 Thelephoric acid is present in several Hydnellum species . This compound , derived metabolically from the shikimic acid pathway , inhibits the enzyme prolyl endopeptidase , which is involved in deteriorating certain neuropeptides that are believed to contribute to memory and learning . Hydnellum caeruleum and H. concrescens have several para @-@ terphenyl derivatives named thelephantins , some of which can inhibit the enzyme alpha @-@ glucosidase . The compounds hydnellins A and B are terphenyls found in H. suaveolens and H. geogerirum . The chemicals responsible for the fragrant anise @-@ like aroma of H. suaveolens have been identified as coumarin and para @-@ anisaldehyde . 
