Design, synthesis, antiviral activities of ferulic acid derivatives

A series of novel ferulic acid derivatives were designed and synthesized, and the twenty-one compounds were evaluated for their antiviral activities against Respiratory syncytial virus (RSV), herpes simplex virus type 1 (HSV-1), and enterovirus type 71 (EV71). These derivatives with the core structure of diphenyl acrylic acids had cis-trans isomers, which were confirmed by ¹H NMR, HPLC, and UV-vis spectra for the first time. The A5 had a selective effect against RSV but no work on herpes simplex virus type 1 and enterovirus type 71, which showed a therapeutic index (TI) of 32 and was significantly better than ferulic acid. The A5 had no scavenging effect on free radicals, but the A2 as the degradation of A5 showed an obvious scavenging effect on DPPH· and ABTS⁺·. In addition, the A5 had no toxicity to endothelial cells and even showed a proliferative effect. Therefore, the A5 is worth further optimizing its structure as a lead compound and investigating the mechanism of inhibiting Respiratory syncytial virus.

Growth and fatty acid composition of Acutodesmus obliquus under different light spectra and temperatures

The combined impact of temperature and light spectra on the fatty acid (FA) composition in microalgae has been sparsely investigated. The aim of this study was to investigate the interactions of light and temperature on the FA composition in Acutodesmus obliquus. For this purpose, A. obliquus was cultivated with different temperatures (20, 30, and 35°C), as well as broad light spectra (blue, green, and red light). Growth and FA composition were monitored daily. Microalgal FA were extracted, and a qualitative characterization was done by gas chromatography coupled with electron impact ionization mass spectrometry (GC-EI/MS). Compared to red light, green and blue light caused a higher percentage of the polyunsaturated fatty acids (PUFA) 16:4, 18:3, and 18:4, at all temperatures. The highest total percentage of these PUFA were observed at the lowest cultivation temperature and blue and green light. These data imply that a combination of lower temperatures and blue-green light (450-550 nm) positively influences the activity of specific FA-desaturases in A. obliquus. Additionally, a lower 16:1 trans/cis ratio was observed upon green and blue light treatment and lower cultivation temperatures. Remarkably, green light treatment resulted in a comparably high growth under all tested conditions. Therefore, a higher content of green light, compared to blue light might additionally lead to a higher biomass concentration. Microalgae cultivation with low temperatures and green light might therefore result in a suitable FA composition for the food industry and a comparably high biomass production.

Correcting cis-trans-transgressions in macromolecular structure models

Many macromolecular X-ray and cryo-EM structure models deposited in the PDB contain biologically relevant small molecule ligands with unsaturated fatty acid acyl chains, whose cis-trans stereochemistry is incorrect. The molecules are either not properly defined in their stereochemical restraint files, or the proper stereochemistry is neglected during model building. Often, the same molecules appear in deposited models in both isomeric configurations, one of which is almost always incorrect, and the use of the same moiety (HET) identifier and restraint files in model refinement is wrong. We present case studies of frequently occurring molecules and a compilation of identified cases of C-C=C-C cis-trans geometry in the deposited structure models. Full listings of cis/trans torsion angles are provided for models with commonly occurring molecules to assist identification and correction of cis-trans errors and prevent inadvertent use of incorrect models. Caveats for users, advice for modellers and suggestions for remediation efforts with a simple but effective restraint file modification are provided.