Figures (2)  Tables (6)
    • Figure 1. 

      (a) Gas ion chromatogram of CAEO. (b) Mass spectrum of thymol.

    • Figure 2. 

      Comparative 2D and 3D interactions of thymol and standard drugs with different target proteins used in the study. 6XYS: PBD ID for the crystal structure of enzyme acetylcholinesterase from the gut of Meloidogyne incognita larvae, 5IVH: PDB ID for the crystal structure of enzyme carboxylesterase from the head capsule of Spodoptera litura larvae, 1YHZ: PDB ID for the crystal structure of enzyme acetohydroxyacid synthase (AHAS) from the weed Raphanus raphanistrum sub sativus, amino acid residues in green rings are showing van der Waals interactions, amino acid residues in pink rings are showing pi-alkyl interactions, amino acid residues in purple rings are showing pi-sigma interactions, amino acids in red rings are showing unfavorable bumps.

    • S.N.CompoundR.I. LitR.I. Exp%Mol. formulaM.F.P.
      Monoterpene hydrocarbon
      1.α-thujene9319293.2C10H16M+ = 136; m/z: 121, 119, 105, 93 (100%), 91, 77, 65, 53, 51, 43, 41, 27
      2.p-cymene102210233.9C10H14M+ = 134; m/z: 132, 120, 119 (100%), 103, 91, 77, 65, 55, 41, 39
      3.γ-terpinene105410542.9C10H16M+ = 136; m/z: 121, 119, 107, 105, 93 (100%), 91, 79, 77, 65, 43, 41, 39, 27
      Total (%)10.0
      Monoterpene oxygenated
      4.Thymol1288128369.6C10H14OM+ = 150; m/z: 136, 135 (100%), 115, 91, 79, 77, 65, 51, 39
      5.carvacrol129612973.2C10H14OM+ = 150; m/z: 136, 135 (100%), 117, 107, 91, 77, 65, 51, 39, 27
      Total (%)72.8
      Sesquiterpene hydrocarbon
      6.Bicyclogermacrene150215012.5C15H24M+ = 204;
      m/z: 189, 176, 161, 147, 136, 133, 121, 107, 93 (100%), 79, 67, 53, 41, 39, 29
      7.(E)-caryophyllene142114233.7C15H24M+ = 204; m/z: 175, 147, 133, 120, 107, 93 (100%), 91, 79, 69, 55, 41, 39, 27
      Total (%)6.2
      Sesquiterpene oxygenated
      8.β-eudesmol164816451.1C15H26OM+ = 222; m/z: 189, 175, 141, 131 (100%), 79, 75, 73, 55
      Total (%)1.1
      Others
      9.1-(3-ethyloxiranyl)-ethanone2.6C6H10O2M+ = 114; m/z: 85, 71, 57, 44, 43 (100%), 38, 31
      10.Carvacrol methyl ether124712512.3C11H16OM+ = 164; m/z: 161, 149 (100%), 91, 79, 71, 53
      11.Thymyl acetate135513551.3C12H16O2M+ = 192; m/z: 150, 136, 135 (100%), 91,43
      12.Carvacrol ethyl ether145614571.2C12H24OM+ = 184; m/z: 138, 124, 109, 95, 82, 67, 57 (100%), 55, 43, 41, 39, 29
      Total (%)7.4
      Total Composition (%)97.5
      CAEO: Coleus aromaticus essential oil; R.T.: Retention time; R.I. Lit.: Retention index (DB-5 column) acquired from literature; R.I. Exp.: Retention index acquired from experimental data; M.F.P.: Mass Fragmentation Pattern.

      Table 1. 

      Chemical composition of CAEO.

    • Dose (µL/mL)Number of eggs hatched in timeMean% Egg hatchability
      24 h48 h72 h96 h
      0.254.665.667.3311.337.2595.39
      0.504.665.666.668.666.4295.92
      1.003.335.005.665.664.9296.87
      Control106.00143.00173.66207.66157.58 ± 43.35
      S.E.M0.340.290.59
      C.D. 1%1.351.172.34
      C.D. 5%0.990.861.73
      C.V.56.90
      CAEO: Coleus aromaticus essential oil; C.D.: Critical Difference; C.V.: Coefficient of Variance, ** p < 0.05.

      Table 2. 

      % Egg hatchability inhibition of CAEO against M. incognita in laboratory conditions.

    • Dose (µL/mL)Number of larvae dead in timeMean
      larvae dead
      % Mortality
      24 h48 h72 h
      0.259.3327.3328.3321.66 ± 10.6913.47
      0.5025.0038.3339.3334.22 ± 8.0027.78
      1.0055.6666.0066.3362.66 ± 6.0652.32
      Control2.008.6611.667.44 ± 4.94
      S.E.M.2.052.053.55
      C.D. 1%8.348.3414.45
      C.D. 5%6.096.0910.55
      C.V.15.56
      CAEO: Coleus aromaticus essential oil; C.D.: Critical Difference; C.V.: Coefficient of Variance, ** p < 0.05.

      Table 3. 

      % Mortality of 2nd stage larvae of M. incognita in different concentrations of CAEO.

    • Dose (µL/mL)Number of seeds germinated in different time intervalsMean seed germinated% Growth inhibition% Root growth inhibition% Shoot growth inhibition
      24 h48 h72 h96 h108 h
      2501.662.663.333.664.663.20 ± 1.1263.7074.7991.93
      5000.661.001.662.333.001.73 ± 0.9580.3485.9194.99
      7500.000.661.001.332.001.00 ± 0.7488.6697.3698.76
      10000.000.000.330.330.330.20 ± 0.1897.7598.11100
      Control7.007.0010.0010.0010.008.80 ± 1.640.00.00.0
      Pendimethalin0.00.00.00.00.00.0100.0100.0100.0
      C.D. 1%0.53
      C.D. 5%0.39
      C.V.18.13
      CAEO: Coleus aromaticus essential oil; C.D.: Critical Difference; C.V.: Coefficient of Variance, ** p < 0.05.

      Table 4. 

      % Phytotoxic activity of CAEO against R. raphanistrum seeds in laboratory conditions.

    • Dose
      (µL/mL)
      Insects observed alive at different time intervalsMean insect survival% mortality
      12 h24 h36 h
      105.005.005.005.00 ± 0.00
      205.004.334.004.44 ± 0.5111.13
      304.663.663.333.88 ± 0.6922.33
      404.004.003.333.77 ± 0.3824.46
      502.001.331.001.44 ± 0.5171.13
      Control5.005.005.005.00 ± 0.00
      Permethrin0.00.00.00.0100.0
      C.D. 1%0.50.71.3
      C.D. 5%0.40.50.9
      C.V.14.7
      CAEO: Coleus aromaticus essential oil; C.D.: Critical Difference; C.V.: Coefficient of Variance, ** p < 0.05.

      Table 5. 

      % Mortality of S. litura against CAEO in laboratory conditions.

    • Major compoundsPredicted biological activities
      Anti-helminthic (nematodes)InsecticidalAnti-fungalAnti-bacterial
      α-thujene0.388 > 0.0470.337 > 0.0670.130 > 0.098
      p-cymene0.633 > 0.0050.391 > 0.0060.368 > 0.058
      γ-terpinene0.642 > 0.0050.443 > 0.0410.325 > 0.051
      thymol0.569 > 0.0080.323 > 0.0130.464 > 0.0370.336 > 0.047
      carvacrol0.722 > 0.0040.351 > 0.0100.449 > 0.0390.319 > 0.053
      bicyclogermacrene0.520 > 0.0140.350 > 0.0100.439 > 0.042
      (E)-caryophyllene0.333 > 0.0800.368 > 0.0080.582 > 0.0200.437 > 0.023
      β-eudesmol0.401 > 0.0490.302 > 0.059
      carvacrol methyl ether0.622 > 0.0050.388 > 0.0070.362 > 0.059
      thymyl acetate0.775 > 0.0030.327 > 00130.456 > 0.0380.324 > 0.052
      dodecanal0.458 > 0.0250.368 > 0.0080.314 > 0.0750.280 > 0.068
      Pa > Pi, Pa = Probable activity and Pi = Probable inactivity.

      Table 6. 

      In silico PASS prediction bioactivities of major compounds in CAEO.