The luminous efficiency of isoluminol is better than that of luminol
Before the chemiluminescent agent acridinium ester, the luminescent substrates are mainly enzymatic chemiluminescent substrates, such as: luminol, isoluminol, peroxyoxalate, etc. Luminol-based reagents have become the most widely used chemiluminescent reagents because of their high luminescence quantum yield and good water solubility, which can chemically react with a variety of oxidants.
The main difference between isoluminol and luminol:
Both isoluminol and luminol are chemiluminescent agents. Under the catalysis of peroxidase or hemoglobin, iron, etc., they react with hydrogen peroxide to emit blue fluorescence, and their emission is similar to that of hydrogen peroxide. proportional to the concentration. In life, we often see the use of luminol to detect trace blood, as well as copper, iron and cyanide in cells. Although isoluminol is not as widely used as luminol, it has an irreplaceable role in blood testing. The cyclic hydrazide structure is the main structure for chemiluminescence of luminol and isoluminol compounds, and related modifications will lead to almost complete loss of chemiluminescence properties; modification of the amino group of luminol and isoluminol compounds , will lead to a significant decrease in the luminous efficiency of luminol, while the luminous efficiency of isoluminol is significantly improved, which can be said to be better.
Synthesis of isoluminol
Taking phthalic hydrazide as raw material to prepare the method for isoluminol, comprising the steps:
Step 1: Preparation of Diacetylphthalohydrazide
Under stirring at room temperature, 60 g of dry phthalohydrazide waste (47% purity) and 200 ml of acetic acid were added to a 500 ml three-necked flask, and the mixture was stirred uniformly. 30 g of sodium acetate was added thereto, and the mixture was stirred at room temperature for 30 minutes, and then 40 g of acetyl chloride was added dropwise, and the drop was completed within 30 minutes. After stirring at room temperature for 1 hour, the temperature was raised to 70°C and the reaction was continued for 5 hours. Spot the plate to confirm that the phthalic hydrazide has been completely converted into the desired product, stop the reaction, and naturally cool the reaction solution to room temperature. The reaction solution was directly carried out to the next step without further treatment.
Step 2: Preparation of Nitrosodiacetylphthalohydrazide
At room temperature, add 15 g of sodium nitrite in batches to the reaction solution in the previous step, and stir at room temperature for 3 hours after adding, and spot the plate to confirm that the diacetyl phthalohydrazide has been completely converted into the desired product. After the reaction is stopped, acetic acid is recovered by distillation under reduced pressure, and the residue is the crude product of 4-nitrosodiacetylphthalic hydrazide, which can be directly used in the next reaction without further treatment.
Step 3: Preparation of Nitrosophthalohydrazide
Under stirring at room temperature, add the crude product of 4-nitrosodiacetylphthalic hydrazide obtained in the previous step to a 500ml three-necked flask, add 200ml of 95v/v% ethanol to it, stir evenly, and add 10g hydrogen in batches. Sodium oxide. After the addition, the reaction was refluxed for 5 hours, and it was confirmed by spotting that 4-nitrosodiacetylphthalic hydrazide had been completely converted into the desired product, the reaction was stopped, and the reaction solution was naturally lowered to room temperature. The reaction solution was directly carried out to the next step without further treatment.
Step 4: Preparation of isoluminol
Under stirring at room temperature, 10 g of sodium thiosulfate was added to the reaction solution in the previous step at one time, and after the addition, the mixture was stirred at room temperature for 30 minutes. Then heating and refluxing for 3 hours, it was confirmed by spotting that 4-nitrosophthalic hydrazide had been completely converted into the desired product, the reaction was stopped, and the reaction solution was naturally lowered to room temperature, followed by filtration to collect the filter cake. The filtrate was rotary-evaporated to recover 95% ethanol, the residue was combined with the filter cake, added to 200 ml of water, heated to 80° C., stirred for 30 minutes, and some solids were still insoluble, filtered while hot. Concentrated hydrochloric acid was added to the filtrate to adjust the pH to 9, followed by natural cooling for crystallization. Filtration yielded 26 g of light yellow powdery product.
Desheng Biochemical, since 2005, has been committed to the research and development, production and sales of blood collection tube additives and blood test reagents. Luminescence reaction substrates and direct luminescence chemiluminescence substrates mainly based on acridine esters and their derivatives. If you want to purchase chemiluminescence reagents, please visit Desheng's official website or call the hotline for more product information.
When it comes to the chemiluminescent reagent Luminol, it is not unfamiliar to everyone and is commonly used in the field of criminal investigation to detect blood stains. Researchers have found that the principle of luminol luminescence can be used to detect specific substances in saliva, such as proteins, DNA, and related indicators of microorganisms, in order to determine physical conditions.