scholarly journals Exploring the Photodynamic Properties of Two Antiproliferative Benzodiazopyrrole Derivatives

2020 ◽  
Vol 21 (4) ◽  
pp. 1246 ◽  
Author(s):  
Concetta Imperatore ◽  
Mohammadhassan Valadan ◽  
Luciana Tartaglione ◽  
Marco Persico ◽  
Anna Ramunno ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Light Emitting Diode ◽  
Uv Spectroscopy ◽  
Ionic Species ◽  
Uv Spectra ◽  
Solution Ph ◽  
Null Cell ◽  
Degree Of Ionization ◽  
Promising Therapeutic Approach ◽  
Led Irradiation

The identification of molecules whose biological activity can be properly modulated by light is a promising therapeutic approach aimed to improve drug selectivity and efficacy on the molecular target and to limit the side effects compared to traditional drugs. Recently, two photo-switchable diastereomeric benzodiazopyrrole derivatives 1RR and 1RS have been reported as microtubules targeting agents (MTAs) on human colorectal carcinoma p53 null cell line (HCT 116 p53-/-). Their IC50 was enhanced upon Light Emitting Diode (LED) irradiation at 435 nm and was related to their cis form. Here we have investigated the photo-responsive behavior of the acid derivatives of 1RR and 1RS, namely, d1RR and d1RS, in phosphate buffer solutions at different pH. The comparison of the UV spectra, acquired before and after LED irradiation, indicated that the trans→cis conversion of d1RR and d1RS is affected by the degree of ionization. The apparent rate constants were calculated from the kinetic data by means of fast UV spectroscopy and the conformers of the putative ionic species present in solution (pH range: 5.7–8.0) were modelled. Taken together, our experimental and theoretical results suggest that the photo-conversions of trans d1RR/d1RS into the corresponding cis forms and the thermal decay of cis d1RR/d1RS are dependent on the presence of diazonium form of d1RR/d1RS. Finally, a photo-reaction was detected only for d1RR after prolonged LED irradiation in acidic medium, and the resulting product was characterized by means of Liquid Chromatography coupled to High resolution Mass Spectrometry (LC-HRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy.

scholarly journals UV spectroscopic properties of principal inorganic ionic species in natural waters

2018 ◽  
Vol 13 (4) ◽  
pp. 879-892 ◽  
Author(s):  
Jan Birkmann ◽  
Christoph Pasel ◽  
Michael Luckas ◽  
Dieter Bathen
Keyword(s):  
Wavelength Range ◽  
Significant Influence ◽  
Natural Waters ◽  
Uv Spectroscopy ◽  
Spectroscopic Properties ◽  
Ionic Species ◽  
Uv Spectra ◽  
Uv Spectrum ◽  
Ionic Solutions ◽  
Study Results

Abstract The UV spectroscopic properties of the principal inorganic ionic species in natural waters were investigated at 25 °C in the wavelength range 195 to 280 nm. All absorbing species were identified and the corresponding molar absorptivities were determined experimentally. No cations were found to influence the UV spectrum. Relatively high molar absorptivities were observed for iodide, bromide and nitrate. The UV spectra of natural waters were calculated using the molar absorptivities and compared with observed signals from synthetic samples. This enabled the dominant components to be determined. Both bromide and nitrate have significant influence on the UV spectrum of natural waters. The study results can be used to predict the UV spectra of ionic solutions and thus evaluate the suitability of UV spectroscopy for given measurement projects.

scholarly journals 7-Bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one

Molbank ◽  
10.3390/m1229 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1229
Author(s):  
Timofey N. Chmovzh ◽  
Oleg A. Rakitin
Keyword(s):  
Mass Spectrometry ◽  
Heterocyclic System ◽  
High Resolution Mass Spectrometry ◽  
Uv Spectroscopy ◽  
Hydrolysis Product ◽  
Selenium Dioxide ◽  
Biologically Active ◽  
Photovoltaic Materials ◽  
Organic Photovoltaic Materials ◽  
Ir And Uv Spectroscopy

New heterocyclic systems containing 1,2,5-chalcogenadiazoles are of great interest for the creation of organic photovoltaic materials and biologically active compounds. In this communication, 3,6-dibromopyridazine-4,5-diamine was investigated in reaction with selenium dioxide in order to obtain 4,7-dibromo-[1,2,5]selenadiazolo[3,4-d]pyridazine. We found that 7-bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one, the first representative of the new heterocyclic system, was isolated as a hydrolysis product of the corresponding 4,7-dibromoderivative. The structure of the newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, 1H, 13C NMR, IR and UV spectroscopy, and mass spectrometry.

scholarly journals Ultraviolet Spectroscopy Used to Fingerprint Five Wild-Grown Edible Mushrooms (Boletaceae) Collected from Yunnan, China

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Li ◽  
Ji Zhang ◽  
Tao Li ◽  
Tianwei Yang ◽  
Yuanzhong Wang ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Hierarchical Cluster Analysis ◽  
Visual Discrimination ◽  
Uv Spectroscopy ◽  
Hierarchical Cluster ◽  
Uv Spectra ◽  
Edible Mushrooms ◽  
Ultraviolet Spectroscopy

Nowadays, wild-grown edible mushrooms which are natural, nutritious, and healthy get more and more popular by large consumers. In this paper, UV spectra of different Boletaceae mushrooms with the aid of partial least squares discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) were shown to be a practical and rapid method for discrimination purpose. The specimens of Boletus edulis, Boletus ferrugineus, Boletus tomentipes, Leccinum rugosiceps, and Xerocomus sp. were described based on the UV spectra. From the results, all the specimens were characterized by strong absorption at the wavelengths of 274 and 284 nm and showed the shoulder at 296 nm. However, changes could be seen in the peak heights at the same wavelength for different samples. After analyzing by chemometrics, visual discrimination among samples was presented and the relationships among them were also obtained. This study showed that UV spectroscopy combined with chemometrics methods could be used successfully as a simple and effective approach for characterization of these five wild-grown edible mushrooms at species and genus levels. Meanwhile, this rapid and simple methodology could also provide reference for the discrimination of edible mushrooms.

scholarly journals Exploring Abundance and Isotope Anomalies in CP Stars with the HST/GHRS: High Resolution UV Spectroscopy of χ Lupi

1993 ◽  
Vol 138 ◽  
pp. 42-59 ◽  
Author(s):  
David S. Leckrone ◽  
Glenn M. Wahlgren ◽  
Sveneric G. Johansson ◽  
Saul J. Adelman
Keyword(s):  
High Resolution ◽  
Uv Spectroscopy ◽  
Uv Spectra ◽  
Heavy Elements

AbstractWe are using the HST/GHRS in a long-term program to obtain UV spectra of unprecedented resolution and precision for bright, ultra-sharp-lined Bp (HgMn) stars and comparable normal stars. To date we have doubled the number of heavy elements for which abundances may be estimated in χ Lupi, and have obtained the first observations of Hg III lines with which to test diffusion scenarios for its extreme Hg isotope anomaly.

Determination of Seawater Salinity by Ultraviolet Spectroscopic Measurements

1997 ◽  
Vol 51 (9) ◽  
pp. 1294-1302 ◽  
Author(s):  
Vito Di Noto ◽  
Mauro Mecozzi
Keyword(s):  
Organic Matter ◽  
Uv Spectroscopy ◽  
Sample Pretreatment ◽  
Uv Spectra ◽  
Linear Calibration ◽  
Synthetic Seawater ◽  
Seawater Salinity ◽  
Seawater Samples ◽  
Nitrate Species

A method for the determination of seawater salinity by ultraviolet (UV) spectroscopy is proposed. The effects of single salt concentrations and of salinity on UV absorption in the 190–250-nm range were investigated. These studies revealed that the absorption spectrum of a solution with a given salinity is due mainly, in order, to KBr >MgCl 2>NaCl. The influence of the temperature and salt concentration on UV spectra was studied by using synthetic seawater samples with the salinities ranging from 1 to 50 parts per thousand (%). Results showed that, in the absence of interferences, the most sensitive and reliable conditions for measuring the salinity are at 212 nm and at temperatures in the range of 25–30 °C. Under these conditions this method shows quite linear calibration curves and allows us to perform salinity determinations in seawater solutions at concentrations as low as 4%. Moreover, it requires no sample pretreatment and offers a precision of 0.20%. The proposed method is very simple and rapid for laboratory and on-board analysis. Finally, the interference of organic matter, nitrite, and nitrate species with the salinity determinations was investigated. These studies show that organic matter does not interfere at concentrations of carbon lower than 1 mg/L and at 210 nm. Interferences due to NO− x species can be ignored if these species are dissolved in solution at concentrations lower than ≈0.2 mg/L and the analyses are carried out at wavelengths lower than 212 nm.

Sign in / Sign up

Export Citation Format

Share Document