionated by liquid extraction combined with TLC, and TAGs were analyzed by HPLC coupled with atmospheric pressure chemical ionization-MS (APCI-MS). Eluted molecular species compositions of the eluted TAG in the complex natural mixture were determined by GC identification of FAME and byLC-atmospheric pressure chemical ionization (APCI)-MS analysis of the lipid. The APCI-MS spectra of most TAG exhibited [M+H]⁺ and [M−RCOO]⁺ ions, which defined the M.W. and the molecular association of fatty acyl residues, respectively. Despite the relatively high degree of saturation, with a saturated/unsaturated ratio of 0.70, no totally saturated TAG nor mixed asymmetric TAG with two saturated FA (SSM or SSU, where S is saturated, M is monounsaturated, and U is unsaturated) were found. This type of molecular structure provides a possible explanation for the relatively low m.p. (12–15°C) and also the high oxidative resistance observed.     

Recoveries of rat lymph FA after administration of specific structured <Superscript>13</Superscript>C-TAG

The potential of the specific structured TAG MLM [where M-caprylic acid (8∶0) and L=linoleic acid (18∶2n−6)] is the simultaneous delivery of energy and EFA. Compared with long-chain TAG (LLL), they may be more rapidly hydrolyzed and absorbed. This study examined the lymphatic recoveries of intragastrically administered L^*L^*, M^*M^*M^*, ML^*M, and ML^*L^* (where ^*=¹³C-labeled FA) in rats. Lymph lipids were separated into lipid classes and analyzed by GC combustion isotope ratio MS. The recoveries of lymph TAG 18∶2n-6 8 h after administration of L^*L^*L^*, ML^*M, and ML^*L^* were 38.6, 48.4, and 49.1%, respectively, whereas after 24 h the recoveries were approximately 50% in all experimental groups. The exogenous contribution to lymph TAG 18∶2n-6 was approximately 80 and 60% at maximum absorption of the specific structured TAG and L^*L^*L^*, respectively, 3–6 h after administration. The tendency toward more rapid recovery of exogenous long-chain FA following administration of specific structured TAG compared with long-chain TAG was probably due to fast hydrolysis. The lymphatic recovery of 8∶0 was 2.2% 24 h after administration of M^*M^*M^*. This minor lymphatic recovery of exogenous 8∶0 was probably due to low stimulation of chylomicron formation. These results demonstrate tendencies toward faster lymphatic recovery of long-chain FA after administration of specific structured TAG compared with long-chain TAG.     

Single-Walled Carbon Nanohorns as Boosting Surface for the Analysis of Low-Molecular-Weight Compounds by SALDI-MS

Limits of Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry (MS) in the study of small molecules are due to matrix-related interfering species in the low m/z range. Single-walled carbon nanohorns (SWCNH) were here evaluated as a specific surface for the rapid analysis of amino acids and lipids by Surface-Assisted Laser Desorption Ionization (SALDI). The method was optimized for detecting twenty amino acids, mainly present as cationized species, with the [M+K]⁺ response generally 2-time larger than the [M+Na]⁺ one. The [M+Na]⁺/[M+K]⁺ signals ratio was tentatively correlated with the molecular weight, dipole moment and binding affinity, to describe the amino acids’ coordination ability. The SWCNH-based surface was also tested for analyzing triglycerides in olive oil samples, showing promising results in determining the percentage composition of fatty acids without any sample treatment. Results indicated that SWCNH is a promising substrate for the SALDI-MS analysis of low molecular weight compounds with different polarities, enlarging the analytical platforms for MALDI applications.     

Volatile compounds and triacylglycerol composition of original Indian fatty plant oils

Some typical original Indian edible and non‐edible fatty plant oils were subject of our investigations. Fundamental research was done on analyzing volatile compounds using HS‐SPME‐GC‐MS. In addition, a sensorial evaluation was applied to receive data on the smell of the samples. Furthermore, the typical and prevailing triacylglycerols (TAG) were investigated by MALDI‐TOF‐MS. Mass spectra reflect the TAG profiles of the whole oil samples based on the detection of [M+Na]⁺ ions. Oil samples exhibit quite unique TAG profiles, which are suitable for rapid characterization of the original plant oils. The fatty acid composition of the corresponding TAG structures was calculated using lipid analysis software based on the known fatty acid composition. Relative quantification of TAG components was in good agreement with the literature, in case appropriate data are available so far.     

Determination of Triacylglycerols in Butterfat by Normal-Phase HPLC and Electrospray–Tandem Mass Spectrometry

Here, we report the identification and quantification of the molecular species of long-, medium-, and short-chain triacylglycerols (TAG) in butterfat (BF), including TAG with an odd number of acyl carbons (ACN) and TAG with unidentified molecular species. In the present study, in addition to auto-MS², a large number of methods, each recording MS² for 1–4 ions, were used for identification of TAG species. For the quantification of long-chain, odd ACN TAG, and TAG with unidentified molecular species, molar correction factors (MCF) were calculated from the uncorrected mol% (area mol%) of each ACN:DB (number of double bonds) class in randomized butterfat (RBF), and the respective mol% in the calculated random composition of RBF. The butyrate, caproate, and medium-chain (C₈, C₁₀) TAG were quantified using regio- or acyl-chain-specific MCF calculated from their area mol% in RBF and mol% in the calculated random composition. These methods enabled us to identify ca. 450 TAG species in 184 quantified peaks of 88 ACN:DB classes. The proportions of saturated, monoene, diene, triene, tetraene, pentaene, and hexaene TAG were 40.0, 38.4, 16.2, 4.5, 0.6, 0.1, and 0.03 mol%, respectively. The proportions of TAG with not identified molecular species and odd ACN TAG were 11.8 and 5.7 mol%, respectively. The most abundant short-chain TAG species were butyroyldipalmitoylglycerol + butyroylmyristoylstearoylglycerol (5.25 mol%) and butyroylpalmitoyloleoylglycerol (4.08 mol%).     

Characterization of castor bean neutral lipids by mass spectrometry/mass spectrometry

A method has been developed for the characterization of intact neutral lipids isolated from castor bean (Ricinus communis L.) by mass spectrometry/mass spectrometry (MS/MS). The molecular weights of the trimethylsilyl (TMS) derivatives of the neutral lipids are determined by using both electron impact and chemical ionization (ammonia). Collision-induced dissociation daughter spectra of the (M-CH₃)⁺ ions yield fragment ions that allow easy determination of the acyloxy groups present. The chainlength and degree of unsaturation for each acyloxy group are indicated by R in the ion represented by the general formula (RCO + 74)⁺. Other ions of diagnostic value include (M-RCOO)⁺, (M-RCOOH)⁺, [(M-CH₃-RCOOH]⁺ and [(M-RCOOH)-16]⁺. The presence of a TMS group in any of these fragments results in the formation of ions representing the loss of OTMSH. Prior to MS/MS analysis, partial fractionation by high-performance liquid chromatography (according to degree of unsaturation in the neutral lipids) is useful because daughter spectra are generated free of any isotopic contamination, and minor components are concentrated in single fractions, which aids their characterization. By using this method, 11 neutral lipids were characterized in castor bean.     

Changes in the Composition of Triacylglycerols in the Fat Bodies of Bumblebee Males During Their Lifetime

The age-dependent changes in the composition of triacylglycerols (TAG) in the fat bodies of bumblebee males were studied using HPLC/MS. Two related species (Bombus terrestris and B. lucorum) were compared, with the age of the males being 0–30 days. The total amount of TAG in B. lucorum was about 2.7 times higher than that in B. terrestris for all of the ages studied. One to three-day-old males had the highest content of TAG in their fat bodies (1.6–2.3 mg/individual in B. terrestris and 3.8–4.2 mg/individual in B. lucorum). The analytical data show different patterns in both species. The qualitative composition of fatty acids in TAG was similar, but the mean relative abundance between B. terrestris and B. lucorum differed: 14:0, 7 and 14%; 16:0, 20 and 44%; 18:3, 62 and 23%; 18:1, 3 and 8%, respectively (the data is based on a GC/MS integration). A statistical evaluation of the dynamic changes in the TAG composition revealed that in B. terrestris different age classes were well separated according to their TAG composition while in B. lucorum the TAG did not change substantially during the male’s life. The TAG analyses provide more precise information on the differences between the classes studied than the FA composition alone.     

Analysis of volatile compounds and triacylglycerol composition of fatty seed oil gained from flax and false flax

Linseed (Linum usitatissimum, L.) and camelina (Camelina sativa, L.) are ancient crops containing seed oils with a high potential for nutritional, medicinal, pharmaceutical and technical applications. In the present study, linseed and camelina oils of plant varieties grown under Central European climate conditions were examined with respect to their volatile and triacylglycerol (TAG) components. Solid‐phase microextraction was applied to the study of volatile compounds of several linseed and camelina oils, which have not been described prior to this publication. Hexanol (6.5–20.3% related to the total level of volatiles), trans‐2‐butenal (1.3–5.0%) and acetic acid (3.6–3.8%) could be identified as the main volatile compounds in the linseed oil samples. Trans‐2‐butenal (9.8%) and acetic acid (9.3%), accompanied by trans,trans‐3,5‐octadiene‐2‐one (3.8%) and trans,trans‐2,4‐heptadienal (3.6%), dominated the headspace of the examined camelina oil samples. TAG were analysed by MALDI‐RTOF‐MS and ESI‐IT‐MS, providing information about the total TAG composition of the oils as well as the fatty acid composition of the individual components. More than 20 TAG could be identified directly from whole linseed oil samples, mainly composed of linolenic (18:3), linoleic (18:2) and oleic (18:1) acid, and to a lesser degree of stearic (18:0) and palmitic (16:0) acid. While in linseed these TAG comprise more than 60% of the oils, Camelina sativa exhibited a wider range of more than 50 constituents, with a considerable amount (>35%) of TAG containing gadoleic (20:1) and eicosadienoic (20:2) acid.     

Analysis of Triacylglycerols and Free Fatty Acids in Algae Using Ultra-Performance Liquid Chromatography Mass Spectrometry

To assess the suitability of microalgal strains for biodiesel production the lipid content and composition, especially individual triacylglycerols (TAG) and free fatty acids (FFA) must be determined. In this study, the compositions and concentrations of TAG and FFA were analysed in four halophytic algal species, Dunaliella salina, D. tertiolecta, D. bardawil, and D. granulata. These species were selected as part of a larger screen to identify species suitable for biofuel feedstocks. An accelerated solvent extraction instrument was used for lipids and fatty acid extraction using a dichloromethane–hexane solvent system. Ultra-performance liquid chromatography coupled with mass spectrometry (MS) detection was optimized and applied to the quantitative analysis of TAG and FFA in the different algal extracts. Individual TAG were characterized structurally using direct electrospray ionization (ESI) MS and MS/MS techniques. Cationic adducts (NH₄ ⁺) of TAG were detected and quantified in the positive ESI MS and MS/MS modes, while the negative ESI mode was used for FFA analysis. Over 20 TAG were identified and quantified in the four Dunaliella strains. Analysis of FFA compositions demonstrated that the most abundant FFA in these four algal species were palmitic, linolenic, linoleic, and oleic acids.     

Quantification of the Molecular Species of TAG and DAG in Lesquerella (Physaria fendleri) Oil by HPLC and MS

Ten diacylglycerols (DAG) and 74 triacylglycerols (TAG) in the seed oil of Physaria fendleri were recently identified by high‐performance liquid chromatography (HPLC) and mass spectrometry (MS). These acylglycerols (AG) were quantified by HPLC with evaporative light scattering detector and electrospray ionization mass spectrometry of the lithium adducts of the AG in the HPLC fractions of lesquerella oil. The MS¹ ion signal intensities of molecular ions [M + Li]⁺ in HPLC fractions of an HPLC peak were used to estimate the ratios of AG in the HPLC peak. The ratios of TAG with the same mass in HPLC fractions were estimated by the ratios of the sums of MS² ion signal intensities from the neutral loss of the three fatty acids [M + Li ? FA]⁺. The ratio of DAG with the same mass were estimated by the ratio of the sums of two MS² ion signal intensities [M + Li ? FA]⁺ and [FA + Li]⁺ from the two different FA of a DAG. We have estimated the contents of ten molecular species of DAG and 74 molecular species of TAG in P. fendleri oil using this new method. The content of ten DAG combined was about 1 % and 74 TAG was about 98 %. The contents of DAG in decreasing order were: LsLs (0.25 %), LsLn (0.25 %), LsO (0.24 %), and LsL (0.11 %); and the contents of TAG in decreasing order were: LsLsO (31.3 %), LsLsLn (24.9 %), LsLsL (15.8 %), LsL‐OH20:2 (4.3 %), LsO‐OH20:2 (2.8 %), and LsLn‐OH20:2 (2.5 %).     

Mechanisms Underlying Decreased Hepatic Triacylglycerol and Cholesterol by Dietary Bitter Melon Extract in the Rat

In these studies, we focused on finding the mechanism(s) underlying the bitter melon (Momordica charantia L.) methanol fraction (MF)-dependent reduction in the concentration of hepatic triacylglycerol (TAG) and cholesterol in the rat. Rats were fed diets containing low (5 %) fat for 2 weeks (experiment 1), or low (5 %) and high (15 %) fat for a longer period of 8 weeks (experiment 2). MF was supplemented at 1 % level in both experiments. After feeding, rats were sacrificed, and their livers were prepared as slices and hepatocytes, followed by incubation with [1(2)-¹⁴C] acetate or [1-¹⁴C] oleic acid (18:1 n-6). Under these conditions, we found that rats fed diets containing MF, as compared to those without MF, showed: (1) no adverse effects on food intake and growth, (2) a decreased hepatic TAG and total cholesterol, irrespective of the difference in dietary fat level or feeding period, and (3) a decreased incorporation of [1(2)-¹⁴C] acetate and [1-¹⁴C] oleic acid into TAG of liver slices and hepatocytes. MF-supplemented rats also showed no altered incorporation of labeled acetate into cholesterol and cholesterol ester, an increased fecal excretion of neutral steroids, but not of acidic steroids, and an enhanced mRNA abundance of carnitine palmitoylacyltransferase I, which is the rate-limiting enzyme for fatty acid oxidation. These results suggest that dietary MF decreases hepatic TAG synthesis while enhancing fatty acid oxidation, thereby reducing the concentration of hepatic TAG. The liver cholesterol-lowering effect of MF, however, is probably mediated through an increased fecal excretion of neutral steroids, without an effect on cholesterogenesis.     

Comprehensive Identification of Principal Lipid Classes and Tocochromanols in Silkworm (Antheraea pernyi and Bombyx mori) Pupae Oils

A comprehensive identification of lipid compositions and tocochromanols in Antheraea pernyi (A. pernyi) and Bombyx mori (B. mori) pupae oil is reported in the present study. Fatty acid profiling shows that both oils contain high levels (79.67% vs 71.11%) of unsaturated fatty acids, especially linoleic acid and linolenic acid. Moreover, linolenic acid is preferentially enriched at the sn‐2 positions of triacylglycerols (TAGs). Liquid chromatograph‐mass spectrometry (LC‐MS) analysis demonstrates that POO (TAG with one palmitoyl and two oleoyls) is the primary TAG form with percentages of 20.18% in A. pernyi and 15.00% in B. mori. The dominating phospholipid species are phosphatidylcholine (PC, 30.40% vs 54.61%) and phosphatidylethanolamine (PE, 34.82% vs 20.39%). Four sterol constituents with total contents of 382.56 ± 3.12 and 371.65 ± 2.98 µg g^?1 are identified and analyzed quantitatively. Additionally, the levels of tocochromanols (20.15 ± 0.89 vs 17.15 ± 0.71 mg g^?1) are quantified in both silkworm pupae oils. Overall, silkworm oil acts as an enriched source of functional lipids and tocochromanols. Practical Applications: A systematic investigation on the principal lipid classes and tocochromanols of Antheraea pernyi pupae and Bombyx mori pupae oil is reported in this study. The informative data provide supporting evidence for comprehensive utilization of silkworm oil for production of nutritional and healthy products.