Eduardo Primo-Yúfera

Analgesic and central depressor effects of the dichloromethanol extract from Schinus molle L.

The analgesic and central depressor effects of the dichloromethanol extract of Schinus molle L. were analysed in in vivo models. This extract showed low acute toxicity, CNS depressor activity and analgesic effect. Following further fractionation, the hexane/dichloromethane (75/25) fraction showed the most interesting results. Thus, this fraction caused a total inhibition of motor activity and significantly reduced the threshold of pain to chemical stimulus.

Chemosterilants as control agents of Ceratitis capitata (Diptera: Tephritidae) in field trials.

Lufenuron is a chitin synthesis inhibitor, which is able to impede Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reproduction. In laboratory trials, following ingestion of lufenuron, the eggs laid by female Ceratitis capitata were prevented from hatching. In field trials in Valencia, Spain, lufenuron showed its effectiveness by reducing C. capitata wild populations and its continuous application to several generations of fruit fly resulted in increased pest control. This field trial was conducted in an isolated valley some 80 ha in size, over a continuous four-year period. In order to maintain the sterilizing effect in the field throughout the whole year, a new lufenuron bait gel was developed. This bait gel was introduced in to delta traps suspended in trees at a density of 24 traps ha-1, and these traps were replaced once a year during the field trial. Monitoring of the adult C. capitata population was conducted to assess the effects of the chemosterilant treatment. In the first year of treatment with sterilizing traps, a reduction of the C. capitata population was observed, indicating that the traps reduce the population right from the first generation. In the second, third and fourth years, a continuous and progressive reduction of the adult Mediterranean fruit fly population was observed. Therefore, the successive application of chemosterilization treatment has a cumulative effect on reducing the fly population year after year. Aerial treatment using malathion does not produce this cumulative effect, and consequently every year it is necessary to start again with the same number of flies as the year before. The possibility of using the chemosterilant method alone or combined with the sterile insect technique is discussed.

Attractiveness of 79 Compounds and Mixtures to Wild Ceratitis capitata (Diptera: Tephritidae) in Field Trials

Abstract Seventy-nine volatile compounds chosen from those emitted by Mediterranean fruit fly males, fruits and food baits, were tested for their attractiveness to females of Ceratitis capitata (Wiedemann) in field trials with a wild population. To correct for density fluctuations, the results were presented as a percentage of males caught in the same type of traps baited with trimedlure, a known male attractant. The mixtures of corn steep liquor with ammonia compounds and amines were the most effective attractants for females. Other compounds exhibiting C. capitata attraction were a mixture ethyl acetate+acetic acid+ethanol for both sexes, and p-cymene, 1,3-diethylbenzene and borneol for females.

Isolation and Synthesis of N-(2-Methyl-3-oxodec-8-enoyl)-2-pyrroline and 2-(Hept-5-enyl)-3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo[2,1-b]1,3-oxazine – Two New Fungal Metabolites with in vivo Anti-Juvenile-Hormone and Insecticidal Activity

Two new natural products, N-(2-methyl-3-oxodec-8-enoyl)-2-pyrroline (2) and 2-(hept-5-enyl)-3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo[2,1-b]-1,3-oxazine (3), have been isolated from Penicillium brevicompactum Dierckx. Compound 2 has shown an important in vivo anti-juvenile-hormone (anti-JH) activity while compound 3 has exhibited insecticidal activity against Oncopeltus fasciatus Dallas. Both products have been synthesized starting from 1,4-hexadiene, by means of a sequence of reactions which includes the preparation of 6-octenoic acid and its transformation into the corresponding acid chloride, in order to acylate Meldrums acid. Subsequent aminolysis with pyrrolidine, followed by methylation at the activated position of the β-oxo amide with iodomethane, introduction of a methoxy group at the pyrrolidine ring by anodic oxidation and final elimination of methanol on SiO2 led to 2 and 3. The fact that both metabolites can be prepared by the same sequence indicates that they must be biogenetically related. Based on structural similarities, compounds 2 and 3 are also closely related to the recently discovered brevioxime (1).

Field trial of an attractant mixture for dipterous, including the pest Ceratitis capitata (Wiedemann) (Dipt., Tephritidae), in Valencia, Spain

In field trials of tentative lures for female Ceratitis capitata, made in two areas of Valencia (Spain), it was observed that a mixture, not previously described, of ethyl acetate, acetic acid and ethanol attracted dipterous of different species, some of them being pests of economic importance (including C. capitata). This mixture appears to be Diptera specific, and suitable for the monitoring or control of the identified species. Coboldia fuscipes Meigen, Drosophila funebris F. and Megaselia sp. are the most attracted.

In vitro studies of methanol and dichloromethanol extracts of Juniperus oxycedrus L.

The present study evaluated the effect of methanol and dichloromethanol extracts obtained from the leaves and stems of Juniperus oxycedrus against neurotransmitter‐induced contraction in different isolated tissues of rats and guinea‐pigs. Diverse concentrations of these extracts inhibit the concentration curve response to histamine, serotonin and acetylcholine. These results contribute to explaining the use of this plant in folk medicine.

Effects on Arterial Blood Pressure of the Methanol and Dichloromethanol Extracts from Schinus molle L. in Rats

The effects on arterial blood pressure of the methanol and dichloromethanol extracts from Schinus molle L. were analysed in urethane anaesthetized rats. In normotensive rats, the mean arterial blood pressure was significantly reduced by the i.v. administration of both extracts. The dichloromethanol extract inhibited the effects of noradrenaline on arterial blood pressure in the anaesthetized rat and it reduced the maximal contractile effect (Emax) induced by noradrenaline on rat vas deferens in the organ bath. However, the methanol extract did not modify the effects of noradrenaline in the evaluated tests.

Isolation, structural assignment and insecticidal activity of (−)-(1S,2R,3R,4S)-1,2-epoxy-1-methyl-4-(1-methylethyl)-cyclohex-3-yl acetate, a natural product from Minthostachys tomentosa

Abstract (−)-(1 S ,2 R ,3 R ,4 S )-1,2-Epoxy-1-methyl-4-(1-methylethyl)-cyclohex-3-yl acetate has previously been identified as the active compound of Minthostachys tomentosa responsible for the insecticidal activity against Oncopeltus fasciatus . Its structure was initially assigned on the basis of spectral data. In order to confirm the structure and to define the stereochemistry, stereoselective synthesis of its enantiomer, (+)-(1 R ,2 S ,3 S ,4 R )-1,2-epoxy-1-methyl-4-(1-methylethyl)-cyclohex-3-yl acetate, starting from ( R )-(−)-piperitone, was carried out using a Sharpless reaction as the key step. The natural product is dextro -rotatory while the synthetic product is levo -rotatory. Measurements of insecticidal activities of the different steroisomers revealed that only the natural product is active.

Cardiovascular effects of the methanol and dichloromethanol extracts from Teucrium flavum L.

The effects on arterial blood pressure and heart rate of the methanol and dichloromethanol extracts from Teucrium flavumL. were analysed in urethane anaesthetized rats. Mean arterial blood pressure was significantly reduced by the i.v. administration of both extracts to normotensive rats. The methanol extract also induced a decrease in the heart rate, while the dichloromethanol extract lacked any effect on this parameter.

Evaluation of the analgesic and CNS actions of different fractions from the methanol extract of Teucrium flavum L.

Different fractions (F‐1, F‐3, F‐5, F‐6, F‐7, F‐8) of the methanol extract from Teucrium flavumL. have been tested for their central nervous system and analgesic activities at a dose of 200 mg/kg. Fractions F‐1, F‐3 and F‐7 showed CNS depressant activity, while fractions F‐5, F‐6 and F‐8 had a slight CNS stimulant action. Fractions F‐5, F‐6, F‐7 and F‐8 were responsible for the analgesic activity of the extract.