A 5-METHYLCHROMONE AND THE PREPARATION METHOD AND APPLICATION THEREOF

Abstract

Disclosed is a 5-methylchromone and the preparation method and application thereof, the 5-methylchromone has the following structure:

##STR00001##

wherein R1 and R2 are alkyl groups. The substituted chromone has the biological activity of inhibiting tyrosinase. The preparation method uses 3,5-dihydroxytoluene as a raw material, and synthesis of chromones substituted with different groups at 2-C through acylation, esterification, rearrangement and cyclization reactions, etc. The 5-methylchromone is a completely new compound in condition that R1 is —CH.sub.2CH.sub.2CH.sub.3, and R2 is —CH.sub.2CH.sub.3, or that R1 is —C(CH.sub.3).sub.3, and R2 is H. All the compounds have obvious inhibitory activity against tyrosinase, and can be used to prepare tyrosinase inhibitors or whitening agents.

Claims

1. A 5-methylchromone, having the structure shown in formula (1): ##STR00023## where R1 is —CH.sub.2CH.sub.2CH.sub.3 and —C(CH.sub.3).sub.3, R2 is H and —CH.sub.2CH.sub.3.

2. The 5-methylchromone according to claim 1, having the structure shown in formula (1-6): ##STR00024##

3. The 5-methylchromone according to claim 1, having the structure shown in formula (1-4): ##STR00025##

4. A preparation method of 5-methylchromone, having reaction formula: ##STR00026## where R1 is —CH.sub.3, —CH.sub.2CH.sub.3, —CH.sub.2CH.sub.2CH.sub.3, —C(CH.sub.3).sub.3; the preparation method comprising: dissolving the compound 1-c and the compound 1-e in the DCM, adding the DMAP, cooling to 0° C., adding the EDCI, raising to room temperature, and stirring to react; after the reaction being completed, extracting with ethyl acetate and water, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography, the purification solvent A being petroleum ether and ethyl acetate, obtaining the compound 1-f; dissolving the compound 1-f in the DMSO, adding the NaOH, and stirring to react; after the reaction being completed, extracting with ethyl acetate and water, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography, the purification solvent B being petroleum ether and ethyl acetate, obtaining the compound 1-g; dissolving compound the 1-g in the 1,4-dioxane, dripping concentrated hydrochloric acid solution, and stirring to react; after the reaction being completed, concentrating under reduced pressure, washing the residue with dichloromethane, obtaining the target compound; wherein if R1 is —CH.sub.3, it is obtained for a target compound 1-1; R1 being —CH.sub.2CH.sub.3, obtained for a target compound 1-2; if R1 is —CH.sub.2CH.sub.2CH.sub.3, it is obtained for a compound 1-3; R1 being —C(CH.sub.3).sub.3, obtained for the target compound 1-4.

5. The preparation method of 5-methylchromone according to claim 4, wherein, in condition that the R1 is —CH.sub.3, —CH.sub.2CH.sub.3, —CH.sub.2CH.sub.2CH.sub.3, the purification solvent A is prepared from petroleum ether and ethyl acetate in a volume ratio of 7:1; the purification solvent B is prepared from petroleum ether and ethyl acetate in a volume ratio of 6:1; in condition that the R1 is —C(CH.sub.3).sub.3, the purification solvent A is prepared from petroleum ether and ethyl acetate in a volume ratio of 8:1; the purification solvent B is prepared from petroleum ether and ethyl acetate in a volume ratio of 7:1.

6. A preparation method of 5-methylchromone, having reaction formula: ##STR00027## the preparation method comprising: dissolving the compound 1-3 according to claim 4 and iodoethane in acetone, then adding K.sub.2CO.sub.3, heating to reflux and stirring to react; after the reaction being completed, concentrating under reduced pressure, separating and purifying the residue by column chromatography, the purification solvent being petroleum ether and ethyl acetate, obtaining the target compound 1-6.

7. A preparation method of 5-methylchromone, wherein the compound 1-3 according to claim 4 is reacted with iodomethane to obtain the compound 1-5, having reaction formula: ##STR00028## the preparation method comprising: dissolving the compound 1-3 and iodomethane in acetone, adding K.sub.2CO.sub.3, heating reflux and stirring to react; after the reaction being completed, concentrating under reduced pressure, and separating and purifying the residue by column chromatography; the purification solvent being petroleum ether and ethyl acetate in a volume ratio of 6:1, obtaining the target compound 1-5.

8. A tyrosinase inhibitor or whitening agent comprising a compound as shown in the formula (1) ##STR00029## wherein the R1 is —CH.sub.3, —CH.sub.2CH.sub.3, —CH.sub.2CH.sub.2CH.sub.3 and —C(CH.sub.3).sub.3, and the R2 is H, —CH.sub.3 and —CH.sub.2CH.sub.3.

9. A tyrosinase inhibitor or whitening agent comprising the compound of claim 1. ##STR00030##

10. A tyrosinase inhibitor or whitening agent comprising the compound of claim 2.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0034] FIG. 1 shows the .sup.1H NMR chart of compound 1-1 of the present invention;

[0035] FIG. 2 shows the .sup.13C NMR chart of compound 1-1 of the present invention;

[0036] FIG. 3 shows the .sup.1H NMR chart of compound 1-2 of the present invention;

[0037] FIG. 4 shows the .sup.13C NMR chart of compound 1-2 of the present invention;

[0038] FIG. 5 shows the .sup.1H NMR chart of compound 1-3 of the present invention;

[0039] FIG. 6 shows the .sup.13C NMR chart of compound 1-3 of the present invention;

[0040] FIG. 7 shows the .sup.1H NMR chart of compound 1-4 of the present invention;

[0041] FIG. 8 shows the .sup.13C NMR chart of compound 1-4 of the present invention;

[0042] FIG. 9 shows the .sup.1H NMR chart of compound 1-5 of the present invention;

[0043] FIG. 10 shows the .sup.13C NMR chart of compound 1-5 of the present invention;

[0044] FIG. 11 shows the .sup.1H NMR chart of compound 1-6 of the present invention;

[0045] FIG. 12 shows the .sup.13C NMR chart of compound 1-6 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0046] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0047] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are conventional methods.

[0048] The materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources unless otherwise specified.

1. Synthesis of Target Compound

Synthesis of Compound 1-b

[0049] ##STR00009##

[0050] Adding the compound 1-a (10 mmol, 1.24 g), anhydrous acetic acid (70 mmol, 4 mL) and boron trifluoride etherate (21 mmol, 2.6 mL) into a 25 mL round bottom flask, and heating to 80° C. and magnetically stirring to react for 12 h; after the reaction being completed, cooling to room temperature, then extracting with ethyl acetate and water twice, taking the organic phase, washing with saturated sodium bicarbonate solution for three times until no bubbles being generated, and then washing with saturated salt aqueous solution once, drying with anhydrous sodium sulfate, concentrating under reduced pressure, then performing the recrystallization, obtaining the compound 1-b (0.99 g, yield 60%) as a yellowish white powder.

Synthesis of Compound 1-c

[0051] ##STR00010##

[0052] Dissolving the compound 1-b (10 mmol, 1.66 g) in 10 mL of dichloromethane, and cooling to 0° C. with an ice bath, slowly dropping MEM-Cl (12 mmol, 1.36 mL), then the temperature being raised naturally, and magnetic stirring to reaction for 3 h; after the reaction being completed, directly concentrating under reduced pressure to remove the solvent. separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=7:1, v/v), obtaining a colorless oily liquid compound 1-c (2.28 g, yield 90%).

Synthesis of Compound 1-1

[0053] ##STR00011##

[0054] Dissolving compound the 1-c (10 mmol, 2.54 g) and compound the 1-e-1 (12 mmol, 0.72 g) in 20 mL of dichloromethane and placing them in a 50 mL round bottom flask, then adding DMAP (2 mmol, 0.244 g), cooling to 0° C., then adding EDCI (20 mmol, 3.82 g), naturally rising to room temperature, and magnetic stirring to reaction for 6 h; after the reaction being completed, extracting with ethyl acetate and water, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography, obtaining a colorless oily liquid compound 141 (2.66 g, yield 90%).

[0055] Dissolving the compound 141 (10 mmol, 2.96 g) in 10 mL of DMSO, adding NaOH (24 mmol, 0.96 g), magnetic stirring at room temperature for 4 h; after the reaction being completed, extracting with ethyl acetate and water for three times, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=6:1, v/v) obtaining a yellow oily liquid compound 1-g-1 (2.66 g, 90% yield).

[0056] Dissolving the compound 1-g-1 (10 mmol, 3.82 g) in 20 mL of 1,4-dioxane, dripping a catalytic amount of concentrated hydrochloric acid solution, and magnetic stirring at room temperature for 6 h; after the reaction being completed, concentrating under reduced pressure, washing the white solid residue with dichloromethane, obtaining a white powdery solid compound 1-1 (1.65 g, yield 87%).

[0057] Nuclear magnetic data of the compound 1-1: white solid powder, .sup.1H NMR (400 MHz, CDCl.sub.3) δ 6.65 (d, J=4 Hz, 1H), 6.61 (s, 1H), 5.96 (s, 1H), 5.75 (s, 1H), 2.64 (s, 3H), 2.26 (s, 3H); .sup.13C NMR (100 MHz, CDCl.sub.3) δ 179.24, 164.79, 161.94, 160.10, 142.35, 117.49, 115.16, 111.65, 101.51, 23.37, 20.30.

Synthesis of Compound 1-2

[0058] ##STR00012##

[0059] Dissolving the compound 1-c (10 mmol, 2.54 g) and the compound 1-e-2 (12 mmol, 0.88 g) in 20 mL of dichloromethane and placing in a 50 mL round bottom flask, adding DMAP (2 mmol, 0.244 g), cooling to 0° C., then adding EDCI (20 mmol, 3.82 g), naturally rising to room temperature, and magnetically stirring to react for 6 h; after the reaction being completed, extracting with ethyl acetate and water, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=7:1, v/v) obtaining a colorless oily liquid compound 1-f-2 (3.07 g, yield 99%).

[0060] Dissolving the compound 1-f-2 (10 mmol, 3.10 g) in 10 mL of DMSO, adding NaOH (24 mmol, 0.96 g), and magnetic stirring at room temperature for 4 h; after the reaction being completed, extracting with ethyl acetate and water for three times, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=6:1, v/v), obtaining a yellow oily liquid compound 1-g-2 (2.85 g, yield 92%).

[0061] Dissolving the compound 1-g-2 (10 mmol, 3.10 g) in 20 mL of 1,4-dioxane, dripping a catalytic amount of concentrated hydrochloric acid solution, and magnetic stirring at room temperature for 6 h; after the reaction being completed, concentrating under reduced pressure, washing the white solid residue with dichloromethane, obtaining a white powdery solid 1-2 (1.73 g, yield 85%).

[0062] Nuclear magnetic data of the compound 1-2: white solid powder, .sup.1H NMR (400 MHz, CDCl.sub.3) δ 6.67 (s, 1H), 6.61 (s, 1H), 5.93 (s, 1H), 5.20 (s, 1H), 2.64 (d, J=4 Hz, 3H), 2.55 (t, J=8 Hz, 2H), 1.17 (t, J=8 Hz, 3H); .sup.13C NMR (100 MHz, CDCl.sub.3) δ 178.95, 168.60, 161.60, 159.66, 141.91, 117.07, 114.82, 109.55, 101.10, 26.55, 22.93, 11.26.

Synthesis of Compound 1-3

[0063] ##STR00013##

[0064] Dissolving the compound 1-c (10 mmol, 2.54 g) and the compound 1-e-3 (12 mmol, 1.05 g) in 20 mL of dichloromethane and placing them in a 50 mL round bottom flask, then adding DMAP (2 mmol, 0.244 g), cooling to 0° C., then adding EDCI (20 mmol, 3.82 g), naturally rising to room temperature, and magnetically stirring to react for 6 h; after the reaction being completed, extracting with ethyl acetate and water, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=7:1, v/v), obtaining a colorless oily liquid compound 1-f-3 (3.20 g, yield 99%).

[0065] Dissolving the compound 1-f-3 (10 mmol, 3.24 g) in 10 mL of DMSO, adding NaOH (24 mmol, 0.96 g), and magnetic stirring at room temperature for 4 h; after the reaction being completed, extracting with ethyl acetate and water for three times, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=6:1, v/v), obtaining a yellow oily liquid compound 1-g-3 (2.91 g, yield 90%).

[0066] Dissolving the compound 1-g-3 (10 mmol, 3.24 g) in 20 mL of 1,4-dioxane, dropping a catalytic amount of concentrated hydrochloric acid solution, and magnetic stirring at room temperature for 6 h; after the reaction being completed, concentrating under reduced pressure, washing the white solid residue with dichloromethane, obtaining a white powdery solid 1-3 (1.91 g, yield 88%).

[0067] Nuclear magnetic data of compound 1-3: white solid powder, .sup.1H NMR (400 MHz, CDCl.sub.3) δ 6.66 (s, 1H), 6.61 (s, 1H), 5.93 (s, 1H), 2.67-2.60 (m, 3H), 1.65 (s, 2H), 0.94 (s, 3H); .sup.13C NMR (100 MHz, CDCl.sub.3) δ 178.88, 167.19, 161.65, 159.71, 141.92, 117.13, 114.84, 110.65, 101.15, 22.99, 20.13, 13.83.

Synthesis of Compounds 1-4

[0068] ##STR00014##

[0069] Dissolving the compound 1-c (10 mmol, 2.54 g) and the compound 1-e-4 (12 mmol, 1.22 g) in 20 mL of dichloromethane and placing them in a 50 mL round bottom flask, then adding DMAP (2 mmol, 0.244 g), cooling to 0° C., then adding EDCI (20 mmol, 3.82 g), naturally rising to room temperature, and magnetic stirring to reaction for 6 h; after the reaction being completed, extracting with ethyl acetate and water, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=8:1, v/v), obtaining a colorless oily liquid compound 1-f-4 (3.04 g, yield 90%).

[0070] Dissolving the compound 1-f-4 (10 mmol, 3.38 g) in 10 mL of DMSO, adding NaOH (24 mmol, 0.96 g), and magnetic stirring at room temperature for 4 h; after the reaction being completed, extracting with ethyl acetate and water for three times, taking the organic phase, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=7:1, v/v) obtaining a yellow oily liquid compound 1-g-4 (3.04 g, yield 90%).

[0071] Dissolving the compound 1-g-4 (10 mmol, 3.38 g) in 20 mL of 1,4-dioxane, dripping a catalytic amount of concentrated hydrochloric acid solution, and magnetic stirring at room temperature for 6 h; after the reaction is completed, concentrating under reduced pressure, washing the white solid residue with dichloromethane, obtaining a white powdery solid 1-4 (1.97 g, yield 85%).

[0072] Nuclear magnetic data of compound 1-3: white solid powder, .sup.1H NMR (400 MHz, CDCl.sub.3) δ 6.67 (s, 1H), 6.61 (s, 1H), 5.93 (s, 1H), 5.20 (s, 1H), 2.64 (d, J=4 Hz, 3H), 2.55 (t, J=8 Hz, 2H), 1.17 (t, J=8 Hz, 3H); .sup.13C NMR (100 MHz, CDCl.sub.3) δ 178.95, 168.60, 161.60, 159.66, 141.91, 117.07, 114.82, 109.55, 101.10, 26.55, 22.93, 11.26.

Synthesis of Compound 1-5

[0073] ##STR00015##

[0074] Dissolving the compound 1-3 (10 mmol, 2.18 g) and iodomethane (12 mmol, 1.70 g) in 20 mL of acetone and placing them in a 50 mL round bottom flask, then adding K.sub.2CO.sub.3 (12 mmol, 1.66 g), heating reflux and magnetically stirring to react for 2 h; after the reaction being completed, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=6:1, v/v), obtaining colorless oily liquid compound 1-5 (2.27 g, yield 98%).

[0075] Nuclear magnetic data of compound 1-5: .sup.1H NMR (400 MHz, CDCl3) δ 6.65 (s, 2H), 6.00 (s, 1H), 3.85 (s, 3H), 2.79 (s, 3H), 2.50 (t, J=4 Hz, 8 Hz, 2H), 1.75-1.70 (m, 2H), 1.00 (t, J=4 Hz, 8 Hz, 3H); .sup.13C NMR (100 MHz, CDCl3) δ180.08, 167.15, 162.52, 159.96, 142.74, 116.44, 116.16, 111.23, 98.59, 55.73, 35.78, 23.18, 20.28, 13.72.

Synthesis of Compound 1-6

[0076] ##STR00016##

[0077] Dissolving the compound 1-3 (10 mmol, 2.18 g) and iodoethane (12 mmol, 1.87 g) in 20 mL of acetone and placing them in a 50 mL round bottom flask, then adding K.sub.2CO.sub.3 (12 mmol, 1.66 g), heating reflux and magnetically stirring to react for 2 h; after the reaction being completed, concentrating under reduced pressure, and separating and purifying the residue by column chromatography (petroleum ether:ethyl acetate=6:1, v/v), obtaining colorless oily liquid 1-6 (2.44 g, yield 99%).

[0078] Nuclear magnetic data of compound 1-6: .sup.1H NMR (400 MHz, CDCl3) δ 6.63 (s, 2H), 5.99 (s, 1H), 4.09-4.04 (m, 2H), 2.78 (s, 3H), 2.94 (t, J=8 Hz, 2H), 1.75-1.68 (m, 2H), 1.43 (t, J=8 Hz, 3H), 0.99 (t, J=8 Hz, 4 Hz, 3H); .sup.13C NMR (100 MHz, CDCl3) δ 179.98, 167.00, 161.79, 159.84, 142.54, 116.43, 116.20, 111.08, 98.93, 63.95, 35.67, 23.05, 20.17, 14.70, 13.62.

2. Number and Structural Formula of the Target Compound

[0079]

TABLE-US-00001 TABLE 1 Series of compound products Serial number Structural formula 1-1 [00017] 1-2 [00018] 1-3 [00019] 1-4* [00020] 1-5 [00021] 1-6* [00022] Note: *Represents a new compound

3. Determination of the Activity of Compounds Inhibiting Tyrosinase

[0080] Method for determining the activity of inhibiting tyrosinase: Firstly, adding the sample: 40 μL (10% DMSO, setting different concentrations (0, 25, 50, 100, 200 μg/mL)) into a 96-well plate (aloesin is the positive control), then adding L-tyrosine: 40 μL (0.1 mg/mL, dissolving in 0.1M potassium phosphate buffer solution, pH=6.8), tyrosinase: 40 μL (48 U/mL, dissolving in 0.1M potassium phosphate buffer solution, pH=6.8), and finally diluting the volume to 200 μL with potassium phosphate buffer solution, and detecting the absorbance at 475 nm on 0 min; after incubating at 37° C. for 30 min, measuring the absorbance.

[00001]$\mathrm{Inhibition}\mathrm{rate}\%=\frac{\left(A-B\right)-\left(C-D\right)}{A-B}$$A:\mathrm{Absorbance}\mathrm{of}\mathrm{blank}\mathrm{solution}\mathrm{after}\mathrm{incubation}$$B:\mathrm{Absorbance}\mathrm{of}\mathrm{blank}\mathrm{solution}\mathrm{before}\mathrm{incubation}$$C:\mathrm{Absorbance}\mathrm{of}\mathrm{sample}\mathrm{solution}\mathrm{after}\mathrm{incubation}$$D:\mathrm{Absorbance}\mathrm{of}\mathrm{sample}\mathrm{solution}\mathrm{before}\mathrm{incubation}$

TABLE-US-00002 TABLE 2 series of compounds inhibit tyrosinase activity Compound No. IC.sub.50 ± SEM.sup.a (mM) 1-1 9.3 ± 0.09 1-2 6.2 ± 0.07 1-3 2.4 ± 0.10 1-4 5.4 ± 0.03 1-5 0.2 ± 0.07 1-6 0.6 ± 0.03 Aloesin 2.7 ± 0.04 Note: .sup.aSEM is the mean standard deviation, aloesin is used as a positive control, n = 3.

[0081] The test results show that each said compound has tyrosinase inhibitory activity, wherein the tyrosinase inhibitory activity of the compounds 1-5 and 1-6 are higher than the tyrosinase inhibitory activity of aloesin. The activity is significantly improved after the 7-position hydroxyl is methylated or ethylated.

[0082] The above description is only the preferred embodiments of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the present invention.