Lipids

Ingestion of 2 g of supplemental dietary calcium carbonate daily over a period of one year by eight hyperlipemic men and two hyperlipemic women caused a significant 25% decrease in serum cholesterol, after these subjects had shown stable levels for the previous year, and when compared to a group without therapy. Body weights for both groups remained stable throughout the period of observation. The experimental group also showed a reversal in the cholesterol-phospholipid ratio from a preexperimental ratio of 1.04 to a ratio of 0.92. In addition there was a 113 mg per 100 ml decrease in serum triglycerides and a 48 mg per 100 ml decrease in serum phospholipids, but these were not statistically significant due to the large between individual variations and the limited sample size. Calcium carbonate should be considered as a potential agent for usage in long term studies designed to produce hypolipemia, since it appears to be effective and without significant side effects.

Thin layer chromatographic and gas chromatographic separation and mass spectrometric identification of mycolic acid subclasses and molecular species from eight strains ofMycobacterium smegmatis were established. Two major adjacent spots and a lower minor one were detected on silica gel thin layer chromatograms of methyl esters. The most abundant subclass showing the highest Rf value on TLC was that of α-mycolic acids (M1), the second was that of α′-mycolic acids (M1′) a shorter homologue than α-mycolates, and the third was the hydroxy mycolic acids (M4) derived from epoxy mycolic acids. They were identified by gas chromatography-mass spectrometry as their trimethylsilylether derivatives. α′-Mycolic acids were monoenoic acids ranging from C60 to C66 and possessing an α-unit of C24∶0. Such profiles of α′-mycolic acids were common in eight strains. α-Mycolates were dienoic acids ranging from C75 to C79 and possessing an α-unit of C24∶0. In most strains, the major molecular species of α-mycolates were odd-carbon-numbered, centering at C77 and C79, possessing a methyl branch in the even-carbon-numbered straight chain. The average carbon number of α-mycolates, from seven strains examined, was about 78, but that of the Takeo strain was 76.3. The profiles of epoxy mycolic acid molecular species composition from eight strains ranging from C75 to C81 were very similar to their M1 subclass profiles.

X-Ray diffraction analyses can determine chemical composition, molecular formula and stereoconfiguration and can provide geometric parameters with uncertainties for bond distances of the order of 0.01 Å and for bond angles of the order of 1°. These analyses are especially useful when the substance analyzed is present only in very small quantities and is of uncertain composition or molecular formula. Only one suitable crystal is required for the analysis to proceed. There are many instances in which such circumstances have prevailed in the diffraction analysis of steroids. Among the examples given here is a new type of natural plant hormone with profound growth-stimulating capabilities when applied in nanogram quantities per plant. The structure determination of this substance has greatly facilitated attempts to synthesize it and thereby to derive sufficient quantities for widespread testing.

Fatty acids (FAs) are essential components of cell membranes and play an integral role in membrane fluidity. The lipophilic index [LI, defined as the sum of the products between FA levels and melting points (°C), divided by the total amount of FA: $${\text{LI}} = \frac{{\mathop \sum \nolimits_{k} [{\text{fatty acid}} \times {\text{melting point}}]}}{{\mathop \sum \nolimits_{k} {\text{fatty acid}} }}$$ ] is thought to reflect membrane and lipoprotein fluidity and may be associated with the risk of coronary heart disease (CHD). Therefore, we examined the associations of dietary and plasma phospholipid (PL) LI with CHD risk among postmenopausal women. We determined dietary LI for the cohort with completed baseline food frequency questionnaires and free of prevalent cardiovascular diseases in the Women’s Health Initiative (WHI) observational study (N = 85,563). We additionally determined plasma PL LI in a matched case-control study (N = 2428) nested within the WHI observational cohort study. Cox proportional hazard regression and multivariable conditional logistic regression were used to calculate HRs/ORs for CHD risk between quartiles of LI after adjusting for potential sources of confounding and selection bias. Higher dietary LI in the cohort study and plasma PL LI in the case-control study were significantly associated with increased risk of CHD: HR = 1.18 (95% CI 1.07–1.31, P for trend <0.01) and OR = 1.76 (95% CI 1.33–2.33, P for trend <0.01) comparing extreme quartiles and adjusting for potential confounders. These associations still persisted after adjusting for the polyunsaturated to saturated fat ratio. Our study indicated that higher LI based on either dietary or plasma measurements, representing higher FA lipophilicity, was associated with elevated risk of CHD among postmenopausal women.

The acute toxicity of saturatedn-alkylhydroxamic acids to salmon (Salmo salar) fry was determined. Within the seriesn-C6H13CONHOH ton-C10H21CONHOH, acute toxicity (indicated by death) increased with chain length. Shorter and longer chain compounds were not toxic under similar conditions. Factors governing the variation in toxicity with chain length and possible mechanisms of action are discussed.

Lipogenesis is the process by which fatty acids are synthesized. In metabolic syndrome, an insulin resistant state along with high plasma levels of free fatty acids (FFA) and hyperglycemia may contribute to the lipogenic process. The aim of the present study was to investigate the effects of oral administration of metformin on the expression of lipogenic genes and glycemic profile in mice fed with low-carbohydrate high-fat diet by evaluating their metabolic profile. SWISS male mice were divided into 4 groups (N = 7) that were fed with standard (ST), standard plus metformin (ST + MET), low-carbohydrate high-fat diet (LCHFD) and low-carbohydrate high-fat diet plus metformin (LCHFD + MET) (100 mg kg−1 diet) diets respectively. Food intake, body weight and blood parameters, such as glucose tolerance, insulin sensitivity, glucose, HDL-c, total cholesterol, triglycerides, ASL and ALT levels were assessed. Histological analyses were performed on hematoxylin and eosin-stained epididymal adipose tissue histological specimens. The expression levels of peroxisome proliferator-activated receptor (PPARγ), sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), were assessed by RT-PCR. This study showed that metformin decreased adipocyte area, body weight and food consumption in obese animals when compared to the standard group. Furthermore, the expression of lipogenic markers in adipose tissue were diminished in obese animals treated with metformin. This data showed that oral administration of metformin improved glucose and lipid metabolic parameters in white adipose tissue by reducing the expression of lipogenesis markers, suggesting an important clinical application of MET in treating obesity-related diseases in metabolic syndrome.