Fig. 1: Purification and structural characterization of sibanin peptide from S. bannaense.

a Schematic diagram of S. bannaense (black fly) feeding on bovine blood. b Isolation of native sibanin (red arrow) from the crude salivary gland of S. bannaense by a C₁₈ RP-HPLC column. Reverse-phase HPLC chromatogram of sibanin purification. Absorbance at 215 nm (a.u.) is plotted against elution time (min), with the arrow indicating the peak corresponding to sibanin. c Summary of the analgesic efficacy against heat-induced pain after intraperitoneal administration of S. bannaense salivary-gland components compared to morphine (0.2 mg/kg). One-way ANOVA with Bonferroni post-hoc correction. n = 5–6 for each peak. d Isolation of native sibanin (red arrow) from the pooled protein fraction by a C₁₈ RP-HPLC column. e MALDI-TOF mass spectrometry confirms the molecular weight of sibanin (10,557.3 Da). f Schematic representation of sibanin’s cysteine framework and sequence motifs. pLDDT = 82.8. pTM = 0.602.