Sulfonamides, also known as diaminosulfonyl, thioamide. The chemical formula SO2 (NH2) 2. The molecular weight is 96.11. Orthogonal plate-like crystals can absorb dry ammonia gas at room temperature to form a colorless ammonia complex, which is stable in acidic, neutral and alkaline aqueous solutions.
Very stable in the air. It decomposes at 250 ° C and mixes with anhydrous H2SO4 to form a transparent solution, but after 15 to 30 minutes, a white precipitate of aminosulfuric acid appears at room temperature.
When concentrated with an aqueous solution of equimolar LiOH, NaOH or Ba (OH) 2, crystals SO2N2H3Li, SO2N2H3Na or (SO2N2H3) 2Ba are formed.
Reacts with AgNO3 to form insoluble SO2 (NHAg) 2, and forms complexes with metal hydroxides, especially with Zn, Cu and Co hydroxides.
At present, the industry mainly uses sulfuryl chloride, liquid aminoacylation, and then hydrolyzed with hydrochloric acid to obtain Sulfonamides products.
How do Sulfonamides work
Sulfonamides mechanism of action
are bacteriostatic drugs, which inhibit the growth and reproduction of bacteria by interfering with their folate metabolism. Unlike human and mammalian cells, bacteria that are sensitive to Sulfonamidess cannot directly use folic acid in the surrounding environment, but can only use p-aminobenzoic acid (PABA) and dihydropteridine to be catalyzed by dihydrofolate synthase in bacteria Dihydrofolate is synthesized, and then tetrahydrofolate is formed by the action of dihydrofolate reductase. The activated form of tetrahydrofolate is a one-carbon unit of transporter, which plays an important role in the formation of purine and pyrimidine nucleotides. The structure of sulfa drugs is similar to p-aminobenzoic acid, so it can compete with p-aminobenzoic acid for dihydrofolate synthase, hindering the synthesis of dihydrofolate, thereby affecting the production of nucleic acids and inhibiting the growth and reproduction of bacteria.
What is Sulfonamides used for
Is Sulfonamides an antibiotic?
Sulfonamides is not an antibiotic but an antibacterial agent because it is not a substance isolated from microorganisms.
Sulfonamidess have a broad antibacterial spectrum and have inhibitory effects on a variety of cocci such as meningococcus, hemolytic streptococcus, pneumococcus, staphylococcus, gonococcus, and certain bacillus such as dysentery bacillus, E. coli, proteus, and plague, It can also inhibit some fungi (such as actinomycetes) and malaria parasites. Clinically used to treat epidemic cerebrospinal meningitis, upper respiratory tract infection (such as pharyngitis, tonsillitis, otitis media, pneumonia, etc.), urinary tract infection (such as acute or chronic urinary tract infection, mild pyelonephritis), intestinal infection Such as bacterial dysentery, enteritis, etc.), plague, local soft tissue or wound infection, eye infection (such as conjunctivitis, trachoma, etc.), malaria, etc.
Can be divided into three categories:
1. Sulfonamides for systemic infections This type of drug can be absorbed after oral administration, but the blood drug concentration duration is different. According to its t1 / 2, it can be divided into three categories: short-acting Sulfonamides (t1 / 2 is about 6 hours), medium-acting Sulfonamides (t1 / 2 is close to 12 hours) and long-acting Sulfonamides (t1 / 2 is more than 24 hours). At present, the main clinical application is medium-acting Sulfonamides, commonly used sulfamethoxazole (SMZ) and sulfadiazine (SD). Others are less used.
2. Intestinal Sulfonamides This kind of Sulfonamides is rarely absorbed after oral administration, and mainly plays a bacteriostatic role in the intestinal tract, including sulfa squina (SG), sulfathiazole succinate (SST), phthalsulfathiazole (PST), phthalaSulfonamides (siramid, PSA), etc.
3. The Sulfonamidess for external use mainly include sodium sulfacetamide (SA: SC-Na), mepyramine (SML), silver sulfadiazine (SD-Ag), etc.
Health hazards: Harmful by inhalation, ingestion or absorption through skin. This product is irritating to eyes, skin, mucous membranes and upper respiratory tract.
Explosion hazard: This product is flammable and irritating.
Dangerous characteristics: Combustible in case of fire or high heat. Decomposition by heat, release toxic gases such as nitrogen and sulfur oxides.
Sulfonamides side effects
Sulfonamides drugs that are difficult to absorb rarely cause adverse reactions. The incidence of easily absorbed adverse reactions accounts for about 5%.
1. Kidney damage. Due to the low solubility of acetylated Sulfonamides, especially when the urine is acidic, crystals are easily precipitated in the renal tubules, causing symptoms such as hematuria, dysuria, and urinary closure. In order to prevent the occurrence of this toxic reaction, the following measures can be taken to prevent: add bicarbonate or citrate to alkalinize the urine and increase the solubility of the discharge; drink plenty of water to increase the urine volume, and also reduce the discharge Concentration; the elderly and those with poor renal function should be used with caution.
2. Influence of hematopoietic system. Sulfa drugs can inhibit the formation of bone marrow leukocytes, causing leukopenia. Occasionally, there is a lack of granulocytes, which can be restored after stopping the drug. Long-term application of sulfa drugs should check the blood. Congenital lack of glucose 6-phosphate dehydrogenase can cause hemolytic anemia. Sulfa drugs can enter the fetal circulation through the mother, compete with free bilirubin for plasma protein binding sites, and increase the concentration of free bilirubin, causing nuclear jaundice. It is not suitable for pregnant women and newborns, especially premature babies.
3. Central nervous system and gastrointestinal reactions. Mostly due to the sufficient amount of Sulfonamides.
Allergy to Sulfonamides
The most common are rashes and fever. It usually occurs 5 to 9 days after medication, especially in children. There is cross-allergy between Sulfonamides, so when a patient is allergic to sulfonamides, it is not safe to switch to other sulfonamides. Once an allergic reaction occurs, the drug should be stopped immediately. Long-acting Sulfonamides have a high rate of binding to plasma proteins, and there are still drugs in the blood for a few days after drug withdrawal, so the risk is great.
Sulfonamides drugs are a class of synthetic bacteriostatic agents that are often used as growth promoters and chemotherapeutic drugs for animals, but the residues of these drugs have the potential to cause carcinogenicity and resistance to the human body.
Sulfonamides Rapid Test Dipsticks can quickly detect whether the honey contains residual sulfonamides. It is not only simple to operate, but also has short detection time and high accuracy, and the test results comply with EU standards.