Synthesis of 6-chloro(dichloro-, trichloro-)-methyl-3-R-6,7-dihydro-2H-[1,2,4]triazino[2,3-c]- quinazolin-2-ones and their modification in reactions with nucleophilic and non-nucleophilic bases

The synthesis of 6-chloro-(dichloro-, trichloro)methyl-3-R-6,7-dihydro-2H-[1,2,4]triazino[2,3-c]quinazolin-2-ones and their modification under the action of nucleophilic and/or basic reagents are described in this article. It was shown that 6-chloro-(dichloro-, trichloro)methyl-3-R-6,7-dihydro-2H-[1,2,4]triazino[2,3-c]quinazolin-2-ones can be prepared by cyclocondensation of 3-(aminophenyl)-6-R-1,2;4-triazine-5(2Н)-ones with chloro-(dichloro-)acetaldehyde or chloral hydrate. The reactivity of the synthesized compounds toward nucleophilic base morpholine and non-nucleophilic base diisopropylethylamine (DIPEA) under different conditions was studied. It was shown that the prepared compounds under the action of morpholine and/or DIPEA can be converted into the products of substitution, elimination or elimination followed by isomerization and substitution. Refluxing of 6-(chloromethyl)-3-R-6,7-dihydro-2Н-[1,2,4]triazino[2,3-с]quinazoline-2-ones with equimolar quantity of morpholine and 10% excess of DIPEA in ethylene glycol monoethyl ether (EGEE) yielded the products on N-alkylation. 6-(Morpholinomethyl)-3-R-2H-[1,2,4]triazino[2,3-с]quinazoline-2-ones were obtained by heating of 6-dichloromethyl-3-R-6,7-dihydro-2Н-[1,2,4]triazino[2,3-с]quinazoline-2-ones with five-fold excess of morpholine in EGEE. Reaction of 3-R-6-(trichloromethyl)-6,7-dihydro-2H-[1,2,4]triazino[2,3-с]quinazolin-2-ones with three-fold excess of DIPEA in EGEE yielded 3-R-2Н-[1,2,4]triazino[2,3-с]quinazoline-2-ones. The physicochemical and spectral characteristics of the prepared compounds were determined and discussed.

Effect of Properties of Silver Nanoparticles Coated with Polar Material and the Antibacterial Activity on Marine Pathogenic Bacteria

Silver nanoparticles (Ag NPs) have become one of the current research hotspots and are used in many fields such as electrochemistry, energy, bioanalysis, and environmental monitoring, especially in the field of antibacterial research. In this study, we investigated the effect of properties of Ag NPs coated with polar materials. Ag NPs covered by a dispersant that was triethylene glycol monoethyl ether was stable and conquered the aggregation of Ag NPs. The effect of the dispersant on biocompatibility was explored through interaction experiments between Ag NPs and DNA sequence. The coated Ag NPs could adsorb DNA, and the fluorescence of FAM-DNA could be quenched by Ag NPs. The adsorption and desorption experiments of DNA showed that the order of DNA functional groups on the interaction process was phosphate>T>C>A>G. Moreover, we selected marine pathogenic bacteria to test the antibacterial effect of Ag NPs coated with a polar dispersant. The polar material had a certain inhibitory effect on the antibacterial activity of Ag NPs. However, small molecules such as bases could interact on the surface Ag NPs and release Ag+ to perform the antibacterial activity. The results could contribute to the further application of Ag NPs.

266 Administering an appeasing substance to beef calves at weaning to optimize welfare and productivity

This experiment evaluated the impacts of bovine appeasing substance (BAS) administration on performance, behavioral, and physiological responses of beef calves upon weaning. Eighty Angus-influenced calves (40 heifers, 40 steers) were weaned at 233 ± 2 d of age (d 0), ranked by age and body weight (BW), and assigned to receive BAS (Nutricorp, Araras, SP, Brazil; n = 40) or placebo (diethylene glycol monoethyl ether; CON; n = 40). Treatments (5 mL) were topically applied to the nuchal skin area of each animal. Within treatment, calves were allocated to 1 of 8 drylot pens (4 pens/treatment) and received a free-choice total mixed ration (TMR) from d 0 to 42, intake of which was assessed daily. On d 0, calves were fitted with a pedometer behind their right shoulder, and pedometer results were recorded weekly during the experiment (d 0 to 42) concurrently with full BW collection and temperament evaluation. Blood samples were collected on d 0, 3, 7, 14, 28, and 42, and hair samples were collected from the tail switch on d 0, 14, 28, and 42. Average daily gain from d 0 to 42 did not differ between treatments (P = 0.52), but was greater (P = 0.05) in BAS vs. CON calves from d 0 to 28. Intake of TMR was greater during the first week for BAS vs. CON calves (P = 0.05), and similar (P ≥ 0.44) from wk 2 to 6 (treatment × week; P = 0.08). Exit velocity was greater (P = 0.03) for CON vs. BAS calves on d 14 and tended (P = 0.08) to be greater for CON vs. BAS calves on d 7 (treatment × day; P = 0.04). Physical activity was greater for CON vs. BAS calves on d 1 (P < 0.01), but greater (P = 0.01) in BAS vs. CON on d 2 (treatment × day; P = 0.01). Mean plasma concentrations of haptoglobin were greater (P = 0.03) in CON vs. BAS calves during the experiment. Hair cortisol concentrations were greater (P = 0.0 5) in CON vs. BAS calves on d 14 (treatment × day interaction; P = 0.03). Results from this experiment indicate BAS calves habituated to their environment more rapidly through increased physical activity, which facilitated a lessened stress response associated with weaning, and accelerated adaptation to a novel environment. This was manifested through improved TMR intake and BW gain during the initial period of the experiment. Collectively, results suggest use of BAS as a strategy to improve calf welfare and productivity upon weaning.

Administering an appeasing substance to optimize performance and health responses in feedlot receiving cattle

This experiment evaluated the impacts of administering a bovine appeasing substance (BAS) at feedlot entry to receiving cattle. Angus-influenced steers (n = 342) from 16 sources were purchased from an auction yard on day –1, and transported (12 hr; 4 trucks) to the feedlot. Upon arrival on day 0, shrunk body weight (BW; 240 ± 1 kg) was recorded and steers were ranked by load, shrunk BW, and source and assigned to receive BAS (IRSEA Group, Quartier Salignan, France; n = 171) or placebo (diethylene glycol monoethyl ether; CON; n = 171). The BAS is a mixture of fatty acids that replicate the composition of the bovine appeasing pheromone. Treatments (5 mL) were topically applied to each individual steer on their nuchal skin area. Steers were allocated to 1 of 24 drylot pens (12 pens/treatment) and received a free-choice diet until day 46. Steers were assessed daily for bovine respiratory disease (BRD) signs, and feed intake was recorded from each pen daily. Steer unshrunk BW was recorded on days 7, 17, 31, 45, and 46. Shrunk BW on day 0 was added an 8% shrink to represent initial BW, and final BW was calculated by averaging BW from days 45 and 46. Blood samples were collected from 5 steers/pen on days 0, 7, 11, 31, and 45. Pen was considered the experimental unit. Steer BW gain was greater (P = 0.04) in BAS vs. CON (1.01 vs. 0.86 kg/d, SEM = 0.05). Feed intake did not differ (P = 0.95) between treatments, resulting in greater (P = 0.05) feed efficiency in BAS vs. CON (171 vs. 142 g/kg, SEM = 10). Plasma cortisol concentration was greater (P = 0.05) and plasma glucose concentration was less in CON vs. BAS on day 7 (treatment × day; P = 0.07 and <0.01, respectively). Mean plasma β-hydroxybutyrate concentration was greater (P < 0.01) in BAS vs. CON (3.23 and 2.75 mg/mL; SEM = 0.12). Incidence of BRD was greater (P ≤ 0.05) in BAS vs. CON from days 6 to 10 and days 19 to 23 (treatment × day; P < 0.01), although overall BRD incidence did not differ (P = 0.20) between treatments (82.4% vs. 76.6%, respectively; SEM = 3.2). A greater proportion (P = 0.04) of BAS steers diagnosed with BRD required one antimicrobial treatment to regain health compared with CON (59.3% vs. 47.6%, SEM = 4.2). Hence, BAS administration to steers upon feedlot arrival improved BW gain during a 45-d receiving period by enhancing feed efficiency. Moreover, results suggest that BAS improved steer performance by facilitating early detection of BRD signs, lessening the disease recurrence upon first antimicrobial treatment.