Investigations of excited‐state redox processes have an exceptional impact on the field of organic photochemistry and its application to the synthesis of complex target molecules. In such a ...photochemical process a single‐electron transfer takes place to produce ion‐radical intermediates, if the reduction and oxidation potentials, as well as excited‐state energies of electron donors and acceptors are chosen appropriately. The Witkop cyclization constitutes an intramolecular variant of such a process, typically with an indole heterocycle as an electron donor. The specific synthetic value of this reaction lies in a CC bond formation without requiring any prefunctionalization of the indole system. Although this photoreaction has been applied to the total synthesis of natural products, it has still not been used to its full capacity. The following review details synthetic efforts using the Witkop cyclization, and aims to incite further applications of reaction in the synthesis of complex molecular architectures.
To wit: The title reaction resembles a photoinduced electron‐transfer process, and allows the direct formation of medium‐sized lactams by CH activation of the indole nucleus. Therefore it is a versatile tool for the construction of polycyclic indole alkaloid scaffolds.
A short stereoselective synthesis of the Elisabethin A skeleton 4 is described, which opens a formal access to the diterpenes Elisapterosin B and Colombiasin A as well. Key reactions were an ...intermolecular endo-selective Diels-Alder reaction to generate the decalin part of the molecule, a chemo- and diastereoselective allylation of an aldehyde with allylzinc, a palladium ene annulation of the cyclopentane ring, and a novel sulfonium ylide induced fragmentation of a polycyclic ketone. Additional insights have been gained for the crucial epimerization at C-2.
Due to the COVID-19 pandemic, European elite football (a.k.a. soccer) leagues played the remaining season 2019/20 without or strongly limited attendance of supporters (i.e., “ghost games”). From a ...sport psychological perspective this situation poses a unique opportunity to investigate the crowd's influence on referee decisions and the associated effect of “home advantage.” A total of 1286 matches–played in the top leagues of Spain, England, Germany, Italy, Russia, Turkey, Austria and the Czech Republic–were analyzed for results, fouls, bookings and reasons for bookings and contrasted between respective matchdays of season 2018/19 (regular attendance) and season 2019/20 (ghost games). Following recent methodological developments in the research on the home advantage effect, four different statistical analyses–including Pollard's traditional method–were used for the assessment of the home advantage effect. There are two main findings. First, home teams were booked significantly more often with yellow cards for committing fouls in ghost games. Most importantly, this effect was
independent
of the course of the games. In contrast, bookings for other reasons (criticism and unfair sportsmanship) changed similarly for
both
home and away teams in ghost games. Second, the overall home performance and home advantage effect in the respective elite leagues–identified in the respective matches of the regular 2018/19 season–vanished in the ghost games of the 2019/20 season. We conclude that the lack of supporters in top European football during the COVID-19 pandemic led to decreased social pressure from the ranks on referees, which also had a potential impact on the home advantage. Referees assessed the play of home teams more objectively, leading to increased yellow cards awarded for fouls committed by the home teams. Since there were no significant changes in referee decisions against the away teams, we argue that our observations reflect a reduction of unconscious favoritism of referees for the home teams.
A gene coding for galactose 6-oxidase from Fusarium oxysporum G12 was cloned together with its native preprosequence and a C-terminal His-tag, and successfully expressed both in Escherichia coli and ...Pichia pastoris. The enzyme was subsequently purified and characterized. Among all tested substrates, the highest catalytic efficiency (kcat/Km) was found with 1-methyl-β-D-galactopyranoside (2.2 mM(-1) s(-1)). The Michaelis constant (Km) for D-galactose was determined to be 47 mM. Optimal pH and temperature for the enzyme activity were 7.0 and 40°C, respectively, and the enzyme was thermoinactivated at temperatures above 50°C. GalOx contains a unique metalloradical complex consisting of a copper atom and a tyrosine residue covalently attached to the sulphur of a cysteine. The correct formation of this thioether bond during the heterologous expression in E. coli and P. pastoris could be unequivocally confirmed by MALDI mass spectrometry, which offers a convenient alternative to prove this Tyr-Cys crosslink, which is essential for the catalytic activity of GalOx.
The phenomenon of home advantage (home bias) is well-analyzed in the scientific literature. But only the COVID-19 pandemic enabled studies on this phenomenon—for the first time in history—on a global ...scale. Thus, several studies to date examined the effects of empty stadiums by comparing regular matches (with supporters) before the COVID-19 restrictions with so-called ghost games (games without supporters) during the pandemic. To synthesize the existing knowledge and offer an overview regarding the effects of ghost games on home advantage we provide a systematic literature review on this topic. Our findings—based on 26 primary studies—indicate that ghost games have a considerable impact on the phenomenon of home advantage. Deeper analysis further indicates that this effect is based on a reduced “referee bias” and a lack of “emotional support from the ranks”. From a psychological perspective, we argue that our conclusions are highly relevant by emphasizing decision making under pressure and crowd-induced motivation in sports. From a socio-economic perspective, we argue that our findings legitimize a discussion regarding compensation of fans after sporting success as plausible and worth considering. Thus, our results are significant for scientists, sports and team managers, media executives, fan representatives and other persons responsible in the football industry.
Mouth-to-nose face masks became ubiquitous due to the COVID-19 pandemic. This ignited studies on the perception of emotions in masked faces. Most of these studies presented still images of an ...emotional face with a face mask digitally superimposed upon the nose-mouth region. A common finding of these studies is that smiles become less perceivable. The present study investigated the recognition of basic emotions in video sequences of faces. We replicated much of the evidence gathered from presenting still images with digitally superimposed masks. We also unearthed fundamental differences in comparison to existing studies with regard to the perception of smile which is less impeded than previous studies implied.
The metabolite α-hydroxybutyrate (α-HB) is an important marker of insulin resistance and impaired glucose tolerance allowing to identify patients at risk of developing diabetes and related metabolic ...disorders before any symptoms become apparent. At present, its exact quantification requires mass spectrometry (LC-MS), which is not compatible with routine laboratory use. Accordingly, a simple enzymatic-based method was assessed and its applicability and measuring accuracy compared with LC-MS was investigated.
Standards, serum, and plasma samples containing α-HB were prepared with routine procedures and their α-HB contents measured with the XpressGT® enzymatic test kit photometrically or with LC-MS and multiple reaction monitoring.
α-HB detection with XpressGT® yielded highly linear calibration curves and 102 % recovery of stocks added to commercial samples. Stability of the analyte in serum and plasma samples prepared with various anti-coagulants was >90 % after 46 h for several widely used preparations and recovery after 3 freeze-thaw cycles was ≥95 % with these anti-coagulants. A direct comparison of 75 samples indicated very good agreement of α-HB levels determined by both methods, 86 % of XpressGT® samples being within ±20 % of LC-MS values and even 93 % within ±20 % considering only samples above 30 μM concentration.
XpressGT®-based detection of α-HB is an easily applicable method which can be used for accurate and reliable quantification of the metabolite in clinical practice. Routine α-HB determination in patients at risk of developing diabetes would allow early establishment of preventive measures or pharmacological intervention reducing the risk for the onset of serious diabetes-related health problems.
•α-hydroxybutyrate (α-HB) is an important early marker of insulin resistance and impaired glucose tolerance.•Currently applied reliable quantitation of the metabolite by LC-MS is not compatible with routine laboratory use.•The enzymatic-based novel XpressGT® kit is presented and its applicability and measuring accuracy compared with LC-MS.•XpressGT® enabled accurate and reliable quantification of α-HB and easy and scalable detection with routine lab equipment.
Chinese hamster ovary (CHO) cells are currently the workhorse of the biopharmaceutical industry. However, yeasts such as Pichia pastoris are about to enter this field. To compare their capability for ...recombinant protein secretion, P. pastoris strains and CHO cell lines producing human serum albumin (HSA) and the 3D6 single chain Fv‐Fc anti‐HIV‐1 antibody (3D6scFv‐Fc) were cultivated in comparable fed batch processes. In P. pastoris, the mean biomass‐specific secretion rate (qp) was 40‐fold lower for 3D6scFv‐Fc compared to HSA. On the contrary, qp was similar for both proteins in CHO cells. When comparing both organisms, the mean qp of the CHO cell lines was 1011‐fold higher for 3D6scFv‐Fc and 26‐fold higher for HSA. Due to the low qp of the 3D6scFv‐Fc producing strain, the space‐time yield (STY) was 9.6‐fold lower for P. pastoris. In contrast, the STY of the HSA producer was 9.2‐fold higher compared to CHO cells because of the shorter process time and higher biomass density. The results indicate that the protein secretion machinery of P. pastoris is much less efficient and the secretion rate strongly depends on the complexity of the recombinant protein. However, process efficiency of the yeast system allows higher STYs for less complex proteins.
Chinese hamster ovary (CHO) cells are currently the workhorse of the biopharmaceutical industry, but yeasts such as Pichia pastoris are about to enter this field. To compare their capability for recombinant protein secretion, P. pastoris strains and CHO cell lines producing two model proteins of different complexity were cultivated in comparable fed batch processes. The results of this study indicate that the protein secretion machinery of P. pastoris is much less efficient and the secretion rate strongly depends on the complexity of the recombinant protein, but process efficiency of the yeast system allows higher space‐time yields for less complex proteins.
During the COVID-19 pandemic the “Austrian Bundesliga”—as in many other European football leagues—resumed the season around the end of May 2020 without supporters in the stadiums. These so-called ...“ghost games” represent a unique and unprecedented opportunity to study the effects of the (missing) audience on the behavior and experience of sports professionals. The present study is the first of its kind, aimed at addressing the psychological effects of these “ghost games” on football players, staff, and officials. The newly developed “Analysis System for Emotional Behavior in Football” (ASEB-F) was used to video analyze and compare the behavior of players, staff, and officials in—in sum—20 games of FC Red Bull Salzburg in the “Championship Groups” of season 2018/19 (“regular games”) and season 2019/20 (“ghost games”). Additionally, the two seasons were compared based on official matchday statistics. Overall, there were 19.5% fewer emotional situations in “ghost games” than in “regular games”. The results further show a relative increase in the number of emotional behaviors “Self-Adaptor” (+0.8%), “Protest” (+4.2%), and “Fair-Play-Behavior” (+3.1%) in “ghost games”, whereas “Words fight” (−5.1%) and “Discussion” (−5.1%) decreased in “ghost games”. In “regular games” referees were actively involved in 39.4% of all documented emotional situations, whereas in “ghost games” referees were actively involved in only 25.2% of all documented emotional situations (−14.2%). Chronological analysis within games—from kick-on to kick-off—further shows substantial differences in the temporal occurrence of emotional behavior between “regular games” and “ghost games”. The study provides unprecedented insights into the effects of missing supporters in the football games during the COVID-19 pandemic on emotional behavior on the pitch. Without the external factor of supporters, players and staff acted more factually and got less carried away with longer-lasting and extensive “Words fights” and “Discussion”. The evidence from this study indicates that—from a sport psychological perspective—the absence of supporters has a substantial influence on the experience and behavior of players, staff, and officials alike.
Lytic polysaccharide monooxygenases (LPMO) release a spectrum of cleavage products from their polymeric substrates cellulose, hemicellulose, or chitin. The correct identification and quantitation of ...these released products is the basis of MS/HPLC-based detection methods for LPMO activity. The duration, effort, and intricate analysis allow only specialized laboratories to measure LPMO activity in day-to-day work. A spectrophotometric assay will simplify the screening for LPMO in culture supernatants, help monitor recombinant LPMO expression and purification, and support enzyme characterization.
Based on a newly discovered peroxidase activity of LPMO, we propose a fast, robust, and sensitive spectrophotometric activity assay using 2,6-dimethoxyphenol (2,6-DMP) and H
O
. The fast enzymatic assay (300 s) consists of 1 mM 2,6-DMP as chromogenic substrate, 100 µM H
O
as cosubstrate, and an adequate activity of LPMO in a suitable buffer. The high molar absorption coefficient of the formed product coerulignone (
= 53,200 M
cm
) makes the assay sensitive and allows reliable activity measurements of LPMO in concentrations of approx. 0.5-50 mg L
.
The activity assay based on 2,6-DMP detects a novel peroxidase activity of LPMO. This activity can be accurately measured and used for enzyme screening, production, and purification, and can also be applied to study binding constants or thermal stability. However, the assay has to be used with care in crude extracts, because other enzymes such as laccase or peroxidase will interfere with the assay. We also want to stress that the peroxidase activity is a homogeneous reaction with soluble substrates and should not be correlated to heterogeneous LPMO activity on polymeric substrates.
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