A compound, composition and method of preparation and use in the preparation of a mulberry pygmy moth attractant

Abstract

The present application relates to the technical field of biological medicine, and particularly discloses a compound, a composition, a preparation method thereof and application of the compound and the composition in preparation of a mulberry caterpillar attractant. The compound is selected from structures shown in formula I or formula II. The composition is a combination of any two or more of the compound with the structure shown in formula I, the compound with the structure shown in formula II and hexadecanal. Research shows that the compound and the composition can cause the antennal potential response of male mulberry caterpillars. In particular, the composition obtained by combining the compound with the structure shown in formula I, the compound with the structure shown in formula II and hexadecanal can improve the antennal potential response of male mulberry caterpillars. Therefore, the compound or the composition can be used as the mulberry caterpillar attractant to efficiently trap mulberry caterpillars, and the compound or the composition is green, has high specificity, is safe and efficient, and has great development prospect.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to a compound, a composition, a method for preparing the same, and its application in the preparation of mulberry leafminer attractants. Background Technology

[0002] The mulberry moth (Diaphania pyloalis Walker) is an insect belonging to the family Pyralidae in the order Lepidoptera. It is one of the major pests of mulberry trees. First and second instar larvae feed on tender mulberry leaves, severely affecting their growth and causing deformities. Furthermore, silkworms feeding on mulberry leaves contaminated with moth excrement are prone to cross-infection. Currently, pesticide control is still the primary method of pest control in production. Because the mulberry moth outbreak period highly overlaps with the silkworm rearing period, only low-toxicity pesticides with short residual effects can be used for control before silkworm rearing. Moreover, older mulberry moths generally feed inside curled leaves, which can help them avoid sprayed pesticides to some extent, leading to reduced control efficacy. The long-term use of single pesticides in production has resulted in varying degrees of pesticide resistance in mulberry moth larvae, making effective pest control difficult.

[0003] Currently, there are numerous reports of using safe and environmentally friendly biological control measures to control agricultural pests. However, the control effects are not very obvious, requiring a certain period to become effective, and the significant environmental impact also restricts the effective implementation of biological control. In contrast, sex pheromone-attracting and trapping technology is green and environmentally friendly, highly specific, safe, and efficient, and has great development potential. 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 method for preparing the same, and its application in the preparation of a mulberry leafminer attractant.

[0005] The technical solution of the present invention is as follows:

[0006] This invention first provides a compound selected from the structure shown in Formula I or Formula II:

[0007] Formula I;

[0008] Formula II.

[0009] The present invention also provides a method for preparing the above-mentioned compound, which uses (3Z,6Z,9Z)-octadecadienoic acid as a raw material to prepare the compound.

[0010] Preferably, (3Z, 6Z, 9Z)-octadecadienoic 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.

[0011] Preferably, (3Z, 6Z, 9Z)-octadecadienoic 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.

[0012] The present invention also provides a composition selected from any two or more of the compounds with the structure shown in Formula I, the compounds with the structure shown in Formula II, and hexadecaldehyde.

[0013] Preferably, the composition comprises a compound with the structure shown in Formula I, a compound with the structure shown in Formula II, and hexadecaldehyde.

[0014] Preferably, the mass ratio of the compound with the structure shown in Formula I, the compound with the structure shown in Formula II, and hexadecaldehyde is 1~5:1~5:1~5.

[0015] More preferably, the mass ratio of the compound with the structure shown in Formula I, the compound with the structure shown in Formula II, and hexadecaldehyde is 1:1~3:1~3.

[0016] Most preferably, the mass ratio of the compound with the structure shown in Formula I, the compound with the structure shown in Formula II, and hexadecaldehyde is 1:2:1.

[0017] The present invention also provides the use of the above composition in the preparation of mulberry leafminer attractant.

[0018] Beneficial effects: Studies have shown that the compounds and compositions described in this invention can induce antennal potential responses in male mulberry borers; in particular, the composition obtained by combining the compounds with the structure shown in Formula I, the compounds with the structure shown in Formula II, and hexadecaldehyde can enhance the antennal potential responses in male mulberry borers; therefore, using the compounds or compositions described in this invention as mulberry borer attractants can achieve highly efficient trapping of mulberry borers, which is environmentally friendly, highly specific, safe and efficient, and has great development prospects.

[0019] Furthermore, this invention starts from commercially available (3Z, 6Z, 9Z)-octadecadienoic acid and prepares compounds with the structure shown in Formula I and the structure shown in Formula II through alkyl iodine substitution reactions. This has the advantages of simple reaction conditions and high overall yield. Attached Figure Description

[0020] Figure 1 The diagram shows the synthetic routes for compounds with the structure shown in Formula I, compounds with the structure shown in Formula II, and hexadecaldehyde.

[0021] Figure 2 This is the NMR spectrum of compound 2.

[0022] Figure 3 This is the NMR spectrum of compound 3.

[0023] Figure 4 The NMR spectrum of hexadecaldehyde is shown.

[0024] Figure 5 This is a diagram showing the EAG reaction results of male mulberry borers with compounds or compositions.

[0025] Figure 6 The figure shows the experimental results of EAG reaction of different ratios of the compositions of the present invention. Detailed Implementation

[0026] The present invention will be further explained below with reference to specific embodiments, but the embodiments do not limit the present invention in any way.

[0027] Example 1: Preparation of compounds with the structure shown in Formula I

[0028] like Figure 1 Step 1: Weigh compound 2a ((3Z,6Z,9Z)-octadecadienoic acid, 300 mg, 1.1 mmol) and dissolve it in 3 mL of DMF. Add potassium carbonate (531 mg, 3.85 mmol) and 2-iodopropane (374 mg, 2.2 mmol). The reaction is carried out at 60 °C. o The reaction was allowed to proceed overnight. After the reaction was confirmed to be complete by TLC, the reaction solution was quenched in water. The mixture was extracted with ethyl acetate and washed with saturated brine. The combined organic phases were dried over anhydrous sodium sulfate. After rotary evaporation, the organic phase was purified by column chromatography to obtain the compound with the structure shown in Formula I (i.e., Figure 1 Compound 2 (hereinafter referred to as compound 2) was 330 mg, with a yield of 93%.

[0029] The NMR data for 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).

[0030] Example 2 Preparation of compounds with the structure shown in Formula II

[0031] like Figure 1Step 2: Weigh compound 2a ((3Z,6Z,9Z)-octadecadienoic acid, 300 mg, 1.1 mmol) and dissolve it in 3 mL of DMF. Add potassium carbonate (531 mg, 3.85 mmol) and 1-iodobutane (405 mg, 2.2 mmol). The reaction is carried out at 60 °C. o The reaction was allowed to proceed overnight. After the reaction was confirmed to be complete by TLC, the reaction solution was quenched in water. The mixture was extracted with ethyl acetate and washed with saturated brine. The combined organic phases were dried over anhydrous sodium sulfate. After rotary evaporation, the organic phase was purified by column chromatography to obtain the compound with the structure shown in Formula II (i.e., Figure 1 Compound 3 (hereinafter referred to as compound 3) was 308 mg, with a yield of 83%.

[0032] The NMR data for 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).

[0033] Example 3 Preparation of hexadecaldehyde

[0034] like Figure 1 Step 3: Weigh out 100 g (0.41 mol) of hexadecyl alcohol and dissolve it in 1000 mL of EtOAc. Add IBX (127 g, 0.45 mol) and react at 80 °C. o After reacting at C for 24 hours, the reaction was checked by TLC plate to confirm its completeness. The reaction solution was then filtered, the organic phase was dried by rotary evaporation, and the volatile mulberry leaf hexadecaldehyde (82 g, yield 82%) was obtained by column chromatography.

[0035] The NMR data for hexadecaldehyde 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).

[0036] Example 4: Antennae Potential Test

[0037] Antennae potential (EAG) is the most commonly used electrophysiological technique in chemical ecology. It is a fundamental testing method for determining whether a substance elicits a stimulating response in a living insect or a part of its organs (such as the antennae), simplifying subsequent wind tunnel and field testing. This experiment utilizes this technique to study the electrophysiological responses of male mulberry borers to synthetic standard compounds, screening for combinations and dosages with optimal indoor activity, and providing a theoretical basis for field attraction experiments.

[0038] Compounds 2, 3, and hexadecaldehyde were prepared at four concentrations: 10 μg / μL, 1 μg / μL, 0.1 μg / μL, and 0.01 μg / μL. Compounds 2, 3, and hexadecaldehyde were mixed in a 1:1:1 ratio for testing. At concentrations of 10 μg / mL, 1 μg / mL, 0.1 μg / mL, and 0.01 μg / mL, 10 μL of each single component and the mixed component were tested, with doses of 100 μg, 10 μg, 1 μg, and 0.1 μg, respectively. The testing sequence for the same treatment was from low to high dose. The average EAG response was measured using an antennal potential analyzer.

[0039] The results are as follows Figure 5 As shown, the antennae of male mulberry borers exhibited antennal potential responses to all three compounds. All three compounds induced antennal potential responses in male mulberry borers at a low stimulating dose of 0.1 μg. Compound 2 showed minimal antennal potential responses at low doses of 0.1 μg and 1 μg, but the response increased significantly (1.20 mV) at a dose of 10 μg. However, the increase in antennal potential response was not significant at 100 μg (1.21 mV), failing to reach saturation. Compound 3 induced higher antennal potential values ​​than compound 2. The antennal potential responses at low doses of 0.1 μg and 1 μg were 0.28 mV and 1.25 mV, respectively. The highest antennal potential response (1.85 mV) was observed at 10 μg. However, the antennal potential response decreased slightly to 1.62 mV at 100 μg. This indicates that compound 3 has a relatively low response threshold to the antennae of male mulberry borers, and high doses may cause a decrease in the response of male mulberry borers antennae. The antennal potential response value of compound hexadecaldehyde is similar to that of compound 2, and it reaches saturation at 10 μg, which is 1.19 mV. Further increasing the dose of hexadecaldehyde does not significantly increase the EAG response value.

[0040] When the three components were mixed in a 1:1:1 ratio, the EAG response value increased significantly with increasing dose at low doses, reaching a maximum of 2.25 mV at a dose of 10 μg. Subsequently, with further increases in dose, the EAG response value decreased (1.90 mV), basically following the same trend as the single-component compound 3. However, the EAG response value induced by the mixed components was significantly higher than that of the single-component compound. At a dose of 10 μg, the EAG response value of the mixed components was more than twice that of the single-component compound.

[0041] Example 5: Preparation of the composition

[0042] Ten different formulations were prepared using hexane with compounds 2 and 3, and hexadecaldehyde. Each formulation represents a composition and is labeled AJ (Table 1). First, compounds 2 and 3, along with hexadecaldehyde, were prepared into 1 μg / μL solutions using hexane. Then, three-component or two-component solutions with different mass ratios were prepared according to experimental requirements, as follows:

[0043] Table 1. Composition and Proportioning of the Composition

[0044] Composition Number Compound composition Mass ratio A Compound 2: Compound 3: Hexadecaldehyde 1:1:1 B Compound 2: Compound 3: Hexadecaldehyde 1:1:0 C Compound 2: Compound 3: Hexadecaldehyde 1:1:2 D Compound 2: Compound 3: Hexadecaldehyde 1:1:5 E Compound 2: Compound 3: Hexadecaldehyde 0:1:1 F Compound 2: Compound 3: Hexadecaldehyde 2:1:1 G Compound 2: Compound 3: Hexadecaldehyde 5:1:1 H Compound 2: Compound 3: Hexadecaldehyde 1:0:1 I Compound 2: Compound 3: Hexadecaldehyde 1:2:1 J Compound 2: Compound 3: Hexadecaldehyde 1:5:1

[0045] 100 μL of each of the different compositions was taken and the average EAG response was measured using an antennal potential analyzer. The results are as follows: Figure 6 As shown, all 10 different ratios of the three components of the sex pheromone composition produced an EAG reaction. Among them, the antennal potentials were higher when the ratios of compound 2:compound 3:hexadecaldehyde were 1:1:1, 1:1:2, and 1:2:1, respectively. The highest EAG reaction value was 2.47 mV at 1:2:1. As the ratio of compound 3 was further increased, the EAG reaction value decreased. The EAG reaction values ​​of compound 2:compound 3:hexadecaldehyde were much higher than the single-component reaction values ​​when they were 1:1:0, 1:1:1, 0:1:1, and 1:0:1, respectively. However, the EAG reaction value of hexadecaldehyde itself was not high. It can be concluded that hexadecaldehyde mainly plays a synergistic role and is indispensable.

[0046] The EAG reaction results showed that the antennae of male mulberry borers were more sensitive to compound 3, indicating that compound 3 plays a major role in inducing the sexual behavior response in male mulberry borers. Compound 2 and hexadecaldehyde played auxiliary roles in inducing the sexual behavior response in male mulberry borers. When the three compounds were mixed in an appropriate ratio, the EAG response significantly increased. However, the overall EAG response produced by the mixture was not a simple summation of the individual component EAG responses, but rather showed a significant synergistic effect, which also illustrates the complexity of the mulberry borer sex pheromone sensing system.

[0047] Most lepidopteran insects exhibit minimum and maximum thresholds for their response to sex pheromones. The dose-response pattern of male mulberry borers to various components of sex pheromones is roughly S-shaped: the response value is low at 0.1 μg, increases significantly at 10 μg, and then slows down or even declines at 100 μg, indicating that high concentrations of sex pheromones may affect the sensory capacity of male mulberry borers' receptors. The highest EAG response dose was 10 μg. However, when using sex pheromones as lures, the possibility of increased dosage due to complex environmental conditions in field applications should be considered. More is not always better; an optimal dosage composition is needed to achieve the best trapping effect. Further research in field trials is required to address these issues.

[0048] Example 6: Behavioral Experiment of Mulberry Moth Lure Composition

[0049] Based on the EAG response results of Example 5, compositions A (1:1:1), C (1:1:2), and I (1:2:1) with high antennal potential values ​​were selected, and their behavioral responses to male mulberry borers were evaluated using a four-arm olfactometer and a wind tunnel system. The experiment included a control group (n-hexane blank) and dose gradient groups (0.1 μg, 10 μg, 100 μg). The compositions were loaded onto rubber stoppers (10 μg / lure), and each group was repeated three times (N=30). A valid response was defined as the insect entering the trap area and remaining there for ≥10 minutes using the four-arm olfactometer; tacticity and antennal wagging frequency were measured in the wind tunnel system. Data analysis was performed using ANOVA (p<0.05).

[0050] Four-arm olfactometer testing showed that composition I (1:2:1) had the highest selectivity (82%), significantly higher than compositions A (68%) and C (72%), while the control group showed no response (0%). In wind tunnel experiments, composition I achieved a tactile response rate of 82% at a dose of 10 μg, with an antennae beating frequency of 5 times / second; as the dose increased to 100 μg, the tactile response rate decreased to 65%, and the antennae beating frequency decreased to 4 times / second, indicating a high-concentration inhibitory effect. Overall, the results indicate that composition I (1:2:1) is the optimal ratio at a dose of 10 μg, combining high efficiency and economy.

Claims

1. Use of a composition for the preparation of a mulberry pygmy moth attractant, characterized in that, The composition comprises a compound with a structure shown in Formula I, a compound with a structure shown in Formula II, and cetyl aldehyde; Formula I; Formula II; The mass ratio of the compound with a structure shown in Formula I, the compound with a structure shown in Formula II, and cetyl aldehyde is 1:1-3:1-3.

2. Use according to claim 1, characterized in that, The mass ratio of the compound with a structure shown in Formula I, the compound with a structure shown in Formula II, and cetyl aldehyde is 1:2:

1. The mass ratio of the compound with a structure shown in Formula I, the compound with a structure shown in Formula II, and cetyl aldehyde is 1:2:1.

Images