No abstract

An automated microsystem for sulfite determination in beverages was developed. It presents higher sampling throughput, lower chemical consumption and less waste generation than previous flow methods, while using the same p-rosaniline-formaldehyde-sulfite reaction. The sampling rate, limit of detection (LOD), and relative standard deviation (RSD) were estimated at 130 h −1 , 80.0 μg L-1 , and < 1.3% (n = 5), respectively. Recoveries ranged from 96.8 to 102.6%.

A new coronavirus appears in China in December 2019, subsequently threatening the world, it was identified as Covid-19. Its main symptomatic characteristic is directly linked to acute respiratory failure, however there are asymptomatic cases of the disease, mainly in the group not considered at risk. For the treatment of the disease a variety ofantiviral drugs have been tested, with conflicting results. The use of computer-assisted drugs is essential for the development of new therapeutic alternatives for various diseases, once they reduce the time consumed in the initial screening tests, in addition to determining the possible mechanisms of action and reducing toxicity. In our study, we evaluated the interaction of viral components of the coronavirus with potassium usnate, salt derived from lichenic origin and with proven antimicrobial and antitumor activities. Derived from ussic acid, potassium usnate showed low energy for complex formation, this interaction occurs between the usnate salt and the structures of proteinase 3CLpro and enzyme Mpro, all key parts of Covid-19. In addition, in order to prove in silico the use of potassium usnate, they were tested and compared with other approved drugs and candidates for clinical trials to combat the new coronavirus.