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Fragments of buckminsterfullerene (C60) include the monumental three compounds corannulene, sumanene, and truxene. These three have served as leading molecules in ongoing research for curved, fused, and π‐extended polyaromatic materials. Achieving more structural variations that join the ranks of these three archetypes remains challenging. Herein we report synthesis of an octacyclic hydrocarbon that is an unexplored C60‐fragment, namely, a 4,11‐dihydrodiindeno[7,1,2‐ghi:7′,1′,2′‐pqr]chrysene (C28H16, which we named Metelykene). The key to success was solution‐compatible synthesis in which double pentagonal rings flank hexagonal ones. This solution‐phase approach, coupled with the resulting non‐planar π‐conjugation, is so straightforward that it offers an entry to a derivative such as a cardo aromatic monomer. [ABSTRACT FROM AUTHOR]

Syntheses of inwardly and outwardly directed allylsilanes those are tethered to new inherently chiral cavitands are described. Oxidized with mCPBA, these allylsilanes result in diastereomeric mixtures of epoxide molecules. Thus, it enables us to have comparative study of cavitand‐structure diastereoselectivity relationship, which revealed that an inward allylsilane group flanked by a dibenzo[f, h]quinoxaline and two bridged methylene groups have the best chemical yield and diastereoselection. [ABSTRACT FROM AUTHOR]

Supramolecular cavitands that contain inwardly directed functional groups have yielded specialized transformations and trapping of reactive intermediates. A recently reported 3‐wall Au cavitand provides exciting opportunities for supramolecular catalysis. In this study, a variety of substituted γ‐alkynoic acids were reacted to give lactones. The interaction of peripheral "R" groups revealed differential catalyst behavior. Extremely large and small groups reacted with appreciable rate. Intermediate sized groups however, slowed significantly: giving support that size‐specific binding is at play when using cavitands as a scaffold for gold catalysis. These results serve as some of the first evidence of the interplay between substrate and cavitand interior in the catalytic sphere. [ABSTRACT FROM AUTHOR]

Keywords: arenes; cardo molecules; dibenzo[g,p]chrysenes; C60 fragments; polycycles EN arenes cardo molecules dibenzo[g,p]chrysenes C60 fragments polycycles 1 1 1 09/05/23 20230901 NES 230901 B The Cover Feature b shows a new C SB 60 sb fragmentary octacycle having six hexagons and two pentagons. Cover Feature: Synthesis of an Octacyclic C60 Fragment (Eur. J. Org. Arenes, cardo molecules, dibenzo[g,p]chrysenes, C60 fragments, polycycles. [Extracted from the article]

The effect of a metallocatalytic cavity flanked by aromatic rings on the catalytic dimerization of terminal alkynes was explored through a comparison with model catalysts that weakened the cavity. The diquinoxaline-spanned resorcin[4]arene provided a definite compartment, in which the two Au centers enticed two alkynes to undergo the coupling reaction. We synthesized two kinds of model compounds in which one lacked two quinoxaline walls and the other had two pyrazine walls and found that these catalysts exhibited much lower reactivity. The two quinoxaline moieties proved to be quintessential for the catalytic event. [ABSTRACT FROM AUTHOR]

A preparative synthesis of an inwardly oriented phosphoramidite-Au dinuclear resorcinarene cavitand complex is described, including a description of potent catalytic abilities. The cavitand structure was determined by crystallographic analysis, which revealed that the phosphoramidite P-N bonds point outside placing the two Au atoms inside. We explored the catalytic proclivity of the cavitand and found that it effeciently catalyzes selective and direct dimerization of terminal alkynes to afford conjugated enynes. Mixed dimerizations give rise to chemoselective products, and macrocyclization by intramolecular dimerization are both trademark capabilities of the method. [ABSTRACT FROM AUTHOR]

A preparative synthesis of an inwardly directed phosphoramidite-Au complex is described and a description of some of its catalytic performance. The molecular structure was determined by crystallographic analysis, which disclosed that the phosphoramidite ligand points 'out' and places the complexed Au 'in'. We investigated its catalytic activities and found that the inwardly directed Au is surrounded by three inert walls that provide new opportunities for supramolecular catalysis and study of reactive intermediates. [ABSTRACT FROM AUTHOR]

Lower rim carboxylic acid calix[n]arenes and upper rim phosphonic acid functionalized calix[4]arenes effect selective transport of distinct molecular payloads through a liquid membrane. The secret to this success lies in the attachment of a receptor-complementary handle. We find that the trimethylammonium ethylene group present in choline is a general handle for the transport of drug and drug-like species. Furthermore, neurotransmitters possessing ionizable amine termini are also transported. Some limitations to this strategy have been uncovered as payloads become increasingly lipophilic. These developments reveal new approaches to synthetic receptor-mediated selective small molecule transport in vesicular and cellular systems. [ABSTRACT FROM AUTHOR]

A series of supramolecular calixarenes efficiently transport distinct molecular species through a liquid membrane when attached to a receptor-complementary choline handle. Calix[6]arene hexacarboxylic acid was highly effective at transporting different target molecules against a pH gradient. Both carboxylic- and phosphonic-acid-functionalized calix[4]arenes effect transport without requiring a pH or ion gradient. NMR binding studies, two-phase solvent extraction, and three-phase transport experiments reveal the necessary and subtle parameters to effect the transport of molecules attached to a choline 'handle'. On the other hand, rescorin[4]arene cavitands, which have similar guest recognition profiles, did not transport guest molecules. These developments reveal new approaches towards attempting synthetic-receptor-mediated selective small-molecule transport in vesicular and cellular systems. [ABSTRACT FROM AUTHOR]

Riboflavin, also known as vitamin B2, is converted by riboflavin kinase (RFK) into flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential cofactors of dehydrogenases, reductases, and oxidases including the phagocytic NADPH oxidase 2 (Nox2). Riboflavin deficiency is common in young adults and elderly individuals, who are at the coincidental risk for listeriosis. To address the impact of acute riboflavin deficiency on host defense against Listeria monocytogenes (L.m.), we generated conditional RFK knockout (KO) strains of mice. Phagocyte-specific RFK KO impaired the capability of phagocytes to control intracellular L.m., which corresponded to a greater susceptibility of mice to in vivo challenge with L.m. The oxidative burst of RFK-deficient phagocytes in response to L.m. infection was significantly reduced. Mechanistically, TNF-induced priming of Nox2, which is needed for oxidative burst, was defective in RFK-deficient phagocytes. Lack of riboflavin in wild-type macrophages for only 6 h shut down TNF-induced, RFK-mediated de novo FMN/FAD generation, which was accompanied by diminished ROS production and impaired anti-listerial activity. Vice versa, ROS production by riboflavin-deprived macrophages was rapidly restored by riboflavin supplementation. Our results suggest that acute riboflavin deficiency immediately impairs priming of Nox2, which is of crucial relevance for an effective phagocytic immune response in vivo. [ABSTRACT FROM AUTHOR]

The bromide profile of the bedded Zechstein 2 rock salts in the Southern Permian Basin is characterized by a continuous increase in the bromide contents from base to top, indicating progressive evaporation of sea water. Former studies have suggested that the bromide distribution in domal salts is more irregular, raising such questions as whether there is a causal relationship between bromide distribution and deformation-related processes or whether various halite types with different primary bromide contents account for such irregularities. In this study, the bromide distribution of a defined stratigraphic section (Hauptsalz) of the Zechstein 2 was investigated in three salt deposits, with bedded salt (Teutschenthal) compared with domal salts (Morsleben and Gorleben). Furthermore, two different halite types ( Kristallbrocken, matrix) were distinguished during sampling. Comparison between the locations reveals that: (i) the characteristic trend of the bromide profile was generally preserved in both the bedded and the more intensely deformed domal salts; (ii) the dispersion of bromide contents along the running average curve is lower in domal salt, especially in the lower half of the Hauptsalz; and (iii) the Kristallbrocken are absent in the lower half of the Hauptsalz of Morsleben and Gorleben. The absence of the Kristallbrocken and the lower dispersion of the bromide contents in the domal salts are clear indications for the influence of salt migration-related processes on the bromide distribution characteristics. It shows that these processes are associated with a redistribution of bromide, which eventually results in a homogenization of the originally varying bromide contents. On the other hand, preservation of the characteristic trend in the bromide profiles indicates that large-scale brecciation, folding processes or circulating bromide-rich fluids played only a minor role during the formation of the salt domes. Selective sampling of the Kristallbrocken and matrix halite displays a disparity in bromide content that is not consistent between the studied locations. These specific phenomena might be related to different depositional locations in the Zechstein Basin or to post-depositional processes. [ABSTRACT FROM AUTHOR]

Preparations of β-adrenergic receptor and Gs from turkey erythrocytes were delipidated by previously developed procedures. Three synthetic phospholipids, dioteoylglycerophosphoethanolamine, dioleoylglycerophosphocholine and dioleoylglycerophosphoserine plus an unphosphorylated lipid, were all required to restore receptor-mediated activation of Gs by GTP[γS]. The same lipids were necessary for the reconstitution of the isoproterenol-enhanced GTPase. The requirement for the unphosphorylated lipid could be fulfilled by l-monooleoyl glycerol, α-tocopherol or oleic acid. Cholesterol hemisuccinate further enhanced the receptor-mediated activity of the relipidated system when present in addition to the lipids specified above. Cholesterol hemisuccinate had no effect on the basal rate of Gs activation and depressed the basal GTPase. It is therefore suggested that cholesterol hemisuccinate affects the receptor or the coupling of the receptor to Gs.
In the system relipidated with the three dioleoyl phospholipids, plus α-tocopherol and cholesterol hemisuccinate, the initial rate of Gs activation per mole receptor appeared to be considerably higher than in the native turkey erythrocyte membrane. [ABSTRACT FROM AUTHOR]

Detergent-solubilized preparations of the β-adrenergic receptor (R) and of the guanyl nucleotide binding proteins (Gs) were extensively treated to remove phospholipids and cholesterol. Reconstitution of an R-Gs system was subsequently performed in the presence of a mixture of natural phosphatidylethanolamine, phosphatidylcholine and phosphatidylserine or the synthetic dioleoyl derivatives of the same phospholipids. In both cases, an additional lipid was required for the agonist-dependent activation of Gs. The requirement could be fulfilled by α-tocopherol, or by unsaturated fatty acids such as oleic acid. Inclusion of this non-phosphorylated lipid in the reconstituted system enhanced the isoproterenol-dependent activation of Gs by guanosine 5'-O-[γ-thio]triphosphate 16-33-fold. The rate of activation was largely dependent on the addition of the agonist. Efficient functional reconstitution of R-Gs was thus achieved in a totally defined lipid system. Additional studies of the reconstituted system and of the native membrane led to the notion that the non-phosphorylated lipid plays a role in the function of the hormone-R complex. [ABSTRACT FROM AUTHOR]

Rat parotid gland slices showed a very slow rate of glucose utilization and lactic acid production, both in the presence and in the absence of oxygen. Epinephrine, which caused rapid enzyme secretion by the slices did not affect the low rate of glycolysis. A rough calculation indicates that in the parotid gland ATP is produced by oxidative phosphorylation 50 times faster than by glycolysis. The mitochondria, when isolated and tested in presence of EDTA or EGTA showed respiratory activity and respiratory control comparable to those of liver mitochondria. Adenosine 3':5'-cyclic phosphate, which is an intermediate in induction of enzyme secretion, showed no clear-cut effect on the functions of the parotid mitochondria. Isolation of the mitochondria in the absence of the above chelators yielded a preparation which was almost depleted of NAD, respired feebly on NAD linked substrates and showed no respiratory control. Addition of NAD+ restored respiration. The damage caused to these mitochondria during isolation was attributed to the high calcium concentrations found in the gland. Addition of small amounts of free calcium to functional parotid mitochondria indeed caused the loss of NAD and the decline of respiration. Tested in parallel experiments, liver mitochondria were much more resistant to added calcium. Their initial calcium content was one tenth that of the parotid mitochondria. The control of calcium distribution in the parotid gland and the possible functions of calcium are discussed. [ABSTRACT FROM AUTHOR]

The influence of mechanical stress on field effect transistors is investigated using a pressure‐deflected membrane for generation various mechanical stresses. It consists of a silicon membrane and transistors, which are designed and manufactured using 1.0 μm‐XC10 technology from X‐Fab. The transducers for sensing mechanical stress are placed on the edges with the maximum stress. Furthermore, the position is optimized by using FEM simulations (Ansys). Different variances of transistors and the impact on their electrical properties are investigated. Transistors are manufactured with different parameters such as channel lengths, widths, and alignments of the channel current to the direction of the mechanical stress, as well as connecting transistors in Wheatstone‐like quarter and half bridges to generate a read‐out voltage that is amplified using an integrated operational amplifier on the same chip. The bridge consists of p‐MOSFETs as transducers on the membrane and n‐MOSFETs as reference transistors (active loads). Transistors bridges are optimized on sensitivity, linearity and temperature behavior by varying channel length (L) and width (W). The influence of the membrane size and deposited technology layers is also investigated. The focus of this publication is presenting an analysis of the electrical behavior of the designed and manufactured transistors for different applied pressures. An experimental setup with a temperature and pressure calibrators is used for characterizing the transducers between 25 and 75 °C and up to 1 bar differential pressure. [ABSTRACT FROM AUTHOR]

The desymmetrization of meso epoxide (I) with nitrogen or oxygen nucleophiles is developed by using Jacobsen-type catalysts. [ABSTRACT FROM AUTHOR]