Compound and insecticide

Abstract

The present disclosure relates to a compound represented by formula (I).

Description

Chemical compounds and pesticides

[0001] The present invention relates to compounds and insecticides.

[0002] Microbial-derived natural compounds are useful in the development of insecticides. For example, okaramins are insecticidal substances produced by Penicillium fungi, and are known to exhibit insecticidal activity by acting on inhibitory glutamate receptors (GluCl) present only in invertebrates (Non-Patent Documents 1 and 2).

[0003] Hideo Hayashi et al., “Structure and Insecticidal Activity of New Indole Alkaloids, Okaramines A and B, from Penicillium simplicissimum AK-40” Agric. Biol. Chem., 53 (2), 461-469, 1989Naoki Kato et al., “Biosynthesis and Structure-Activity Relationship Studies of Okaramines That Target Insect Glutamate-Gated Chloride Channels” ACS Chem. Biol. 2018, 13, 561-566

[0004] The development of drug resistance caused by the repeated use of the same insecticide is a problem for pest insects (especially lepidopteran pests such as moth larvae). To avoid drug resistance, it is recommended to rotate insecticides with different insecticidal active ingredients. Therefore, the development of new insecticidal active ingredients is desired.

[0005] An object of the present invention is to provide a novel compound having insecticidal activity, and an object of the present invention is to provide an insecticide containing the compound.

[0006] The present invention relates to the following inventions: [1] A compound represented by the following formula (I): [In formula (I), R １ represents an alkylcarbonyl group having 2 to 6 carbon atoms, and R ２ represents a hydrogen atom or a halogen atom, and R３ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkyloxycarbonyl group having 2 to 6 carbon atoms; R ４ represents a hydrogen atom or a halogen atom, and R ５ represents a hydrogen atom or a methoxy group, and R ６ represents a hydrogen atom or a hydroxy group, and the double line consisting of a solid line and a dashed line represents a carbon-carbon single bond or a carbon-carbon double bond.] [2] The compound according to [1], wherein the double line consisting of a solid line and a dashed line is a carbon-carbon double bond. [3] The compound according to [1], wherein the R １ is an alkylcarbonyl group having 2 to 3 carbon atoms. [4] The compound according to any one of [1] to [3], represented by the following formula (Ia): [In formula (Ia), R １ａ represents an acetyl group or an ethylcarbonyl group, and a double line consisting of a solid line and a dashed line represents a carbon-carbon single bond or a carbon-carbon double bond.] [5] The R １ａ is an ethylcarbonyl group, and the double line consisting of a solid line and a dashed line is a carbon-carbon double bond. [6] An insecticide comprising the compound according to any one of [1] to [5].

[0007] According to the present invention, it is possible to provide a novel compound having insecticidal activity, and an insecticide containing the compound.

[0008] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0009] In this specification, numerical ranges indicated using "to" indicate ranges that include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. Furthermore, unless specifically stated otherwise, the units of the numerical values ​​before and after "to" are the same. In numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of a numerical range of another stage. Furthermore, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, the upper and lower limits individually described can be arbitrarily combined. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified. Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more types.

[0010] The compounds herein include all stereoisomers (e.g., enantiomers and diastereomers) derived from a quaternary carbon atom, and may be mixtures thereof (e.g., racemates).

[0011] [Compound] The compound according to this embodiment is a compound represented by the following formula (I) (hereinafter also referred to as "compound (I)").

[0012] R １ represents an alkylcarbonyl group having 2 to 6 carbon atoms. The alkylcarbonyl group having 2 to 6 carbon atoms is represented by -C(=O)-R, where R is an alkyl group having 1 to 5 carbon atoms. The alkyl group represented by R may be linear or branched. R １ The upper limit of the number of carbon atoms in the alkyl group represented by the formula (I) is 5 or less, and may be 4 or less, 3 or less, or 2 or less.

[0013] R １ Examples of the alkylcarbonyl group having 2 to 6 carbon atoms represented by the formula (I) include an acetyl group (—CO—CH ３ ), ethylcarbonyl group (—CO—CH ２ CH ３), n-propylcarbonyl group, i-propylcarbonyl group, n-butylcarbonyl group, i-butylcarbonyl group, t-butylcarbonyl group, n-pentylcarbonyl group, i-pentylcarbonyl group, t-pentylcarbonyl group, and the like.

[0014] R １ The alkylcarbonyl group having 2 to 6 carbon atoms represented by the formula (I) may be an alkylcarbonyl group having 2 to 3 carbon atoms, an acetyl group, or an ethylcarbonyl group, and may be an ethylcarbonyl group because this further improves the insecticidal activity.

[0015] R ２ represents a hydrogen atom or a halogen atom. ２ Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0016] R ３ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkyloxycarbonyl group having 2 to 6 carbon atoms.

[0017] R ３ The alkyl group having 1 to 5 carbon atoms represented by R may be linear or branched. ３ The upper limit of the number of carbon atoms in the alkyl group represented by R is 5 or less, and may be 4 or less, 3 or less, or 2 or less. ３ Examples of the alkyl group having 1 to 5 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, an n-pentyl group, an i-pentyl group, and a t-pentyl group.

[0018] R ３ The alkylcarbonyl group having 2 to 6 carbon atoms represented by R １ The alkyl group may be the same as the alkylcarbonyl group having 2 to 6 carbon atoms represented by the following formula:

[0019] R ３ The alkyloxycarbonyl group having 2 to 6 carbon atoms, represented by the formula: means a group represented by -C(=O)-O-R, in which R is an alkyl group having 1 to 5 carbon atoms.

[0020] R ３Examples of the alkyloxycarbonyl group having 2 to 6 carbon atoms represented by the formula (I) include a methyloxycarbonyl group, an ethyloxycarbonyl group, an n-propyloxycarbonyl group, an i-propyloxycarbonyl group, an n-butyloxycarbonyl group, an i-butyloxycarbonyl group, a t-butyloxycarbonyl group, an n-pentyloxycarbonyl group, an i-pentyloxycarbonyl group, and a t-pentyloxycarbonyl group.

[0021] R ４ represents a hydrogen atom or a halogen atom. ４ Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0022] R ５ is a hydrogen atom or a methoxy group (-OCH ３ ) indicates. ６ represents a hydrogen atom or a hydroxy group (—OH). ５ The configuration of the compound may be the configuration (β configuration) shown in the following formula (i).

[0023] The double line consisting of a solid line and a dashed line in formula (I) represents a carbon-carbon single bond (-CH ２ -CH ２ The double line consisting of a solid line and a broken line in formula (I) may be a carbon-carbon double bond, as this further improves the insecticidal activity.

[0024] Compound (I) is a compound represented by the formula (I) in which R ２ , R ３ and R ４ is a hydrogen atom, and R ５ is a methoxy group, and R ６ is a hydroxy group.

[0025] In formula (Ia), R １ａ The double line consisting of a solid line and a broken line has the same definition as that described in formula (I).

[0026] The compound represented by formula (Ia) may be a compound represented by the following formulas (1) to (3).

[0027] Compound (I) is represented by formula (Ia) and R １ａ is an ethylcarbonyl group, and the double line consisting of a solid line and a broken line is a carbon-carbon double bond (a compound represented by formula (3)).

[0028] Compound (I) can be obtained, for example, by derivatizing okaramine B represented by the following formula (II). There are no particular limitations on the method for obtaining okaramine B. Okaramine B obtained by the methods described in known literature (e.g., Non-Patent Documents 1 and 2) can be used.

[0029] The method for producing compound (I) includes, for example, an acylation step of acylating the hydroxy group bonded to the carbon atom at position 3a in okaramine B. The acylation can be carried out by reacting the starting material with an acylating agent.

[0030] The method for producing compound (I) includes, for example, converting a carbon-carbon double bond (-CH=CH-) formed by the carbon atom at the 4' position and the carbon atom at the 5' position in okaramine B into a carbon-carbon single bond (-CH ２ -CH ２ -).

[0031] [Insecticide] The insecticide according to this embodiment contains the above-mentioned compound (I) as an active ingredient. In this specification, the term "active ingredient" refers to a component that exerts an insecticidal effect.

[0032] Examples of targets for the insecticide include arthropods belonging to the order Lepidoptera (Lepidoptera), Diptera (Diptera), Hemiptera (Hemiptera), Acarina (Acarina), Coleoptera (Coleoptera), Hymenoptera (Hymenoptera), Orthoptera (Orthoptera), Isopoda (Isopoda), Centipede (Chilopoda), Millipede (Diplopoda), Araneae, etc. The insecticide according to this embodiment can be suitably used as an insecticide against Lepidoptera pests (particularly larvae, pupae and adults of Lepidoptera pests).

[0033] Examples of arthropods belonging to the order Lepidoptera include insects belonging to the families Noctuidae, Plutellidae, Pieridae, Pyralidae, Tortricidae, Sphingidae, and Geometridae.

[0034] Examples of Noctuidae insects include Spodoptera litura, Helicoverpa armigera, Spodoptera litura, Mythimna separata, Spodoptera litura, Spodoptera frugiperda, Spodoptera litura, and Agrotis ipsilon.

[0035] Examples of insects of the Plutella family include diamondback moth (Plutella xylostella), Plutella singillella, and Plutella polynoxa.

[0036] The insecticide may further contain other components in addition to compound (I). Examples of other components include surfactants, solvents, binders, stabilizers, dispersants, thickeners, foam agents, and flavoring agents.

[0037] Examples of surfactants include alkylphenol ethoxylate and sodium lauryl sulfate. Examples of solvents include xylene, toluene, methanol, and isopropyl alcohol. Examples of binders include polyvinyl alcohol, starch, and cellulose. Examples of stabilizers include antioxidants (BHT) and ultraviolet absorbers. Examples of dispersants include lignin sulfonic acid and polyacrylates. Examples of thickeners include xanthan gum and carboxymethyl cellulose. Examples of foaming agents include polyoxyethylene alkyl ethers and alkyl sulfonate esters. Examples of flavoring agents include peppermint oil and eucalyptus oil.

[0038] The content of the active ingredient in the insecticide (content of compound (I)) can be appropriately determined depending on the target of insecticide, dosage form, etc.

[0039] (Liquid Insecticides) In the case of agricultural liquid insecticides, the content of the active ingredient may be, for example, 1 w / v% to 50 w / v% based on the total amount of the agricultural liquid insecticide. In the case of agricultural pyrethroid insecticides, the content of the active ingredient may be, for example, 5 w / v% to 30 w / v% based on the total amount of the agricultural pyrethroid insecticide. In the case of household liquid insecticides, the content of the active ingredient may be, for example, 0.1 w / v% to 5 w / v% based on the total amount of the household liquid insecticide. Examples of household liquid insecticides include mosquito repellent sprays and cockroach sprays.

[0040] (Powder / Granular Insecticides) The content of the active ingredient in agricultural granules may be, for example, 1 w / v% to 20 w / v% based on the total amount of the agricultural granules. For example, in the case of soil treatment insecticides, the content of the active ingredient may be 5 w / v% to 15 w / v% based on the total amount of the soil treatment insecticide. The content of the active ingredient in household powders is in the range of 0.5 w / v% to 10 w / v% based on the total amount of the household powder. Household powders are found in products used to exterminate ants and fleas.

[0041] (Bait / Attractant) The content of the active ingredient in the ant bait may be 0.01 w / v% to 1 w / v% based on the total amount of the ant bait. The content of the active ingredient in the cockroach bait may be 0.05 w / v% to 2 w / v% based on the total amount of the cockroach bait.

[0042] (Other Specific Examples) Compound (I) can be used in the same manner as imidacloprid (neonicotinoid), fenitrothion (organophosphate), cypermethrin (pyrethroid), and Cefina (natural product-derived). Imidacloprid (neonicotinoid) is generally used at a content of 20 w / v% in a liquid formulation and 5 w / v% in a granule formulation. Fenitrothion (organophosphate) can be used at a content of 50 w / v% in an emulsion liquid and 2 w / v% to 5 w / v% in a powder formulation. Cypermethrin (pyrethroid) is generally used at a content of 0.2 w / v% to 1 w / v% in a household spray and 10 w / v% to 25 w / v% in an agricultural liquid formulation. Cefina (natural product-derived) can be used at a content of 4.9 w / v% in an agricultural liquid formulation.

[0043] Examples of the formulation of insecticides include wettable powders, emulsifiable concentrates, dusts, oils, resin vaporizers, flowables, microcapsules, fumigants, and total spray aerosols.

[0044] [Insecticidal method] The insecticidal method according to this embodiment comprises a step of contacting a target with compound (I). Compound (I) may be contacted with a target in the form of an insecticide containing compound (I). Specific embodiments of the insecticidal method can be those described as specific embodiments of compound (I) and the insecticide.

[0045] Specifically, compound (I) can be used, for example, as a liquid insecticide, a powder / granular insecticide, a bait / attractant, etc. The preferred amount of the active ingredient when using each of these agents is as described above.

[0046] The present disclosure will be described in more detail below using examples and comparative examples, but the present disclosure is not limited to the following examples.

[0047] 1. Synthesis of Okaramine B Derivatives 1-1. Synthesis of Okaramine B Derivative 1 Okaramine B derivative 1 (Biosci. Biotechnol. Biochem., 64(7), 1519-1521, 2000) represented by the following formula was synthesized using Okaramine B as a starting material according to the following procedure.

[0048] Okaramine B (2 mg) in ethanol (300 μL) was added to Pd(OH) ２ 1.3 mg of okaramine B derivative 1 was added to the reaction mixture, and the mixture was stirred under a hydrogen gas atmosphere for 5 hours. After the reaction was completed, the reaction solution was filtered through Celite, and the solvent was removed from the filtrate under reduced pressure to obtain a crude product. The crude product was purified by preparative thin-layer chromatography (PTLC) to obtain okaramine B derivative 1 (1.1 mg).

[0049] 1-2. Synthesis of Okaramine B Derivative 2 Okaramine B derivative 2 represented by the following formula was synthesized using Okaramine B as a raw material according to the following procedure.

[0050] Okaramine B (3.1 mg) in a pyridine / acetic anhydride solution (1:1, 400 μL) was stirred for 12 hours. After the reaction was completed, the solvent was distilled off under reduced pressure to obtain a crude product, which was then purified using PTLC to obtain Okaramine B derivative 2 (2.5 mg).

[0051] 1 ​H-NMR(500 MHz, CDCl3) δ:8.38 (s, 1H), 7.87 (d, J = 8.0 Hz, 1H), 7.71 (s, 1H), 7.41 (d, J = 8.0 Hz, 1H),7.34 (d, J = 6.5 Hz, 1H), 7.24-7.21 (m, 2H), 7.10 (t, J = 7.2 Hz, 1H), 6.84 (d,J = 7.5 Hz, 1H), 5.94 (d, J = 8.0 Hz, 1H), 5.72 (d, J = 8.0 Hz, 1H), 4.60 (s,1H), 4.10 (s, 1H), 3.85 (s, 3H), 3.25 (q, J = 7.5 Hz, 1H), 2.05 (s, 3H), 1.82(s, 3H), 1.78 (s, 3H), 1.65 (s, 3H), 1.26 (d, J = 7.5 Hz, 3H), 0.89 (s, 3H)

[0052] 1-3. Synthesis of Okaramine B Derivative 3 Okaramine B Derivative 3 represented by the following formula was synthesized using Okaramine B Derivative 1 as a raw material according to the following procedure.

[0053] Okaramine B derivative 1 (1.8 mg) in a pyridine / acetic anhydride solution (1:1, 200 μL) was stirred for 12 hours. After completion of the reaction, the solvent was distilled off from the reaction solution under reduced pressure to obtain a crude product, which was then purified by PTLC to obtain Okaramine B derivative 3 (1.2 mg).

[0054] 1 ​H-NMR (600 MHz, CDCl3) δ: 8.40 (s, 1H), 7.83 (dd, J = 8.4, 2.4 Hz, 1H), 7.71 (s, 1H), 7.41(d, J = 7.8 Hz, 1H), 7.36 (dd, J = 8.4, 2.4 Hz, 1H), 7.24-7.21 (m, 2H), 7.09 (t,J = 7.2 Hz, 1H), 6.85 (d, J = 7.8 Hz, 1H), 4.47 (s, 1H), 4.13 (s, 1H), 3.92 (brd, J = 12.6 Hz, 1H), 3.89 (s, 3H), 3.53 (td, J = 13.8, 5.0 Hz, 1H), 3.22 (q, J= 7.8 Hz, 1H), 2.31 (q, J = 13.8, 4.8 Hz, 1H), 2.05 (s, 3H), 1.76 (s, 3H), 1.56(s, 3H), 1.50 (br d, J = 12.0 Hz, 1H), 1.46 (s, 3H), 1.26 (d, J = 7.2 Hz, 3H),0.88 (s, 3H)

[0055] 1-4. Synthesis of Okaramine B Derivative 4 Okaramine B derivative 4 represented by the following formula was synthesized using Okaramine B as a raw material according to the following procedure.

[0056] Okaramine B (3.0 mg) in a pyridine / propionic anhydride solution (1:1, 300 μL) was stirred for 12 hours. After completion of the reaction, the solvent was distilled off from the reaction solution under reduced pressure to obtain a crude product, which was then purified using PTLC to obtain Okaramine B derivative 4 (2.2 mg).

[0057] 1 ​H-NMR (600 MHz, CDCl3) δ: 8.44 (s, 1H), 7.86 (d, J = 6.6 Hz, 1H), 7.69(s, 1H), 7.41 (d, J = 7.8 Hz, 1H), 7.34 (d, J = 6.0 Hz, 1H), 7.25-7.21 (m, 2H),7.10 (t, J = 7.8 Hz, 1H), 6.84 (d, J = 7.8 Hz, 1H), 5.93 (d, J = 8.4 Hz, 1H),5.72 (d, J = 8.4 Hz, 1H), 4.63 (s, 1H), 4.14 (s, 1H), 3.83 (s, 3H), 3.27 (q, J= 7.8 Hz, 1H), 2.31 (qd, J = 7.2, 2.4 Hz, 2H), 1.82 (s, 3H), 1.78 (s, 3H), 1.65(s, 3H), 1.25 (d, J = 7.2 Hz, 3H), 1.07 (t, J = 7.2Hz, 3H), 0.89 (s, 3H)

[0058] 2. Evaluation of Insecticidal Activity of Okaramine B Derivatives The insecticidal activity of Okaramine B and Okaramine B Derivatives 1 to 4 was evaluated by the method described in the following reference: Naozumi Kondo et al., "The Establishment of a Highly Sensitive Insecticidal Activity Detection System Using Silkworm First Instar Larvae Enables an Efficient Search Method for Insecticide Seed Compounds," ACS Agric. Sci. Technol. 2023, 3, 3, 278-286

[0059] 2-1. Evaluation of Silkworm Insecticidal Activity (Test Method) Using an aqueous solution containing 10% dimethyl sulfoxide (DMSO) (10% DMSO solution), test solutions containing okaramin B and okaramin B derivatives 1 to 4 at concentrations of 100 ppm, 30 ppm, 10 ppm, 3 ppm, 1 ppm, 0.3 ppm, 0.1 ppm, 0.03 ppm, 0.01 ppm, 0.003 ppm, or 0.001 ppm were prepared.

[0060] 100 μL of the test solution was added to 1 g of artificial diet for silkworms. First-instar silkworm larvae were fed the artificial diet containing the test solution, and the activity was evaluated after 5 days of observation. A group in which all silkworm larvae were dead or not growing was considered to be active (ED １００ (10 animals per group, n=3). A solution containing 1 ppm of abamectin was used as a positive control. A 10% DMSO solution was used as a negative control.

[0061] (Results) In the group administered with 0.03 ppm of Okaramin B, all first-instar silkworm larvae died (n=3). From this result, it was found that the EDTA of Okaramin B on first-instar silkworm larvae was １００ was determined to be 0.03 ppm.

[0062] In the group administered with 3 ppm of Okaramine B derivative 1, all first-instar silkworm larvae died. In the group administered with 1 ppm, although the insecticidal effect was confirmed, some individuals survived. From these results, it can be seen that the ED of Okaramine B derivative 1 １００ was determined to be 3 ppm.

[0063] In the group administered with 0.03 ppm of Okaramine B derivative 2, all first-instar silkworm larvae died. In the group administered with 0.01 ppm, although the insecticidal effect was confirmed, some individuals survived. From these results, it can be seen that the ED of Okaramine B derivative 2 １００ was determined to be 0.03 ppm.

[0064] In the group administered with 3 ppm of Okaramine B derivative 3, all first-instar silkworm larvae died. In the group administered with 1 ppm, although the insecticidal effect was confirmed, some individuals survived. From these results, it can be seen that the ED of Okaramine B derivative 3 １００ was determined to be 3 ppm.

[0065] In the group administered with 0.003 ppm of Okaramine B derivative 4, all first-instar silkworm larvae died. In the group administered with 0.001 ppm, although the insecticidal effect was confirmed, some individuals survived. From these results, it can be seen that the ED of Okaramine B derivative 4 １００ was determined to be 0.003 ppm.

[0066] 2-2. Evaluation of insecticidal activity against Spodoptera litura (Test method) Using a 10% DMSO solution, test solutions containing Okaramine B derivatives 1 to 4 at concentrations of 1,000 ppm, 300 ppm, 100 ppm, 30 ppm, 10 ppm, or 3 ppm were prepared.

[0067] 100 μL of the test solution was added to 1 g of artificial diet for Spodoptera litura. First-instar larvae of Spodoptera litura were fed the artificial diet containing the test solution, and activity was evaluated after 5 days of observation. A group in which all Spodoptera litura larvae were dead or not growing was considered to be active (ED １００ (Groups of 20 or more mice, n=3). A solution containing 30 ppm of spinosad was used as a positive control. A 10% DMSO solution was used as a negative control.

[0068] (Results) In the group administered with 1,000 ppm of Okaramine B derivative 1, all first-instar larvae of Spodoptera litura died. In the group administered with 300 ppm, the insecticidal effect was confirmed, but some surviving individuals were found in some of the evaluated lots. From these results, it can be seen that the ED of Okaramine B derivative 1 １００ was determined to be 1,000 ppm.

[0069] In the group administered with 100 ppm of Okaramine B derivative 2, all first-instar larvae of Spodoptera litura died. In the group administered with 300 ppm, the insecticidal effect was confirmed, but some surviving individuals were found in some of the evaluated lots. From these results, it can be seen that the ED of Okaramine B derivative 2 １００ was determined to be 100 ppm.

[0070] In the group administered with 300 ppm of Okaramine B derivative 3, all first-instar larvae of Spodoptera litura died. In the group administered with 100 ppm, the insecticidal effect was confirmed, but some surviving individuals were found in some of the evaluated lots. From these results, it can be seen that the ED of Okaramine B derivative 3 １００ was determined to be 300 ppm.

[0071] In the group administered with 30 ppm of Okaramine B derivative 4, all first-instar larvae of Spodoptera litura died. In the group administered with 10 ppm, the insecticidal effect was confirmed, but some surviving individuals were found in some of the evaluated lots. From these results, it can be seen that the ED of Okaramine B derivative 4 １００ was determined to be 30 ppm.

[0072] Non-Patent Document 1 reports the insecticidal activity of okaramins A and B. Non-Patent Document 1 also shows that the acetylated form of okaramins A, in which the hydroxy group bonded to the carbon atom at the 3a position is acetylated, has significantly reduced activity compared to okaramins A. Perhaps in light of these results, there have been no reports to date on the synthesis and insecticidal activity of acylated forms of okaramins B. Unlike okaramins A, okaramins B derivatives 2 to 4, in which the hydroxy group bonded to the carbon atom at the 3a position of okaramins B is acylated, have sufficient insecticidal activity.

[0073] The above results indicate that okaramin B derivatives 2 to 4 are compounds that can be used as novel insecticidal active ingredients. Okaramin B derivative 4 had particularly significant insecticidal activity against silkworms and common cutworms.

Claims

1. A compound represented by the following formula (I): [In formula (I), R １ represents an alkylcarbonyl group having 2 to 6 carbon atoms; R ２ represents a hydrogen atom or a halogen atom, R ３ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkyloxycarbonyl group having 2 to 6 carbon atoms; R ４ represents a hydrogen atom or a halogen atom, R ５ represents a hydrogen atom or a methoxy group, R ６ represents a hydrogen atom or a hydroxy group, and a double line consisting of a solid line and a dashed line represents a carbon-carbon single bond or a carbon-carbon double bond.] 2. The compound according to claim 1, wherein the double line consisting of a solid line and a dashed line is a carbon-carbon double bond.

3. The above R １ The compound according to claim 1, wherein is an alkylcarbonyl group having 2 to 3 carbon atoms.

4. The compound according to claim 1, represented by the following formula (Ia): [In formula (Ia), R １ａ represents an acetyl group or an ethylcarbonyl group, and a double line consisting of a solid line and a dashed line represents a carbon-carbon single bond or a carbon-carbon double bond.] 5. The above R １ａ is an ethylcarbonyl group, and the double line consisting of a solid line and a dashed line is a carbon-carbon double bond.

6. An insecticide comprising the compound according to any one of claims 1 to 5 as an active ingredient.

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