Ilex paraguariensis St. Hil. is a dioecious tree native to the subtropical forests of South America, whose leaves and small branches are processed to prepare the stimulating and popular infusion known as “mate”. On the basis of the exploration, from the transcriptomic, genomic and phylogenetic perspective of the xanthine biosynthetic pathway, it was possible to discover pseudogenes through comparative analysis with other plants of agronomic importance. The transcripts of I. paraguariensis were analyzed using the elite material developed by INTA EAA-Cerro Azul de Misiones as reference genome and the data provided from the transcriptome sequenced by Debat et. al in 2014. A phylogenetic examination of enzymes from a large family of SABATH genes that catalyze the methylation of oxygen atoms of a wide variety of carboxylic acids was performed. The most recently evolved genes of the SABATH family are those corresponding to the Xanthine Methyltransferases (XMT) and Caffeine Synthase (CS) pathways. Investigating the different types of methyltransferases that yerba mate presents in the metabolic process of caffeine conversion, several SABATH enzymes were categorized, of which three corresponded to pseudogenes within the caffeine synthase group. ; Ilex paraguariensis St. Hil. is a dioecious tree native to the subtropical forests of South America, whose leaves and small branches are processed to prepare the stimulating and popular infusion known as “mate”. On the basis of the exploration, from the transcriptomic, genomic and phylogenetic perspective of the xanthine biosynthetic pathway, it was possible to discover pseudogenes through comparative analysis with other plants of agronomic importance. The transcripts of I. paraguariensis were analyzed using the elite material developed by INTA EAA-Cerro Azul de Misiones as reference genome and the data provided from the transcriptome sequenced by Debat et. al in 2014. A phylogenetic examination of enzymes from a large family of SABATH genes that catalyze the methylation of ...