Hemiterpenoids and Pyrazines in the Odoriferous Urine of the Maned Wolf (Chrysocyon brachyurus)

Abstract

Maned wolves (Chrysocyon brachyurus) are endemic to South America, monogamous, solitary, and threatened in the wild. Maned wolf urine has a pungent and powerful odour and is used for scent marking. There is evidence to suggest that the presence of a male may be required to initiate oestrus and/or ovulation, thus implying the presence of a primer pheromone. We have employed solid phase dynamic extraction (SPDE)/GC-MS to identify a number of volatile compounds in maned wolf urine. These include sulphur-containing hemiterpenoids which are predominantly responsible for the distinctive urinary odour, hemiterpenoid alcohols which are known bark beetle pheromones, and a variety of pyrazines, some of which are known to be insect pheromones. Hemiterpenoids are most likely biosynthesised via a shunt of the mevalonate pathway, while pyrazines are thought to be products of amino acid metabolism. The abundance of some of these compounds increases as the urine ages, perhaps providing a timed release of putative chemical signals.