C31 alkane as well as preparation method and application thereof

Abstract

The invention discloses C31 alkane and a preparation method and application thereof, and belongs to the technical field of geochemistry, the C31 alkane comprises a compound 1 or a compound 2, and the compound 1 and the compound 2 are stereoisomers; wherein the chemical structural formulas of the compound 1 and the compound 2 are respectively # imgabs0 #, namely the two compounds provided by the invention can be used as novel grape algae biomarker compounds for indicating grape algae biosources and reflecting the deposition environment of oxidation reduction, and can be used as heavy carbon isotope standard samples in the carbon isotope analysis process.

Description

Technical Field

[0001] The present invention belongs to the technical field of geochemistry, and particularly relates to a C 31 alkane and its preparation method and application. Background Art

[0002] Fossil fuels are mixtures of hydrocarbons or hydrocarbon derivatives, including natural coal, petroleum, natural gas, etc., which are mainly formed by the remains of ancient organisms after millions or even hundreds of millions of years through a series of complex changes. The biomarker compounds therein are substances derived from ancient living organisms and remain after hundreds of millions of years of evolution. Therefore, these compounds have a certain stability, basically preserving the carbon skeletons of the original biochemical components and recording the special molecular structure information of the original biological parent material, also known as molecular fossils. In the field of organic geochemistry, the compositional characteristics and structural information of biomarker compounds are often used to judge the type of oil-generating parent material and sedimentary environment of fossil fuels or sediments / rocks, and to study the diagenetic evolution and microbial degradation of organic matter, and are widely used in the research of petroleum origin theory and the source study of hydrocarbons. In the past decade or so, they have also been applied to the fields of reservoir geochemistry research, secondary migration of crude oil, oil-oil correlation, oil-source correlation, exploration of the source of severely biodegraded oil, global change, paleovegetation, paleotemperature, paleoprecipitation, paleoatmospheric CO 2 concentration and paleomonsoon restoration.

[0003] Botryococcane is a biomarker compound that is only produced by Botryococcus of genus B (Botryococcus braunii). Botryococcus is a freshwater green alga that can produce a large amount of liquid hydrocarbons, and its chemical composition is similar to that of petroleum. It is a "petroleum plant" and is also known as oil algae. The study of modern Botryococcus is conducive to promoting the development of the field of biofuel exploration and development. For ancient Botryococcus, it can only be studied through biomarker compounds representing Botryococcus in fossil fuels or other geological samples. The study of these characteristic biomarker compounds not only contributes to the research of petroleum origin, petroleum source, and geological environment evolution, but may also provide new ideas and references for the cultivation of modern Botryococcus, promoting the development of the field of bioenergy exploration and development. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a C 31 alkane and its preparation method and application.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention:

[0007] A C 31 alkane, the chemical structure of which is shown in Formula I (Compound 1) or Formula II (Compound 2):

[0008]

[0009]

[0010] Among them, Formula I and Formula II are stereoisomers of each other. The chemical name of Formula I is 2,3,6,7,10(R),12,15,16,19,20-decamethylhenicosane; the chemical name of Formula II is 2,3,6,7,10(S),12,15,16,19,20-decamethylhenicosane.

[0011] Furthermore, the monomer carbon isotopes δ 13 C of the Compound 1 and Compound 2 are -5.6‰ and -5.3‰ respectively, where δ 13 C is a representation method of the carbon isotope ratio, used to describe the 13 C / 12 C ratio deviation of the sample relative to the standard reference point (VPDB). It is a relative measurement value, usually expressed in per mill (‰).

[0012] The second technical solution of the present invention:

[0013] The application of the above-mentioned C 31 alkanes in indicating the Botryococcus origin in geological samples and the geological hydrogenation and reduction environment.

[0014] The third technical solution of the present invention:

[0015] The application of the above-mentioned C 31 alkanes as heavy carbon isotope standard samples in the process of carbon isotope analysis.

[0016] The fourth technical solution of the present invention:

[0017] The preparation method of the above-mentioned C 31 alkanes includes the following steps:

[0018] (1) Crude extraction: Using the shale in the Maoming Basin, Guangdong (the oil shale of the Youganwo Formation of the Tertiary in the Maoming Basin, southwestern Guangdong Province) as a sample, successively carry out extraction, centrifugation, chromatographic separation, elution and rotary evaporation to obtain a saturated hydrocarbon fraction;

[0019] (2) Fine preparation of monomer compounds: Use an Agilent 7890-Gerstel PFC gas preparation chromatograph for fine preparation;

[0020] Among them, the temperature rising condition in the gas preparation chromatograph is: the initial temperature is 80°C, hold at this temperature for 2 min, rise to 295°C at a rate of 25°C / min, and hold at this temperature for 32 - 45 min.

[0021] Optionally, the solvent used in the extraction process of step (1) is a mixed solution of CH 2 Cl 2 and CH 3 OH (v / v: 9:1);

[0022] Furthermore, the column packing material in the chromatographic column used in the chromatographic separation process of step (1) is silica gel and alumina;

[0023] Among them, the volume ratio of the silica gel to the alumina is 4:1.

[0024] Furthermore, the silica gel is 80 - 230 mesh.

[0025] Optionally, in step (2), when collecting through the collection tube with a retention time of 40.78 - 40.85 min, the collected substance is Compound 1, which is 2,3,6,7,10(R),12,15,16,19,20 - decamethyheneicosane.

[0026] Optionally, in step (2), when collecting through the collection tube with a retention time of 41.05 - 41.13 min, the collected substance is Compound 2, which is 2,3,6,7,10(S),12,15,16,19,20 - decamethyheneicosane.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] What is directly synthesized in Botryococcus braunii is botryococcene. The present invention provides two C 31 alkanes that are stereoisomers generated from botryococcene under geological action, namely 2,3,6,7,10(R),12,15,16,19,20 - decamethyheneicosane and 2,3,6,7,10(S),12,15,16,19,20 - decamethyheneicosane. These two compounds can be used as new Botryococcus biological marker compounds to indicate the Botryococcus biological source and reflect the redox sedimentary environment. They can be used as standard samples in the analysis of biological marker compounds and as heavy carbon isotope standard samples in the carbon isotope analysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 is the HR - EI - MS spectrum of Compound 1;

[0031] Figure 2 for Compound 1 11H NMR spectrum;

[0032] Figure 3 for Compound 1 13 13C NMR spectrum;

[0033] Figure 4 HMQC spectrum of Compound 1;

[0034] Figure 5 for Compound 1 1 1H- 1 1H COSY spectrum;

[0035] Figure 6 HMBC spectrum of Compound 1;

[0036] Figure 7 FI-TOF MS spectrum of Compound 2;

[0037] Figure 8 for Compound 2 1 1H NMR spectrum;

[0038] Figure 9 for Compound 2 13 13C NMR spectrum;

[0039] Figure 10 HMQC spectrum of Compound 2;

[0040] Figure 11 for Compound 2 1 1H- 1 1H COSY spectrum;

[0041] Figure 12 HMBC spectrum of Compound 2;

[0042] Figure 13 Schematic diagram of the formation of Compound 1 and Compound 2. Detailed implementation mode

[0043] Now, various exemplary implementation modes of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0044] It should be understood that the terms described in the present invention are only for describing specific implementation modes and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0045] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although only preferred methods and materials are described in this invention, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0046] Without departing from the scope or spirit of the present invention, various modifications and variations can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0047] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0048] Embodiments of the present invention provide two stereoisomeric C 31 alkane compounds that can indicate the origin of Botryococcus braunii, reflect the sedimentary environment, and the geological reducing environment, and can be used as standard samples in the analysis of biomarker compounds and as heavy carbon standard samples in the carbon isotope analysis process.

[0049] Embodiments of the present invention disclose a C 31 alkane, whose chemical name is: 2,3,6,7,10(R),12,15,16,19,20-decamethylhenicosane; its chemical structure is shown in Formula I:

[0050]

[0051] Embodiments of the present invention also disclose another isomeric C 31 alkane, whose chemical name is: 2,3,6,7,10(S),12,15,16,19,20-decamethylhenicosane; its chemical structure is shown in Formula II:

[0052]

[0053] Embodiments of the present invention disclose the applications of the above two C 31 alkanes in indicating the origin of Botryococcus braunii and reflecting the redox sedimentary environment; and their applications as standard samples in the analysis of biomarker compounds and as heavy carbon standard samples in the carbon isotope analysis process.

[0054] Embodiments of the present invention disclose a C 31Method for preparing alkane compounds, the method comprising the following steps:

[0055] (1) Crude extraction: The sample is crushed to 100 mesh, extracted with dichloromethane / methanol (v / v = 9:1), and the extract is concentrated and dried to obtain chloroform bitumen "A"; The chloroform bitumen "A" is fully dissolved in n-hexane, and after centrifuging and separating insoluble asphaltenes multiple times, the supernatant is concentrated to 1 mL, and column chromatography separation is carried out. The filling material of the chromatography column is silica gel (80 - 230 mesh) and alumina filled column with a volume ratio of 4:1; After loading the sample, it is eluted with 80 mL of n-hexane to obtain the saturated hydrocarbon fraction;

[0056] (2) Precision preparation is carried out using an Agilent 7890 - Gerstel PFC gas preparation chromatograph, and the separation column is a large-capacity gas chromatography column (60 m × 0.530 mm × 1.50 μm); The saturated hydrocarbon fraction extracted in step (1) is fully dissolved in isooctane; The gas preparation chromatograph temperature program is: initial temperature 80°C (retaining at this temperature for 2 min), rising to 295°C at 25°C / min (retaining at this temperature for 35 min), the sample concentration is 20 mg / mL, automatic continuous injection, and compound 1 with a retention time of 40.78 - 40.85 min is collected through the collection tube, which is 2,3,6,7,10(R),12,15,16,19,20-decamethyl - hentriacontane; Compound 2 with a retention time of 41.05 - 41.13 min is collected, which is 2,3,6,7,10(S),12,15,16,19,20-decamethyl - hentriacontane.

[0057] The sample used in the embodiment of the present invention is the shale of the Guangdong Maoming Basin.

[0058] The technical solution of the present invention is further described below through examples.

[0059] Example 1

[0060] 1. Sample pretreatment and crude extraction

[0061] The sample is crushed to 100 mesh, 100 g of the sample is taken, and CH 2 Cl 2 / CH 3Extract with OH (v / v = 9:1). After the extract is concentrated under reduced pressure, the organic mixture chloroform bitumen "A" is obtained. Dissolve the chloroform bitumen "A" thoroughly in n-hexane, use a centrifuge, centrifuge and mix multiple times to separate the insoluble asphaltenes. After the n-hexane solution is concentrated under reduced pressure to 1 mL, separate it by column chromatography. Among them, the chromatography column uses a hollow glass column with a length of 30 cm and a diameter of 1 cm, filled with silica gel (80-100 mesh) and chemically pure alumina, and the volume ratio of the filler is 4:1. After adding the sample, elute with 80 mL of n-hexane to obtain the saturated hydrocarbon fraction, collect it with a 100 mL pear-shaped flask. After the obtained saturated hydrocarbon fraction is dried of the solvent by a rotary evaporator, transfer the sample to a 4 mL vial for constant weight. Finally, dissolve it thoroughly with isooctane, adjust the concentration to 20 mg / mL, and use a 2 mL injection vial for sample injection preparation for the following step 2.

[0062] 2. Preparation of monomeric compounds:

[0063] Prepare using an Agilent 7890-Gerstel PFC (fully automatic gas chromatographic fraction collector) gas preparation chromatograph. The separation chromatographic column uses an Agilent DB-5 gas chromatographic column with dimensions of 60 m × 0.530 mm × 1.50 μm. Helium gas is used as the carrier gas with a flow rate of 3 mL / min. A fraction fractionator is equipped at the rear end of the chromatographic column, so that 10% of the sample flowing out of the chromatographic column enters the FID detector and 90% enters the fraction collection device, and the target compound is collected by cold trap capture. The cold trap has 6 sample capture traps (using two of them) and 1 waste capture trap, and the capture time can be designed.

[0064] Fully dissolve the saturated hydrocarbon fraction obtained in step 1 in isooctane, with a concentration of 20 mg / mL, and inject the sample. The gas chromatographic temperature program is as follows: the initial temperature is 80 °C (2 min), and then it is raised to 295 °C at a rate of 25 °C / min (35 min). The sample is placed in a 2 mL injection vial for continuous automatic injection. When preparing 2,3,6,7,10(R),12,15,16,19,20-decamethylhenicosane, collect the compound with a retention time of 40.78 - 40.85 min. When preparing 2,3,6,7,10(S),12,15,16,19,20-decamethylhenicosane, collect the compound with a retention time of 41.05 - 41.13 min. The masses of the collected compound 1 and compound 2 are about 2.1 mg and 2.3 mg respectively, and the specific structures are determined by high-resolution mass spectrometry and nuclear magnetic resonance.

[0065] The high-resolution mass spectrometry and nuclear magnetic resonance data of compound 1 are as Figures 1-6 shown, and thus it is determined that compound 1 is 2,3,6,7,10(R),12,15,16,19,20-decamethylhenicosane, and its structure is as shown in formula I;

[0066] The high-resolution mass spectrometry, nuclear magnetic resonance, and infrared data of Compound 2 are as follows Figures 7-12 shown. Thus, Compound 2 was determined to be 2,3,6,7,10(S),12,15,16,19,20-decamethylhenicosane, and its structure is shown in Formula II.

[0067] Example 2

[0068] The monomeric carbon isotopes δ 13 C of Compound 1 and Compound 2 can be detected by GC-irMS analysis to be -5.6‰ and -5.3‰ respectively, which are very heavy and can be used as heavy carbon isotope reference standards for monomeric carbon isotope analysis of organic compounds in the field of geochemistry.

[0069] In addition, the monomeric carbon isotopes of Compound 1 and Compound 2 are similar to those of the products of Botryococcus braunii and its derivative product botryococcane, δ 13 C (-7.0‰) (Liao et al., 2018), indicating a high possibility of homology. At the same time, the skeletons of the two compounds are similar to that of botryocenene. Therefore, Compound 1 of the present invention: 2,3,6,7,10(R),12,15,16,19,20-decamethylhenicosane and Compound 2: 2,3,6,7,10(S),12,15,16,19,20-decamethylhenicosane are derived from botryocenene in oil algae and are homologous to botryococcane. As Figure 13 shown, the generation schematic diagrams of the two compounds are shown. Specifically, botryocenene is generated in Botryococcus braunii. During the deposition of dead algal bodies, under the oxidative environment of lake water, the vinyl group of botryocenene undergoes double-bond photooxidation and cracking to form a carboxyl group, and other double bonds undergo hydrogenation reduction to first generate the intermediate product C 32 algaenoic acid. Subsequently, through decarboxylation and hydration in the water environment, two stereoisomeric intermediate products C 31 algaenol can be generated. During diagenesis, C 31 algaenol undergoes dehydration and hydrogenation reduction to generate Compound 1 and Compound 2. Therefore, the two new compounds, as biomarker compounds, not only indicate the biological origin of Botryococcus braunii but also reflect the redox environment during biological deposition.

[0070] References

[0071] Liao, J., Lu, H., Feng, Q., Zhou, Y., Shi, Q., & Sheng, G. (2018). Identification of a novel C33 botryococcane and C33 botryococcanone in the Maoming Basin, China. Organic Geochemistry, 124, 103-111.

[0072] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A C 31 Alkanes, characterized in that comprising compound 1 or compound 2; Wherein, the chemical structures of compound 1 and compound 2 are shown in formula I and formula II respectively:

2. A C according to claim 1 31 Alkanes, characterized in that The monomer carbon isotope δ of compound 1 and compound 2 13 C is -5.6‰ and -5.3‰ respectively.

3. C according to claim 1 or 2 31 Application of alkanes in indicating the origin of grape algae in geological samples and geological hydrogenation reduction environment.

4. C as claimed in claim 1 or 2 31 The application of alkanes as heavy carbon isotope standards in carbon isotope analysis.

5. A C as claimed in claim 1 or 2 31 A method for preparing alkanes, characterized in that: The following steps are involved: (1) The shale from Maoming Basin, Guangdong Province was used as a sample, and extraction, centrifugation, chromatography separation, elution and rotary evaporation were performed in sequence to obtain saturated hydrocarbon components; (2) The saturated hydrocarbon component is continuously introduced into an Agilent 7890-Gerstel PFC gas phase preparation chromatograph, and the temperature is increased to prepare C 31 Alkanes; The conditions in the heating process are as follows: 80°C as the initial temperature, heating to 295°C at a rate of 25°C / min, and maintaining the temperature at 295°C for 32-45 minutes.

6. A C according to claim 5 31 A method for preparing alkanes, characterized in that: The solvent used in the extraction process of step (1) is a mixture of CH2Cl2 and CH3OH, and the volume ratio of the two is 9:

1.

7. A C according to claim 5 31 A method for preparing alkanes, characterized in that: The filling materials of the chromatography column used in the chromatographic separation process of step (1) are silica gel and alumina; Wherein, the volume ratio of silica gel to alumina is 4:

1.

8. A C according to claim 5 31 A method for preparing alkanes, characterized in that: In step (2), the substance with a retention time of 40.78 to 40.85 min is collected, which is compound 1.

9. A C according to claim 5 31 A method for preparing alkanes, characterized in that: In step (2), the substance with a retention time of 41.05 to 41.13 min is collected, which is compound 2.

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