Ute Müller

Novel Amide‐Based Molecular Knots: Complete Enantiomeric Separation, Chiroptical Properties, and Absolute Configuration

By comparison of experimental and theoretical CD curves the absolute configurations of chromatographically baseline-separated enantiomers of new trefoil molecular knots could be determined. From the results of syntheses with differently substituted starting materials, conclusions can be drawn about the knot-formation mechanism.

Dendrimers with a 4,4′-bipyridinium core and electron-donor branches. Electrochemical and spectroscopic properties

The synthesis, characterization, and electrochemical and spectroscopic properties of a new family of dendrimers comprising a 4,4′-bipyridinium core and 1,3-dimethyleneoxybenzene-type dendrons are described. The electrochemical results show that there is no significant inhibition of electron transfer involving the dendrimer core by the dendrons. The strong fluorescence of the 1,3-dimethyleneoxybenzene units of the branches is completely quenched as a result of charge-transfer interactions with the core.

Physiological and conjugated linoleic acid-induced changes of adipocyte size in different fat depots of dairy cows during early lactation

The aim of this study was to investigate the effects of lactation and conjugated linoleic acid (CLA) supplementation on adipocyte sizes of subcutaneous (s.c.) and visceral (VC) fat depots in primiparous dairy cows during the first 105 d in milk (DIM). German Holstein heifers (n=25) were divided into a control (CON) and a CLA group. From 1 DIM until sample collection, CLA cows were fed 100g of CLA supplement/d (about 6% of c9,t11 and t10,c12 isomers each), whereas the CON cows received 100g of fatty acid mixture/d instead of CLA. The CON cows (n=5 each) were slaughtered at 1, 42, and 105 DIM, and the CLA cows (n=5 each) were slaughtered at 42 and 105 DIM. Adipose tissues from 3s.c. depots (tailhead, withers, and sternum) and from 3 VC depots (omental, mesenteric, and retroperitoneal) were sampled. Hematoxylin-eosin staining was done to measure adipocyte area (μm(2)). Retroperitoneal adipocyte sizes were mostly larger than adipocytes from the other sites, independent of lactation time and treatment. Significant changes related to duration of lactation were limited to retroperitoneal fat: adipocyte sizes were significantly smaller at 105 DIM than at 1 DIM in CON cows. Adipocyte sizes were decreased in s.c. depots from the tailhead at 105 DIM and from the sternum at 42 DIM in CLA versus CON cows, whereas for VC depots, adipocyte sizes were decreased in mesenteric fat at 42 and 105 DIM, and in omental and retroperitoneal fat, at 105 DIM in CLA versus CON cows. Within the CLA group, adipocyte sizes were smaller in the s.c. depot from the tailhead at 105 DIM than at 42 DIM. Adipocyte sizes and depot weights were significantly correlated in s.c. depots (r=0.795) in the CLA group and in retroperitoneal fat both in the CON (r=0.698) and the CLA (r=0.723) group. In conclusion, CLA-induced decreases in adipocyte size indicate lipolytic or antilipogenic effects of CLA, or both effects, on adipose tissue in primiparous dairy cows.

Bovine haptoglobin as an adipokine: Serum concentrations and tissue expression in dairy cows receiving a conjugated linoleic acids supplement throughout lactation

The present study aimed to characterize serum haptoglobin (Hp) concentrations throughout an entire lactation period in both primi- and multiparous cows and to compare them to the Hp mRNA expression in liver and - in view of Hp being potentially an adipokine - also in different subcutaneous (s.c.) and visceral fat depots. In addition, potential anti-inflammatory effects of long-term supplementation with conjugated linoleic acids (CLA) were evaluated by assessing Hp. Trial 1 comprised 33 cows and 16 Holstein heifers from day 21 ante partum until day 252 postpartum. The animals received 100 or 50 g/day CLA or a control fat supplement. Blood samples and biopsy (tail head fat and liver) samples were collected. Trial 2 included 25 Holstein heifers, 5 animals were slaughtered on the day of parturition, the remaining animals were allocated to either CLA (100 g/day, n=10) or control fat supplement (n=10) and slaughtered on days 42 and 105 postpartum, respectively. At slaughter, fat samples were collected from 3 different visceral depots, 3 s.c. depots and from liver tissue. Results indicated no effects of CLA on serum Hp and liver Hp mRNA for both trials and on Hp mRNA in biopsies from s.c. tail head fat. In omental and s.c. withers fat from trial 2, CLA reduced Hp mRNA on both day 42 and day 105. Hp mRNA was detectable in fat tissues from both trials with abundance values being significantly lower than in liver. The Hp mRNA abundance in the s.c. fat depots was generally higher than in the visceral depots. Haptoglobin mRNA abundance in the different tissues from trial 2 was correlated whereby all s.c. depots were interrelated. The evidence of Hp mRNA expression in adipose tissues and the presence of Hp-immune staining in histological fat sections confirm that Hp can be classified as a bovine adipokine. The lack of an evident relationship between circulating Hp concentrations and normal body fat portions in dairy cattle demonstrates that varying degrees of adiposity are not confounding factors when using Hp as inflammatory marker. The physiological changes in serum Hp concentration seem to be limited to parity and parturition. In view of the lack of effects of CLA on serum Hp concentrations, the observed reaction in two out of six different fat depots seems of marginal importance for the organisms as an entity.

Chlamydophila species in dairy farms: Polymerase chain reaction prevalence, disease association, and risk factors identified in a cross-sectional study in western Germany

The prevalence of Chlamydophila spp. was determined in a cross-sectional study carried out in 2007 using 100 randomly selected dairy herds in the western part of Germany. Ten dairy cows per herd were sampled in herds with fewer than 100 cows; in bigger herds, 10% of the cows were sampled. For the detection of Chlamydophila spp., vaginal swabs from early lactating dairy cows were analyzed using an established highly sensitive genus-specific real-time PCR. In consideration of the discontinuous shedding of the pathogen, a herd was classified as positive if at least 1 animal per herd tested positive for Chlamydophila spp. By use of these methods and definitions, 61% of the dairy herds and 13.5% of the cows were detected as PCR-positive for Chlamydophila spp., which is indicative for ongoing infections. To compare herd health and herd performance between herds testing positive or negative and to identify risk factors for the presence of Chlamydophila spp., a questionnaire was designed to evaluate farm characteristics and management practices. In addition, the performance recordings of the state dairy recording organization were used for these purposes. Milk yield, number of lactations, and calving to first-service interval were lower in herds testing positive for Chlamydophila spp. compared with negative herds. For all these variables, there was no interaction between Chlamydophila status and lactation number. Replacement of animals from outside sources, use of breeding bulls, lack of separate calving pens, and low scores for cleanliness of beddings, walkways, and cows were identified as the main risk factors for Chlamydophila spp.

Quaternary Tröger bases as new inclusion hosts; the first X-ray structures of a Tröger base and of a dioxane clathrate

New clathrates of various onium salts (2)–(5), (7), and (8)of the Troger bases (1) and (6) are described, including X-ray structures of the free host (6), and of an inclusion compound of (2b) with dioxane.

Corynebacterium frankenforstense sp. nov. and Corynebacterium lactis sp. nov., isolated from raw cow milk

Two groups of Gram-stain positive, aerobic bacterial strains were isolated from raw cows milk, from a milking machine and from bulk tank milk. Based on their 16S rRNA gene sequences these isolates formed two distinct groups within the genus Corynebacterium. The sequence similarities of the isolates to the type strains of species of the genus Corynebacterium were below 98.4%. The presence of menaquinones MK-8(H2) and MK-9(H2), the predominant fatty acid 18:1 cis 9 and a polar lipid pattern with several phospholipids but without aminolipids was in accord with the characteristics of this genus. The results of DNA-DNA hybridization, biochemical tests and chemotaxonomic properties allowed genotypic and phenotypic differentiation of the strains from all known species of the genus Corynebacterium. Therefore, the isolates were assigned to two novel species of this genus for which the names Corynebacterium frankenforstense sp. nov. (type strain ST18(T) =DSM 45800(T) = CCUG 63371(T)), and Corynebacterium lactis sp. nov. (type strain RW2-5(T) = DSM 45799(T) = CCUG 63372(T)) are proposed, respectively.

Trans-Cinnamic Acid Increases Adiponectin and the Phosphorylation of AMP-Activated Protein Kinase through G-Protein-Coupled Receptor Signaling in 3T3-L1 Adipocytes

Adiponectin and intracellular 5′adenosine monophosphate-activated protein kinase (AMPK) are important modulators of glucose and fat metabolism. Cinnamon exerts beneficial effects by improving insulin sensitivity and blood lipids, e.g., through increasing adiponectin concentrations and AMPK activation. The underlying mechanism is unknown. The Gi/Go-protein-coupled receptor (GPR) 109A stimulates adiponectin secretion after binding its ligand niacin. Trans-cinnamic acid (tCA), a compound of cinnamon is another ligand. We hypothesize whether AMPK activation and adiponectin secretion by tCA is transmitted by GPR signaling. Differentiated 3T3-L1 cells were incubated with pertussis toxin (PTX), an inhibitor of Gi/Go-protein-coupling, and treated with different tCA concentrations. Treatment with tCA increased adiponectin and the pAMPK/AMPK ratio (p ≤ 0.001). PTX incubation abolished the increased pAMPK/AMPK ratio and adiponectin secretion. The latter remained increased compared to controls (p ≤ 0.002). tCA treatment stimulated adiponectin secretion and AMPK activation; the inhibitory effect of PTX suggests GPR is involved in tCA stimulated signaling.

Lactation driven dynamics of adiponectin supply from different fat depots to circulation in cows

Adipose tissue (AT) depots are heterogeneous in terms of morphology and adipocyte metabolism. Adiponectin, one of the most abundant adipokines, is known for its insulin sensitizing effects and its role in glucose and lipid metabolism. Little is known about the presence of adiponectin protein in visceral (vc) and subcutaneous (sc) AT depots. We assessed serum adiponectin and adiponectin protein concentrations and the molecular weight forms in vc (mesenterial, omental, and retroperitoneal) and sc (sternum, tail-head, and withers) AT of primiparous dairy cows during early lactation. Primiparous German Holstein cows (n = 25) were divided into a control (CON) and a conjugated linoleic acid (CLA) group. From day 1 of lactation until slaughter, CLA cows were fed 100 g of a CLA supplement/d (approximately 6% of cis-9, trans-11 and trans-10, cis-12 isomers each), whereas the CON cows received 100 g of a fatty acid mixture/d instead of CLA. Blood samples from all animals were collected from 3 wk before calving until slaughter on day 1 (n = 5, CON cows), 42 (n = 5 each of CON and CLA cows), and 105 (n = 5 each of CON and CLA cows) of lactation when samples from different AT depots were obtained. Adiponectin was measured in serum and tissue by ELISA. In all AT depots adiponectin concentrations were lowest on day 1 than on day 42 and day 105, and circulating adiponectin reached a nadir around parturition. Retroperitoneal AT had the lowest adiponectin concentrations; however, when taking total depot mass into consideration, the portion of circulating adiponectin was higher in vc than sc AT. Serum adiponectin was positively correlated with adiponectin protein concentrations but not with the mRNA abundance in all fat depots. The CLA supplementation did not affect adiponectin concentrations in AT depots. Furthermore, inverse associations between circulating adiponectin and measures of body condition (empty body weight, back fat thickness, and vc AT mass) were observed. In all AT depots at each time, adiponectin was present as high (approximately 300 kDa) and medium (approximately 150 kDa) molecular weight complexes similar to that of the blood serum. These data suggest differential contribution of AT depots to circulating adiponectin.

Synthesis of highly phenylene substituted p-phenylene oligomers from pyrylium salts

A transition metal free route to phenyl substituted oligophenylenes that tolerates halogens is described.