An investigation of the iridoids of Picconia excelsa from Tenerife provided 17 iridoid glucosides together with verbascoside. Major constituents (> 0.5%) were loganin, ketologanin, oleoacteoside and the new picconioside I-a bisiridoid consisting of loganin esterified with deoxyloganin. Minor constituents were secoxyloganin, 8-epi-kingiside, 8-epi-kingisidic, oleoside 11-methyl ester, excelsioside, ligstroside and loganic acid together with the new compounds ketologanic acid, 6 beta-hydroxy-7-epi-loganin and picconiosides II-V, the latter four being esters of loganin and menthiafolic, foliamenthic, 6-(Z)-foliamenthic or 6,7-dihydrofoliamenthic acid. The structures were mainly elucidated by NMR spectroscopy. (C) 1997 Elsevier Science Ltd.