Phenylisothiocyanate

Carbula marginella adults (Fig. 1) were collected in the village of Boudtenga (12° 29′
11′′ N; 1° 15′ 57′′ W) in the North Sudanian zone in December 2016. C. butyrospermi (Fig. 2), at the fourth stage of its development (larval stage), was collected in the South Sudanian zone from July to August 2015 and 2017 in the village of Koumi (N 11° 07′ 54.7′′, W 004° 25′ 41.5′′). The insects were immediately placed in cooler boxes containing ice and brought to the laboratory. Specimen were identified at the Department of Environment and Forests using the Scholtz classification [18 (link)]. Samples were cleaned and the inedible parts were removed. Then, they were washed with distilled water and dried for 24 h in an oven at 40–50 °C.Fig. 1

Carbula marginella

Fig. 2

Cirina butyrospermi

Alpha-chymotrypsin (MP Biomedicals, USA), nitric acid (Carlo Erba, France, 96%), boric acid (Sigma-Aldrich, USA, 98%), ethanol (Chromasolv, absolute, for HPLC, Sigma-Aldrich, Germany), n-hexane (Chromasolv, Germany), hydrochloric acid (Carlo Erba, France, 37%), Kjeldahl catalyst (Carlo Erba, Germany), phenylisothiocyanate (Thermo Scientific, USA), methanol (HPLC Gradient Grade for free amino acids analysis, Prolabo Chemicals, France), Pico Tag diluent (Waters, USA), sodium hydroxide (Carlo Erbo, France), triethylamine (Sigma-Aldrich, Belgium, 99%) and trypsin from bovine pancreas (Sigma Aldrich, USA) were used.