Compound, composition, preparation method of compound and composition, and application of compound and composition in preparation of mulberry moth attractant

Abstract

The invention relates to the technical field of biological medicines, and particularly discloses a compound, a composition, a preparation method of the compound and the composition and application of the compound and the composition in preparation of a mulberry moth attractant. The compound is selected from a structure as shown in a formula I or a formula II. The composition is a combination of any two or more of a compound with a structure as shown in a formula I, a compound with a structure as shown in a formula II and hexadecanal. Researches show that the compound and the composition provided by the invention can cause the antennal potential reaction of male mulberry borers; particularly, the composition obtained by combining the compound with the structure shown in the formula I, the compound with the structure shown in the formula II and hexadecanal can improve the antennopotential reaction of male mulberry stem borers; therefore, when the compound or the composition is used as a mulberry moth attractant for trapping mulberry moths, the mulberry moths can be efficiently trapped, and the compound or the composition is green, environment-friendly, high in specificity, safe and efficient and has a great development prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedicine, and in particular to a compound, a composition, a preparation method thereof, and application thereof in the preparation of a mulberry borer attractant. Background Art

[0002] The mulberry borer (Diaphania pyloalis Walker), a member of the Lepidoptera family Pyralidae, is a major pest of mulberry trees. First- and second-instar larvae of the borer feed on young mulberry leaves, severely impacting their growth and causing deformities. Furthermore, silkworms feeding on leaves contaminated by borer feces can easily lead to cross-infection. Currently, pesticides are still the primary method of controlling mulberry borer damage in production. Because the mulberry borer outbreak period overlaps significantly with the silkworm breeding season, low-toxicity, short-lived pesticides can only be used before silkworm rearing. Furthermore, older borers typically feed within curled leaves, allowing them to avoid sprays to a certain extent, reducing control effectiveness. The long-term use of a single pesticide has led to varying degrees of pesticide resistance in mulberry borer larvae, making effective control difficult.

[0003] Currently, there are numerous reports of using safe and environmentally friendly biological control measures to control agricultural pests. However, these measures are not very effective, requiring a period of time to be effective. Furthermore, they are significantly impacted by the environment, which also hinders their effective implementation. However, pheromone-based trapping technology is environmentally friendly, highly specific, safe, and efficient, offering great potential for development. Summary of the Invention

[0004] In order to overcome at least one technical problem existing in the prior art, the present invention provides a compound, a composition, a preparation method thereof, and an application thereof in preparing a mulberry borer attractant.

[0005] The technical solutions of the present invention are as follows: The present invention first provides a compound selected from the structure shown in Formula I or Formula II: Formula I; Formula II.

[0006] The present invention also provides a method for preparing the above compound, which uses (3Z, 6Z, 9Z)-octadecatrienoic acid as a raw material to prepare the compound.

[0007] Preferably, (3Z, 6Z, 9Z)-octadecatrienoic acid is dissolved in a solvent, potassium carbonate and 2-iodopropane are added, and the reaction is carried out at 50-70° C. for 6-20 h to obtain a compound with the structure shown in Formula I.

[0008] Preferably, (3Z, 6Z, 9Z)-octadecatrienoic acid is dissolved in a solvent, potassium carbonate and 1-iodobutane are added, and the reaction is carried out at 50-70° C. for 6-20 h to obtain a compound with the structure shown in Formula II.

[0009] The present invention also provides a composition, which is a combination of any two or more selected from the group consisting of a compound having a structure represented by formula I, a compound having a structure represented by formula II, and hexadecanal.

[0010] Preferably, the composition comprises a compound having a structure represented by Formula I, a compound having a structure represented by Formula II, and hexadecanal.

[0011] Preferably, the mass ratio of the compound represented by formula I, the compound represented by formula II, and hexadecanal is 1-5:1-5:1-5.

[0012] More preferably, the mass ratio of the compound represented by formula I, the compound represented by formula II, and hexadecanal is 1:1-3:1-3.

[0013] Most preferably, the mass ratio of the compound represented by formula I, the compound represented by formula II, and hexadecanal is 1:2:1.

[0014] The present invention also provides an application of the composition in preparing a mulberry borer attractant.

[0015] Beneficial effects: Studies have shown that the compounds and compositions described in the present invention can induce the antennae potential response of male mulberry borers; in particular, the composition obtained by combining the compound represented by the structure of formula I, the compound represented by the structure of formula II and hexadecanal can improve the antennae potential response of male mulberry borers; therefore, using the compounds or compositions described in the present invention as mulberry borer attractants for trapping mulberry borers can achieve efficient trapping of mulberry borers, is green and environmentally friendly, has high specificity, is safe and efficient, and has great development prospects.

[0016] In addition, the present invention starts from commercially available (3Z, 6Z, 9Z)-octadecatrienoic acid and prepares compounds represented by formula I and formula II through alkyl iodide substitution reaction, which has the advantages of simple reaction conditions and high overall yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention provides a compound having a structure shown in formula I, a compound having a structure shown in formula II, and a synthesis route of hexadecanal.

[0018] Figure 2 is the NMR spectrum of compound 2.

[0019] Figure 3 is the NMR spectrum of compound 3.

[0020] Figure 4 This is the NMR spectrum of hexadecanal.

[0021] Figure 5 The graph shows the results of an EAG experiment on male mulberry borer to compounds or compositions.

[0022] Figure 6 This is a graph showing the EAG reaction test results of compositions with different ratios of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further explained below with reference to specific examples, but the examples do not limit the present invention in any form.

[0024] Example 1 Preparation of the compound represented by formula I like Figure 1 Step 1: Compound 2a ((3Z, 6Z, 9Z)-octadecatrienoic acid, 300 mg, 1.1 mmol) was weighed and dissolved in 3 mL of DMF. Potassium carbonate (531 mg, 3.85 mmol) and 2-iodopropane (374 mg, 2.2 mmol) were added and the reaction was continued at 60 o C and react overnight. After the reaction is complete as determined by TLC, the reaction solution is poured into water to quench, extracted with ethyl acetate and washed with saturated brine. The organic phases are combined and dried over anhydrous sodium sulfate. The organic phases are then separated and purified by column chromatography to obtain a compound of formula I (i.e. Figure 1 The compound 2 in the mixture (hereinafter referred to as compound 2) was 330 mg, with a yield of 93%.

[0025] The NMR data of compound 2 are as follows: 1 H NMR (400 MHz, CDCl3) δ 5.43 – 5.22 (m, 6H), 4.99 (dt, J = 12.5, 6.3 Hz, 1H), 2.85 – 2.71 (m, 4H), 2.24 (t, J = 7.5 Hz, 2H), 2.11 – 1.96 (m, 4H), 1.67 – 1.52 (m, 2H), 1.33 – 1.27 (m, 8H), 1.21 (d,J = 6.3 Hz, 6H), 0.96 (t, J = 7.5 Hz, 3H).

[0026] Example 2 Preparation of the compound represented by formula II like Figure 1Step 2: Compound 2a ((3Z, 6Z, 9Z)-octadecatrienoic acid, 300 mg, 1.1 mmol) was weighed and dissolved in 3 mL of DMF. Potassium carbonate (531 mg, 3.85 mmol) and 1-iodobutane (405 mg, 2.2 mmol) were added and the reaction was continued at 60 o C and react overnight. After the reaction is complete as determined by TLC, the reaction solution is poured into water to quench, extracted with ethyl acetate and washed with saturated brine. The organic phases are combined and dried over anhydrous sodium sulfate. The organic phases are then separated and purified by column chromatography to obtain a compound of formula II (i.e. Figure 1 The compound 3 in the mixture (hereinafter referred to as compound 3) was 308 mg, with a yield of 83%.

[0027] The NMR data of compound 3 are as follows: 1 H NMR (400 MHz, CDCl3) δ 5.50 – 5.23 (m, 6H), 4.06 (t, J = 6.7 Hz, 2H), 2.87 – 2.74 (m, 4H), 2.28 (t, J = 7.5 Hz, 2H), 2.12– 1.96 (m, 4H), 1.64 – 1.53 (m, 4H), 1.36 – 1.24 (m, 10H), 0.99 – 0.85 (m, 6H).

[0028] Example 3 Preparation of Hexadecanal like Figure 1 Step 3: Weigh the compound hexadecanol (100 g, 0.41 mol) and dissolve it in 1000 mL of EtOAc. Add IBX (127 g, 0.45 mol) and react at 80 o C for 24 h. After the reaction was complete as detected by TLC plate, the reaction solution was filtered, and the organic phase was dried and separated and purified by column chromatography to obtain hexadecanal (82 g, yield 82%) as a mulberry leaf volatile.

[0029] The NMR data of hexadecanal are as follows: 1 H NMR (400 MHz, CDCl3) δ 9.76 (t, J = 1.9 Hz,1H), 2.41 (td, J = 7.4, 1.9 Hz, 2H), 1.67 – 1.57 (m, 2H), 1.32 – 1.21 (m,24H), 0.87 (t, J = 6.8 Hz, 3H).

[0030] Example 4 Experimental test of antennal potential The electroantennographic (EAG) technique is the most commonly used electrophysiological technique in chemical ecology. It is a fundamental test for determining whether a substance stimulates a living insect or a part of its organ (such as its antennae). It can simplify subsequent wind tunnel and field testing. This experiment utilized this technique to investigate the electrophysiological responses of male mulberry borers to synthetic standard compounds, identifying the optimal combination and dosage for indoor activity and providing a theoretical basis for field luring experiments.

[0031] Compound 2, Compound 3, and hexadecanal were prepared at four concentrations: 10 μg / μL, 1 μg / μL, 0.1 μg / μL, and 0.01 μg / μL. Compound 2, Compound 3, and hexadecanal were then mixed at a 1:1:1 ratio for testing. 10 μL of each individual component and mixture was tested at concentrations of 10 μg / mL, 1 μg / mL, 0.1 μg / mL, and 0.01 μg / mL, respectively. Doses were 100 μg, 10 μg, 1 μg, and 0.1 μg, respectively. Within each treatment, testing was performed in ascending order of dose. The average EAG response was measured using a potentiometry instrument.

[0032] The results are as follows Figure 5 As shown, the antennae of male mulberry borers exhibited electroantennae responses to all three compounds, eliciting electroantennae responses at a low stimulating dose of 0.1 μg. Compound 2 elicited only a modest electroantennae response at low doses of 0.1 μg and 1 μg, but the response increased significantly (1.20 mV) at 10 μg. The response increased modestly (1.21 mV) at 100 μg, but did not reach saturation. Compound 3 elicited higher electroantennae responses than compound 2. The electroantennae responses at low doses of 0.1 μg and 1 μg were 0.28 mV and 1.25 mV, respectively. The response peaked at 10 μg, reaching 1.85 mV. As the dose increased to 100 μg, the electroantennae response decreased, reaching 1.62 mV. This indicates that the reaction threshold of compound 3 to the antennae of male mulberry borer is relatively low, and a large dose will cause the reaction of male mulberry borer antennae to decrease; the antennal potential response value of compound hexadecanal is relatively similar to that of compound 2, and reaches saturation at 10 μg, which is 1.19 mV. When the dose of hexadecanal is increased, the EAG response value does not increase significantly.

[0033] When the three components were mixed in a 1:1:1 ratio, the EAG response values ​​increased significantly with increasing dose at low doses, reaching a maximum of 2.25 mV at 10 μg. Subsequently, the EAG response value decreased (1.90 mV) with further dose increases, essentially mirroring the trend observed with single-component compound 3. However, the EAG response values ​​induced by the mixed components were significantly higher than those of the single components. At a dose of 10 μg, the EAG response values ​​of the mixed components were more than double those of the single components.

[0034] Example 5: Configuration of the composition Ten different formulations of compounds 2, 3, and hexadecanal were prepared in n-hexane. Each formulation represents a composition, labeled A-J (Table 1). Compounds 2, 3, and hexadecanal were first prepared in n-hexane to a 1 μg / μL solution. Three-component or two-component solutions were prepared in varying mass ratios according to the experimental requirements, as follows: Table 1 Composition components and ratios Composition number Compound composition Quality ratio A Compound 2: Compound 3: Hexadecanal 1:1:1 B Compound 2: Compound 3: Hexadecanal 1:1:0 C Compound 2: Compound 3: Hexadecanal 1:1:2 D Compound 2: Compound 3: Hexadecanal 1:1:5 E Compound 2: Compound 3: Hexadecanal 0:1:1 F Compound 2: Compound 3: Hexadecanal 2:1:1 G Compound 2: Compound 3: Hexadecanal 5:1:1 H Compound 2: Compound 3: Hexadecanal 1:0:1 I Compound 2: Compound 3: Hexadecanal 1:2:1 J Compound 2: Compound 3: Hexadecanal 1:5:1 100 μL of each composition was taken and the average EAG response was measured using an antenna potential meter. The results are as follows: Figure 6 As shown, 10 different ratio combinations of the three components of the sex pheromone composition can produce EAG reactions, among which compositions A, C and I, namely compound 2: compound 3: hexadecanal, are 1:1:1 and 1:1:2, and 1:2:1 respectively, which cause higher antennal potentials. The highest EAG reaction value is 2.47mV at 1:2:1. As the ratio of compound 3 continues to increase, the EAG reaction value decreases instead. The EAG reaction values ​​of compound 2: compound 3: hexadecanal at 1:1:0 and 1:1:1, 0:1:1, and 1:0:1 are much higher than those of the single component reactions, while the EAG reaction value of hexadecanal itself is not high. It can be concluded that hexadecanal mainly plays a synergistic role and is indispensable.

[0035] EAG results showed that male mulberry borer antennae were more sensitive to compound 3, indicating that compound 3 plays a primary role in eliciting sexual behavioral responses in male mulberry borers. Compound 2 and hexadecanal play a supporting role in inducing sexual behavioral responses in male mulberry borers. When the three compounds were combined in appropriate proportions, the EAG response significantly increased. However, the overall EAG response produced by the mixture was not simply the sum of the individual EAG responses of the individual components, but rather exhibited a significant synergistic effect, demonstrating the complexity of the mulberry borer's sex pheromone sensing system.

[0036] Most lepidopteran insects exhibit a minimum and maximum threshold for responding to sex pheromones. The dose-response of male mulberry borers to the various sex pheromone components exhibits a roughly S-shaped pattern. The response is low at a dose of 0.1 μg, while the EAG response increases significantly at 10 μg. However, when the dose is increased to 100 μg, the increase in EAG response slows and even decreases, suggesting that high concentrations of sex pheromones may affect the sensitivity of male mulberry borer receptors. The highest EAG response was observed at a dose of 10 μg. However, when using sex pheromones as bait, consideration should be given to the potential for increased doses in field applications due to complex environments. A higher dose is not always better; an optimal dose composition is crucial for optimal trapping. These findings require further investigation in field trials.

[0037] Example 6 Behavioral experiment on mulberry borer attractant composition Based on the EAG results in Example 5, compositions A (1:1:1), C (1:1:2), and I (1:2:1) with higher antennal potential values ​​were selected for evaluation of their behavioral responses to male mulberry borers using a four-arm olfactometer and wind tunnel system. A control group (n-hexane blank) and dose gradient groups (0.1 μg, 10 μg, and 100 μg) were set up. Each composition was loaded onto a rubber stopper (10 μg / lure), with three replicates per group (N=30). A valid response was defined in the four-arm olfactometer as long as the insect entered the trap and remained there for 10 minutes or longer. The wind tunnel system measured the rate of approach and antennal beat frequency. Data were analyzed using ANOVA (p<0.05).

[0038] Four-arm olfactometer testing revealed that Composition I (1:2:1) had the highest selection rate (82%), significantly higher than Compositions A (68%) and C (72%). The control group showed no response (0%). In wind tunnel testing, Composition I exhibited a 10 μg dose with an 82% tendency to approach the insects, with an antennal oscillation frequency of 5 beats per second. At a dose of 100 μg, this decreased to 65% and a frequency of 4 beats per second, demonstrating a high-concentration inhibitory effect. Overall, these results indicate that Composition I (1:2:1) is the optimal ratio at a 10 μg dose, combining high efficiency and cost-effectiveness.

Claims

1. A compound, characterized in that Selected from the structure shown in Formula I or Formula II: Formula I; Formula II.

2. The method for preparing the compound according to claim 1, characterized in that The compound according to claim 1 is prepared using (3Z, 6Z, 9Z)-octadecatrienoic acid as a raw material.

3. The preparation method according to claim 2, characterized in that Dissolve (3Z, 6Z, 9Z)-octadecatrienoic acid in a solvent, add potassium carbonate and 2-iodopropane, and react at 50-70° C. for 6-20 hours to obtain a compound with the structure shown in Formula I.

4. The preparation method according to claim 2, characterized in that Dissolve (3Z, 6Z, 9Z)-octadecatrienoic acid in a solvent, add potassium carbonate and 1-iodobutane, and react at 50-70° C. for 6-20 h to obtain a compound with the structure shown in Formula II.

5. A composition, characterized in that A combination of any two or more selected from the group consisting of the compound represented by formula I, the compound represented by formula II, and hexadecanal according to claim 1.

6. The composition according to claim 5, characterized in that The invention comprises a compound with a structure shown in formula I, a compound with a structure shown in formula II and hexadecanal.

7. The composition according to claim 6, characterized in that The mass ratio of the compound represented by formula I, the compound represented by formula II and hexadecanal is 1-5:1-5:1-5.

8. The composition according to claim 6, characterized in that The mass ratio of the compound represented by formula I, the compound represented by formula II and hexadecanal is 1:1-3:1-3.

9. The composition according to claim 6, characterized in that The mass ratio of the compound represented by formula I, the compound represented by formula II and hexadecanal is 1:2:

1.

10. Use of the compound according to claim 1 or the composition according to any one of claims 5 to 9 in the preparation of a mulberry borer attractant.

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