Synthesis, Thermochromic Properties and Thermal Behavior of some Schiff Bases.Part I. p,p'-Diaminodiphenylmethane-Schiff Bases and Sulphonamide Schiff Base

p,p'-Diaminodiphenylmethane-Schiff bases (SB) of general formula (R)-phCH=N- ph-CH2-ph-N=CHph(R), where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, and sul- phonamide Schiff bases (SB) of general formula (R)-phCH=N-ph-SO2NH2, where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, were synthesized and their structure have been characterized by the melting pointing, 1HNMR, MS, and elemental analysis. They are thermolabile and undergo thermo-chromism and thermal decomposition after melting. The TG. and DSC measurement were recorded in dynamic air and interpreted.

Synthesis of Caffeic Acid Sulphonamide Derivatives and Preliminary Exploration of Their Biological Applications

Stnictural modification of native compounds is an effective way to develop new dmgs with increased pharmacological activities and improved material characteristics.In this study,cafteic acid sulphonamide derivatives(CSs)were synthesised by conjugating sulphonamides to the backbone of cafteic acid.The structures of these derivatives were elucidated by means of Fourier traiisfonn infrared spectroscopy(FTIR),1H NMR,13C NMR,and electrospray ionization mass spectroscopy(ESI-MS).A content determination method was established by ultraviolet detection.The lipophilicity,2,2-diphenyl-l-picrylhydrazy free radical(DPPH)scavenging capacity,anti-coagulant eitects,anti-bacterial activity,cytotoxicity,in vitro anti-proliterative activity against tumour cells,and the ability of the compounds to promote the proliferation of chondrocytes were evaluated.The results indicate that CSs exliibit strong DPPH scavenging activity,high lipophilicity,good anti-coagulant activities,wide anti-bacterial activity range,low cytotoxicity,and an excellent ability to promote chondrocyte proliferation.

Efficacy of oxytetracycline and potentiated sulphonamide oral therapies against Aeromonas hydrophila infection in Nile tilapia Oreochromis niloticus

Objective: To assess the efficacy of feeds containing approved antibiotics, viz., oxytetracycline (OTC) or potentiated sulphonamide [(sulphamethoxazole-trimethoprim) SMZ-TMP] at 1 g, 2 g, 3 g and 4 g of respective antibiotics/kg feed at 2% body weight ration in preventing the Aeromonas hydrophila (A. hydrophila) infection in Oreochromis niloticus. Methods: Commercial pellet feed was top dressed with respective antibiotics using 5 mL vegetable oil as a binder. Fish were injected intramuscularly with A. hydrophila at ≈ 6.0 × 107–8.6 × 107 CFU/fish, and fed subsequently with OTC and SMZ-TMP feeds for 10 and 5 days, respectively. Fish mortalities were recorded during the pre-treatment, treatment and post-treatment periods. Results: Highest mortalities (7.42%–8.33%) were observed in challenged and untreated fish. The mortalities observed in fish fed with OTC or SMZ-TMP were 0%–6.66% with decreasing concentrations of antibiotics from 4 to 1 g/kg feed. Significant differences existed in the mortalities among fish fed with different doses of antibiotics (P < 0.05). The relative percent survival values were 20, 40, 40 and 60 for 1 g, 2 g, 3 g and 4 g OTC/kg feed groups, respectively;while in SMZ-TMP fed fish, the respective relative percent survival values were 10, 100, 100, and 100. Conclusions: The fish fed with feed containing 2 g antibiotic/kg at 2% body weight was the lowest concentration that recorded significantly lower mortality (P < 0.05), which could be the treatment of choice for the control of A. hydrophila in Oreochromis niloticus in tropical condition.

Immune system as a new therapeutic target for antibiotics

Since the discovery of penicillin by Fleming in 1928, the knowledge of the antibiotics’ spectrum and mechanism of action has been steadily increasing. Antibiotics became an effective tool in the fight against many pathogens, changing the prognosis of outcome for many serious diseases. It is already known that antibiotics not only have the antibacterial activity, but many of them—e.g. macrolides, sulphonamides and tetracyclines—have immunomodulating effect, affecting functions of lymphocytes, macrophages and costimulatory molecules, macrophage migration and phagocytosis, as well as proinflammatory cytokine secretion. The expanding knowledge of the effects of antibiotics on the immune system has brought with it new applications of antibiotics in organ transplantation, invasive cardiology and treatment of autoimmune diseases such as rheumatoid arthritis or asthma.

Efficacy of Different Concentrations of Aloe chabaudii Leaf Gel as a Substitute for a Sulfonamide for the Control of Avian Coccidiosis

The objective of this study was to investigate the effectiveness of Aloe chabaudii schonland juice as a potential substitute of sulphonamide drugs and to measure its effects when administered at different concentrations in the control of avian coccidiosis. 30 cobb and 500 broiler chickens were used for the experiment. The broilers were randomised into six groups of five birds each and the groups were assigned to six treatments in a Complete Randomised Design (CRD). Four of the groups were given any one of the following treatments, different concentrations of Aloe (weight/volume: 10%, 20% and 30%) and a sulphonamide. There was a control group which was not given a treatment and one cohort group which was neither infected nor treated. At two weeks of age, 25 of the birds were infected with coccidia via drinking water using infected chicken fecal matter, while the remaining five birds were left uninfected. Infection proceeded for 1 week and after the infection period, fecal oocysts were counted from each individual bird using the McMaster technique. Treatments started one day after the infection and continued for one week after 20 gram samples of fecal matter were taken from each bird per treatment and oocysts were counted. After oocyst counting, all birds were slaughtered and lesion scoring was done on the intestines using the Johnson and Reid technique. Data was analysed for oocysts count in different treatments, fecal egg count reduction, relative risk of coccidiosis and the effectiveness of Aloe concentrations as a substitute for a commercial sulphonamide. The results showed that the concentrations of Aloe used in the experiment were not effective as compared to the sulphonamide in controlling coccidiosis as the fecal egg reduction was below 90% for all concentrations. The relative risk of coccidiosis infection in the farm was found to be 100%, meaning that coccidiosis is a disease of economic importance at the farm. However, there was a reduction in the fecal oocyst count with increase in Aloe juice concentration to control coccidiosis, though this could not be compared to sulphonamide (ESB3) which was more effective (p 0.05). This study has shown that there is potential for use of Aloe chabaudii leaf gel as a chemotherapeutic though much research is needed to determine absolute concentrations which will make it comparable to commercially available drugs in terms of efficacy.

Potential for natural and enhanced attenuation of sulphanilamide in a contaminated chalk aquifer

Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry（IRMS）method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ^（13）C of8.44‰ from-26.56（at the contaminant source） to-18.12‰（300 m downfield of the source）.These results confirm reductions in sulphanilamide concentrations（from 650 to 10 mg/L）across the contaminant plume to be attributable to biodegradation（56%） vs. other natural attenuation processes, such as dilution or dispersion（42%）. To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity（~50% mineralisation） to degrade sulphanilamide under high（263 mg/L）, moderate（10 mg/L） and low（0.02 mg/L） substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.