Thiocyanic acid group substituted Schiff base copper-containing complex as well as preparation method and application of thiocyanic acid group substituted Schiff base copper-containing complex

Abstract

The invention discloses a thiocyanic acid group substituted Schiff base copper-containing complex, a preparation method and application, the molecular formula of the compound is C30H34CuN4O2S2, and the molecular structural formula is as follows: # imgabs0 #. The compound provided by the invention has a good urease inhibition effect, the inhibition rate of 50 [mu] g.mL <-1 > on urease is 93%, the IC50 value is 0.22 + / -0.07 [mu] g.mL <-1 >, and the compound can be used as a urease inhibitor in industrial application; the preparation method provided by the invention avoids complex organic synthesis process, high temperature and other reaction conditions, is simple to operate, reduces energy consumption, and the prepared compound is high in yield (83-93%), high in purity and good in stability.

Description

Technical Field

[0001] The present invention relates to the field of preparation of new compounds, and in particular to a thiocyanate-substituted Schiff base copper-containing complex, a preparation method and application thereof. Background Art

[0002] Schiff base compounds have good physiological and pharmacological activities and have good application prospects in antibacterial, anti-inflammatory and enzyme inhibition. The introduction of sulfur-containing groups into Schiff base compounds helps to enhance the physiological and pharmacological activities of the target compounds. At the same time, Schiff base compounds contain donor atoms such as O and N, which can easily form complexes with various transition metal ions and play a catalytic role in certain organic reactions. The complexes formed by Schiff base and copper usually have good urease inhibition effects. The Schiff base copper complexes containing thiocyanate ligands reported in the literature have inhibitory effects on urease: (1) IC 50 = 2.7 μmol·L -1 (i.e. 2.13 μg mL -1 )[Baihui He, Qiyu Wang, Xiaoqing Zhang, Dahua Shi, Zhonglu You. Inorg. Chim. Acta, 2023, 558, 121738];(2) IC 50 = 1.3 μmol·L -1 (i.e. 0.78 μg mL -1 )[Xinhui Feng, Wenlong Wu, Yuqing Gu, Li Zhang, Shiyi Wang,Jie Zhao, Jing Ji, Dahua Shi, Zhonglu You. Journal of Coordination Chemistry,2022, 75, 720-728]. The Schiff base copper complexes without thiocyanate group reported in the literature have inhibitory effects on urease: (1) IC 50 = 1.2 μmol·L -1 (i.e. 0.40 μg mL -1 ) and 1.0 μmol·L -1 (i.e. 0.37 μg mL -1 ) [Jing Ji, Shiyi Wang, Jie Zhao, Ting Yang, Jiaqi Wang, Zhonglu You. Journal of Coordination Chemistry, 2022, 75, 120-135].

[0003] Existing Schiff base compounds containing sulfur groups mainly contain thiol, thioether bond, thiocarbonyl, etc., while Schiff base compounds containing thiocyanate are rarely reported due to their complex organic reaction process, and there are no relevant reports on thiocyanate-substituted Schiff base copper-containing complexes. Summary of the invention

[0004] The present invention aims to solve the above technical problems existing in the prior art and provides a thiocyanate-substituted Schiff base copper-containing complex, a preparation method and use thereof.

[0005] The technical solution of the present invention is: a thiocyanate-substituted Schiff base copper-containing complex, the molecular formula of which is C 30 H 34 CuN4O2S2, the molecular structure is shown in Formula I:

[0006] Formula Ⅰ.

[0007] A method for preparing the thiocyanate-substituted Schiff base copper-containing complex according to claim 1, comprising the following steps: Step 1. Dissolve 3-tert-butyl salicylaldehyde and 1,2-cyclohexanediamine in alcohol solvents respectively, add the alcohol solution of 1,2-cyclohexanediamine to the alcohol solution of 3-tert-butyl salicylaldehyde, then add ammonium thiocyanate and copper chloride, and stir to react at 0-40° C.; the molar ratio of 3-tert-butyl salicylaldehyde, 1,2-cyclohexanediamine, ammonium thiocyanate, and copper chloride is 2:1:2:1-2; Step 2. Evaporate the alcohol solvent to precipitate crystals, and filter to obtain the compound of formula I.

[0008] Preferably, the alcohol solvent is methanol or ethanol.

[0009] Preferably, the molar ratio of the 3-tert-butyl salicylaldehyde, 1,2-cyclohexanediamine, ammonium thiocyanate and cupric chloride is 2:1:2:1.

[0010] Preferably, the stirring reaction temperature is 20-25°C.

[0011] Preferably, the temperature for evaporating the alcohol solvent is 20-25°C.

[0012] A use of the above-mentioned thiocyanate-substituted Schiff base copper-containing complex as a urease inhibitor.

[0013] The thiocyanate-substituted Schiff base copper-containing complex provided by the present invention has good urease inhibition effect, 50 μg·mL -1 The inhibition rate of urease was 93%, IC 50 The value was 0.22±0.07μg·mL -1The preparation method provided avoids complicated organic synthesis processes and reaction conditions such as high temperature, is simple to operate, reduces energy consumption, and the prepared compounds have high yield (83-93%), high purity, and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Graph showing the molecular structure of the compounds of the present invention.

[0015] Figure 2 It is the infrared spectrum of the compound of the embodiment of the present invention.

[0016] Figure 3 is the X-ray powder diffraction pattern of the example compound of the present invention.

[0017] Figure 4 It is a time-absorbance graph of the inhibitory activity of the example compounds of the present invention on urease.

[0018] Figure 5 The graph is a concentration-inhibition rate graph of the inhibitory activity of the example compounds of the present invention on urease. DETAILED DESCRIPTION Example

[0019] 3-tert-Butyl salicylaldehyde (3.6 g, 0.020 mol) and 1,2-cyclohexanediamine (1.1 g, 0.010 mol) were dissolved in methanol (50 mL) respectively. The methanol solution of 1,2-cyclohexanediamine was added to the methanol solution of 3-tert-butyl salicylaldehyde, and the mixture was reacted at 20°C for 10 minutes. Then, ammonium thiocyanate (1.5 g, 0.020 mol) and cupric chloride (1.3 g, 0.010 mol) were added, and the mixture was stirred for 10 minutes. The filtrate was slowly evaporated at 20-25°C to obtain crystals with a yield of 92%.

[0020] Embodiment 2: 3-tert-Butyl salicylaldehyde (3.6 g, 0.020 mol) and 1,2-cyclohexanediamine (1.1 g, 0.010 mol) were dissolved in methanol (50 mL) respectively. The methanol solution of 1,2-cyclohexanediamine was added to the methanol solution of 3-tert-butyl salicylaldehyde. The mixture was reacted in an ice-water bath (0°C) for 10 minutes. Then, ammonium thiocyanate (1.5 g, 0.020 mol) and cupric chloride (1.3 g, 0.010 mol) were added. The mixture was stirred for 10 minutes. The filtrate was slowly evaporated at 20-25°C to obtain crystals with a yield of 83%.

[0021] Embodiment 3: 3-tert-Butyl salicylaldehyde (3.6 g, 0.020 mol) and 1,2-cyclohexanediamine (1.1 g, 0.010 mol) were dissolved in methanol (50 mL) respectively. The methanol solution of 1,2-cyclohexanediamine was added to the methanol solution of 3-tert-butyl salicylaldehyde and reacted at 30°C for 10 minutes. Then, ammonium thiocyanate (1.5 g, 0.020 mol) and cupric chloride (1.3 g, 0.010 mol) were added and stirred for 10 minutes. The filtrate was slowly evaporated at 20-25°C to obtain crystals with a yield of 93%.

[0022] Embodiment 4: 3-tert-Butyl salicylaldehyde (3.6 g, 0.020 mol) and 1,2-cyclohexanediamine (1.1 g, 0.010 mol) were dissolved in methanol (50 mL) respectively. The methanol solution of 1,2-cyclohexanediamine was added to the methanol solution of 3-tert-butyl salicylaldehyde and reacted at 40°C for 10 minutes. Then, ammonium thiocyanate (1.5 g, 0.020 mol) and cupric chloride (1.3 g, 0.010 mol) were added and stirred for 10 minutes. The filtrate was slowly evaporated at 20-25°C to obtain crystals with a yield of 93%.

[0023] Embodiment 5: 3-tert-Butyl salicylaldehyde (3.6 g, 0.020 mol) and 1,2-cyclohexanediamine (1.1 g, 0.010 mol) were dissolved in ethanol (50 mL) respectively. The methanol solution of 1,2-cyclohexanediamine was added to the methanol solution of 3-tert-butyl salicylaldehyde. The mixture was reacted at 20°C for 10 minutes. Then, ammonium thiocyanate (1.5 g, 0.020 mol) and cupric chloride (1.3 g, 0.010 mol) were added. The mixture was stirred for 10 minutes. The filtrate was slowly evaporated at 20-25°C to obtain crystals with a yield of 87%.

[0024] Embodiment 6: 3-tert-Butyl salicylaldehyde (3.6 g, 0.020 mol) and 1,2-cyclohexanediamine (1.1 g, 0.010 mol) were dissolved in methanol (50 mL) respectively. The methanol solution of 1,2-cyclohexanediamine was added to the methanol solution of 3-tert-butyl salicylaldehyde, and the mixture was reacted at 20°C for 10 minutes. Then, ammonium thiocyanate (0.76 g, 0.010 mol) and cupric chloride (2.6 g, 0.020 mol) were added, and the mixture was stirred for 10 minutes. The filtrate was slowly evaporated at 20-25°C to obtain crystals with a yield of 89%.

[0025] The molecular formula of the crystals obtained in Examples 1-6 of the present invention is C 30 H 34CuN4O2S2, the molecular structure is as follows:

[0026] Molecular structure diagram Figure 1 shown.

[0027] The infrared spectrum of the compound of Example 1 of the present invention is as follows Figure 2 As shown. Figure 2 It can be seen that: at 2149 cm -1 The strong absorption peak can be attributed to the stretching vibration absorption of thiocyanate group, which is located at 1621 cm -1 The strong absorption peak can be attributed to the C=N stretching vibration absorption of the specific functional group of Schiff base, indicating that a Schiff base compound containing thiocyanate group has been prepared.

[0028] The X-ray powder diffraction pattern of the compound in Example 1 of the present invention is as follows Figure 3 As shown. Figure 3 It can be seen that the compound is in pure phase and its molecular structure is consistent with the structure of the crystal tested for single crystal diffraction.

[0029] Experiment on the inhibition of urease activity by the compound of Example 1 of the present invention: 1) Preparation of buffer solution Weigh 31.2 g of sodium dihydrogen phosphate and 71.6 g of disodium hydrogen phosphate, prepare 1000 mL of each solution, and then prepare phosphate buffers with different pH values.

[0030] Prepare a phosphate buffer solution with a pH of 6.8. The volume ratio of sodium dihydrogen phosphate solution to sodium hydrogen phosphate solution is 255:245.

[0031] A phosphate buffer solution with a pH of 7.7 was prepared with a volume ratio of sodium dihydrogen phosphate solution to sodium dihydrogen phosphate solution of 502.5:449.75.

[0032] 2) Preparation of urease solution and substrate: Weigh 24 mg of urease into a brown bottle, add 6 mL of pH = 6.8 phosphate buffer solution, and shake to fully dissolve the urease.

[0033] Measure 100 mL of pH = 6.8 buffer solution, add 0.002% (2 mg) phenol red and 500 mmol urea to prepare a substrate solution with pH = 6.8.

[0034] Measure 100 mL of pH = 7.7 buffer solution and add 0.002% (2 mg) phenol red to prepare a substrate solution with pH = 7.7.

[0035] 3) Prepare 1 mg·mL -1 The test solution: Weigh 1 mg of the compound sample of Example 1 of the present invention, add 1 mL of DMSO to prepare a concentration of 1 mg·mL -1 Solution to be tested.

[0036] 4) Design of 96-well plate: Blank: 25 μL of urease was measured with a 100 μL micropipette, 2.5 μL of DMSO was measured with a 10 μL pipette, and then 22.5 μL of phosphate buffer solution with pH = 6.8 was added, and pre-incubated for 3 hours.

[0037] Sample: Use a 100 μL micropipette to measure 25 μL of urease, add 2.5 μL of sample measured with a 10 μL pipette, and then add 22.5 μL of pH = 6.8 phosphate buffer solution, pre-incubate for 3 hours.

[0038] Standard: Use a 100 μL micropipette to measure 50 μL of pH = 7.7 phosphate buffer solution.

[0039] The sample and standard curve were run 3 times, and the blank curve was run 6 times to reduce experimental errors.

[0040] 5) Measurement of urease inhibitory activity: After incubation for 3 hours, add 200 μL of pH = 6.8 substrate solution to the blank and sample wells of the 96-well plate, add 200 μL of pH = 7.7 substrate solution to the standard wells, and immediately place it in the microplate reader, set the temperature to 37°C, the time to 40 min, absorb light at a wavelength of 570 nm, and test the absorbance value.

[0041] 6) IC 50 test: The solution of the compound of Example 1 of the present invention was divided into 5 gradient concentrations (μg·mL -1 ): 0.001, 0.01, 0.1, 1, 10, and test their absorbance values ​​using the same experimental method as in the previous step.

[0042] 7) Inhibition of urease activity by compounds: With time (min) as the abscissa and absorbance value as the ordinate, a time-absorbance graph of the inhibitory activity of the compound in Example 1 of the present invention on urease was drawn, as shown in FIG. Figure 4As shown. Urease reacts with urea to produce ammonia, which increases the pH value of the substrate solution, and the color of the substrate solution containing phenol red changes from yellow to red. The compound in Example 1 of the present invention inhibits the activity of urease, slowing down the rate at which urea is hydrolyzed to produce ammonia. The slope of the compound curve is compared with the slope of the blank curve. The smaller the ratio, the smaller the change in absorbance value, and the better its inhibitory activity.

[0043] according to Figure 4 , the calculated concentration is 50 μg·mL -1 The inhibitory activity of the compound on urease is calculated as follows: Inhibition rate (%) = (1 – K 化合物 / K 空白 ) × 100% = 93%.

[0044] The present invention also tested the IC of the compound of Example 1 of the present invention for inhibiting urease activity. 50 The concentration is used as the horizontal axis and the inhibition rate is used as the vertical axis to draw a concentration-inhibition rate curve of the inhibitory activity of the compound on urease, such as Figure 5 As shown, its IC 50 The value was 0.22±0.07μg·mL -1 .

Claims

1. A thiocyanate-substituted Schiff base copper-containing complex, characterized in that: The molecular formula is C 30 H 34 CuN4O2S2, the molecular structure is shown in Formula I: Formula Ⅰ.

2. A method for preparing the thiocyanate-substituted Schiff base copper-containing complex as claimed in claim 1, characterized in that Follow these steps: Step 1. Dissolve 3-tert-butyl salicylaldehyde and 1,2-cyclohexanediamine in alcohol solvents respectively, add the alcohol solution of 1,2-cyclohexanediamine to the alcohol solution of 3-tert-butyl salicylaldehyde, then add ammonium thiocyanate and copper chloride, and stir to react at 0-40° C.; the molar ratio of 3-tert-butyl salicylaldehyde, 1,2-cyclohexanediamine, ammonium thiocyanate, and copper chloride is 2:1:2:1-2; Step 2. Evaporate the alcohol solvent to precipitate crystals, and filter to obtain the compound of formula I.

3. The method for preparing the thiocyanate-substituted Schiff base copper-containing complex according to claim 2, characterized in that: The alcohol solvent is methanol.

4. The method for preparing the thiocyanate-substituted Schiff base copper-containing complex according to claim 3, characterized in that: The molar ratio of the 3-tert-butyl salicylaldehyde, 1,2-cyclohexanediamine, ammonium thiocyanate and cupric chloride is 2:1:2:

1.

5. The method for preparing the thiocyanate-substituted Schiff base copper-containing complex according to claim 4, characterized in that: The temperature of the stirring reaction is 20-25°C.

6. The method for preparing the thiocyanate-substituted Schiff base copper-containing complex according to claim 5, characterized in that: The temperature of evaporating the alcohol solvent is 20-25°C.

7. Use of the thiocyanate-substituted Schiff base copper-containing complex as claimed in claim 1 as a urease inhibitor.

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