Hemiterpenoids and Pyrazines in the Odoriferous Urine of the Maned Wolf

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.