Chemically-induced dynamic nuclear polarization probe, compound, and method for evaluating chemical induction function

Abstract

The present invention uses, as a chemically-induced dynamic nuclear polarization probe, a polarization source precursor that generates a polarization source of dynamic nuclear polarization by a chemical reaction. According to the present invention, in vivo or the like, it is possible to perform detecting a substance, tracking a chemical reaction, etc., by using a simple method.

Description

Chemically induced dynamic nuclear polarization probe, compound, and chemically induced functional evaluation method

[0001] The present invention relates to a chemically induced dynamic nuclear polarization probe, a compound used therefor, and a method for evaluating chemically induced function.

[0002] When atomic nuclei (nuclear spins) with magnetic moments are placed in a static magnetic field, they undergo precession. When electromagnetic waves of the same frequency as the precession are irradiated in this state, the nuclear spins resonate and absorb the energy of the electromagnetic field, resulting in the nuclear magnetic resonance (NMR) phenomenon. The resonant frequency of this NMR phenomenon varies depending on the nuclide and the chemical or magnetic environment in which the nuclei are placed. Therefore, in the fields of organic chemistry and biochemistry, NMR spectroscopy is widely used to analyze the molecular structure and physical properties of compounds by observing the frequency spectrum (chemical shift value) of the NMR signal, which converts the amount of energy absorbed by the resonance into an electrical signal. In addition, in the medical field, magnetic resonance imaging (MRI), which adds positional information to the NMR signal to create an image, is used for non-invasive examination of biological organs such as the brain. Here, when a static magnetic field is applied to such a collection of nuclear spins, for example, in the case of protons, they split into an energy state in which the spins are parallel to the magnetic field and an energy state in which the spins are antiparallel to the magnetic field. Here, the value obtained by dividing the difference in the number of spins (occupancy number) in each energy state by the total number of spins is called the polarization factor, and the intensity of the NMR signal is said to be proportional to this polarization factor. However, the polarization factor of nuclear spins is usually very low, less than one tens of thousands at room temperature, and this is the cause of the limitation of the sensitivity of NMR spectroscopy and MRI.

[0003] Therefore, as a method for highly polarizing nuclear spins, dynamic nuclear polarization (DNP) has been proposed. This involves transferring electron spin polarization to surrounding nuclei through solid-state effects or integral solid-state effects induced by electromagnetic wave irradiation, thereby highly polarizing nuclear spins. Here, radicals or photoexcited triplet molecules are used as the electron spin source. Photoexcited triplet molecules, among others, have the advantage of being able to effectively highly polarize nuclear spins even at room temperature because the electron spin population is highly biased toward a specific energy state regardless of temperature (photoexcited DNP). To achieve this type of DNP, it is necessary to appropriately combine a dye that can be excited by light irradiation with an electron donor that can donate electrons to form radical pairs. Since some biomolecules function as electron donors, DNP can be performed in vivo using appropriate dyes to analyze the structure and function of biomolecules. For example, structural analysis has been performed by highly polarizing the nuclear spins of amino acid residues present on protein surfaces and performing NMR measurements (see Non-Patent Documents 1-3).

[0004] Kaptein, R. et al., Nature 1978, 274 (5668), 293-294.Schlorb, C. et al., J. Am. Chem. Soc. 2006, 128 (6), 1802-1803.Im, J. et al., J. Am. Chem. Soc. 2022, 144 (37), 17010-17021.

[0005] Because in vivo photoinduced dynamic nuclear polarization highly polarizes the nuclear spins of biomolecules, it is necessary to select a dye suitable for the target biomolecule. It is also necessary to create an environment in which the selected dye can efficiently highly polarize the nuclear spins of biomolecules. Because it is not always easy to meet these requirements, the scope of in vivo application of photoinduced dynamic nuclear polarization is limited, limiting its scope of in vivo application. Therefore, in order to solve these problems of the prior art, the present inventors have conducted extensive research with the aim of providing a probe that can utilize photoinduced dynamic nuclear polarization to efficiently detect in vivo substances and track in vivo reactions in a simple manner.

[0006] As a result of extensive research, the present inventors have found that the problems can be solved by the present invention having the following configuration. [1] A chemically induced dynamic nuclear polarization probe including a polarization source precursor that generates a polarization source for dynamic nuclear polarization by a chemical reaction. [2] The chemically induced dynamic nuclear polarization probe according to [1] for in vivo application. [3] The chemically induced dynamic nuclear polarization probe according to [1] or [2], wherein the polarization source is substituted or unsubstituted phenol, substituted or unsubstituted imidazole, substituted or unsubstituted indole, substituted or unsubstituted methylthiopropylamine, substituted or unsubstituted guanine, substituted or unsubstituted adenine, or substituted or unsubstituted quinone. [4] The chemically induced dynamic nuclear polarization probe according to any one of [1] to [3], wherein the polarization source has a fluorine atom. [5] The chemically induced dynamic nuclear polarization probe according to any one of [1] to [4], wherein the polarization source precursor has a structure in which the dynamic nuclear polarization active site of the polarization source is protected with a protecting group, and the protecting group is removed by the chemical reaction to generate the polarization source. [6] The chemically induced dynamic nuclear polarization probe according to [5], wherein the dynamic nuclear polarization active site of the polarization source is a phenolic hydroxy group. [7] The chemically induced dynamic nuclear polarization probe according to [6], wherein the protecting group is an acyl group, a glycosyl group, a phosphate group, a sulfonate group, or a protecting group that is removed by inducing a chain reaction within the protecting group due to a change in a functional group within the protecting group caused by the chemical reaction. [8] The chemically induced dynamic nuclear polarization probe according to any one of [5] to [7], wherein the chemical reaction is a hydrolysis reaction. [9] The chemically induced dynamic nuclear polarization probe according to any one of [5] to [8], wherein the chemically induced dynamic nuclear polarization probe is used to evaluate enzyme activity.

[10] The chemically induced dynamic nuclear polarization probe according to [9], wherein the enzyme is lipase, esterase, glycosidase, galactosidase, phosphatase, sulfatase, protease, disulfide isomerase, or oxidase.

[11] The chemically induced dynamic nuclear polarization probe according to any one of [1] to [4], wherein the polarization source precursor has a group that is converted into a dynamic nuclear polarization active site of the polarization source by the chemical reaction (provided that the group that is converted into a dynamic nuclear polarization active site does not have a structure in which the dynamic nuclear polarization active site is protected with a protecting group).

[12] The chemically induced dynamic nuclear polarization probe according to

[11] , wherein the group that converts into a dynamic nuclear polarization active site is a boronic acid group.

[13] The chemically induced dynamic nuclear polarization probe according to

[11] or

[12] , which is used for evaluating oxidase activity or detecting hydrogen peroxide.

[14] The chemically induced dynamic nuclear polarization probe according to any one of [1] to [4], wherein the polarization source precursor is a dynamic nuclear polarization source having a paramagnetic group that undergoes paramagnetic relaxation, and the chemical reaction is a reaction that converts the paramagnetic group into a group that does not undergo paramagnetic relaxation.

[15] The chemically induced dynamic nuclear polarization probe according to

[14] , wherein the paramagnetic group has a nitroxy radical.

[16] The chemically induced dynamic nuclear polarization probe according to any one of [1] to

[15] , wherein an NMR signal having a specific chemical shift value is first observed as a result of the chemical reaction.

[17] The chemically induced dynamic nuclear polarization probe according to any one of [1] to

[15] , wherein the chemical reaction increases the intensity of an NMR signal having a specific chemical shift value.

[18] The chemically induced dynamic nuclear polarization probe according to any one of [1] to [4], wherein the polarization source precursor has a reactive site that reacts with the chemical reaction at a site different from the dynamic nuclear polarization active site of the polarization source.

[19] The chemically induced dynamic nuclear polarization probe according to

[18] , wherein the polarization source precursor is also a polarization source for dynamic nuclear polarization, and the chemical reaction changes the NMR chemical shift.

[20] The chemically induced dynamic nuclear polarization probe according to

[19] , wherein the chemical reaction is a complex formation reaction.

[21] The chemically induced dynamic nuclear polarization probe according to

[20] , wherein the reactive site is a site that undergoes a complex formation reaction with a metal ion.

[22] The chemically induced dynamic nuclear polarization probe according to

[21] , wherein the chemically induced dynamic nuclear polarization probe is used to detect metal ions.

[23] The chemically induced dynamic nuclear polarization probe according to any one of [1] to

[10] , wherein the polarization source precursor has a structure represented by the following general formula (1): General formula (1): [In general formula (1), X represents a group represented by Pro-O- or a group that can be converted into a hydroxy group by the above-mentioned chemical reaction. Pro represents a protecting group. R １ ~R ５each independently represents a hydrogen atom or a substituent.]

[24] The chemically induced dynamic nuclear polarization probe according to

[23] , wherein Pro represents a substituted or unsubstituted acyl group, for example, an unsubstituted acyl group, for example, an acetyl group.

[25] The chemically induced dynamic nuclear polarization probe according to

[23] , wherein Pro represents a sugar chain, for example, a sugar chain containing glycol.

[26] X is (RO) ２ B-, and each R is independently an alkyl group, or two R are linked together to form a cyclic structure.

[27] R １ ~R ５

[28] The chemically induced dynamic nuclear polarization probe according to any one of

[23] to

[26] , wherein at least one of R is a fluorine atom. １ ~R ５

[29] The chemically induced dynamic nuclear polarization probe according to any one of

[23] to

[27] , wherein R is independently one atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a carbonyl group, a hydroxyl group, and an amino group, or a group in which two or more atoms are combined. １ ~R ５

[30] The chemically induced dynamic nuclear polarization probe according to any one of

[23] to

[28] , wherein at least one of R is a group having a nitroxy radical. １ ~R ５

[31] The chemically induced dynamic nuclear polarization probe according to any one of

[23] to

[29] , wherein at least one of R has a group capable of forming a complex with a metal ion. １ ~R ５The chemically induced dynamic nuclear polarization probe according to any one of

[23] to

[30] , wherein at least three of the atoms are hydrogen atoms.

[32] A compound having a polarization source precursor moiety that becomes a polarization source for dynamic nuclear polarization through a chemical reaction, a dye moiety, and a linking group connecting the polarization source precursor moiety and the dye moiety.

[33] The compound according to

[32] , which is for use in a chemically induced dynamic nuclear polarization probe.

[34] The compound according to

[32] or

[33] , wherein the polarization source precursor moiety highly polarizes nuclear spins through chemically induced dynamic nuclear polarization.

[35] The compound according to any one of

[32] to

[34] , wherein the distance between the polarization source precursor moiety and the dye moiety is 10 Å or more.

[36] The compound according to

[35] , wherein the distance between the polarization source precursor moiety and the dye moiety is 10 to 20 Å.

[37] The compound according to any one of

[32] to

[36] , wherein the linking chain length of the linking group is 2 to 20 atoms.

[38] The compound according to any one of

[32] to

[37] , wherein the linking group is a hydrophilic linking group.

[39] The compound according to any one of

[32] to

[38] , wherein the linking group includes an alkylene linking group, a polyalkyleneoxy linking group, or a polypeptide linking group.

[40] The compound according to any one of

[32] to

[39] , wherein the dye moiety is a porphyrin derivative.

[41] The compound according to any one of

[32] to

[40] , wherein the polarization source precursor moiety is a monovalent group of a polarization source precursor defined in any one of [5] to

[31] (e.g., having a protecting group for a hydroxy group).

[42] A method for evaluating chemical reaction induction function, comprising introducing the chemically induced dynamic nuclear polarization probe according to any one of [1] to

[31] into a specific environment and measuring the degree of dynamic nuclear polarization by the chemically induced dynamic nuclear polarization probe, thereby evaluating the chemical reaction induction function in the environment.

[43] The method for evaluating chemical reaction induction function according to

[42] , wherein the environment is an environment within a living body.

[44] The method for evaluating chemical reaction induction function according to

[42] or

[43] , wherein the evaluation evaluates the function of a chemical substance present in the environment.

[45] The method for evaluating chemical reaction induction function according to

[44] , wherein the chemical substance is a drug administered within a living body.

[46] The method for evaluating chemical reaction induction function according to

[44] , wherein the chemical substance is a chemical substance secreted or produced within a living body.

[47] The method for evaluating a chemical reaction induction function according to any one of

[42] to

[46] , wherein the measurement is carried out by NMR.

[0007] According to the present invention, photoinduced dynamic nuclear polarization can be used to easily detect substances and track reactions, which is particularly useful for detecting substances that require time to react in vivo and tracking reactions in vivo over a long period of time.

[0008] 1A is a schematic diagram illustrating the dynamic nuclear polarization mechanism of the polarization source of the present invention; １ (b) is the H-NMR spectrum after irradiating the solution with laser light. １ (a) is a H-NMR spectrum of a solution containing compound 2s. １ (b) is the H-NMR spectrum after irradiating the solution with laser light. １ 1H-NMR spectrum of a solution containing compound 7. １ (b) is the H-NMR spectrum after irradiating the solution with laser light. １ 1H-NMR spectrum. 2. A graph comparing enhancement factors. 3. A graph comparing fluorescence quantum yields. 4. A graph comparing the ratio of non-radiative transitions. (a) is the 1H-NMR spectrum of the sample without lipase. １ H-NMR spectrum of the lipase-added sample. １ 1H-NMR spectrum of the lipase-added sample. １ 1 is a graph showing the relationship between the integrated signal intensity of H-NMR spectrum. １９ (b) is the F-NMR spectrum of the lipase 5 days after its addition. １９ (a) shows the F-NMR spectrum of the sample containing alkaline phosphatase. １９ (b) is a graph showing the change over time in the signal intensity at about -124 ppm. (a) is a graph showing the change over time in the signal intensity of the sample to which glucose oxidase was added. １９ (b) is a graph showing the time course of the signal intensity at approximately -135.5 ppm. (a) is a graph showing the time course of the F-NMR spectrum of the sample to which β-glucosidase was added. １９(b) is a graph showing the change over time in the signal intensity at about −123 ppm. (a) is a graph showing the change over time in the signal intensity at about −123 ppm before adding hydrogen peroxide solution. １９ (b) is the F-NMR spectrum after adding hydrogen peroxide solution. １９ F-NMR spectrum.

[0009] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments or specific examples of the present invention, but the present invention is not limited to such embodiments or specific examples. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. In addition, the compound (H ２ O and D ２ The isotopes of hydrogen atoms present in the molecule (excluding O) are not particularly limited, and for example, １ H, or part or all of ２ The "excitation light" in this specification refers to light that excites an object to cause it to emit light, and light having a wavelength that matches the absorption wavelength of the object can be used. The "room temperature" in this specification is 20°C.

[0010] <Chemically Induced Dynamic Nuclear Polarization Probe> The chemically induced dynamic nuclear polarization probe of the present invention includes a polarization source precursor that generates a polarization source for dynamic nuclear polarization through a chemical reaction. The "polarization source for dynamic nuclear polarization" in the present invention refers to an object (object to be polarized) that aims to highly polarize nuclear spins in dynamic nuclear polarization, which highly polarizes nuclear spins by transferring spin polarization from electrons to nuclei. Here, "polarization" or "spin polarization" refers to the difference in the number of spins occupied at each energy level when a static magnetic field is applied to an assembly of spins to cause Zeeman splitting. Furthermore, when a combination of any two of the split energy levels is considered, the number of spins occupied at one energy level, N, is １ and the number of spins in the other energy level, N ２to the total number of spins, i.e., (N １ -N ２ ) / (N １ +N ２ ) is called the polarization rate. Here, among all combinations of Zeeman split energy levels, those with a polarization rate of 0 are not spin polarized, while those with at least one combination whose absolute value of the polarization rate exceeds 0 (either positive or negative) are spin polarized. The larger the polarization rate, the greater the spin polarization, which means that there is an excess of spin in one of the energy levels.

[0011] The mechanism of chemically induced dynamic nuclear polarization is shown in Figure 1. Chemically induced dynamic nuclear polarization consists of a dye excitation process and a high polarization process. [1] Dye excitation process In this process, the dye is irradiated with excitation light to transition to an excited triplet state. When irradiated with excitation light, the dye transitions to the ground singlet state S as shown in Figure 1. ０ to the excited singlet state S １ and then transitions to the excited singlet state S １ Intersystem crossing occurs from the excited triplet state T ｎ Next, the excited triplet state T ｎ However, it undergoes a stepwise internal conversion to lower excited triplet states, eventually reaching the lowest energy excited triplet state T １ This excited triplet state T １ The number of Zeeman levels of electron spin (triplet electron spin) in a nucleus is three, which correspond to the magnetic quantum number m = -1, 0, +1, respectively, and among these, the electron spin is highly polarized, with a large distribution of electron spins at specific Zeeman levels. On the other hand, the number of Zeeman levels of a nucleus is １ H ＋ In the example, there are two levels corresponding to the magnetic quantum numbers m = +1 / 2 and -1 / 2. Of these, the Zeeman level m = +1 / 2 has a slightly higher number of nuclear spins, but the polarization is 10 －６The nuclear spin polarization is extremely low, approximately 100%. [2] High Polarization Step: In this step, the polarization of triplet electron spins generated in the dye is transferred to nuclear spins, resulting in highly polarized nuclear spins. Specifically, the dye in which triplet electron spins have been generated is irradiated with, for example, electromagnetic waves with which the electron spins resonate, and a magnetic field sweep is performed. Then, due to the integral solid-state effect, the electron spin polarization is transferred to the nuclei, resulting in highly polarized nuclear spins. At this time, the polarization of the triplet electron spins in the dye is efficiently transferred to the polarization target, significantly improving the nuclear spin polarization rate. A highly polarized nuclear spin (polarized target) can thus produce a high-intensity NMR signal, achieving high measurement sensitivity in NMR spectroscopy and MRI. The conditions for high polarization are not particularly limited, but can be appropriately selected from the following ranges: external magnetic field strength of 0.1 to 1 T, electromagnetic wave frequency of 2 to 20 GHz, and electromagnetic field strength of 0.1 to 100 W. In the above steps [1] and [2], step [2] may be performed after step [1], or step [1] and step [2] may be performed simultaneously. In the latter case, an external magnetic field is applied to the composition, and the composition is simultaneously irradiated with excitation light and electromagnetic waves that resonate with electron spins.

[0012] In the present invention, a "polarization source precursor" refers to a material that generates a polarization source through a chemical reaction. The polarization source must be one that highly polarizes nuclear spins through dynamic nuclear polarization (a nuclear spin-polarized object). On the other hand, it is preferable that the polarization source precursor does not polarize nuclear spins through dynamic nuclear polarization. It is possible to use a polarization source precursor that polarizes nuclear spins through dynamic nuclear polarization. In this case, however, it is preferable that the polarization of nuclear spins is clearly smaller than that of the polarization source generated from the polarization source precursor, or that the chemical shift of the NMR signal observed due to the polarization of nuclear spins of the polarization source precursor differs from the chemical shift of the NMR signal observed due to the polarization of nuclear spins of the polarization source.

[0013] The nuclear spin polarization target produced from the polarization source precursor by chemical reaction can be one that can be used as a nuclear spin polarization target for photoexcited dynamic nuclear polarization. It may be selected from among conventionally known nuclear spin polarization targets. For example, compounds containing a phenol structure, an imidazole structure, an indole structure, a methylthiopropylamine structure, a guanine structure, an adenine structure, or a quinone structure (particularly a parabenzoquinone structure) that function as a nuclear spin polarization target can be selected and used. Compounds with fluorine atoms introduced into these structures can also be preferably used.

[0014] The polarization source precursor in the present invention is preferably a derivative of these nuclear spin polarization targets. In one embodiment of the present invention, a polarization source precursor can be used in which functional groups at the dynamic nuclear polarization active sites of a nuclear spin polarization target are protected with protecting groups. The term "dynamic nuclear polarization active site" refers to a site necessary for dynamic nuclear polarization; if this site is missing, dynamic nuclear polarization cannot be performed. For example, the phenolic hydroxy group in a nuclear spin polarization target having a phenol structure is an example of a dynamic nuclear polarization active site. The table below lists specific examples of polarization source precursors in which the hydroxy groups present in fluorinated phenols and their derivatives, which are nuclear spin polarization targets, are protected. Here, acetic acid derivatives and tyrosine derivatives are shown as examples of fluorinated phenol derivatives. However, derivatives with other substituents can also be used as long as they do not adversely affect the dynamic nuclear polarization active sites. Furthermore, the positions of these substituents can also be changed as appropriate as long as they do not adversely affect the dynamic nuclear polarization active sites. For example, derivatives in which the fluorine substitution position is changed to another position on the benzene ring can also be used. In the table below, examples of hydroxyl group protection include acyl groups (particularly acetyl groups), sugars (particularly glucosyl groups), phosphate groups, and sulfonate groups. However, other hydroxyl group-protecting groups can also be used. Furthermore, when protecting a functional group in the dynamic nuclear polarization active site other than a hydroxyl group, a protecting group that can be used for that functional group can be selected and used. These protecting groups can be selected appropriately depending on the intended use and environment of the polarization source precursor.

[0015] A polarization source precursor with a protected functional group at the dynamic nuclear polarization active site generates a nuclear spin-polarized object by deprotection in the environment in which the present invention is used. By highly polarizing the nuclear spins of the generated nuclear spin-polarized object using photoexcited dynamic nuclear polarization, a unique NMR signal can be detected. Therefore, the use of the polarization source precursor allows for determining whether the environment is one in which the protecting group is deprotected. For example, since it is possible to determine the presence or absence of a substance that has the effect of deprotecting the protecting group, the polarization source precursor can be used as a probe to determine whether a specific substance (e.g., an enzyme) is present in the environment. The following table shows the relationship between the types of protecting groups present in the polarization source precursor and the enzymes that promote the deprotection reaction. By selecting the type of protecting group depending on the enzyme or reaction to be detected, the present invention can be used for enzyme detection and functional evaluation, as well as reaction tracking. The reaction is not limited to hydrolysis; it can also be used to detect and track other reactions in which the protecting group can be deprotected.

[0016] Instead of relying on a simple deprotection reaction of the protecting group as described above, it is also possible to generate a nuclear spin-polarized object by inducing a chain reaction within the protecting group through a change in the functional group within the protecting group. In the present invention, it is also possible to employ a polarization source precursor that causes such a chain reaction. For example, examples having a self-immolative linker are shown in the table below.

[0017] In the present invention, the polarization source precursor can also be a compound having a group that can be converted into a dynamic nuclear polarization active site by a chemical reaction other than deprotection. For example, a boronic acid group can be used as such a group. The boronic acid group reacts with hydrogen peroxide to convert it into a hydroxy group, as shown below. Therefore, a polarization source precursor having a boronic acid group can be used as a probe for detecting hydrogen peroxide. Furthermore, because hydrogen peroxide is a by-product in the reaction process of some oxidases, it can also be used indirectly to detect and evaluate the activity of oxidases.

[0018] In the present invention, it is also possible to use as the polarization source precursor a compound whose nuclear spins are highly polarized by dynamic nuclear polarization and which has a paramagnetic group that undergoes paramagnetic relaxation. Even if the nuclear spins of such a compound are highly polarized, NMR signals cannot be observed due to paramagnetic relaxation. By converting the paramagnetic group to a group that does not undergo paramagnetic relaxation through a chemical reaction, NMR signals can be observed. An example of such a paramagnetic species is the nitroxy radical. Paramagnetic species such as the nitroxy radical can be quenched by active oxygen and the like, and therefore can be used to detect active oxygen and the like.

[0019] In the present invention, the polarization source precursor may be a compound whose nuclear spins are highly polarized by dynamic nuclear polarization and which has a reactive site that reacts through the chemical reaction at a site different from the dynamic nuclear polarization active site. Such a compound is preferably a compound whose nuclear spins are highly polarized by dynamic nuclear polarization and whose NMR signal chemical shift value changes before and after the chemical reaction. It is particularly preferable to use a compound whose NMR signal with a specific chemical shift value is observed only after undergoing a chemical reaction. For example, a compound having the following structure can be used as the polarization source precursor. Here, by forming a complex with a metal ion, a new NMR signal with a specific chemical shift value is observed. Therefore, this compound can be used to detect metal ions.

[0020] In the present invention, a compound whose nuclear spins are highly polarized by dynamic nuclear polarization and whose NMR signal intensity at a specific chemical shift value increases after a chemical reaction can also be used as the polarization source precursor. When using such a compound, the NMR signal intensity is preferably at least 10 times, more preferably at least 100 times, and even more preferably at least 1000 times, after a chemical reaction.

[0021] As an example of a compound group that can be used as a polarization source precursor of the present invention, a compound group represented by the following general formula (1) will be exemplified below.

[0022] In general formula (1), X represents a group represented by Pro-O- or a group that is converted to a hydroxy group by a chemical reaction. Here, Pro represents a protecting group. Examples of Pro include, but are not limited to, substituted or unsubstituted acyl groups (for example, unsubstituted acyl groups, such as acetyl groups), sugar chains (for example, sugar chains containing glycol), and sugars (for example, glycosyl groups). When X represents a group that is converted to a hydroxy group by a chemical reaction, X is (RO) ２ In this case, each R is independently an alkyl group or a linking group necessary for two Rs to join together to form a cyclic structure. １ ~R ５ Each independently represents a hydrogen atom or a substituent. １ ~R ５ are each independently one atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a carbonyl group, a hydroxy group, and an amino group, or a group consisting of a combination of two or more atoms. １ ~R ５ It is more preferable that at least one of R is a fluorine atom. １ ~R ５ At least one of R may be a group having a nitroxy radical. １ ~R ５ At least one of R may be a group that forms a complex with a metal ion. １ ~R ５ At least three of the above may be hydrogen atoms. These conditions may be used in appropriate combination.

[0023] In the present invention, the polarization source precursor can be a compound having a polarization source precursor moiety that becomes a polarization source for dynamic nuclear polarization through a chemical reaction, a dye moiety, and a linking group connecting the polarization source precursor moiety and the dye moiety. That is, a compound can be used in which the polarization source precursor moiety is bonded to a linking group, and the linking group is bonded to the dye moiety. The bond is preferably a covalent bond. Use of such a linked compound enables efficient chemically induced dynamic nuclear polarization after photoexcitation. The structure of the polarization source precursor described above with specific examples can be used for the polarization source precursor moiety (adopted as the monovalent group of the polarization source precursor). That is, a compound having a structure in which a portion of the structure of the polarization source precursor is replaced with a linking group to which a dye is bonded can be used as the polarization source precursor of the present invention. In one aspect of the present invention, the polarization source precursor moiety highly polarizes nuclear spins through chemically induced dynamic nuclear polarization. In another aspect of the present invention, the polarization source precursor moiety does not polarize nuclear spins through chemically induced dynamic nuclear polarization. The distance between the polarization source precursor moiety and the dye moiety can be, for example, 10 Å or more, 20 Å or more, or 30 Å or more, or 60 Å or less, 50 Å or less, or 40 Å or less. For example, it may be selected within a range of 10 to 20 Å or within a range of 20 to 30 Å. The distance between the polarization source precursor moiety and the dye moiety here refers to the distance between the center of the benzene ring of the polarization source precursor moiety and the center of the chromophore of the dye moiety. The shortest linking chain length of the linking group connecting the polarization source precursor moiety and the dye moiety can be selected within a range of 2 to 20 atoms, 3 to 15 atoms, or 4 to 10 atoms. It may also be selected within a range of 10 to 20 atoms. The shortest linking chain length here refers to the number of atoms comprising the shortest linking path connecting the polarization source precursor moiety and the dye moiety. There are no particular limitations on the type of linking group, as long as it does not adversely affect chemically induced dynamic nuclear polarization. Examples of such a linking group include an alkylene linking group, a polyalkyleneoxy linking group, and a polypeptide linking group. The linking group preferably has a hydrophilic group. The type of linking group is preferably selected in consideration of the environment in which the present invention is applied, solubility, biocompatibility, and availability of materials.The dye moiety can be a dye used in chemically induced dynamic nuclear polarization. In one embodiment of the present invention, the dye moiety is a porphyrin derivative. The bond formation reaction between the polarization source precursor moiety and the dye moiety is shown below. １ and R ２ One of the bonded structures represents a polarization source precursor moiety and the other represents a dye moiety. Note that the following bonded structures are merely examples, and the scope of the present invention should not be construed as being limited by these examples.

[0024] The compounds described above as polarization source precursors can be used as chemically induced dynamic nuclear polarization probes. They can be used in a wide variety of applications, including detecting specific substances, substances with specific properties, determining whether an environment satisfies specific conditions, determining whether a specific reaction is proceeding, detecting reaction by-products, detecting reaction products, and tracking their changes over time (especially tracking reactions). The substances referred to here may be industrial materials or biological substances (e.g., enzymes).

[0025] <Method for Evaluating Chemical Reaction Induction Function> The method for evaluating chemical reaction induction function of the present invention involves introducing the above-mentioned chemically induced dynamically nuclear polarized probe into a specific environment and measuring the degree of dynamic nuclear polarization by the chemically induced dynamically nuclear polarized probe to evaluate the chemical reaction induction function in that environment. The specific environment here refers to an environment in which the chemical reaction induction function is to be evaluated, and may be an in vivo environment or an industrial system. The degree of dynamic nuclear polarization is typically measured by NMR measurement. The chemical shift of the NMR signal can be confirmed or the signal intensity of a specific chemical shift can be measured. The chemical reaction induction function is evaluated based on the results of these measurements. Evaluating the chemical reaction induction function also leads to the functional evaluation of chemical substances present in that environment. For example, the method for evaluating chemical reaction induction function of the present invention can be used to evaluate the function of a drug administered in vivo. The method for evaluating chemical reaction induction function of the present invention can also be used to evaluate the function of chemical substances secreted in vivo or produced in vivo.

[0026] The features of the present invention will be explained in more detail below with reference to examples. The materials, processing details, processing procedures, etc. shown below can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below. NMR signal measurements were performed using an NMR apparatus (JEOL: JNM-ECA400). ESR spectrum measurements and dynamic nuclear polarization were performed using a combination of a 527 nm pulsed laser, an electromagnet, a microwave generator (Analog Devices: HMC-T2220), and an ESR detector.

[0027] (Synthesis Example 1) Synthesis of Compound 1

[0028] Acetic anhydride (24 mmol) was added to a biphasic mixture of a dichloromethane solution of compound 1s (10 mmol) and aqueous sodium hydroxide solution, and the mixture was stirred at room temperature for 1 hour. Dichloromethane was added to extract the organic phase, which was then dried over anhydrous sodium sulfate and filtered. The resulting solution was concentrated and purified by flash column chromatography (dichloromethane / methanol), followed by concentration to obtain compound 1 as a white powder. 1 H-NMR (400 MHz, d6-DMSO): δ (ppm), 7.20 (dt, 2H), 6.97 (dt, 2H), 3.50 (s, 2H), 2.18 (s, 3H).

[0029] (Synthesis Example 2) Synthesis of Compound 2

[0030] Acetic anhydride (4.8 mmol) was added to a biphasic mixture of a dichloromethane solution of compound 2s (2 mmol) and aqueous sodium hydroxide solution, and the mixture was stirred at room temperature for 1 hour. Dichloromethane was added to extract the organic phase, which was then dried over anhydrous sodium sulfate and filtered. The resulting solution was concentrated and purified by flash column chromatography (dichloromethane / methanol), followed by concentration to obtain compound 2 as a white powder. 1 H-NMR (400 MHz, d6-DMSO): δ (ppm), 7.33 (dd, 1H), 7.26 (t, 1H), 7.16 (dd, 1H), 3.67 (s, 2H), 2.37 (s, 3H).

[0031] (Synthesis Example 3) Synthesis of Compound 7 and Compound 8

[0032] Compound a was reacted with compound b (n=2) in N,N-dimethylformamide (DMF) at 80°C to obtain compound c (n=2). Compound c (n=2) was reacted with compound d at 80°C to obtain compound 7 (n=2). Compound a was reacted with compound b (n=3) in N,N-dimethylformamide (DMF) at 80°C to obtain compound c (n=3). Compound c (n=3) was reacted with compound d at 80°C to obtain compound 8 (n=3).

[0033] (Preparation method) Preparation of sample solution Disodium hydrogen phosphate and sodium dihydrogen phosphate were dissolved in water (H ２ O) or heavy water (D ２ 0) to prepare a 200 mM phosphate buffer solution (pH = 7.2), and sodium trimethylsilylpropanesulfonate (DSS) was dissolved to prepare a 100 mM standard solution. Similarly, a 1 mM tetrakis(4-carboxyphenyl)porphyrin (TCPP) solution and a 20 mM polarizer or polarizer precursor solution were prepared. Each of the prepared solutions was mixed with phosphate buffer and then boiled to prepare a sample solution containing 100 μM TCPP, 10 mM polarizer or polarizer precursor, 5 mM DSS, and 200 mM buffer. Note that the concentrations of the compounds in the samples were varied in some examples.

[0034] (Measurement 1) NMR Measurement of Compound 1s and Compound 1 A deuterium oxide solution (D 2 ) containing TCPP (100 μM), Compound 1s (10 mM), DSS (5 mM), and phosphate buffer (200 mM) was used. ２ O solution), １ The H-NMR spectrum was measured (Figure 2(a)). The same solution was also irradiated with a 520 nm laser beam (1 W) for 4 seconds. １ The H-NMR spectrum was measured (FIG. 2(b)). １By comparing the H-NMR spectra, it was confirmed that a signal with a strong negative polarization appeared at about 6.8 ppm due to laser light irradiation. A solution was prepared using compound 1 instead of compound 1s, and similarly, a signal with a strong negative polarization appeared due to laser light irradiation. １ The changes in the H-NMR spectrum were observed. As a result, no signal with negative polarization was observed even when irradiated with laser light. From these results, it was confirmed that dynamic nuclear polarization was observed in compound 1s, but not in compound 1, in which the hydroxy group of compound 1s was protected with an acetyl group. In other words, it was suggested that dynamic nuclear polarization could be observed by hydrolyzing compound 1, in which dynamic nuclear polarization was not observed, and deprotecting the acetyl group.

[0035] (Measurement 2) NMR Measurement of Compound 2s and Compound 2 A deuterium oxide solution (D 2 ) containing TCPP (100 μM), Compound 2s (10 mM), DSS (5 mM), and phosphate buffer (200 mM) was used. ２ O solution), １ The H-NMR spectrum was measured (Figure 3(a)). The same solution was also irradiated with a 520 nm laser beam (1 W) for 4 seconds. １ The H-NMR spectrum was measured (FIG. 3(b)). １ By comparing the H-NMR spectra, it was confirmed that a signal with a strong negative polarization appeared at about 6.8 ppm due to laser light irradiation. １９ When the F-NMR spectrum was measured, it was confirmed that a signal appeared at about -136 ppm upon irradiation with laser light. A solution was prepared using compound 2 instead of compound 2s, and similarly, a signal appeared at about -136 ppm upon irradiation with laser light. １ Changes in H-NMR spectrum １９ The change in the F-NMR spectrum was observed. １ No negatively polarized signals were observed in the H-NMR spectrum. １９No signal appeared at approximately -136 ppm in the F-NMR spectrum. These results confirmed that dynamic nuclear polarization was observed in compound 2s, but not in compound 2, in which the hydroxy group of compound 2s was protected with an acetyl group. This suggests that dynamic nuclear polarization can be observed by hydrolyzing compound 2, in which dynamic nuclear polarization is not observed, and deprotecting the acetyl group.

[0036] (Measurement 3) Measurement of the polarization accumulation rate of Compound 2 The polarization accumulation rate of Compound 2 due to fluorine T1 and dynamic nuclear polarization was measured. ２ This solution was irradiated with a 520 nm laser beam (1 W) for 4 seconds. １９ When the F-NMR spectrum was measured, a signal was observed at approximately -135.7 ppm. The change in the intensity of this signal over time was observed, and it was confirmed that the accumulation constant was 2.5 seconds and the relaxation time was approximately 16 seconds. This indicates that the molecules are saturated with laser light irradiation for approximately 4 seconds, and that the amount of molecular reaction can be quantitatively estimated from the signal intensity.

[0037] (Measurement 4) NMR Measurement of Compound 7 and Compound 8 Compound 7 (200 μM), DSS (5 mM), phosphate buffer (10 mM) in deuterated N,N-dimethyl sulfoxide and water (H ２ 0) to prepare a 2:1 mixture solution, １ The H-NMR spectrum was measured (Figure 4(a)). The same solution was also irradiated with a 520 nm laser beam (1 W) for 4 seconds. １ The H-NMR spectrum was measured (Fig. 4(b)). １ By comparing the H-NMR spectra, it was confirmed that a signal with a strong negative polarization appeared at 6.7 ppm upon laser irradiation, and the signal at 3.4 ppm was intensified. A solution was prepared in the same manner using compound 8 instead of compound 7. １Measurement of the H-NMR spectrum confirmed that, similar to compound 7, a signal with strong negative polarization appeared at 6.7 ppm upon laser irradiation, and that the signal at 3.4 ppm was also enhanced. It was confirmed that dynamic nuclear polarization could be observed by using a compound having both a dye moiety and a polarization source moiety in one molecule. These results demonstrate that a chemically induced dynamic nuclear polarization probe can be provided by using a compound having both a dye moiety and a polarization source precursor moiety in one molecule. Solutions were prepared in the same manner using a mixture of the following compound E1 and compound 1s, and a mixture of the following compound E2 and compound 1s, instead of compound 7. １ When the H-NMR spectrum was measured, it was confirmed that, similar to compound 7, a signal with strong negative polarization appeared at 6.7 ppm upon laser irradiation, and the signal at 3.4 ppm was also enhanced. ＤＮＰ ), compound concentration (C ＤＮＰ ), number of protons (N ＤＮＰ ) and the DSS signal intensity (N ｒｅｆ ), compound concentration in DSS (C ｒｅｆ ), the number of protons in the DSS (N ｒｅｆ ) was used to calculate the enhancement factor ε using the following formula. The enhancement factors ε were calculated in the same manner for solutions of Compound 7 and Compound 8, and the results are shown in Figure 5. It was confirmed that the S / N ratios of the solutions of Compound 7 and Compound 8 were improved by more than 1,000 times compared to the mixtures of Compound E1 and Compound 1s and Compound E2 and Compound 1s. Furthermore, Figure 6 shows the fluorescence quantum yields of these four solutions, and Figure 7 shows the ratios of non-radiative transitions. When Compound 7 and Compound 8 were used, it was demonstrated that energy was transferred efficiently between the dye moiety and the polarization source moiety.

[0038] (Example 1) Detection and tracking of lipase-catalyzed enzymatic reaction (using Compound 1) A heavy water solution (D) containing TCPP (100 μM), Compound 1 (10 mM), DSS (5 mM), and phosphate buffer (200 mM) was used. ２A lipase-added sample was prepared by adding lipase to this heavy water solution to a concentration of 0.1 g / L, and a lipase-free sample was prepared by not adding lipase. The sample was irradiated with a 520 nm laser beam (1 W) for 4 seconds before the addition of lipase (0 h), and 3 hours (3 h), 10 hours (10 h), and 44 hours (44 h) after the addition of lipase. １ The H-NMR spectrum was measured. The results are shown in Figure 8. Figure 8(a) shows the H-NMR spectrum of the sample to which lipase was not added. １ 8(b) is the H-NMR spectrum of the lipase-added sample. １ 1H-NMR spectrum. No change was observed in the lipase-free sample, but in the lipase-added sample, the negatively polarized signal at approximately 6.8 ppm increased over reaction time. Figure 9 is a graph showing the relationship between reaction time and integrated signal intensity. In the lipase-added sample, the signal intensity increased over reaction time. The ratio of integrated signal intensity relative to DSS revealed that the enhancement factor of the signal at approximately 6.8 ppm was 40 times. These results indicate that compound 1 can be used to detect and track lipase-mediated enzymatic reactions. Furthermore, the increase in signal intensity was observed even 44 hours after the start of the reaction, demonstrating that, unlike conventional probes using dynamic nuclear polarization, it is possible to monitor the progress of reactions over long periods of time without the constraints of observable reaction time.

[0039] (Example 2) Detection and tracking of lipase-catalyzed enzymatic reaction (using Compound 2) An aqueous solution (H) containing TCPP (100 μM), Compound 2 (10 mM), DSS (5 mM), and phosphate buffer (200 mM) was used. ２ A lipase-added sample was prepared by adding lipase to this solution at a concentration of 1 g / L, and a lipase-free sample was prepared by adding no lipase. The sample was irradiated with a 520 nm laser beam (1 W) for 4 seconds before the addition of lipase (0 h) and 5 days after the addition of lipase (120 h). １９ The F-NMR spectrum was measured. The results of the lipase-added sample are shown in Figure 10. Figure 10(a) shows the F-NMR spectrum of the lipase-added sample (0 h) before the addition of lipase. １９10(b) shows the F-NMR spectrum of the lipase solution 5 days (120 h) after its addition. １９ This is the F-NMR spectrum. The sample was irradiated with laser light 5 days after the addition of lipase. １９ When F-NMR spectrum was measured, a signal was observed at approximately -137 ppm. This signal was measured 5 hours after the addition of lipase without irradiating the sample with laser light. １９ This was not observed in the F-NMR spectrum, and was measured in the sample before the addition of lipase. １９ This signal was not observed in the F-NMR spectrum. Furthermore, the intensity of this signal was almost the same as the signal intensity after the reaction of compound 2s with lipase. From the results of Measurement 3 above, the signal obtained after 4 seconds of laser light irradiation was saturated, and there is a correlation between the reaction rate and the signal intensity. Therefore, the above results indicate that the acetyl group of compound 2 was hydrolyzed. In addition, even in the sample to which lipase was not added, the signal intensity after 5 days (120 hours) was １９ A weak signal may be observed at approximately -137 ppm in the F-NMR spectrum, but this is due to the autolysis of the acetyl group of compound 2. By replacing the acetyl group of compound 2 with an appropriate, highly stable protecting group, it is possible to prevent the signal from being observed in a solution to which lipase has not been added. The above results indicate that compound 2 can be used to detect and track enzymatic reactions catalyzed by lipase. In particular, compound 2 can be used to detect and track water (H ２ In addition to being able to detect １９ This method is advantageous in that the reaction can be quantitatively observed from the signal intensity of the F-NMR spectrum.

[0040] (Example 3) Detection and tracking of enzymatic reactions using alkaline phosphatase

[0041] An aqueous solution containing TCPP (100 μM), compound 3 (10 mM), DSS (5 mM), and phosphate buffer (50 mM) (H ２ The solution was irradiated with 520 nm laser light (1 W) for 4 seconds. １９Alkaline phosphatase was added to this solution to a concentration of 4 μM, and the solution was irradiated with a 520 nm laser beam (1 W) for 4 seconds. １９ The F-NMR spectrum was measured. １９ A signal of about -124 ppm was observed in the F-NMR spectrum. １９ The F-NMR spectrum was measured, and the time-dependent change in the signal intensity at about -124 ppm was observed. The results are shown in Figure 11. Figure 11(a) shows the change in the signal intensity of the sample with alkaline phosphatase added. １９ 11(b) is a graph showing the time course of the F-NMR spectrum, and FIG. 11(c) is a graph showing the time course of the signal intensity at approximately -124 ppm. Compound 3, which did not exhibit dynamic nuclear polarization, was hydrolyzed by alkaline phosphatase to produce compound 3s, a polarization source, and dynamic nuclear polarization was observed due to compound 3s. This confirms that compound 3 is useful as a chemically induced dynamic nuclear polarization probe that can detect and track the enzymatic reaction of alkaline phosphatase.

[0042] (Example 4) Detection and tracking of enzyme reactions using glucose oxidase

[0043] An aqueous solution (H ) containing TCPP (200 μM), compound 4 (6.7 mM), glucose (67 mM), DSS (5 mM), and phosphate buffer (50 mM) was prepared. ２ The solution was irradiated with 520 nm laser light (1 W) for 4 seconds. １９ Glucose oxidase (0.01 mg / 1 ml) was added to this solution, and the solution was irradiated with a 520 nm laser beam (1 W) for 4 seconds. １９ The F-NMR spectrum was measured. １９ A signal at approximately -135.5 ppm was observed in the F-NMR spectrum. １９ The F-NMR spectrum was measured, and the time-dependent change in the signal intensity at about -135.5 ppm was observed. The results are shown in Figure 12. Figure 12(a) shows the change in the signal intensity of the sample with glucose oxidase added. １９Figure 12(b) shows the F-NMR spectrum, and Figure 12(c) is a graph showing the time-dependent change in the signal intensity at approximately -135.5 ppm. Glucose oxidase generates hydrogen peroxide when oxidizing glucose. The generated hydrogen peroxide hydrolyzes compound 4, which does not exhibit dynamic nuclear polarization, to produce compound 4s, a polarization source. Dynamic nuclear polarization was observed due to compound 4s. This confirms that compound 4 is useful as a chemically induced dynamic nuclear polarization probe that can detect and track the enzymatic reaction of glucose oxidase.

[0044] (Example 5) Detection and tracking of enzymatic reactions by β-glucosidase

[0045] An aqueous solution containing TCPP (100 μM), compound 5 (10 mM), DSS (5 mM), and phosphate buffer (50 mM) (H ２ The solution was irradiated with 520 nm laser light (1 W) for 4 seconds. １９ β-glucosidase (1 mg / 1 ml) was added to this solution, and the solution was irradiated with a 520 nm laser beam (1 W) for 4 seconds. １９ The F-NMR spectrum was measured. １９ A signal of about -123 ppm was observed in the F-NMR spectrum. １９ The F-NMR spectrum was measured, and the time-dependent change in the signal intensity at about -123 ppm was observed. The results are shown in Figure 13. Figure 13(a) shows the change in the signal intensity of the sample with added β-glucosidase. １９ 13(b) is a graph showing the time course of the F-NMR spectrum, and FIG. 13(c) is a graph showing the time course of the signal intensity at approximately -123 ppm. Compound 5, which did not exhibit dynamic nuclear polarization, was hydrolyzed by β-glucosidase to produce compound 5s, a polarization source, and dynamic nuclear polarization was observed due to compound 5s. This confirmed that compound 5 is useful as a chemically induced dynamic nuclear polarization probe that can detect and track the enzymatic reaction of β-glucosidase.

[0046] (Example 6) Detection and tracking of oxidation reaction by hydrogen peroxide (near-infrared light excitation) A solution of N,N-dimethyl sulfoxide and water (H ２ A 1:1 mixed solution of 1:1 HCl and 1:1 HCl was prepared. The solution was irradiated with a 735 nm laser beam (1 W) for 4 seconds. １９ To this solution, 9.20 μL of hydrogen peroxide solution was added, and the solution was again irradiated with 735 nm laser light (1 W) for 4 seconds. １９ The F-NMR spectrum was measured. The results are shown in Figure 14. Figure 14(a) shows the F-NMR spectrum before adding hydrogen peroxide solution. １９ 14(b) shows the F-NMR spectrum after adding hydrogen peroxide solution. １９ The F-NMR spectrum shows the results. Compound 6, which does not exhibit dynamic nuclear polarization, was hydrolyzed by hydrogen peroxide to produce compound 6s, and dynamic nuclear polarization was observed for compound 6s. This confirmed that compound 6 is useful as a chemically induced dynamic nuclear polarization probe capable of detecting and tracking hydrogen peroxide. Furthermore, the chemically induced dynamic nuclear polarization probe was able to function by irradiating it with near-infrared light rather than visible light. When the same observation was performed using the following dye C2, a bacteriochlorin derivative, instead of dye C1, dynamic nuclear polarization was also observed. Dynamic nuclear polarization was also observed when a dye in which the fluorine atoms of the following dye C2 were replaced with hydrogen atoms was used.

[0047] According to the present invention, it is possible to easily detect substances and track reactions by utilizing photoexcited dynamic nuclear polarization. This is particularly useful in that it allows time-consuming detection of substances in vivo and tracking of in vivo reactions over long periods of time. Therefore, the present invention has a high industrial applicability.

Claims

1. A chemically induced dynamic nuclear polarization probe, comprising a polarization source precursor that generates a polarization source for dynamic nuclear polarization by a chemical reaction.

2. The chemically induced dynamic nuclear polarization probe according to claim 1 for in vivo application.

3. The chemically induced dynamic nuclear polarization probe of claim 1, wherein the polarization source is a substituted or unsubstituted phenol, a substituted or unsubstituted imidazole, a substituted or unsubstituted indole, a substituted or unsubstituted methylthiopropylamine, a substituted or unsubstituted guanine, a substituted or unsubstituted adenine, or a substituted or unsubstituted quinone.

4. The chemically induced dynamic nuclear polarization probe of claim 1, wherein said polarization source comprises fluorine atoms.

5. The chemically induced dynamic nuclear polarization probe described in claim 1, wherein the polarization source precursor has a structure in which the dynamic nuclear polarization active site of the polarization source is protected with a protecting group, and the protecting group is removed by the chemical reaction to generate the polarization source.

6. The chemically induced dynamic nuclear polarization probe of claim 5, wherein the dynamic nuclear polarization active site of said polarization source is a phenolic hydroxy group.

7. The chemically induced dynamic nuclear polarization probe of claim 6, wherein the protecting group is an acyl group, a glycosyl group, a phosphate group, a sulfonate group, or a protecting group that is removed by inducing a chain reaction within the protecting group by changing a functional group within the protecting group through the chemical reaction.

8. The chemically induced dynamic nuclear polarization probe of claim 5, wherein the chemical reaction is a hydrolysis reaction.

9. The chemically induced dynamic nuclear polarization probe according to claim 5, which is used for evaluating enzyme activity.

10. The chemically induced dynamic nuclear polarization probe of claim 9, wherein the enzyme is a lipase, esterase, glycosidase, galactosidase, phosphatase, sulfatase, protease, disulfide isomerase, or oxidase.

11. The chemically induced dynamic nuclear polarization probe described in claim 1, wherein the polarization source precursor has a group that is converted into a dynamic nuclear polarization active site of the polarization source by the chemical reaction (with the caveat that the group that is converted into the dynamic nuclear polarization active site does not have a structure in which the dynamic nuclear polarization active site is protected by a protecting group).

12. The chemically induced dynamic nuclear polarization probe of claim 11, wherein the group that converts into a dynamic nuclear polarization active site is a boronic acid group.

13. The chemically induced dynamic nuclear polarization probe according to claim 11, which is used for evaluating oxidase activity or detecting hydrogen peroxide.

14. The chemically induced dynamic nuclear polarization probe of claim 1, wherein the polarization source precursor is a dynamic nuclear polarization source having a paramagnetic group that undergoes paramagnetic relaxation, and the chemical reaction is a reaction that converts the paramagnetic group into a group that does not undergo paramagnetic relaxation.

15. The chemically induced dynamic nuclear polarization probe of claim 14, wherein the paramagnetic group comprises a nitroxy radical.

16. The chemically induced dynamic nuclear polarization probe of claim 1, wherein the chemical reaction results in the first observation of an NMR signal having a specific chemical shift value.

17. The chemically induced dynamic nuclear polarization probe of claim 1, wherein the chemical reaction increases the intensity of NMR signals having specific chemical shift values.

18. The chemically induced dynamic nuclear polarization probe of claim 1, wherein the polarization source precursor has a reactive site that reacts with the chemical reaction at a site different from a dynamic nuclear polarization active site of the polarization source.

19. The chemically induced dynamic nuclear polarization probe of claim 18, wherein the polarization source precursor is also a dynamic nuclear polarization source, and the chemical reaction results in a change in NMR chemical shift.

20. The chemically induced dynamic nuclear polarization probe of claim 19, wherein the chemical reaction is a complex formation reaction.

21. The chemically induced dynamic nuclear polarization probe of claim 20, wherein the reactive site is a site that undergoes a complexation reaction with a metal ion.

22. The chemically induced dynamically nuclear polarized probe of claim 21 for detecting metal ions.

23. The chemically induced dynamic nuclear polarization probe according to claim 1, wherein the polarization source precursor has a structure represented by the following general formula (1): In the general formula (1), X is a group represented by Pro-O- or a group that is converted to a hydroxy group by the above-mentioned chemical reaction. Pro represents a protecting group. R １ ~R ５ each independently represents a hydrogen atom or a substituent.

24. The chemically induced dynamic nuclear polarization probe of claim 23, wherein Pro represents a substituted or unsubstituted acyl group, e.g., an unsubstituted acyl group, e.g., an acetyl group.

25. The chemically induced dynamic nuclear polarization probe of claim 23, wherein Pro represents a glycan, e.g., a glycol-containing glycan.

26. X is (RO) ２ 24. The chemically induced dynamic nuclear polarization probe of claim 23, wherein R is B- and each R is independently an alkyl group or two R are linked together to form a cyclic structure.

27. R １ ~R ５ 24. The chemically induced dynamic nuclear polarization probe of claim 23, wherein at least one of is a fluorine atom.

28. R １ ~R ５ is independently one atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a carbonyl group, a hydroxyl group and an amino group, or a combination of two or more of these.

29. R １ ~R ５ 24. The chemically induced dynamic nuclear polarization probe of claim 23, wherein at least one of is a group having a nitroxy radical.

30. R １ ~R ５ 24. The chemically induced dynamic nuclear polarization probe of claim 23, wherein at least one of said probes has a group that complexes with a metal ion.

31. R １ ~R ５ 24. The chemically induced dynamic nuclear polarization probe of claim 23, wherein at least three of are hydrogen atoms.

32. A compound having a polarization source precursor moiety that becomes a polarization source for dynamic nuclear polarization upon chemical reaction, a dye moiety, and a linking group connecting the polarization source precursor moiety and the dye moiety.

33. The compound of claim 32 for use as a chemically induced dynamic nuclear polarization probe.

34. The compound of claim 32, wherein the polarization source precursor moiety hyperpolarizes nuclear spins by chemically induced dynamic nuclear polarization.

35. The compound of claim 32, wherein the distance between the polarization source precursor moiety and the dye moiety is 10 Å or greater.

36. The compound of claim 35, wherein the distance between the polarization source precursor moiety and the dye moiety is 10 to 20 Å.

37. The compound of claim 32, wherein the linking group has a linking chain length of 2 to 20 atoms.

38. The compound of claim 32, wherein the linking group is a hydrophilic linking group.

39. The compound of claim 32, wherein the linking group comprises an alkylene linking group, a polyalkyleneoxy linking group, or a polypeptide linking group.

40. The compound of claim 32, wherein the dye moiety is a porphyrin derivative.

41. The compound of claim 32, wherein the polarizable precursor moiety has a protecting group for a hydroxy group.

42. A method for evaluating a chemical reaction induction function, comprising: introducing a chemically induced dynamic nuclear polarization probe according to any one of claims 1 to 31 into a specific environment; and measuring the degree of dynamic nuclear polarization caused by the chemically induced dynamic nuclear polarization probe, thereby evaluating the chemical reaction induction function in the environment.

43. The method for evaluating a chemical reaction induction function according to claim 42, wherein the environment is an in vivo environment.

44. The method for evaluating a chemical reaction induction function according to claim 42, wherein the evaluation is an evaluation of a function of a chemical substance present in the environment.

45. The method for evaluating a chemical reaction induction function according to claim 44, wherein the chemical substance is a drug administered into a living body.

46. ​​The method for evaluating a chemical reaction induction function according to claim 44, wherein the chemical substance is a chemical substance secreted or produced in a living body.

47. The method for evaluating a chemical reaction induction function according to claim 42, wherein the measurement is carried out by NMR.

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