Synthesis And Biological Activity of Amide Derivatives Derived From Natural Product Waltherione F

Structural optimization based on natural products has become an effective way to develop new green fungicides, which provide important guiding significance for practicing the new development concept and promoting the green development of pesticides. In this project, combined with the fungicidal amide lead compound X-I-4 discovered in our previous work and fungicidal piperazine derivatives reported in literatures, the target compounds containing 4-quinolone and piperazine substructures based on waltherione F were designed, synthesized and screened for their biological activity. The bioassay results indicated that compounds I-3, I-5, II-3, II-7, II-10, II-11 and II-13 displayed higher inhibition rates against Rhizoctonia solani than other tested compounds. The in vitro cellular cytotoxicity assay revealed the compounds II-6 and II-11 exhibited higher cytotoxicity against HepG2 than other tested compounds. The fluorescence characteristics investigation showed that the absolute fluorescence QY value of the methanol solution of the compound I-6 was higher than those of I-2, I-3, I-7 and I-8, which was further elucidated by TD-DFT.

Considerations for MESF-bead based assignment of absolute fluorescence values to nanoparticles and extracellular vesicles by flow cytometry

Flow cytometry is a promising technique to characterize nanoparticles (NPs) and extracellular vesicles (EVs). However, the majority of reported experiments, use arbitrary units to indicate fluorescence intensity. This hampers comparison of results from different laboratories and different platforms. We investigated the advised use of calibrated molecules of equivalent soluble fluorophores (MESF)-beads for assignment of absolute fluorescence to NPs and EVs. Firstly, we evaluated the use of two different FITC MESF bead sets as calibrators on three different flow cytometry platforms (BD Influx, CytoFLEX LX and SORP BD FACSCelesta). Secondly, NPs and biological 4T1 mammary carcinoma-EVs were analyzed using the BD Influx and their fluorescence signals calibrated by using different sets of FITC and PE MESF beads. Although fluorescence calibration, using bright calibrators designed for cellular flow cytometry, makes inter-platform comparison possible for fluorescently labeled cells and brightly labeled particles, but the uncertainty of the currently available calibrators, which are far out of the fluorescence range of the sub-micron particles, hampers a reliable assignment of absolute MESF numbers based on extrapolation into the dim fluorescence range. Our results illustrate the need for calibration materials specifically designed for NPs and EVs to enable a reliable assignment of absolute fluorescence values in the lower fluorescent ranges.

A ratiometric fluorescence platform composed of MnO2 nanosheets and nitrogen, chlorine co-doped carbon dots and its logic gate performance for glutathione determination

Herein, a ratiometric fluorescence strategy based on the MnO2 nanosheets and nitrogen, chlorine co-doped carbon dots (N, Cl-CDs) was constructed for selective determination glutathione (GSH) and the absolute fluorescence quantum...

Nopinone-based aggregation-induced emission (AIE)-active difluoroboron β-diketonate complex: photophysical, electrochemical and electroluminescence properties

Four difluoroboron (BF2) β-diketonate nopinone complexes 3a–3d which exhibited typical AIE property were synthesized. Owing to high absolute fluorescence quantum yields of 3b, EL device based on 3b was fabricated, which exhibits a blue-green light.

Cyanine dyes as ratiometric fluorescence standards for the far-red spectral region

Absolute fluorescence quantum yields are reported for a group of commercially available dyes suitable for use as secondary standards across the far-red spectral window.

Synthesis and performances of extended conjugated stilbene fluorescent dye

Purpose The purpose of this paper is to explore the optic performance of extended stilbene derivative. Design/methodology/approach Five steps were adopted to synthesise novel 4, 4′-bis (2-cyanostyryl) stilbene, which contained three vinyl units in the skeleton (S3E). The structure of S3E was characterised by 1H NMR and EI-MS. Its absorption and emission spectra were also given. Findings Compared to C.I. Fluorescent Brightener 199, which contains two vinyl units in the skeleton, S3E showed obvious bathochromic shifts in both UV-VIS and FL spectra. The maximum absorption wavelength and fluorescent wavelength were at 390 nm and 464 nm, respectively, with Stoke’s shift of 74 nm. The absolute fluorescence quantum yield was 0.42. Thermogravimetric analysis (TGA) revealed that the weight loss of S3E was less than 5 per cent at 300 °C. Moreover, the light resistance test showed that S3E in PVC plate can keep the good fluorescent intensity for more than seven days exposed to xenon light. Therefore, it is believed that S3E could satisfy the requirements of colouring PVC as a fluorescent dye. Practical implications S3E can be used as a candidate of fluorescent dye in the development of thermoplastics. Originality/value The present paper designed and synthesised a new derivative of stilbene, which showed its preference to be a colourant of thermoplastics.