Amines 2 Animals 2 Anura 2 Arginine 2 Article 2 Bufanolides 2 Chordata 2 Chromatography, High Pressure Liquid 2 Desorption 2 Electrospray ionization 2 Esters 2 Female 2 MALDI-MS 2 Male 2 Mass spectrometry 2 Parotid Gland 2 Physiology 2 Principal Component Analysis 2 Proteins 2 Rhinella arenarum 2 Seasons 2 Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization 2 Tandem Mass Spectrometry 2 Ultraviolet lasers 2 adult 2 age 2 analogs and derivatives 2 animal 2 arginine 2 argininylbufadienolide ester 2