The essential oil extracted from the dried flower buds of clove, Eugenia caryophyllata L. Merr. & Perry (Myrtaceae), is used as a topical application to relieve pain and to promote healing and also finds use in the fragrance and flavouring industries. The main constituents of the essential oil are phenylpropanoids such as carvacrol, thymol, eugenol and cinnamaldehyde. The biological activity of Eugenia caryophyllata has been investigated on several microorganisms and parasites, including pathogenic bacteria, Herpes simplex and hepatitis C viruses. In addition to its antimicrobial, antioxidant, antifungal and antiviral activity, clove essential oil possesses antiinflammatory, cytotoxic, insect repellent and anaesthetic properties. This short review addresses the chemical composition and biological effects of clove essential oil, and includes new results from GC/MS analysis and a study of its antimicrobial activity against a large number of multi-resistant Staphylococcus epidermidis isolated from dialysis biomaterials.

The chemical composition and biological activity of clove essential oil, Eugenia caryophyllata (Syzigium aromaticum L. Myrtaceae): a short review.

A review of botanical phytochemicals with mosquitocidal potential.

The methanolic crude extracts of some commonly used medicinal plants were screened for their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical. The overall antioxidant activity of green tea (Camellia sinensis Linn.) was the strongest, followed in descending order by black tea (Camellia sinensis Linn.), Eugenia caryophyllus (Spreng.) Bullock and Harrison, Piper cubeba Linn., Zingiber officinale Roscoe and Piper nigrum Linn. Trigonella foenum graecum Linn. and Elettaria cardamomum (Linn.) Maton showed weak free radical scavenging activity with the DPPH method. All the methanolic extracts exhibited antioxidant activity significantly. The IC50 of the methanolic extracts ranged between 6.7 ± 0.1 and 681.5 ± 8.4 µg/ml and that of ascorbic acid was 8.9 ± 0.1 µg/ml. The study reveals that the consumption of these spices would exert several beneficial effects by virtue of their antioxidant activity.

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Antioxidant Activity of Some Common Plants

A comparative study was conducted to assess the contact and fumigant toxicities of eleven monoterpenes on two important stored products insects—, Sitophilus oryzae, the rice weevil, and Tribolium castaneum, the rust red flour beetle. The monoterpenes included: camphene, (+)-camphor, (−)-carvone, 1-8-cineole, cuminaldehyde, (l)-fenchone, geraniol, (−)-limonene, (−)-linalool, (−)-menthol, and myrcene. The inhibitory effect of these compounds on acetylcholinesterase (AChE) activity also was examined to explore their possible mode(s) of toxic action. Although most of the compounds were toxic to S. oryzae and T. castaneum, their toxicity varied with insect species and with the bioassay test. In contact toxicity assays, (−)-carvone, geraniol, and cuminaldehyde showed the highest toxicity against S. oryzae with LC50 values of 28.17, 28.76, and 42.08 μg/cm2, respectively. (−)-Carvone (LC50 = 19.80 μg/cm2) was the most effective compound against T. castaneum, followed by cuminaldehyde (LC50 = 32.59 μg/cm2). In contrast, camphene, (+)-camphor, 1-8-cineole, and myrcene had weak activity against both insects (i.e., LC50 values above 500 μg/cm2). In fumigant toxicity assays, 1-8-cineole was the most effective against S. oryzae and T. castaneum (LC50 = 14.19 and 17.16 mg/l, respectively). Structure-toxicity investigations revealed that (−)-carvone—, a ketone—, had the highest contact toxicity against the both insects. 1-8-Cineole—, an ether—, was the most potent fumigant against both insects. In vitro inhibition studies of AChE from adults of S. oryzae showed that cuminaldehyde most effectively inhibited enzyme activity at the two tested concentrations (0.01 and 0.05 M) followed by 1-8-cineole, (−)-limonene, and (l)-fenchone. 1-8-Cineole was the most potent inhibitor of AChE activity from T. castaneum larvae followed by (−)-carvone and (−)-limonene. The results of the present study indicate that (−)-carvone, 1,8-cineole, cuminaldehyde, (l)-fenchone, and (−)-limonene could be effective biocontrol agents against S. oryzae and T. castaneum.

Fumigant and Contact Toxicities of Monoterpenes to Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) and their Inhibitory Effects on Acetylcholinesterase Activity

Chemical compositions of leaf essential oils from eight provenances of indigenous cinnamon (Cinnamomum osmophloeum Kaneh.) were compared. According to GC-MS and cluster analyses, the leaf essential oils of the eight provenances and their relative contents were classified into five chemotypescinnamaldehyde type, linalool type, camphor type, cinnamaldehyde/cinnamyl acetate type, and mixed type. The larvicidal activities of leaf essential oils and their constituents from the five chemotypes of indigenous cinnamon trees were evaluated by mosquito larvicidal assay. Results of larvicidal tests demonstrated that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde/cinnamyl acetate type had an excellent inhibitory effect against the fourth-instar larvae of Aedes aegypti. The LC50 values for cinnamaldehyde type and cinnamaldehyde/cinnamyl acetate type against A. aegypti larvae in 24 h were 36 ppm (LC90 = 79 ppm) and 44 ppm (LC90 = 85 ppm), respectively. Results of the 24-h mosquito larvicidal assays a...

Chemical Composition and Mosquito Larvicidal Activity of Essential Oils from Leaves of Different Cinnamomum osmophloeum Provenances

Insecticidal activities of constituents identified in the essential oil from leaves of Chamaecyparis obtusa against Callosobruchus chinensis (L.) and Sitophilus oryzae (L.)

The insecticidal activity of materials derived from the fruits of Piper nigrum against third instar larvae of Culex pipiens pallens, Aedes aegypti, and A. togoi was examined and compared with that of commercially available piperine, a known insecticidal compound from Piper species. The biologically active constituents of P. nigrum fruits were characterized as the isobutylamide alkaloids pellitorine, guineensine, pipercide, and retrofractamide A by spectroscopic analysis. Retrofractamide A was isolated from P. nigrum fruits as a new insecticidal principle. On the basis of 48-h LC(50) values, the compound most toxic to C. pipiens pallens larvae was pipercide (0.004 ppm) followed by retrofractamide A (0.028 ppm), guineensine (0.17 ppm), and pellitorine (0.86 ppm). Piperine (3.21 ppm) was least toxic. Against A. aegypti larvae, larvicidal activity was more pronounced in retrofractamide A (0.039 ppm) than in pipercide (0.1 ppm), guineensine (0.89 ppm), and pellitorine (0.92 ppm). Piperine (5.1 ppm) was relatively ineffective. Against A. togoi larvae, retrofractamide A (0.01 ppm) was much more effective, compared with pipercide (0.26 ppm), pellitorine (0.71 ppm), and guineensine (0.75 ppm). Again, very low activity was observed with piperine (4.6 ppm). Structure-activity relationships indicate that the N-isobutylamine moiety might play a crucial role in the larvicidal activity, but the methylenedioxyphenyl moiety does not appear essential for toxicity. Naturally occurring Piper fruit-derived compounds merit further study as potential mosquito larval control agents or as lead compounds.

Larvicidal activity of isobutylamides identified in Piper nigrum fruits against three mosquito species

The insecticidal and fumigant activities of Cinnamomum cassia (Blume) bark-derived materials against the oak nut weevil (Mechoris ursulus Roelofs) were examined using filter paper diffusion and fumigation methods and compared to those of the commercially available Cinnamomum bark-derived compounds (eugenol, salicylaldehyde, trans-cinnamic acid, and cinnamyl alcohol) The biologically active constituent of the Cinnamomum bark was characterized as trans-cinnamaldehyde by spectroscopic analysis In a test with the filter paper diffusion method, trans-cinnamaldehyde showed 100 and 833% mortality at rates of 25 and 10 mg/filter paper, respectively At 25 mg/paper, strong insecticidal activity was produced from eugenol (900% mortality) and salicylaldehyde (88 9%), whereas trans-cinnamic acid revealed moderate activity (733%) At 5 mg/paper, weak insecticidal activity (500%) was produced from cinnamyl alcohol In a fumigation test, the Cinnamomum bark-derived compounds were much more effective against M ursulus larvae in closed cups than in open ones These results indicate that the insecticidal activity of test compounds was attributable to fumigant action, although there is also significant contact toxicity As a naturally occurring insect-control agent, the Cinnamomum bark-derived materials described could be useful as a new preventive agent against damage caused by M ursulus

Insecticidal and fumigant activities of Cinnamomum cassia bark-derived materials against Mechoris ursulus (Coleoptera: attelabidae).

Biological Characteristics of Lycorma delicatula and insecticidal activity of some insecticides against nymphs of L. delicatula was investigated. Nymph of L. delicatula had 4 instars, and color of body was black. There were white spots on the body of 1st-3rd nymph. Upper body became red at 4th nymph. Adult forewings were brownish, and had black spots. Color of hind wing were red. The egg mass was covered with a yellowish brown secretion. The adult of L. delicatula emerged once a year. Among test insecticides, deltamethrin 1% EC and fenitrothion 50% EC showed very quick and strong insecticidal activity against the 2nd-3rd nymphs of L. delicatula. Imidacloprid 4% SL and clothianidin 8% SC showed 100% insecticidal activity at 24h after treatment. Thiacoprid 10% SC revealed the weakest insecticidal activity among the insecticides tested.

Biological Characteristics of Lycorma delicatula and the Control Effects of Some Insecticides

The antifeeding activity of 3 isoquinoline alkaloids identified from roots of Coptis japonica Makino toward 4th-instar larvae of Hyphantria cunea Drury and adults of Agelastica coerulea Baly was examined using the leaf-dipping bioassay. The biologically active constituents of the Coptis roots were characterized as the isoquinoline alkaloids berberine, palmatine and coptisine by spectroscopic analysis. In a test with H. cunea larvae, the antifeeding activity was much more pronounced in an application of a mixture of palmatine iodide and berberine chloride (1:1, wt:wt) at 250 ppm (82.3%) and 500 ppm (100%), compared with palmatine iodide (76.0%) and berberine chloride (75.4%) alone at 500 ppm. These results indicate a synergistic effect. With A. courulea adults, berberine chloride showed 57.5 and 91.1% antifeeding activity at 125 and 250 ppm, respectively; whereas, weak activity was obtained in application of 500 ppm of palmatine iodide (41.4%) and coptisine chloride (52.4%) alone. The Coptis root-derived compounds merit further study as potential insect-control agents.

https://bioone.org/journals/journal-of-economic-entomology/volume-93/issue-2/0022-0493-93.2.331/Antifeeding-Activity-of-Isoquinoline-Alkaloids-Identified-in-Coptis-japonica-Roots/10.1603/0022-0493-93.2.331.pdf

Antifeeding Activity of Isoquinoline Alkaloids Identified in Coptis japonica Roots Against Hyphantria cunea (Lepidoptera: Arctiidae) and Agelastica coerulea (Coleoptera: Galerucinae)

Ji-Doo Park

Papers

Insecticidal activities of constituents identified in the essential oil from leaves of Chamaecyparis obtusa against Callosobruchus chinensis (L.) and Sitophilus oryzae (L.)

Larvicidal activity of isobutylamides identified in Piper nigrum fruits against three mosquito species

Insecticidal and fumigant activities of Cinnamomum cassia bark-derived materials against Mechoris ursulus (Coleoptera: attelabidae).

Biological Characteristics of Lycorma delicatula and the Control Effects of Some Insecticides

Antifeeding Activity of Isoquinoline Alkaloids Identified in Coptis japonica Roots Against Hyphantria cunea (Lepidoptera: Arctiidae) and Agelastica coerulea (Coleoptera: Galerucinae)