Fig. 1

Identification and quantification of small molecules in snake venoms. (A) Base peak chromatograms (BPC) of two snake venoms and D4-ketamine (certified reference standard) separated by C18-RP HPLC at early retention times, with the extracted ion chromatograms (EIC) of protonated pilocarpine (grey), ketamine (black) and isotopically-labeled D4-ketamine (red). (B) Structure, MS and (C) MS2 comparison of in-venom and standard D4-ketamine, with isotope mass shift (dotted line). Internal EIC quantification of ketamine (black) versus spiked reference standard D4-ketamine (0.5 ng/µL) in (D) H. n. nasicus and (E) H. n. kennerlyi venom. (F) Structure, MS and (G) MS2 of pilocarpine in venom; data shown for H. n. nasicus.