Method for estimating structure of acyl group-containing compound of interest

Abstract

A method for estimating the structure of a target compound containing an acyl group, which is a method for estimating the structure of a target compound containing a straight-chain acyl group, and which comprises: a step for analyzing a sample containing the target compound by chromatography and determining the retention time; and a step for estimating the combination of the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds in the target compound from the retention time on the basis of formula 1 and formula 2 described below. (In formula 1, N represents the total number of carbon atoms in the acyl group, f (T) represents a function derived from a homolog of a saturated compound corresponding to the target compound, and the function represents the correlation between the total number of carbon atoms and the retention time; in formula 2, t represents the retention time, D represents a coefficient derived from a carbon-carbon double bond, and m represents the total number of carbon-carbon double bonds. ) N = f (T)... (Equation 1) T = t / Dm... (Equation 2)

Description

Technical Field

[0001] The present application relates to a method for estimating the structure of a target compound containing an acyl group. Background Art

[0002] Triacylglycerol (TAG) refers to a compound formed by ester bonding of one glycerol molecule and three fatty acid molecules, and is one of the neutral fats belonging to simple lipids. TAG is the main component of edible oils and fats, and is contained in, for example, vegetable oils, butter, margarine, milk, beef, pork, chicken, soybeans, and nuts. The composition ratio of TAG varies depending on its source. For example, in olive oil, which is a vegetable oil, the content of oleic acid (C18:1, carbon number: 18, double bond number: 1) as a fatty acid constituting TAG is high, and in soybean oil, the content of linoleic acid (C18:2, carbon number: 18, double bond number: 2) is high. In addition, in cocoa butter, which is a raw material for chocolate, the fatty acids constituting TAG mainly include palmitic acid (C16:0, carbon number: 16, double bond number: 0), stearic acid (C18:0, carbon number: 18, double bond number: 0) and oleic acid, which are saturated fatty acids. That is, if the types and ratios of fatty acids (acyl groups) constituting TAGs are analyzed, the types of fats and oils can be estimated, and therefore, it is desired to establish a method for identifying fatty acids constituting TAGs.

[0003] For example, Patent Document 1 (Japanese Patent No. 7019281) discloses a method for analyzing the triglyceride composition of a composition containing two or more different triglycerides having the same total number of fatty acid residues (total number of carbon atoms), which method includes the following steps (a) and (b).

[0004] (a) decomposing each triglyceride into corresponding diglycerides and fatty acid fragments by mass spectrometry analysis;

[0005] (b) decomposing each diacylglycerol detected in step (a) into corresponding fatty acid fragments by mass spectrometry analysis. Summary of the invention

[0006] However, the method described in Patent Document 1 is time-consuming and laborious, and therefore, it is desirable to develop a method that can be analyzed more simply. In addition, the combination of fatty acids in TAG is huge (at least 3,000 or more), and it is not easy to prepare all the standard products corresponding to the assumed combination before analyzing TAG. Therefore, it is desirable to develop a method that can infer the fatty acids constituting TAG even if there are no standard products corresponding to the assumed combination of fatty acids.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for simply estimating the total number of carbon atoms of acyl groups and the total number of carbon-carbon double bonds of acyl groups in a target compound containing acyl groups.

[0008] The present inventors have conducted intensive studies and found that there is a correlation between the retention time in chromatographic analysis and the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds of the acyl group in the target compound, thereby completing the present invention.

[0009] A first aspect of the present invention is a method for estimating the structure of a target compound containing a linear acyl group, comprising the following steps:

[0010] A step of analyzing a sample containing the target compound using chromatography to determine the retention time; and

[0011] A step of estimating a combination of the total number of carbon atoms of the acyl groups and the total number of carbon-carbon double bonds in the target compound from the retention time according to the following Formula 1 and Formula 2.

[0012] N=f(T)…(Formula 1)

[0013] T=t / D m …(Formula 2)

[0014] (In Formula 1, N represents the total number of carbon atoms in the acyl group, f(T) represents a function derived from a homologue of a saturated compound corresponding to the target compound, and the function represents the correlation between the total number of carbon atoms and the retention time; in Formula 2, t represents the retention time, D represents a coefficient derived from a carbon-carbon double bond, and m represents the total number of carbon-carbon double bonds.)

[0015] A second aspect of the present invention relates to a recording medium that can be read by a computer and that records a database for causing the computer to execute the structure estimation method according to the first aspect.

[0016] The database stores the analysis conditions of the chromatogram, and the function f(T) derived when the homologue is analyzed using the analysis conditions, and the coefficient D derived from the carbon-carbon double bond in association with each other.

[0017] According to the present invention, a method for easily estimating the total number of carbon atoms of acyl groups and the total number of carbon-carbon double bonds of acyl groups in a target compound containing acyl groups can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure (left) shows the results of analyzing fully saturated triglycerides using supercritical fluid chromatography, and the figure (right) shows the correlation between the total number of carbon atoms of acyl groups in triglycerides (horizontal axis) and retention time (vertical axis) based on the results of the analysis. In the left figure, the horizontal axis represents retention time (minutes) and the vertical axis represents detection intensity.

[0019] Figure 2A graph showing the results of triglyceride analysis using supercritical fluid chromatography (left) and a table showing the correlation between the total number of carbon-carbon double bonds of acyl groups in triglyceride and retention time based on the analysis results (right).

[0020] Figure 3 This is a diagram showing the results of triglyceride analysis using supercritical fluid chromatography. DETAILED DESCRIPTION

[0021] Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") is described. However, this embodiment is not limited thereto. In this specification, the expression in the form of "A to Z" refers to the upper and lower limits of the range (i.e., above A and below Z). When there is no unit recorded at A and only at Z, the unit of A is the same as the unit of Z.

[0022] 《Method for estimating the structure of a target compound containing a straight-chain acyl group》

[0023] A first aspect of the present invention relates to a method for estimating a structure of a target compound containing a linear acyl group, comprising the following steps:

[0024] A step of analyzing a sample containing the target compound using chromatography to determine the retention time; and

[0025] A step of estimating a combination of the total number of carbon atoms of the acyl groups and the total number of carbon-carbon double bonds in the target compound from the retention time according to the following Formula 1 and Formula 2.

[0026] N=f(T)…(Formula 1)

[0027] T=t / D m …(Formula 2)

[0028] (In Formula 1, N represents the total number of carbon atoms in the acyl group, f(T) represents a function derived from a homologue of a saturated compound corresponding to the target compound, and the function represents the correlation between the total number of carbon atoms and the retention time; in Formula 2, t represents the retention time, D represents a coefficient derived from a carbon-carbon double bond, and m represents the total number of carbon-carbon double bonds.)

[0029] <Step of analyzing a sample containing a target compound using chromatography to determine retention time>

[0030] In this step, a sample containing a target compound is analyzed by chromatography to determine the retention time. The target compound contains a linear acyl group. Here, "retention time" refers to the time required from the injection of a solute into a chromatographic column to the elution.

[0031] (Target compound)

[0032] In the present embodiment, the target compound is not particularly limited as long as it is a compound containing at least one straight-chain acyl group, and can be a compound of the analysis object. The above-mentioned acyl group can be a straight-chain saturated acyl group, or a straight-chain unsaturated acyl group. The number of carbon atoms in each of the above-mentioned acyl groups can be more than 2 and less than 30, or more than 6 and less than 24. The number of carbon-carbon double bonds in each of the above-mentioned acyl groups can be more than 0 and less than 6, or more than 0 and less than 3. The number of the above-mentioned acyl groups in the above-mentioned target compound can be more than 1 and less than 3, or more than 1 and less than 2.

[0033] Examples of the target compound include triacylglycerol (hereinafter sometimes referred to as "TAG"), diacylglycerol, monoacylglycerol, sterol lipids, glycerophospholipids, sphingomyelin, etc. In one aspect of the present embodiment, the target compound is preferably triacylglycerol.

[0034] In the present embodiment, the sample containing the target compound is not particularly limited and can be a liquid or a solid. From the viewpoint of easy analysis using chromatography, the sample is preferably a liquid. In one aspect of the present embodiment, the sample can be derived from an organism or from food.

[0035] In this embodiment, the chromatography is not particularly limited, and a known chromatography can be used. Examples of the chromatography include liquid chromatography and supercritical fluid chromatography. In one aspect of this embodiment, the chromatography is preferably liquid chromatography or supercritical fluid chromatography.

[0036] In the present embodiment, the analysis conditions based on chromatography are not particularly limited and can be appropriately set. For example, the analysis conditions described in the examples described later can be cited.

[0037] <Step of estimating a combination of the total number of carbon atoms of acyl groups and the total number of carbon-carbon double bonds in the target compound based on the retention time>

[0038] In this step, the combination of the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds in the target compound is estimated from the retention time according to the following formula 1 and formula 2.

[0039] N=f(T)…(Formula 1)

[0040] T=t / D m …(Formula 2)

[0041] (Formula 1: Function representing the correlation between the total number of carbon atoms N in the acyl group and the retention time T of the saturated compound corresponding to the target compound)

[0042] In the above formula 1, N represents the total number of carbon atoms in the above acyl group, and f(T) represents a function derived from the homologue of the saturated compound corresponding to the above target compound, which function represents the correlation between the total number of carbon atoms N and the retention time T of the above saturated compound.

[0043] In the present embodiment, "N = f(T)" means that if the retention time T of the saturated compound corresponding to the target compound is determined, the total number of carbon atoms N in the corresponding acyl group is determined to be one. It can also be considered that the total number of carbon atoms N in the corresponding acyl group is a function of the retention time T of the saturated compound corresponding to the target compound. At this time, f(T) can be expressed by a mathematical formula or not. In one aspect of the present embodiment, when f(T) is expressed by a mathematical formula, the mathematical formula can be a formula fitted by a straight line (linear function) or a formula fitted by a spline curve (quadratic function, etc.).

[0044] In the present embodiment, f(T) is a function derived from the homologue of the saturated compound corresponding to the above-mentioned target compound. Here, the "saturated compound corresponding to the target compound" refers to a compound obtained by changing all the carbon-carbon double bonds of the acyl group in the target compound to single bonds. When the acyl group in the above-mentioned target compound does not have a carbon-carbon double bond, the above-mentioned target compound and the saturated compound corresponding to the above-mentioned target compound become the same compound. In the present embodiment, the "homologue of a saturated compound" refers to a group of compounds with different numbers of carbon atoms in the acyl group based on the saturated compound.

[0045] In one aspect of the present embodiment, the above-mentioned target compound, the saturated compound corresponding to the above-mentioned target compound, and the homologue of the above-mentioned saturated compound have the same main chemical structure. Here, the "main chemical structure" refers to the chemical structure other than the acyl group in the above-mentioned target compound. For example, in the case where the target compound is triacylglycerol, the main chemical structure becomes a chemical structure derived from glycerol. Since the chemical structure as the target is determined at the stage of starting the analysis, the main chemical structure in the above-mentioned target compound is determined in advance. For example, when triacylglycerol is used as the target compound for analysis, at the stage of selecting triacylglycerol as the target, it can be determined that the main chemical structure is a chemical structure derived from glycerol.

[0046] In the present embodiment, "the total number of carbon atoms in the acyl group" means the total number of carbon atoms of each acyl group bonded to the target compound.

[0047] In this embodiment, T in f(T) refers to the retention time of the saturated compound corresponding to the target compound. The retention time T of the saturated compound is calculated using Formula 2 described below.

[0048] f(T) can be derived, for example, by the following steps. First, two or more homologues of the above-mentioned saturated compound are prepared. In this case, the homologues are compounds in which the total number of carbon atoms N in the acyl group is known. The prepared homologues are analyzed by chromatography, and the retention time T corresponding to each homologue is obtained. By plotting the correlation between the total number of carbon atoms N in the above-mentioned acyl group and the corresponding retention time T, f(T) (for example Figure 1 ). Based on the obtained plot, a fitting formula can be obtained and set as a formula representing f(T). That is, in one aspect of the present embodiment, f(T) in Formula 1 is preferably a function derived from two or more homologous compounds.

[0049] (Formula 2: Relationship between the retention time t of the target compound and the retention time T of the saturated compound corresponding to the target compound)

[0050] In the above formula 2, t represents the retention time of the target compound, D represents the coefficient derived from the carbon-carbon double bond, and m represents the total number of carbon-carbon double bonds.

[0051] It is known that when the total number of carbon atoms in the acyl group of triglycerol is the same, the retention time tends to decrease as the total number of carbon-carbon double bonds in the acyl group increases, but the specific regularity is unknown. The present inventors have repeatedly conducted in-depth studies and have found for the first time that when the total number of carbon atoms in the acyl group of triglycerol is the same, the retention time T of the saturated compound is proportional to the retention time t of the target compound, and the proportionality constant is (1 / D m ). According to the above formula 1 and formula 2, the combination of the total number of carbon atoms N of the acyl groups in the target compound containing the acyl group and the total number of carbon-carbon double bonds m of the acyl groups can be easily estimated from the retention time t.

[0052] The coefficient D derived from the carbon-carbon double bond exceeds 0 and is less than 1. In one aspect of the present embodiment, when the reduction ratio of the retention time caused by increasing one carbon-carbon double bond is constant regardless of the total number of carbon-carbon double bonds, the structure inference method described in the present embodiment can be suitably used. The coefficient D derived from the carbon-carbon double bond can be obtained, for example, by the following operation. First, prepare two or more compounds with the same main chemical structure and the same total number of carbon atoms in the acyl group, and different total numbers of carbon-carbon double bonds in the acyl group. The prepared compounds are analyzed separately by chromatography to obtain the retention time corresponding to each compound. According to the total number of carbon-carbon double bonds in the above-mentioned acyl group and the corresponding retention time, the reduction ratio of the retention time caused by increasing one carbon-carbon double bond is obtained respectively. When the deviation of the obtained reduction ratio is small, the average value of the obtained reduction ratio is set to D. On the other hand, when it is desired to improve the analytical accuracy of the target compound with a large deviation of the obtained reduction ratio and a smaller degree of unsaturation, the reduction ratio of the retention time caused by increasing the total number of the above-mentioned carbon-carbon double bonds from 0 to 1 is set to D.

[0053] In the present embodiment, the total number m of carbon-carbon double bonds in Formula 2 is not particularly limited, and may be 0 or more and 6 or less. By setting it in such a range, the structure estimation method of the present embodiment can be preferably used.

[0054] By using the above formula 1 and formula 2, the total number of carbon atoms N of the above acyl groups in the target compound can be calculated based on the retention time t of the target compound and the total number of carbon-carbon double bonds m assumed. That is, the combination of the total number of carbon atoms N of the acyl groups in the target compound and the total number of carbon-carbon double bonds m can be estimated based on the retention time t of the target compound. In this embodiment, "estimation" also includes narrowing the candidates for the above combination under consideration. For example, in the case of triacylglycerols, three acyl groups are bonded, and as each acyl group, there are mainly 28 chemical structures known (see Table 1). In this case, 3276 combinations of three acyl groups can be considered. If the structure estimation method described in this embodiment is used, the total number of carbon atoms N of the acyl groups is determined to be one for the total number of carbon-carbon double bonds m assumed, which can greatly reduce the candidates for the triacylglycerols to be analyzed.

[0055] [Table 1]

[0056] Total carbon atoms Total number of double bonds Abbreviation 6 0 6∶0 8 0 8∶0 10 0 10：0 12 0 12：0 14 0 14：0 14 1 14：1 16 0 16：0 16 1 16：1 18 0 18：0 18 1 18：1 18 2 18：2 18 3 18：3 18 4 18：4 20 0 20：0 20 1 20：1 20 2 20：2 20 3 20：3 20 4 20：4 20 5 20：5 22 0 22：0 22 1 22：1 22 2 22：2 22 3 22∶3 22 4 22：4 22 5 22：5 22 6 22∶6 24 0 24：0 24 1 24∶1

[0057] <Other Processes>

[0058] In one aspect of this embodiment, it is preferred that the method further comprises the step of analyzing the target compound using a mass spectrometer.

[0059] The ionization method based on the mass spectrometry device is not particularly limited, and matrix-assisted laser desorption ionization (MALDI) method, electrospray ionization (ESI) method, nano-electrospray ionization (nano-LSI) method, etc. can be used. In the present embodiment, the ionization method is preferably the ESI method. In the ionization in mass spectrometry, any one of the positive ion mode and the negative ion mode can be used. Mass spectrometry can be carried out in multiple stages.

[0060] Examples of the mass spectrometer include a Fourier transform mass spectrometer, a time-of-flight (Q-TOF) mass spectrometer, a triple quadrupole mass spectrometer, a single quadrupole mass spectrometer, etc. In the present embodiment, from the viewpoint of analyzing known components with good accuracy in a short time, the mass spectrometer is preferably a triple quadrupole mass spectrometer.

[0061] In one aspect of the present embodiment, the following operations can be performed continuously: analyzing a sample containing a target compound using a chromatogram; and analyzing the target compound using a mass spectrometer. For example, by using a liquid chromatography-tandem mass spectrometer, the two steps can also be performed continuously. Typically, the liquid chromatography-tandem mass spectrometer is a liquid chromatography-triple quadrupole mass spectrometer, or a liquid chromatography-quadrupole / time of flight (Q-TOF) mass spectrometer. Usually, in such a liquid chromatography-tandem mass spectrometer, the analysis parameters are determined in a manner that maximizes the detection sensitivity of each component in the eluent after separation by liquid chromatography, in other words, in an optimal state.

[0062] The structure estimation method according to the first aspect of the present invention has been described above. This structure estimation method may be performed directly by a measurer or by a computer.

[0063] 《Recording medium readable by a computer》

[0064] A second aspect of the present invention relates to a recording medium that can be read by a computer and that records a database for causing the computer to execute the structure estimation method according to the first aspect.

[0065] The database stores the analysis conditions of the chromatogram, and the function f(T) derived when the homologous compound is analyzed using the analysis conditions, and the coefficient D derived from the carbon-carbon double bond in association with each other.

[0066] Examples of the analytical conditions for the chromatography include the type of mobile phase, the flow rate of the mobile phase, the gradient conditions of the mobile phase, the type of stationary phase, the measurement temperature, and the pressure.

[0067] Examples of other information stored in the database include mass spectrum information of the analysis object, retention time information, and detector signal intensity.

[0068] The recording medium is not particularly limited as long as it is a commonly used recording medium, and examples thereof include optical disks (CD-ROM, DVD-ROM, BD-ROM, etc.), magneto-optical disks, and flash memories.

[0069] Example

[0070] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0071] <Experiment 1: Correlation between the total number of carbon atoms N in the acyl group and the retention time T>

[0072] The following experiment was conducted to investigate the correlation between the total number of carbon atoms N in the acyl group and the retention time T. First, a standard sample of triacylglycerol (hereinafter sometimes referred to as "TAG") shown below was prepared. For any standard sample, a compound (saturated compound) in which the total number of carbon-carbon double bonds in the acyl group was 0 was used.

[0073] (Triglyceride standard)

[0074] Saturated triglyceride mixed standard (total carbon number is 26 to 54)

[0075] The above-mentioned standard products were analyzed by supercritical fluid chromatography (manufactured by Shimadzu Corporation, product name: Nexera UC) to determine the retention time. The analysis conditions at this time are as follows.

[0076] (Analysis conditions of supercritical fluid chromatography)

[0077] Column: Shim-pack XR-ODSIII, 150×2.0mm ID, 2.2m

[0078] Flow Rate: 0.8mL / min

[0079] Modifier (Pump B): Acetonitrile

[0080] Time program B conc.10%

[0081] Back Pressure Regulator: 10MPa

[0082] Oven Temperature: 25°C

[0083] Injection Volume: 0.5L

[0084] LCMS-8050 and interfacial conditions

[0085] Make-up solvent: 0.2 mL / min (methanol containing 10 mM ammonium acetate)

[0086] Interface: DUIS

[0087] MS Mode: Positive mode

[0088] Block Temperature: 40°C

[0089] DL Temperature: 235°C

[0090] Nebulizing Gas Flow: 2L / min

[0091] Drying Gas Flow: 10L / min

[0092] Heating Gas Flow (heating gas flow rate): 10L / min

[0093] A graph showing the results of analyzing fully saturated triglycerides by supercritical fluid chromatography (left) and a graph showing the correlation between the total number of carbon atoms of acyl groups in triglycerides (horizontal axis) and the retention time (vertical axis) based on the results of the analysis (right) are shown. Figure 1 .exist Figure 1 In the right figure, the circular plots represent the measurement results of the triglyceride standard, and the cross plots represent the retention prediction obtained by the function of N=f(T). Figure 1 The right figure shows that the total number of carbon atoms N of the acyl groups in the triglycerides is a function of the retention time T. The figure was fitted using the least squares method, and the following formula 1' was derived.

[0094] N=f(T)=0.0000271053186070559×(T 4 )-0.00363140807472355×(T 3 )

[0095] +0.186952207220782×(T 2)-4.24830631212859×(T)+36.3581033113478…(Formula 1')

[0096] <Experiment 2: Correlation between the total number m of carbon-carbon double bonds in acyl groups and retention time t>

[0097] In order to investigate the correlation between the total number m of carbon-carbon double bonds in the acyl group and the retention time t, the following experiment was conducted. First, the following triacylglycerol standard samples were prepared. All standard samples used a compound having a total number of carbon atoms of 48 in the acyl group.

[0098] (Triglyceride standard)

[0099] Mixed samples of triglycerides shown as (48:0), (48:1), (48:2) and (48:3)

[0100] The above-mentioned standard products were analyzed by supercritical fluid chromatography (manufactured by Shimadzu Corporation, product name: Nexera UC) to determine the retention time. The analysis conditions at this time were the same as those in Experiment 1.

[0101] A graph showing the results of triglyceride analysis using supercritical fluid chromatography (left) and a table showing the correlation between the total number of carbon-carbon double bonds of acyl groups in triglyceride and retention time based on the results of the analysis (right) are shown in FIG. Figure 2 .according to Figure 2 It can be seen from the table that for every increase in the total number m of carbon-carbon double bonds of the acyl groups in triglycerides, the retention time t decreases at a ratio of 0.83 to 0.88 times. The following formula 2' is derived from this table. In formula 2', T refers to the retention time of the saturated compound corresponding to the above-mentioned standard (target compound). t and m refer to the retention time of the above-mentioned standard (target compound) and the total number of carbon-carbon double bonds of the acyl groups, respectively. D refers to the reduction ratio of the retention time caused by the increase of the above-mentioned carbon-carbon double bond by one (the coefficient derived from the carbon-carbon double bond). In other words, it can be seen that the retention time T of the saturated compound corresponding to the above-mentioned standard is proportional to the retention time t of the above-mentioned standard, and the proportional constant is (1 / D m , D=0.83~0.88).

[0102] T=t / D m …(Formula 2')

[0103] <Experiment 3: Estimation of retention time>

[0104] Based on the results of Experiments 1 and 2, the retention time of triacylglycerol (TAG (52: 2)) with N = 52 and m = 2 is estimated. The change in retention time due to an increase in the total number of carbon-carbon double bonds is independent of the change in retention time due to the total number of carbon atoms in the acyl group, so it can be considered that the same D value can be used to some extent for both the case of N = 48 (Experiment 2) and the case of N = 52 (Experiment 3). The retention time of the saturated compound (TAG (52: 0)) corresponding to TAG (52: 2) was previously calculated and the result was 8.55 minutes. Based on Experiment 2, it can be estimated that the reduction ratio of the retention time caused by the increase in the total number of carbon-carbon double bonds from 0 to 1 is 0.83, so the retention time of TAG (52: 2) can be estimated to be 5.89 (minutes).

[0105] On the other hand, TAG (52:2) was analyzed by supercritical fluid chromatography under the same conditions as in Experiment 1. The retention time was 5.862 minutes, which is consistent with the above-estimated retention time ( Figure 3 ).

[0106] As described above, from the results of Experiments 1 to 3, it is known that by using Formulas 1 and 2, the combination of the total number of carbon atoms of acyl groups and the total number of carbon-carbon double bonds of acyl groups in the target compound containing acyl groups can be easily estimated from the retention time t of the target compound.

[0107] [Way]

[0108] It should be understood by those skilled in the art that the above-described multiple exemplary embodiments are specific examples of the following aspects.

[0109] (Item 1) A structure inference method described in one embodiment is a structure inference method for a target compound containing a straight-chain acyl group, comprising the following steps: a step of analyzing the sample containing the target compound using chromatography to determine the retention time; and a step of inferring the combination of the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds in the target compound from the retention time according to the following Formulas 1 and 2.

[0110] N=f(T)…(Formula 1)

[0111] T=t / D m …(Formula 2)

[0112] (In Formula 1, N represents the total number of carbon atoms in the acyl group, f(T) represents a function derived from a homologue of a saturated compound corresponding to the target compound, and the function represents the correlation between the total number of carbon atoms and the retention time; in Formula 2, t represents the retention time, D represents a coefficient derived from a carbon-carbon double bond, and m represents the total number of carbon-carbon double bonds.)

[0113] According to the structure estimation method described in Item 1, a method for easily estimating the total number of carbon atoms of acyl groups and the total number of carbon-carbon double bonds of acyl groups in a target compound containing acyl groups can be provided.

[0114] (Item 2) In the structure estimation method according to Item 1, the target compound is triacylglycerol. According to the structure estimation method according to Item 2, the chemical structure of triacylglycerol can be easily estimated.

[0115] (Item 3) In the structure estimation method described in Item 1 or Item 2, the aforementioned f(T) in Formula 1 is a function derived from two or more of the aforementioned homologous compounds. According to the structure estimation method described in Item 3, the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds of the acyl group in the target compound containing the acyl group can be estimated simply and with good accuracy.

[0116] (Item 4) In the structure estimation method according to any one of Items 1 to 3, the chromatogram is liquid chromatography or supercritical fluid chromatography. According to the structure estimation method according to Item 4, the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds of the acyl group in the target compound containing the acyl group can be estimated simply and with good accuracy.

[0117] (Item 5) In the structure estimation method described in any one of Items 1 to 4, the step of analyzing the target compound using a mass spectrometer is further included. According to the structure estimation method described in Item 5, the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds of the acyl group in the target compound containing the acyl group can be easily estimated, and on this basis, more detailed structural information can be obtained.

[0118] (Item 6) In the structure estimation method described in Item 5, the mass spectrometer is a triple quadrupole mass spectrometer. According to the structure estimation method described in Item 6, the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds of the acyl group in the target compound containing the acyl group can be easily estimated, and on this basis, more detailed structural information can be obtained.

[0119] (Item 7) The recording medium described in one embodiment is a recording medium that can be read by a computer, and records a database for enabling a computer to execute the structure inference method described in any one of Items 1 to 6, wherein the database stores the analysis conditions of the chromatogram, and the function f(T) derived when analyzing the homologue using the analysis conditions and the coefficient D derived from the carbon-carbon double bond in an associated manner.

[0120] According to the recording medium described in item 7, it is possible to cause a computer to execute the structure estimation method described in any one of items 1 to 6.

[0121] As mentioned above, although embodiment and Example of this invention were demonstrated, it is originally planned that the structure of each embodiment and each Example mentioned above can be combined suitably.

[0122] The embodiments and examples disclosed herein are illustrative in all aspects and have no limiting effect. This means that the scope of the present invention is indicated by the claims rather than the embodiments and examples described above, and includes all changes within the meaning and scope equivalent to the claims.

Claims

1. A method for estimating a structure of a target compound containing a linear acyl group, comprising the following steps: A step of analyzing a sample containing the target compound using chromatography to determine a retention time; and A step of estimating a combination of the total number of carbon atoms of the acyl group and the total number of carbon-carbon double bonds in the target compound from the retention time according to the following formula 1 and formula 2, N=f(T)…(Formula 1) T=t / D m …(Formula 2) In Formula 1, N represents the total number of carbon atoms in the acyl group, f(T) represents a function derived from the homologues of the saturated compound corresponding to the target compound, and the function represents the correlation between the total number of carbon atoms and the retention time; in Formula 2, t represents the retention time, D represents the coefficient derived from the carbon-carbon double bond, and m represents the total number of carbon-carbon double bonds.

2. The structure estimation method according to claim 1, wherein: The target compound is triglyceride.

3. The structure estimation method according to claim 1 or 2, wherein: The f(T) in Formula 1 is a function derived from two or more homologous compounds.

4. The structure estimation method according to claim 1 or 2, wherein: The chromatography is liquid chromatography or supercritical fluid chromatography. 5 . The structure estimation method according to claim 1 , further comprising the step of analyzing the target compound using a mass spectrometer.

6. The structure estimation method according to claim 5, wherein: The mass spectrometer is a triple quadrupole mass spectrometer.

7. A recording medium that can be read by a computer, the recording medium recording a database for causing the computer to execute the structure estimation method according to any one of claims 1 to 6, The database stores the analysis conditions of the chromatogram, and the function f(T) derived when the homologous compounds are analyzed using the analysis conditions, and the coefficient D derived from the carbon-carbon double bond in association with each other.

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