sentences:  The surprising green fluorescence is attributed to hyloin compounds, mainly hyloin-L1, hyloin-L2 and hyloin-G1.These fluorescent molecules, in the dihydroisoquinolinone family and derived from the isoquinoline (a benzene ring fused to a pyridine ring), in an alkaloid protecting mucous membrane, have been identified in the lymph tissue, skin and glandular secretions of the frog.Because it is linked to secretions from skin glands, they can also leave fluorescent markings on surfaces where they have been.