The total syntheses of (+/-)-aspercyclide A (1) and its C19 methyl ether (15a) featuring Heck-Mizoroki macrocyclisation to form the 11-membered (E)-styrenyl biaryl ether lactone core are described.

Two highly convergent syntheses of a fully protected C1-C19 polyol subunit of the brasilinolide family of immunosuppressive macrolides are described, exploiting boron-mediated 1,5-anti aldol couplings to form the C8-C9 and C13-C14 bonds.

The quassinoids are a group of complex, highly oxygenated, degraded triterpene mostly found in Simaroubaceae family. Two quassinoids (degraded triterpenes), 1 and 2 were isolated first time from the stem bark of Ailanthus excelsa. Compound 1 is C19 quassinoid. C19 quassinoid derived biogenetically from a C20 quassinoid, via a 1,2 – dioxo derivative. The structural elucidation is based on the an...

İntroduction
 Covid 19 (C19) disease causes mortal complications due to both respiratory system involvement and extrapulmonary involvement. C19 patients may present with gastrointestinal symptoms such as nausea-vomiting, diarrhea loss of appetite, well serious conditions acute mesenteric ischemia. is a proinflammatory condition that thrombus formation.
 Material method
 The first...

Abstract Introduction COVID-19 is connected with varying degrees of emotional stress. Patients (pts) who are hospitalized severe (C19) located in single rooms without a permanent attendant to prevent contamination. All personnel serving these pts come into contact patients personal full-body protective garment. Ambulatory C19 pts, usually less presentation, treated more comfortable conditions. ...

Androgens play an important role in metabolic homeostasis and reproductive health in both men and women. Androgen signalling is dependent on androgen receptor activation, mostly by testosterone and 5α-dihydrotestosterone. However, the intracellular or intracrine activation of C19 androgen precursors to active androgens in peripheral target tissues of androgen action is of equal importance. Intr...

The complex bis-spiroacetal polyether ionophore salinomycin has been identified as a uniquely selective agent against cancer stem cells and is also strikingly effective in an animal model of latent tuberculosis. The basis for these important activities is unknown. We show here that deletion of the salE gene abolishes salinomycin production and yields two new analogues, in both of which the C18...

In the gibberellin (GA) biosynthesis pathway, 20-oxidase catalyzes the oxidation and elimination of carbon-20 to give rise to C19-GAs. All bioactive GAs are C19-GAs. We have overexpressed a cDNA encoding 20-oxidase isolated from Arabidopsis seedlings in transgenic Arabidopsis plants. These transgenic plants display a phenotype that may be attributed to the overproduction of GA. The phenotype in...