KR101056769B1 - Sensor comprising flavone derivative having mercury ion selectivity and mercury ion detection method using same - Google Patents

Abstract

The present invention relates to a sensor comprising a flavone derivative having mercury ion selectivity and a method for detecting mercury ions using the same, and more particularly, a flavone derivative including a sulfur atom and a mercuric ion selectively react to generate a desulfurization reaction. By measuring the increase in fluorescence intensity, mercury ions can be detected easily and quickly. In addition, the selective reaction of the flavone derivatives with the mercury ions exhibits a color change in which the color turns yellow to colorless, so that the presence or absence of mercury ions can be detected with the naked eye.

Mercury ions, flavone derivatives, fluorescent sensors

Description

Sensor containing flavone derivatives having mercury ion selectivity and method for detecting mercury ion using same {Flavone derivatives having selectivity for Hg2 + and method for monitoring Hg2 + using the same}

The present invention relates to a sensor comprising a flavone derivative having mercury ion selectivity and a method for detecting mercury ions using the same, and more particularly, a flavone derivative including a sulfur atom and a mercuric ion selectively react to generate a desulfurization reaction. The present invention relates to a sensor including a flavone derivative having mercury ion selectivity capable of easily and quickly detecting mercury ions by measuring an increase in fluorescence intensity, and a method for detecting mercury ions using the same.

Because of the toxicity of mercury ions and the practical impact of mercury in the environment, the development of selective signaling systems of mercury ions has attracted interest in the field of fluorescent sensors. The human body is constantly exposed to increasing amounts of mercury resources, and the toxicity of mercury has been reported in detail. Many new systems have been developed that can signal mercury and mercury-containing compounds at various sample concentrations. Recently, reports have been reported on the successful and selective signaling of mercury ions, often through a chemosimetric approach. Starting with the existing anthracene-based dosimeters developed by Czarnik et al., Several mercury based various fluorophores such as rhodamine, fluorescein, anthracene, 1,8-naphthalimide, squaraine dyes, and organopalladium Selective systems have been developed. In particular, various types of signaling systems based on derivatives of sulfur-containing structures among these dosimeters have been developed. For example, desulfurization or structural modification reactions of thioamides, thioureas, and thions are used.

It is an object of the present invention to provide a fluorescent sensor using a flavone derivative having a structure containing sulfur capable of selectively detecting only mercury ions and a short detection time, and a mercury ion detection method using the same.

In order to achieve the above object, the present invention provides a sensor for detecting mercury ions comprising a compound represented by the following formula (1):

[Formula 1]

Where

R ₁ and R ₂ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 aromatic ring,

R ₃ and R ₄ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 aromatic ring,

R ₅ represents a 5 to 12 reduced aryl group.

The present invention also provides a composition for detecting mercury ions comprising the compound represented by the formula (1).

The present invention also provides a method for detecting mercury ions comprising the step of reacting the compound represented by the formula (1) with mercury ions.

The flavone derivative having a sulfur-containing structure of the present invention selectively reacts with mercury ions, and thus can be used as a selective fluorescent sensor for mercury ions because the fluorescence intensity is significantly increased through desulfurization.

In addition, as the desulfurization reaction rate is fast, mercury ions can be detected quickly, and the color in the aqueous solution can be detected visually by changing from yellow to colorless during the reaction.

Hereinafter, the configuration of the present invention will be described in detail.

The present invention relates to a sensor for detecting mercury ions comprising a compound represented by the following formula (1):

[Formula 1]

Where

R ₁ and R ₂ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 aromatic ring,

R ₃ and R ₄ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 aromatic ring,

R ₅ represents a 5 to 12 reduced aryl group.

The terms used in the substituent definitions of the compounds of the present invention are as follows.

"Alkyl" refers to a straight, branched or cyclic saturated hydrocarbon having 1 to 6 carbon atoms, for example 1 to 6 carbon atoms, unless otherwise noted. Examples of C _1-6 alkyl groups include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, isobutyl, sec-butyl, or tert-butyl, isopropyl, isopentyl, isohexyl, and the like. Do not.

"Aromatic ring" includes monocyclic and fused rings as aromatic rings of 5 to 12 reductions unless otherwise stated.

Specifically, the compound of Formula 1,

R ₁ is hydrogen, R ₂ represents hydrogen, a hydroxy group or an alkyl group having 1 to 4 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 reduced aromatic ring,

R ₃ and R ₄ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms, or R ₃ and R ₄ together may form an aromatic ring having 5 to 12 reductions.

More specifically, the compound of Formula 1

R ₁ and R ₂ represent hydrogen,

R ₃ and R ₄ may together form a 3 to 6 aromatic ring.

The above embodiments include any one of the compounds represented by the following Formulas 1a to 1d:

[Formula 1a]

[Chemical Formula 1b]

[Formula 1c]

≪ RTI ID = 0.0 &

The flavone derivative of Chemical Formula 1 generates a desulfurization reaction by reacting with mercury ions, thereby increasing the fluorescence intensity, and thus may be used as a fluorescent sensor for selectively detecting mercury ions.

According to the mechanism of Scheme 1, the thioketone group of the flavone derivative of formula 1 reacts with mercury ions and gradually changes to a ketone group, and the free sulfur atoms form stable HgS with mercury ions, which results in a weak fluorescent flavothione. It is transformed into fluorescent flavones:

Scheme 1

The flavone derivative having a sulfur structure of Formula 1 according to the present invention shows a selective increase in fluorescence at a wavelength of 438 nm depending on the concentration of Hg ²⁺ in an aqueous solution. Mercury ions can be detected using a fluorescent probe of -On "type.

According to one embodiment, Cd ²⁺ , Zn ²⁺ , Ni ²⁺ , Cu ²⁺ , Pb ²⁺ , Na ⁺ , K ⁺ , Co ²⁺ , Ca ²⁺ , Mg ²⁺ , Fe ²⁺ , or Ag Metal ions, such as ⁺ , do not exhibit fluorescence changes, but the reaction of mercury ions with a flavone derivative having a structure containing sulfur of Formula 1 shows a large fluorescence change in a concentration-dependent manner.

According to another embodiment, the flavone derivative having the structure of sulfur according to the present invention has a large fluorescence change by selectively reacting with mercury ions even if other kinds of metal ions are present in the aqueous solution. Indicates.

In addition, detection of mercury ion can also be measured visually through a color change. More specifically, the flavone derivative of the structure containing sulfur of Formula 1 according to the present invention in the aqueous solution shows a color change from yellow to colorless as the concentration of reacting mercury ions increases.

The compound of Chemical Formula 1 of the present invention may be prepared by reacting a flavone compound with a Lawesson reagent in an organic solvent.

According to one embodiment of the present invention, as shown in Scheme 2, Chemical Formula 1a may be prepared by reacting naphthoflavone and Laweson reagent of Chemical Formula 2 with sulfur in an organic solvent:

Scheme 2

In the method for preparing the compound of Formula 1, the organic solvent is toluene, benzene, xylene, tetrahydrofuran, bis (2-butoxyethyl) ether, diphenylmethane, dibenzyl ether, benzyl benzoate, 1-phenyl Naphthalene, or a mixed solvent thereof, may be used, and toluene is preferably used, but is not limited thereto.

In the method for preparing the compound of Formula 1, the molar ratio of the flavone compound and the Laweson reagent is preferably 1: 1.

According to one embodiment, the compound of Formula 2 is dispersed in an organic solvent, and the mixture is cooled after heating by adding Laweson reagent. Preferably, heating is performed at 110 to 130 ° C. for 1 to 2 days, but is not particularly limited thereto.

The solvent of the reactant may be removed, the precipitate may be separated using dichloromethane and water, and the organic layer may be separated and purified to yield the compound of Chemical Formula 1. Separation and purification technology of the crude extract can be carried out according to a conventional method is not particularly limited, for example, can be separated and purified through column chromatography under a suitable solvent.

The sensor for detecting mercury ions of the present invention may be provided as a conventional kit that can check the presence or absence of mercury ions by mixing with a sample solution to detect mercury ions.

The present invention also relates to a composition for detecting mercury ions comprising the compound represented by the formula (1).

The composition for detecting mercury ions may include a buffer solution in addition to the compound represented by Chemical Formula 1. The type and concentration of the buffer solution are not particularly limited, but may be appropriately changed depending on the application of the composition for detecting mercury ions.

The present invention also relates to a method for detecting mercury ions comprising the step of reacting the compound represented by the formula (1) with mercury ions.

The flavone derivative having a sulfur-containing structure of Chemical Formula 1 of the present invention is a sensor of "OFF-ON" type that can detect mercury ions in an aqueous solution state. The sensor is a sensor type that senses the fact that the intensity of fluorescence becomes very large (ON). The reaction rate is fast, and mercury ions can be detected quickly.

According to one embodiment of the invention, the reaction is completed within about 30 minutes, so it is possible to quickly detect the mercury ions.

In addition, the detection of mercury ions by the flavone derivatives having a sulfur-containing structure of the formula (1) is carried out under an aqueous solution or a mixed aqueous solution containing an organic solvent such as methanol, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, dioxane It is possible.

As the aqueous solution, a buffer solution such as Tris buffer may be used, but is not particularly limited thereto.

In addition, the detection of mercury ions by the flavone derivative of the sulfur-containing structure of the formula (1) is to measure the change in the fluorescence intensity, since the fluorescence intensity increases depending on the concentration of mercury ions can be measured.

In addition, the detection of the mercury ion can be measured through the color change of the aqueous solution. The reaction of the flavone derivative and the mercury ion of the structure containing sulfur of Formula 1 can be observed visually to change the color in the aqueous solution from yellow to colorless.

Hereinafter, the present invention will be described in more detail through examples according to the present invention and comparative examples not according to the present invention, but the scope of the present invention is not limited to the examples given below.

Example 1 Preparation of Thio Derivatives of a-naphthoflavones

[Formula 1a]

The flavone derivatives used in the present examples are compounds represented by Chemical Formula 1a, and are used in preparing the compounds, such as a-naphthoflavone 2, flavone, 6-hydroxyflavone, β-naphthoflavone and Lawesson's reagents were purchased and used and did not undergo further purification before use. All solvents purchased anhydride or spectroscopic grades. ¹ H NMR (300 MHz) and ¹³ C NMR (75 MHz) spectra were obtained on a Varian Gemini 2000 NMR spectrometer and were referenced for residual solvent signals. UV-vis spectra were obtained on a Jasco V-550 spectrophotometer. Fluorescence spectra were measured on an Aminco-Bowman Series 2 Spectrophotometer.

α-naphthoflavones (0.27 g, 1.0 mmol) were dispersed in toluene and Laweson reagent (0.44 g, 1.1 mmol) was added to the reaction mixture. The mixture was heated at 120 ° C. for 1 day and then cooled to room temperature. The solvent was evaporated under reduced pressure and the precipitate was separated into dichloromethane and water. The organic layer was separated, washed with water and evaporated under reduced pressure. The crude extract was purified by column chromatography (silica gel, 1st CH ₂ Cl _2, 2nd hexane-ethyl acetate = 3: 1, v / v), and the thio derivative (compound of formula 1) of a-naphthoflavone was purified. Obtained (yield 0.17 g, 62%).

¹ H NMR (300 MHz, DMSO-d ₆ ) δ 8.76-8.72 (m, 1H), 8.43 (d, J = 9.0 Hz, 2H), 8.32 (dd, J ₁ = 9.0 Hz, J ₂ = 1.5 Hz, 2H), 8.12-8.08 (m, 1H), 8.06 (s, 1H), 7.97 (d, J = 9.0 Hz, 1H), 7.87-7.80 (m, 3H), 7.70-7.61 (m, 3 H); ¹³ C NMR (75 MHz, CDCl ₃ ) δ 200.74, 153.44, 148.42, 136.06, 131.82, 131.20, 129.66, 129.38, 128.21, 126.89, 126.43, 126.24, 124.07, 123.96, 122.98, 121.24; HRMS (EI); m / z calcd for C ₁₉ H ₁₂ OS [M] ⁺ : 288.0609, found 288.0607.

Experimental Example 1 UV-vis Spectrum for Metal Ions

The physiologically relevant alkaline, alkaline earth, and transition metal ions representative processes the compounds of formula (1) to the metal ion in 50% aqueous methanol solution (1.0 × 10 ^-3 M) compounds of the formula I for the (1.0 × 10 ^-5 M UV-vis spectra were measured.

As shown in FIG. 1, the compound of Formula 1 exhibited a strong absorption band at 370 and 400 nm. Significant changes were observed in the absorption spectrum when interacting with various metal ions, particularly mercury ions and copper ions.

In addition, a color change from yellow to colorless was observed. Other metal ions caused a relatively weak change in the absorption spectrum of the compound of formula (1).

In general, flavothione is known to exhibit very weak release compared to other flavone analogs. In the same solvent system, fluorescence signal generation of the compound of formula 1 was investigated in the presence of 100 equivalents of representative metal ions. To this end, for the metal ions (5.0 × 10 ⁻⁴ M) of the compound of formula 1 (5.0 10 ⁻⁶ M) in H ₂ O: CH ₃ OH (1: 1) in pH 8.09 (10 mM tris buffer) Fluorescence change was observed. The excitation wavelength (l _ex ) was measured using 350 nm.

As shown in FIG. 2, the compound of formula 1 had a weak fluorescence concentration near 440 nm and showed an apparent “off-on” type of signal generation for mercury ions. Upon reaction with various metal ions, the fluorescence intensity at 438 nm was significantly increased (45 times) in mercury ions.

On the other hand, the other metal ions did not cause any pronounced reaction ( I / I _o varied between 0.57 for Na ⁺ and 1.79 for Cd ²⁺ ) (FIG. 3).

Experimental Example 2 ¹ H-NMR Measurement of the Compound of Formula 1

The modification was confirmed by ¹ H-NMR measurement of the compound of Formula 1 (5.0 × 10 ⁻³ M) before and after the addition of mercury ions (1.0 × 10 ⁻² M) in DMSO-d ₆ . When two equivalents of mercury ions were treated, the ¹ H-NMR spectrum of the compound of formula 1 was converted to the compound of formula 2 (FIG. 4). UV-vis and fluorescence measurements also confirmed the conversion of flavothione to flavone (FIG. 5).

In addition, the reversible experiment of the compound-Hg ²⁺ system of Formula 1 upon EDTA treatment demonstrated the chemi-dose characteristics of the signal. To this end, compounds of formula 1 (5.0 × 10 ⁻⁶ M), Hg ²⁺ (5.0 × 10 ⁻⁵ M) and H ₂ O: CH ₃ OH (1: 1) under pH 8.09 (10 mM tris buffer) and EDTA (5.0 × 10 ^-4 M) was mixed and reacted. The excitation wavelength (l _ex ) was measured using 350 nm.

As shown in FIG. 6, the increase in fluorescence of the Compound-Hg ²⁺ system of Formula 1 was not affected by EDTA treatment, but the fluorescence of the compound of Formula 1 in the presence of EDTA did not improve upon mercury ion addition. This demonstrates that the Compound-Hg ²⁺ system of Formula 1 operates on the basis of an irreversible stoichiometric process.

Experimental Example 3 Investigation of Mercury Ion Selectivity of Compound of Formula 1 Under Metal Ions

Under competitive conditions, the effect of other common metal ions (5.0 × 10 ⁻⁴ M) on mercury ion (5.0 × 10 ⁻⁵ M) signal generation of the compound of formula (5.0 × 10 ⁻⁶ M) was evaluated. The excitation wavelength (l _ex ) was measured using 350 nm.

As shown in FIG. 7, 100 equivalents of other metal ions except copper ions were not affected by fluorescence increase to a significant extent. In the presence of copper ions, the increase in fluorescence was somewhat reduced to reach 83% of the Compound-Hg ²⁺ system of Formula 1. This means that mercury ion selective signal generation is maintained even in the presence of metal ions which are of ordinary physiological and environmental significance except for copper ions.

Experimental Example 4 Fluorescence Titration

Fluorescence titration was performed to quantitatively determine the signal generation of the compound of Formula 1 for mercury ions. To this end, the compound of Formula 1 (1.0 × 10 ⁻⁵ M) was reacted with mercury ions in H ₂ O: CH ₃ OH (1: 1) under pH 8.09 (10 mM tris buffer). The excitation wavelength (l _ex ) was measured using 350 nm.

As shown in FIG. 8, as the concentration of mercury ions increased, the fluorescence intensity gradually increased without any shift in the maximum emission band. Through the concentration-dependent signal generation tendency of mercury ions, the limit of detection of the compound of formula 1 for the analysis of mercury ions was estimated to be 1.6 × 10 ⁻⁶ M.

Experimental Example 5 Measurement of Signal Generation Rate for Mercury Ions of Compound 1

The signal generation rate for the mercury ion of the compound of Formula 1 was measured. To this end, the reaction of the compound of formula 1 (5.0 × 10 ^-6 M) and mercury ion (5.0 × 10 ^-4 M) in H ₂ O: CH ₃ OH (1: 1) in pH 8.09 (10 mM tris buffer) And measured by time zone. The excitation wavelength (l _ex ) was measured using 350 nm.

As shown in FIG. 9, as a result of measurement by time zone, signal generation was completed within about 30 minutes. Flavothiones, such as 3-hydroxyflavothione, which are structurally very close to the compound of Formula 1, are known to readily photodegrade. In this case, the compound of Formula 1 was also found to degrade, but spontaneous decomposition of the compound of Formula 1 itself was rather slow under the same experimental conditions, about 0.3% after 30 minutes of sample preparation, and about 2% after 3 hours. This means that selective detection of mercury ions by increasing fluorescence can be practically carried out in the compound of formula (1).

Figure 1 shows the UV-Vis spectral results of the compound of formula 1 of the present invention in the presence of various metal ions.

Figure 2 shows the fluorescence spectrum change of the compound of formula 1 in the presence of various metal ions.

3 shows the fluorescence intensity ratio (I / Io) at 438 nm of the compound of formula 1 of the present invention in the presence of various metal ions.

4 shows partial ¹ H-NMR spectra of compounds of Formula 1 of the present invention in DMSO-d ₆ .

Figure 5 shows the UV-vis spectrum (a) and fluorescence spectrum (b) results of the compound of formula 1, the compound of formula 1-Hg ²⁺ system and the compound of formula 2 of the present invention.

Figure 6 shows the effect of EDTA on the fluorescent signal generation of mercury ions using the compound of formula (1) of the present invention.

FIG. 7 shows fluorescence spectra of the Compound-Hg ²⁺ system of Formula 1 in the presence of various metal ions.

8 is a fluorescence titration result of the compound of formula 1 of the present invention for mercury ions.

9 is a time-phase result of signal generation of mercury ions of the compound of formula 1 of the present invention.

Claims (14)

Mercury ion detection sensor comprising a compound represented by the formula (1): [Formula 1]

Where R ₁ and R ₂ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 aromatic ring, R ₃ and R ₄ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 aromatic ring, R ₅ represents a 5 to 12 reduced aryl group. The method of claim 1, R ₁ is hydrogen, R ₂ represents hydrogen, a hydroxy group or an alkyl group having 1 to 4 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 reduced aromatic ring, R ₃ and R ₄ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 aromatic ring for mercury ion detection. The method of claim 1, R ₁ and R ₂ represent hydrogen, A sensor for detecting mercury ions, wherein R ₃ and R ₄ together form an aromatic ring of 3 to 6 reduction. The method of claim 1, Sensor for detecting mercury ion represented by any one of the general formula 1a to 1d: [Formula 1a]

[Chemical Formula 1b]

[Formula 1c]

≪ RTI ID = 0.0 &

Mercury ion detection composition comprising a compound represented by the formula (1):  [Formula 1]

Where R ₁ and R ₂ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 aromatic ring, R ₃ and R ₄ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 aromatic ring, R ₅ represents a 5 to 12 reduced aryl group. The method of claim 5, R ₁ is hydrogen, R ₂ represents hydrogen, a hydroxy group or an alkyl group having 1 to 4 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 reduced aromatic ring, R ₃ and R ₄ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms, or R ₃ and R ₄ together form a mercury ion detection composition to form an aromatic ring of 5 to 12 reduction. The method of claim 5, R ₁ and R ₂ represent hydrogen, R ₃ and R ₄ together form a mercury ion detection to form an aromatic ring of 3 to 6 reduction. A method for detecting mercury ions comprising reacting a compound represented by Formula 1 with mercury ions: [Formula 1]

Where R ₁ and R ₂ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 aromatic ring, R ₃ and R ₄ each independently represent hydrogen, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 aromatic ring, R ₅ represents a 5 to 12 reduced aryl group. The method of claim 8, R ₁ is hydrogen, R ₂ represents hydrogen, a hydroxy group or an alkyl group having 1 to 4 carbon atoms, or R ₁ and R ₂ together form a 5 to 12 reduced aromatic ring, R ₃ and R ₄ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms, or R ₃ and R ₄ together form a 5 to 12 reduced aromatic ring. The method of claim 8, R ₁ and R ₂ represent hydrogen, R ₃ and R ₄ together detect a mercury ion forming a 3 to 6 aromatic ring. The method of claim 8, A method for detecting mercury ions carried out under an aqueous solution. The method of claim 11, A method for detecting mercury ions, wherein the aqueous solution is a buffer solution. The method of claim 8, The method of detecting mercury ions, wherein the detection of mercury ions is to measure the increase in fluorescence intensity. The method of claim 8, The method for detecting mercury ions is to detect mercury ions by measuring color change from yellow to colorless.

Images