7β-Hydroxy octalone derivatives are obtained efficiently by allylic hydroxylation of 4 and 6 with Rhizopus arrhizus.

Radical decarboxylation of isolongifolic acid 3a affords in good yield the thio-ether 4 through a reaction involving a clean 1,5-transannular hydrogen shift. The thio-ether 4 was further converted in almost quantitative yield into the olefin 7 through sequential oxidation-elimination.

Cardiac arrhythmia occurs frequently worldwide, and in severe cases can be fatal. Mitochondria are the power plants of cardiomyocytes. In recent studies, mitochondria under certain stimuli produced excessive reactive oxygen species (ROS), which affect the normal function of cardiomyocytes through ion channels and related proteins. Mitochondrial oxidative stress (MOS) plays a key role in diseases with multifactorial etiopathogenesis, such as arrhythmia; MOS can lead to arrhythmias such as atrial fibrillation and ventricular tachycardia. This review discusses the mechanisms of arrhythmias caused by MOS, particularly of ROS produced by mitochondria. MOS can cause arrhythmias by affecting the activities of Ca2+-related proteins, the mitochondrial permeability transition pore protein, connexin 43, hyperpolarization-activated cyclic nucleotide-gated potassium channel 4, and ion channels. Based on these mechanisms, we discuss possible new treatments for arrhythmia. Targeted treatments focusing on mitochondria may reduce the progression of arrhythmias, as well as the occurrence of severe arrhythmias, and may be effective for personalized disease prevention.

An important parasitic threat to honey bees, the mite Varroa jacobsoni, is attracted to its major prey, drone larvae, by methyl and ethyl esters of straight-chain fatty acids, in particular methyl palmitate. These esters were extracted from drone larvae with n-hexane and were identified by gas chromatography-mass spectrometry. Their behavioral effect was evaluated with the use of a four-arm airflow olfactometer.

Accounting may well be on its way to becoming the queen of the human sciences, but, regrettably, if so, this will be because it has taken on all the least desirable features of technocratically defined “human” science. The critics of accounting practice see this and although they differ among themselves, the differences between the critics and the mainstream practitioners (and their “theorists”) define a chasm. I try to exhibit this by showing that the chasm stems from different assumptions in the philosophy (or theory) of science and different assumptions regarding the nature of society. Current criticisms suggest to me a profound pedagogic task.

Human coronavirus (HCoV) infection causes respiratory diseases with mild to severe outcomes. In the last 15 years, we have witnessed the emergence of two zoonotic, highly pathogenic HCoVs: severe acute respiratory syndrome coronavirus (SARS-CoV) and ...Read More

Pentacyclic triterpenoids of the hopane family were found in about half of some 100 strains of prokaryotes belonging to diverse taxonomic groups, such a wide distribution indicating the biological significance of these compounds. Hopanoids were found in almost all the cyanobacteria and obligate methylotrophs examined, in all the purple non-sulphur bacteria studied and in many taxonomically diverse Gram-negative or Gram-positive chemohetero-trophs. They were absent in all archaebacteria and purple sulphur bacteria examined as well as in various other Gram-positive or Gram-negative genera. The C30 hopanoids, diploptene and diplopterol, are present in almost all hopanoid-containing prokaryotes. The major compounds are always the C35 bacteriohopanepolyols, which are present at a level of 0.1-2 mg per g dry weight, the most common one being bacteriohopanetetrol. Because of their structural characteristics and their influence on the properties of biological membrane models, these compounds might be the structural equivalents of the sterols found in eukaryotes.

AbstractAus Sedimenten und Petroleum werden die Inhaltsstoffe (I) bzw. (II) isoliert und identifiziert.

A novel family of hexacyclic hopanoids, the benzohopanes 1 (C32–C35), has been identified in geological sources by X-ray crystallography. These compounds must be formed from bacterial C35 hopanoid precursors during early stages of sedimentation.