Intraocular pressure measurement with Corvis ST in comparison with applanation tonometry and Tomey non-contact tonometry.

Purpose: Intraocular pressure (IOP) measurement can be performed with different methods. Newer methods have to be compared to the standard method, the Goldmann applanation tonometry (GAT). We herein compare two air-puff tonometers, the non-contact tonometer (Tomey NCT) and the Corvis ST (CST) with GAT in eyes with a broad spectrum of IOP.

Profiling withanolide A for therapeutic targets in neurodegenerative diseases.

To identify new potential therapeutic targets for neurodegenerative diseases, we initiated activity-based protein profiling studies with withanolide A (WitA), a known neuritogenic constituent of Withania somnifera root with unknown mechanism of action. Molecular probes were designed and synthesized, and led to the discovery of the glucocorticoid receptor (GR) as potential target. Molecular modeling calculations using the VirtualToxLab predicted a weak binding affinity of WitA for GR.

Long-term follow-up of intraocular pressure and pressure-lowering medication in patients after ab-interno trabeculectomy with the Trabectome.

Background: The minimally invasive ab-interno trabeculectomy (AIT) via electro-ablation with the Trabectome has been on the European market since 2009. Many studies have proven the safety and efficacy of the procedure. Up until now, studies investigating the long-term effect of AIT have been sparse.

Pyrrolizidines for direct air capture and CO conversion.

Greenhouse gases such as CO2 strongly contribute to the rising temperatures of our planet, but as long as our society is dependent on fossil fuels, this trend will even increase in the near future. Therefore, CO2 capture and subsequent utilization constitute an approach for decarbonization and CO2 mitigation, and for this purpose, amine scrubbing remains the industrially most established process. In this article, we describe the CO2 capture-ability of pyrrolizidine-based diamines, a scaffold with remarkably good properties to fulfill this challenge.

Antiprotozoal Isoprenoids from Salvia hydrangea.

Fractionation of the n-hexane extract of Salvia hydrangea afforded seven isoprenoids including six new compounds (1-6) and salvadione A (7). Their structures were established by comprehensive spectroscopic and spectrometric data analysis (1D and 2D NMR, HRMS). The absolute configuration of salvadione A (7) was established by single-crystal X-ray diffraction analysis with Cu/Kα radiation.

Domino Pd -Catalyzed C(sp )-H Arylation/Electrocyclic Reactions via Benzazetidine Intermediates.

The Pd -catalyzed C(sp )-H arylation of 2-bromo-N-methylanilides leads to unstable benzazetidine intermediates that rearrange to benzoxazines through 4π electrocyclic ring-opening and 6π electrocyclization. The introduction of a bulky, non-activatable amide group on the nitrogen atom was key to favor the challenging reductive elimination step and disfavor undesired reaction pathways.

Mixed-Valent Molecular Triple Deckers.

Two phenothiazine (PTZ) moieties were connected via naphthalene spacers to a central arene to result in stacked PTZ-arene-PTZ structure elements. Benzene and tetramethoxybenzene units served as central arenes mediating electronic communication between the two PTZ units. Based on cyclic voltammetry, UV/Vis-NIR absorption, EPR spectroscopy, and computational studies, the one-electron oxidized forms of the resulting compounds behave as class II organic mixed-valence species in which the unpaired electron is partially delocalized over both PTZ units.

Catalyst-Controlled Stereodivergent Synthesis of Atropisomeric Multiaxis Systems.

Molecular scaffolds with multiple rotationally restricted bonds allow a precise spatial positioning of functional groups. However, their synthesis requires methods addressing the configuration of each stereogenic axis. We report here a catalyst-stereocontrolled synthesis of atropisomeric multiaxis systems enabling divergence from the prevailing stereochemical reaction path.

Chiral macrocyclic terpyridine complexes.

The syntheses of novel chiral M(ii) bis(terpyridine) cage complexes and are described. The extraordinary design of the precursors and allows perfect preorganization for the final closing step. Due to the rigidity of the spacers between the two terpyridine moieties, the two isolated enantiomers barely racemize at room temperature in solution.

Biosynthesis of fragin is controlled by a novel quorum sensing signal.

Members of the diazeniumdiolate class of natural compounds show potential for drug development because of their antifungal, antibacterial, antiviral, and antitumor activities. Yet, their biosynthesis has remained elusive to date. Here, we identify a gene cluster directing the biosynthesis of the diazeniumdiolate compound fragin in Burkholderia cenocepacia H111.

Bleb-related infections and long-term follow-up after trabeculectomy.

Purpose: Bleb-related infections are serious complications after trabeculectomy. They can be limited to the bleb or disseminate and lead to endophthalmitis. We herein report on all bleb-related infections that have been diagnosed at the Eye Center of the University of Freiburg, Germany, since 1999.

Chiral Bifunctional Phosphine-Carboxylate Ligands for Palladium(0)-Catalyzed Enantioselective C-H Arylation.

Previous enantioselective Pd -catalyzed C-H activation reactions proceeding via the concerted metalation-deprotonation mechanism employed either a chiral ancillary ligand, a chiral base, or a bimolecular mixture thereof. This study describes the development of new chiral bifunctional ligands based on a binaphthyl scaffold which incorporates both a phosphine and a carboxylic acid moiety. The optimal ligand provided high yields and enantioselectivities for a desymmetrizing C(sp )-H arylation leading to 5,6-dihydrophenanthridines, whereas the corresponding monofunctional ligands showed low enantioselectivities.

Synthesis of trinorbornane.

Herein we report the synthesis and characterisation of the until recently unreported chiral C skeleton of tetracyclo[5.2.2.

Trabeculotomy opening size and IOP reduction after Trabectome® surgery.

Background: Trabeculotomy with the Trabectome® is an effective surgical procedure to lower intraocular pressure (IOP). However, in some patients it does not lead to a significant IOP reduction despite a gonioscopically well visible opening of Schlemm's canal. This study investigated whether the size of the trabeculotomy opening and other parameters, including anterior chamber depth (ACD) are related to IOP reduction.

Palladium(0)-catalyzed asymmetric C(sp)-H arylation using a chiral binol-derived phosphate and an achiral ligand.

The first efficient palladium(0)-catalyzed enantioselective C(sp)-H activation reaction using a catalytic chiral base and an achiral phosphine ligand is reported. Fine-tuning the binol-derived phosphoric acid pre-catalyst and the reaction conditions was found to be crucial to achieve high levels of enantioselectivity for a variety of indoline products containing both tri- and tetrasubstituted stereocenters.

Intramolecular Light-Driven Accumulation of Reduction Equivalents by Proton-Coupled Electron Transfer.

The photochemistry of a molecular pentad composed of a central anthraquinone (AQ) acceptor flanked by two Ru(bpy) photosensitizers and two peripheral triarylamine (TAA) donors was investigated by transient IR and UV-vis spectroscopies in the presence of 0.2 M p-toluenesulfonic acid (TsOH) in deaerated acetonitrile. In ∼15% of all excited pentad molecules, AQ is converted to its hydroquinone form (AQH) via reversible intramolecular electron transfer from the two TAA units (τ = 65 ps), followed by intermolecular proton transfer from TsOH (τ ≈ 3 ns for the first step).

A nor-diterpene from Salvia sahendica leaves.

Phytochemical investigation of n-hexane extract of Salvia sahendica by normal phase column chromatography resulted in the isolation of six compounds. Structures were established by 1D and 2D NMR spectroscopy, and HRMS, as a new norditerpene 1, and known terpenoids, sclareol (2), oleanolic acid (3), β-sitosterol (4), salvigenin (5) and 3α-hydroxy-11α,12α-epoxyoleanan-28,13β-olide (6). The absolute configuration of 1 was confirmed by a combination of X-ray single crystal analysis and electronic circular dichroism spectroscopy.

Intramolecular Inverse Electron-Demand [4 + 2] Cycloadditions of Ynamides with Pyrimidines: Scope and Density Functional Theory Insights.

4-Aminopyridines are valuable scaffolds for the chemical industry in general, from life sciences to catalysis. We report herein a collection of structurally diverse polycyclic fused and spiro-4-aminopyridines that are prepared in only three steps from commercially available pyrimidines. The key step of this short sequence is a [4 + 2]/retro-[4 + 2] cycloaddition between a pyrimidine and an ynamide, which constitutes the first examples of ynamides behaving as electron-rich dienophiles in [4 + 2] cycloaddition reactions.

Collective Syntheses of Icetexane Natural Products Based on Biogenetic Hypotheses.

A divergent synthesis of 10 icetexane natural products based on a proposed biogenetic cationic ring expansion of a reduced carnosic acid derivative is described. Of these icetexanes, (+)-salvicanol, (-)-cyclocoulterone, (-)-coulterone, (-)-obtusinone D, and (-)-obtusinone E have been synthesized for the first time. In addition, the hypothesis for the non-enzymatic biogenesis of benzo[1,3]dioxole natural products has been experimentally investigated.

Securigenin glycosides as hypoglycemic principles of Securigera securidaca seeds.

Seeds of Securigera securidaca (Fabaceae) are used in Iranian folk medicine as an antidiabetic treatment. In this study, the antihyperglycemic activity of chloroform and methanol fractions (CF and MF) from S. securidaca seed extract was investigated and their bioactive constituents were identified.

Spin-Delocalization in a Helical Open-Shell Hydrocarbon.

Neutral open-shell molecules, in which spin density is delocalized through a helical conjugated backbone, hold promise as models for investigating phenomena arising from the interplay of magnetism and chirality. Apart from a handful of examples, however, the chemistry of these compounds remains largely unexplored. Here, we examine the prospect of extending spin-delocalization over a helical backbone in a model compound naphtho[3,2,1-no]tetraphene, the first helically chiral open-shell hydrocarbon, in which one benzene ring is fused to [5]helicene, forming a phenalenyl subunit.

Formal Total Synthesis of (-)-Jiadifenolide and Synthetic Studies toward seco-Prezizaane-Type Sesquiterpenes.

Synthetic studies toward highly oxygenated seco-prezizaane sesquiterpenes are reported, which culminated in a formal total synthesis of the neurotrophic agent (-)-jiadifenolide. For the construction of the tricyclic core structure, an unusual intramolecular and diastereoselective Nozaki-Hiyama-Kishi reaction involving a ketone as electrophilic coupling partner was developed. In addition, synthetic approaches toward the related natural product (2R)-hydroxy-norneomajucin, featuring a Mn-mediated radical cyclization for the tricycle assembly and a regioselective OH-directed C-H activation are presented.

Inorganic Cyanide as Protecting Group in the Stereospecific Reconstitution of Vitamin B from an Artificial Green Secocorrinoid.

The synthesis of vitamin B in four steps from an artificial green secocorrinoid is presented. The stereospecific reconstitution of the B-ring of the cobalamin involves a quantitative and rapid ligand-centered radical ring closure reaction leading first to a new B derivative with antivitamin activity that is subsequently converted to the natural product. Chemoselectivity in the one-electron reduction of the macrocycle was achieved by introducing inorganic cyanide as an axially coordinating protecting group of the otherwise reduction-sensitive Co-ion.