Abstract Significant opportunities exist in the use of seafood by-products to create new beneficial products. Moreover, cephalopod skin is a good source of bioactive compounds. The present study compares the chemical structure properties and antioxidant activity of pigments extracted from the skin of Octopus vulgaris (OVS) and Dosidicus gigas (DGS) with methanol-HCl (T1) and ethanol-HCl (T2). The solubility and spectroscopic analysis (UV-Vis and 1H NMR) indicated that extracted pigments belonged to the ommochrome family. Xanthommatin, dihydroxanthommatin, and kynurenine compounds were identified in the extracts using correlated homonuclear spectroscopy (COSY). The results showed that OVS yielded a higher recovery rate of pigments with antioxidant activity (DPPH, ABTS, and FRAP) than DGS in both solvents. T1 extracted the highest level of antioxidant pigments. The kynurenine proportion and proton peaks observed at 3.0-5.0 ppm (amino-aromatics) in the 1H NMR spectra may explain the differences in antioxidant activity of OVS and DGS.

Lantana camara L. is a widespread plant species mostly native to subtropical and tropical regions of the world. In this study, insecticidal and repellent activities of L. camara essential oil were evaluated against Callosobruchus maculatus (Fabricius) (Col: Bruchidae). Analysis of chemical composition by gas chromatography/mass spectrometry (GC/MS) showed high amounts of sesquiterpenes, mainly α-humelene (23.3%) and cis-caryophyllene (16.2%). The results showed that the essential oil of L. camara has strong repellent activity against adults of C. maculatus at all tested concentrations. After 2 and 4 h, 97.4 and 100% repellency was seen at highest concentrations of 0.4 μL cm-2, respectively. Moreover, the oil was found to be toxic to adults when applied by fumigation. Responses varied with the gender of insect and exposure time. The LC50 values were 282.7 and 187.9 μL L-1 for females and males, respectively. An increase in the exposure time from 3 to 24 h caused increasing in mortality from 23.6 to 100% in males and from 14.1 to 97.1% in females, at highest concentration (1160 μL L-1). According to these results, L. camara essential oil may be useful as an alternative for bean protection against C. maculatus.

Lantana camara L. es una especie vegetal nativa de las regiones subtropicales y tropicales del mundo. En este estudio se evaluaron las actividades insecticida y repelente del aceite esencial de L. camara contra Callosobruchus maculatus (Fabricius). El análisis de la composición volátil de este aceite esencial mediante cromatografía de gas/ espectrometría de masa (GC/MS) demostró la presencia de elevadas cantidades de sesquiterpenos, principalmente α-humuleno (23.3%) y ci’s-cariofileno (16.2%). Los resultados obtenidos demostraron que el aceite esencial de L. camara tiene una elevada actividad repelente contra los adultos de C. maculatus a todas las concentraciones ensayadas. Después de 2 y 4 h la concentración de 0.4 μL cm-2 causó 97,4% y 100% de actividad repelente, respectivamente. Además, este aceite esencial fue tóxico para los adultos cuando se aplicó mediante fumigación. Las respuestas a este tratamiento dependieron del sexo del insecto y del tiempo de exposición. Los valores de LC50 fueron 282,7 y 187,9 μL L-1 para hembras y machos, respectivamente. Un incremento del tiempo de exposición desde 3 a 24 h causó un aumento de la mortalidad de 23,6% a 100% en machos y desde 14,1% a 97,1% en hembras, a la mayor concentración ensayada (1160 μL L-1). De acuerdo a estos resultados, podemos concluir que el aceite esencial de L. camara puede ser una alternativa útil en la protección de legumbres contra los ataques de C. maculatus