In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk.

This study aimed to evaluate, in vitro, the use of leaf extracts of Azadirachta indica (A. indica) and Melia azedarach (M. azedarach) as antivirals against caprine lentivirus (CLV) in colostrum and milk of goat nannies. These were collected from eight individuals and infected with the standard strain of CLV. Samples were then subdivided into aliquots and treated with 150 µg/mL of crude extract, and with ethyl acetate and methanol fractions for 30, 60, and 90 min. Next, somatic cells from colostrum and milk were co-cultured with cells from the ovine third eyelid. After this step, viral titers of the supernatants collected from treatments with greater efficacy in co-culture were assessed. The organic ethyl acetate fractions of both plants at 90 min possibly inhibited the viral activity of CLV by up to a thousandfold in colostrum. In milk, this inhibition was up to 800 times for the respective Meliaceae. In conclusion, the ethanolic fraction of ethyl acetate from both plants demonstrated efficacy against CLV in samples from colostrum and milk when subjected to treatment, which was more effective in colostrum.

Synthesis and in silico study of chenodeoxycholic acid and its analogues as an alternative inhibitor of spike glycoprotein of SARS-CoV-2.

COVID-19, caused by SARS-CoV-2, is a viral infection that has generated one of the most significant health problems in the world. Spike glycoprotein is a crucial enzyme in viral replication and transcription mediation. There are reports in the literature on using bile acid in the fight against this virus through in vitro tests. This work presents the synthesis of nine chenodeoxycholic acid derivatives (1-9), which were prepared by oxidation, acetylation, formylation, and esterification reactions, and the analogs 6-9 have not yet been reported in the literature and the possibility of conducting an in silico study of bile acid derivatives as a therapeutic alternative to combat the virus using glycoprotein as a macromolecular target. As a result, five compounds (1, 6-9) possessed favorable competitive interactions with the lowest energies compared to the native ligand (BLA), and the highlighted compound 9 got the best scores. At the same time, analog 1 presented the best ADME filter result. Molecular dynamics also simulated these compounds to verify their stability within the active protein site to seek new therapeutic propositions to fight against the pandemic. Physical and spectroscopic data have fully characterized all the compounds.Communicated by Ramaswamy H. Sarma.

Development of a UPLC-ESI-MS method for simultaneous determination of flavonoids and diterpenes in Egletes viscosa (L.) Less herbal products.

Egletes viscosa (L.) Less (Asteraceae) is a tropical aromatic herb whose flower buds are used for gastrointestinal disorders. Its gastroprotective properties have been attributed to the flavonoid ternatin and the furan diterpenes tanabalin and centipedic acid. The aim of this study was to develop a method of ultra-performance liquid chromatography coupled to electrospray ionization and mass spectrometry (UPLC-ESI-MS) for identifying the constituents from E. viscosa flower buds as well as quantifying its bioactive compounds in herbal products. Infusions and tincture from wild and commercial E. viscosa materials were directly injected on a UPLC-quadrupole-time-of-flight system (UPLC-q-TOF). Afterwards, reference standards were used to quantify ternatin, tanabalin and centipedic acid in these samples, employing a UPLC-single quadrupole system set up for positive mode and Selected Ion Monitoring (SIM). Seventeen compounds were identified, including caffeic acid derivatives, flavonoids and diterpenes, from which seven have been reported for the first time in this specie. The quantification method showed good linearity (R > 0.99), accuracy, precision and sensitivity. The intra-day and inter-day precisions presented relative standard deviations inferior to 6.04 and 8.78%, respectively. The recoveries of all the analytes varied 82.25-117.87%. The limits of detection and quantification ranged between 10-25 µg/L and 25-75 µg/L, respectively. For the samples, the contents of ternatin, tanabalin and centipedic acid ranged from 0.89 to 8.03 mg/L, 0.84-16.8 mg/L and 3.21-16.8 mg/L, respectively. The method demonstrated to be rapid, sensitive and reliable for the quality control of E. viscosa-based products, besides being applicable to other plant extracts containing flavonoids and diterpenes.