Compound obtained through strain metabolism and preparation and application thereof

Abstract

The invention relates to the field of biological medicines and pesticides, in particular to a compound (16-membered macrolide and peniorcinol compounds) obtained through strain metabolism and preparation and application of the compound. The compound is a 16-membered macrolide compound which is represented by a compound 1 and has a theta-keto-alpha, beta, gamma, delta-unsaturated lactone structure fragment, and is a peniorcinol compound represented by a compound 2. The fungus secondary metabolite has the activity of reducing blood sugar, promoting seed germination or resisting oxidation, and can be used as a lead compound for reducing blood sugar, promoting seed germination or resisting oxidation and the like. The compound can be produced through fungal fermentation, the preparation method is simple and efficient, and the obtained product is high in purity. The method has a good application prospect. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the fields of biomedicine and pesticides, and in particular to a compound (16-membered macrolide and peniorcinol compound) obtained by bacterial strain metabolism, and the preparation and application thereof. Background Art

[0002] Diabetes is a chronic and common metabolic disease, which is divided into type 1 diabetes and type 2 diabetes. Type 2 diabetes (T2DM), also known as non-insulin-dependent diabetes, accounts for 90% of the total number of diabetes patients worldwide. The World Health Organization reports that more than 400 million people suffer from diabetes, and it is expected to exceed 592 million by 2035. α-glucosidase is an important target enzyme associated with T2DM. After a meal, α-glucosidase present on the brush border of the small intestinal mucosa hydrolyzes carbohydrates in food into glucose, which is absorbed into the blood circulation and then increases blood sugar. Therefore, α-glucosidase is one of the main target enzymes for controlling postprandial blood sugar. α-glucosidase inhibitors can reversibly inhibit α-glucosidase in the small intestine, reduce the hydrolysis of carbohydrates, delay the production and absorption of glucose, and then lower the postprandial blood sugar level. They are symptomatic treatment drugs for controlling postprandial blood sugar. To date, there are three main naturally occurring α-glucosidase inhibitors, including voglibose, miglitol, and acarbose.

[0003] In recent years, with the rapid development of free radical theory, the occurrence of aging and various diseases has been proven to be closely related to the excessive production of free radicals. Supplementing the body with exogenous antioxidants or administering compounds that help restore the body's endogenous antioxidants plays an auxiliary role in the treatment of aging and some diseases. Traditional antioxidants are generally derived from chemical synthesis and have disadvantages such as poor stability and strong toxic side effects. Natural antioxidants have the advantages of safety, non-toxicity, strong stability, and naturalness, which are more in line with consumer requirements. Some have been well developed and utilized. Therefore, the research and development of natural antioxidants has become a research hotspot in the fields of food, traditional Chinese medicine and cosmetics.

[0004] Seed germination is the most important stage in the plant life cycle. In agricultural production, rapid and consistent seed germination is also a necessary condition for high yield. The huge plant diversity has shaped a rich and unique diversity of endophytic fungi, which can produce rich and diverse secondary metabolites that promote seed germination. Summary of the invention

[0005] The present invention aims to provide a compound (16-membered macrolide and peniorcinol compound) obtained by bacterial strain metabolism and its preparation and application.

[0006] To achieve the above purpose, the present invention adopts the following technical solution:

[0007] A compound obtained by bacterial strain metabolism, the compound is a 16-membered macrolide compound with a θ-keto-α, β, γ, δ-unsaturated lactone structure fragment shown in compound 1, and a peniorcinol compound shown in compound 2,

[0008]

[0009] A method for preparing a compound obtained by metabolism of the strain, wherein the compound is obtained by separating and purifying the fermentation broth of the endophytic fungus F4a after culturing;

[0010] The plant endophytic fungus F4a is a strain with a deposit number of CCTCC NO: M 2012531, the depository name is China Center for Type Culture Collection, the address is Wuhan University, Wuhan, China, the deposit date is December 18, 2012, and the Latin name of the classification is Eupenicillium brefeldianum F4a.

[0011] Specifically:

[0012] 1) Inoculate the plant endophytic fungus F4a on a PSA solid culture medium and culture it for 48-96 hours to activate it. After activation, inoculate it into a liquid culture medium and culture it at 28-32° C. for 48-72 hours to obtain a culture as a seed solution; mix the obtained seed solution with the liquid culture medium at a volume ratio of 1:27-1:13, and culture it at 26-30° C. with shaking for 7-9 days;

[0013] 2) The fermentation broth is centrifuged to remove the bacterial cells to obtain the fermentation supernatant, and the active ingredients in the fermentation broth are solid-phase adsorbed with a macroporous adsorption resin HP20, with the volume ratio of the resin to the fermentation broth being 1:14-1:26; the adsorption is carried out for 1-3 hours, and the crude extract is obtained by washing after adsorption; the separated bacterial cells are extracted with acetone to obtain a crude extract, and the crude extracts are combined to obtain a total extract A; the total extract A is separated and purified to obtain the compound.

[0014] Further,

[0015] 1) Inoculating the plant endophytic fungus F4a on a PSA solid culture medium and culturing for 48-96 hours to activate it, inoculating it into a liquid culture medium after activation and culturing it at 28-32° C. for 48-72 hours to obtain a culture as a seed solution; mixing the obtained seed solution with the liquid culture medium at a volume ratio of 1:27-1:13, and culturing it at 26-30° C. with shaking for 7-10 days;

[0016] 2) The fermentation liquid is centrifuged to remove the bacterial cells to obtain the fermentation supernatant, and the active ingredients in the fermentation liquid are solid-phase adsorbed with macroporous adsorption resin HP20, and the volume ratio of resin to fermentation liquid is 1:14-1:26; adsorption is carried out for 1-3 hours, and the crude extract is obtained by washing after adsorption; the separated bacterial cells are extracted with acetone to obtain a crude extract, and the crude extracts are combined to obtain the total extract A.

[0017] 3) The total extract A was separated by silica gel column chromatography, and the components were collected according to a gradient elution of dichloromethane:methanol (v / v) ratio of 100:0-0:100 to obtain the target secondary metabolite enrichment.

[0018] 4) The above enriched product was separated by silica gel column chromatography, and pure dichloromethane was eluted as fraction F a , dichloromethane: methanol (v / v) ratio is 100:1-100:3 and eluted as fraction F b , dichloromethane: methanol (v / v) ratio is 100:4-100:6 and eluted as fraction F c , dichloromethane: methanol (v / v) ratio of 100:7-10:9 eluted as fraction F d , dichloromethane: methanol (v / v) ratio is 100:10-100:15 and eluted as fraction F e .

[0019] Fraction F b Separate with gel LH20 and divide into 4 sub-fractions according to the volume of eluted methanol. Receive 50-70 mL of methanol as sub-fraction F according to the elution order. b4 Receive 80-120 mL of methanol as sub-fraction F b3 Receive 120-140 mL of methanol as sub-fraction F b2 Receive 145-160 mL of methanol as sub-fraction F b1 . Substream fraction F b4 After ODS reverse phase column chromatography and methanol-water gradient separation, a total of 4 sub-fractions (F b4a -F b4d ), of which 30-40% methanol-water elution is F b4a , 42-45% methanol water elution is F b4b , 46-50% methanol water elution is F b4c , 52-55% methanol-water elution is F b4d . F b4d Purify by semi-preparative HPLC, eluting with 50-60% aqueous methanol at a flow rate of 2.0 mL / min to obtain compound 1-2.

[0020] The liquid culture medium contains 12-14 g starch, 18-22 g glucose, 0.5-1.5 g yeast extract, 0.3-0.7 g soybean cake powder, 2-3 g barley extract, 0.5-1.5 g ammonium sulfate, 0.5-1.1 g potassium nitrate, 3-5 g calcium carbonate, 2-3 g magnesium sulfate heptahydrate, 2-4 g potassium dihydrogen phosphate, 0.01-0.03 g copper sulfate per liter of water, and a pH of 6.5-7.5.

[0021] An application of the compound obtained by metabolism of the strain, wherein the 16-membered macrolide compound having a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment shown in compound 1 among the compounds obtained by metabolism of the strain is used in the preparation of a hypoglycemic agent.

[0022] An application of the compound obtained by metabolism of the strain, wherein the 16-membered macrolide compound having a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment shown in compound 1 among the compounds obtained by metabolism of the strain is used in the preparation of a seed germination promoter.

[0023] An application of the compounds obtained by metabolism of the strain, and an application of the peniorcinol compound shown as compound 2 among the compounds obtained by metabolism of the strain in the preparation of antioxidants.

[0024] The advantages of the present invention are:

[0025] The invention provides a 16-membered macrolide having a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment which has not been reported yet and a peniorcinol compound which has not been reported yet.

[0026] The 16-membered macrolide and peniorcinol compounds described in the present invention are new compounds produced by fungal fermentation and obtained through a specific separation process.

[0027] The 16-membered macrolide compounds obtained by the present invention have α-glucosidase inhibitory activity and seed germination promotion activity, and the peniorcinol compounds have an ABTS equivalent to that of the positive control drug vitamin C. +· scavenging activity, they may serve as ideal candidate compounds for lowering blood sugar, promoting seed germination or anti-oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Compound 1-2 provided in the embodiments of the present invention 1 H- 1 Significant correlation between H COSY and HMBC.

[0029] Figure 2 NMR calculation and DP4+ analysis of compound 1 provided in the examples of the present invention.

[0030] Figure 3 The experimental ECD spectrum and calculated ECD spectrum of compound 1 in CH3OH provided in the examples of the present invention. DETAILED DESCRIPTION

[0031] In order to better understand the content of the present invention, further description is given below in conjunction with specific embodiments, but the protection content of this patent is not limited to this.

[0032] Example 1 Preparation method of 16-membered macrolides and peniorcinol compounds produced by fermentation of plant endophytic fungus F4a

[0033] The liquid culture medium used was 10 g starch, 20 g glucose, 1 g yeast extract, 0.5 g soybean cake powder, 2.5 g barley extract, 1 g ammonium sulfate, 0.8 g potassium nitrate, 4 g calcium carbonate, 2.5 g magnesium sulfate heptahydrate, 3 g potassium dihydrogen phosphate, 0.02 g copper sulfate per liter of water, pH 7.0.

[0034] The plant endophytic fungus F4a (CCTCCM 2012531) was inoculated on PSA solid medium and cultured for 48 hours for activation, and then inoculated into the above liquid medium and cultured at 28℃ for 72 hours as seed liquid; the seed liquid obtained by fermentation was then inoculated into the same fermentation medium at a volume ratio of 1:18 and cultured at 28℃ for 7 days. The fermentation liquid was centrifuged to remove the bacteria to obtain the fermentation supernatant, and the macroporous adsorption resin HP20 was added to the fermentation liquid for solid phase adsorption of active ingredients, and the volume ratio of resin to fermentation liquid was 1:25; after 2 hours of adsorption, the resin was washed with distilled water and 15% methanol aqueous solution, and then desorbed with methanol to recover the methanol solvent to obtain a crude extract. The bacteria were ultrasonicated with acetone for 30 minutes, and the crude extract was obtained after the acetone solvent was recovered. The two crude extracts were combined to obtain the total extract A.

[0035] Extract A was separated by flash silica gel column chromatography, and eluted with a gradient of dichloromethane:methanol (v / v) from 100:0 to 0:100 to obtain 5 fractions (F a -F e ), wherein pure dichloromethane is eluted as fraction F a , dichloromethane: methanol (v / v) ratio is 100:1-100:3 and eluted as fraction F b , dichloromethane: methanol (v / v) ratio of 100:4-100:6 is fraction F c , dichloromethane: methanol (v / v) ratio is 100:7-10:9. d , dichloromethane: methanol (v / v) ratio of 100:10-100:15 is fraction F e .

[0036] The collected fraction F b Separate with gel LH20 and divide into 4 sub-fractions according to the volume of eluted methanol. Receive 40-60 mL of methanol as sub-fraction F according to the elution order. b4 , receive 62-100 mL of methanol as sub-fraction F b3Receive 102-120 mL of methanol as sub-fraction F b2 Receive 125-140 mL of methanol as sub-fraction F b1 . Substream fraction F b4 After ODS reverse phase column chromatography and methanol-water gradient separation, a total of 4 sub-fractions (F b4a -F b4d ), of which 30-40% methanol-water elution is F b4a , 42-45% methanol water elution is F b4b , 46-50% methanol water elution is F b4c , 52-55% methanol-water elution is F b4d . F b4d Semi-preparative HPLC purification, eluting with 50-60% methanol in water at a flow rate of 2.0 mL / min, gave compound penidione A (1, 4.3 mg, t R =21.8min) and peniorcinol D (2, 3.3mg, t R =19.8min).

[0037] The structures of the sixteen-membered macrolide and peniorcinol compounds obtained above were analyzed (see Table 1 and Figure 1-3 ):

[0038] Compound 1 is a white powder. HRESIMS data showed an m / z of 303.1560 [M+Na] + (calcd for C 16 H 24 O4Na, 303.1572), and its molecular formula is estimated to be C 16 H 24 O4, unsaturation is 5. 1 The H NMR (600 MHz, DMSO-d6) spectrum shows the presence of four olefinic hydrogen proton signals δ H 7.03 (1H, dd, J = 15.4, 11.3 Hz), 6.37 (1H, ddd, J = 15.2, 11.3, 1.3 Hz), 5.81 (1H, d, J = 15.4 Hz) and 5.77 (1H, dd, J = 15.2, 3.7 Hz), two oxygen-containing methine proton signals δ H 4.30 (1H, m) and 4.84 (1H, m), a group of aliphatic methyl proton signals δ H 1.20 (3H, d, J = 6.4 Hz) (Table 1). 13C NMR (150 MHz, DMSO-d6) and HSQC spectra showed the presence of one ketone carbonyl, one ester carbonyl, four olefinic hydrogen carbons, two oxygen-containing methine carbons, seven methylene carbons and one methyl carbon (Table 1). 2 In addition to the hybridized olefinic hydrogen carbon (Ω=2), a keto carbonyl group (Ω=1) and an ester carbonyl group (Ω=1), there is still one unsaturation remaining, so it is inferred that compound 1 is a 16-membered macrocyclic lactone. 1 H- 1 The H-2 / H-3 / H-4 / H-5 / H-6 / H-7 / H-8 related signals in H COSY and the H-2 and H-3 in HMBC spectrum were remotely correlated with C-1, respectively, suggesting that compound 1 contained a 6-hydroxy-2,4-dioctenoic acid fragment ( Figure 1 ).Depend on 1 H- 1 The H-10 / H-11 / H-12 / H-13 / H-14 / H-15 / H-16 related signals in H COSY suggest the presence of 2-heptanol fragments ( Figure 1 ). From the HMBC spectrum, we can see that H-7, H-8, H-10 have long-range correlation signals with C-9, and H-15 has long-range correlation signals with C-1. It is speculated that the above two fragments are connected by ester bonds and keto carbonyl groups ( Figure 1 ). The coupling constants of the two double bonds are 15.4 Hz and 15.2 Hz, respectively, which indicates that both double bonds are in trans configuration.

[0039] In order to determine the relative configuration of compound 1, NMR calculations were performed in combination with DP4+ analysis ( Figure 2 ). The following two configurations were calculated: (2E, 4E, 6S*, 15R*)-1a and (2E, 4E, 6S*, 15S*)-1b. Combined with DP4+ analysis, the relative configuration of compound 1 is 1a (99.99%) ( Figure 2 ). The calculated ECD curve was fitted with the experimental ECD curve, and the absolute configurations of compound 1 were determined to be 2E, 4E, 6S, and 15R ( Figure 3 ). Therefore, compound 1 can be determined to be an unreported 16-membered macrocyclic lactone with a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment, named penidione A.

[0040] Compound 2 is a white powder. HRESIMS data showed an m / z of 247.1325 [M+H] + (calcd for C 15 H 19 O3, 247.1334), and its molecular formula is estimated to be C 15 H18 O3, the unsaturation degree is 7. Combining 1D NMR and HSQC spectrum analysis (Table 1), compound 2 has the same 4-hydroxy-2-methoxy-6-methylbenzyl fragment as peniorcinols AC (J. Fungi 2021, 7, 913). 1 H- 1 There are correlation signals between H-10 / H-11 in H COSY, long-range correlation signals between H-11 and C-8, C-9 and C-12 in HMBC spectrum, and long-range correlation signals between H-13 and C-11 and C-12, respectively. It can be inferred that compound 2 has a 3-methylcyclopent-2-en-1-one fragment. It can be seen from the HMBC spectrum that H-7 has long-range correlation signals with C-2, C-9 and C-12, respectively, which indicates that the above two fragments are connected by a methylene group ( Figure 1 ). Therefore, compound 2 can be identified as an unreported peniorcinol compound and named peniorcinol D.

[0041] Table 1 Hydrogen spectrum and carbon spectrum of compound 1-2 (DMSO-d6, 600 / 150MHz, δin ppm)

[0042]

[0043]

[0044] Example 2 α-Glucosidase Inhibitory Activity of Compound 1-2

[0045] α-glucosidase plays an important role in the food absorption process. Food can only be digested and absorbed after it is combined with it. The hypoglycemic mechanism of α-glucosidase inhibitors is to inhibit α-glucosidase on the intestinal mucosa, slow down the rate of starch decomposition into glucose, reduce and delay the absorption of glucose in the small intestine, and thus lower blood sugar. It has a more obvious effect on postprandial hyperglycemia.

[0046] Determination method: Accurately pipette 20 μL of each test solution, add 30 μL of α-glucosidase solution, then add 800 μL of 0.1M phosphate buffer solution (pH 6.8), and heat at 37°C for 5 minutes; add 150 μL of pNPG solution (10 mM), mix well, and heat at 37°C for 30 minutes; add 650 μL of Na2CO3 stop solution (1M) to terminate the reaction, use an enzyme reader to measure the sample, and measure the absorbance value at 405 nm. The positive control is acarbose, and the negative control is 20 μL of DMSO. Each test product (compound 1-2, positive control and negative control) is measured three times.

[0047] α-glucosidase inhibition rate % = (1-A samp / A cont )×100%, where A samp Represents the absorbance value of the test solution, A cont Represents the absorbance value of the negative control solution. The final experimental results are expressed in EC 50 Values ​​are expressed in μM.

[0048] Experimental results: The results of the α-glucosidase inhibition test of compounds 1-2 are shown in Table 2. The results show that only compound 1 and the positive control acarbose (EC 50 =2.5 μM), showed weak α-glucosidase inhibitory activity (EC 50 =52.3 μM). It is worth noting that the hypoglycemic activity of the 16-membered macrolide compound of the θ-keto-α,β,γ,δ-unsaturated lactone structural fragment is reported for the first time. Compound 2 did not show α-glucosidase inhibitory activity.

[0049] Example 3 Antioxidant activity of compound 1-2

[0050] There are many methods for evaluating and screening the antioxidant activity of substances in vitro. The 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH) method and the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)ammoniumsalt (ABTS) method have the advantages of good stability, high sensitivity, and simple operation. Both methods have been widely used in the quantitative analysis of free radical scavenging ability worldwide.

[0051] (1)DPPH · Scavenging activity

[0052] Determination method: Accurately pipette 100 μL of each of the above test sample solutions and 100 μL of DPPH ethanol solution into a 96-well plate, mix well, react in the dark at room temperature for 30 minutes, put into an ELISA reader, and measure the absorbance at 517 nm. Vitamin C is used as a positive control, and 100 μL of anhydrous ethanol is used as a negative control. Each test sample (compound 1-2, positive control, and negative control) was measured three times. DPPH · The calculation formula of clearance rate is as follows: Clearance rate % = (1-A samp / A cont )×100%, where Asamp Represents the absorbance value of the test solution, A cont Represents the absorbance value of the negative control solution. The final experimental results are expressed in EC 50 Values ​​are expressed in μM.

[0053] Experimental results: DPPH of compound 1-2 · The results of the scavenging activity experiments are shown in Table 2. The results showed that neither compound 1 nor compound 2 showed DPPH · Scavenging activity.

[0054] (2)ABTS +· Scavenging activity

[0055] Determination method: Prepare ABTS + The solution was diluted with 0.01M phosphate buffer solution, approximately 32 times, and placed away from light for 30 minutes after dilution (to ensure the measured absorbance value is accurate). The absorbance value was measured with a UV spectrophotometer, and it was qualified within 0.7±0.02 and could be used. Accurately pipette 100μL of each of the above test sample series solutions and ABTS +· 3 mL of the solution was added to a glass test tube, mixed, reacted in the dark at room temperature for 6 min, placed in an ELISA reader, and the absorbance was measured at 734 nm. The positive control was vitamin C, and the negative control was 100 μL of anhydrous ethanol. Each test sample (compound 1-2, positive control, and negative control) was measured three times. ABTS +· The calculation formula of clearance rate is the same as DPPH · The calculation formula of clearance rate, the final experimental results are expressed as EC 50 Values ​​are expressed in μM.

[0056] Experimental results: ABTS of compound 1-2 +· The results of the scavenging activity test are shown in Table 2. The results show that the ABTS +· Scavenging activity (EC 50 =29.8 μM) and positive control vitamin C (EC 50 =22.3 μM), compound 1 did not show ABTS +· Scavenging activity.

[0057] Table 2 α-glucosidase inhibitory activity and antioxidant activity of compound 1-2

[0058]

[0059] ND stands for not detected.

[0060] Example 4 Seed germination promoting activity of compound 1

[0061] First, the monomer compound 1 and the positive control 3-indoleacetic acid were dissolved in a methanol solution, and a test solution with a concentration of 0.01 μM was prepared with sterile water (methanol ratio 1%). Then, the pakchoi seeds and rice seeds were sterilized with 75% alcohol for 5 minutes and washed with distilled water 5 times. The treated seeds (N=30-60) were then placed in a glass culture dish containing 9 cm cellulose filter paper, and 5 mL of the test solution was added to the culture dish. After incubation in the dark at 24°C for 48 hours, the seed germination rate was calculated. When the radicle protruded more than 2 mm, the seeds were considered to have germinated.

[0062] The results of the seed germination experiment showed that compound 1 promoted the germination growth rate of pakchoi seeds by 7.4% at a concentration of 0.01 μM, which was stronger than the positive control 3-indoleacetic acid (germination growth rate 5.6%). In addition, it was observed that compound 1 promoted the germination growth rate of rice seeds by 14.3% at a concentration of 0.01 μM, which was the same as the positive control 3-indoleacetic acid. Therefore, compound 1 has significant activity in promoting seed germination.

Claims

1. A compound obtained by metabolism of a strain, characterized in that: The compound is a 16-membered macrolide compound having a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment as shown in compound 1, and a peniorcinol compound as shown in compound 2.

2. A method for preparing a compound obtained by metabolism of the strain according to claim 1, characterized in that: Separating and purifying the fermentation broth of the endophytic fungus F4a after culturing to obtain the compound of claim 1; The plant endophytic fungus F4a is a strain with a preservation number of CCTCC NO: M 2012531.

3. The method for preparing a compound obtained by bacterial strain metabolism according to claim 2, characterized in that: 1) Inoculate the plant endophytic fungus F4a on a PSA solid culture medium and culture it for 48-96 hours to activate it. After activation, inoculate it into a liquid culture medium and culture it at 28-32° C. for 48-72 hours to obtain a culture as a seed solution; mix the obtained seed solution with the liquid culture medium at a volume ratio of 1:27-1:13, and culture it at 26-30° C. with shaking for 7-9 days; 2) The fermentation broth is centrifuged to remove the bacterial cells to obtain the fermentation supernatant, and the active ingredients in the fermentation broth are solid-phase adsorbed with a macroporous adsorption resin HP20, with the volume ratio of the resin to the fermentation broth being 1:14-1:26; adsorption is carried out for 1-3 hours, and a crude extract is obtained by washing after adsorption; the separated bacterial cells are extracted with acetone to obtain a crude extract, and the crude extracts are combined to obtain a total extract A; the total extract A is separated and purified to obtain the compound according to claim 1.

4. The method for preparing a compound obtained by bacterial strain metabolism according to claim 3, characterized in that: The liquid culture medium contains 12-14 g starch, 18-22 g glucose, 0.5-1.5 g yeast extract, 0.3-0.7 g soybean cake powder, 2-3 g barley extract, 0.5-1.5 g ammonium sulfate, 0.5-1.1 g potassium nitrate, 3-5 g calcium carbonate, 2-3 g magnesium sulfate heptahydrate, 2-4 g potassium dihydrogen phosphate, 0.01-0.03 g copper sulfate per liter of water, and a pH of 6.5-7.

5.

5. An application of a compound obtained by metabolism of the strain according to claim 1, characterized in that: The strain is metabolized to obtain a 16-membered macrolide compound having a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment as shown in compound 1, and the compound is used in the preparation of a hypoglycemic agent.

6. An application of a compound obtained by metabolism of the strain according to claim 1, characterized in that: The strain metabolizes the compound obtained by the strain to obtain a 16-membered macrocyclic lactone compound having a θ-keto-α, β, γ, δ-unsaturated lactone structural fragment as shown in compound 1, and the compound is used in the preparation of a seed germination promoter.

7. An application of a compound obtained by metabolism of the strain according to claim 1, characterized in that: The strain is metabolized to obtain the peniorcinol compound shown in compound 2, and the compound is used in the preparation of antioxidants.

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