Orthocarpus cuspidatus
Open grassy slopes above Deep Lake,
Marble Mountain Wilderness, CA
July 2005

Orthocarpus purpurascens
(= Castilleja exserta)
Transverse Ranges, CA
Spjut 14666, Apr 2002

Orthocarpus purpurascens
(= Castilleja exserta)
Peninsular Ranges, CA
Spjut 15214, Apr 2003

Orthocarpus tolmei

Rocky Mts. — Utah: Wasatch Co., Uinta NF: Eastern shore of Strawberry Reservoir, south of Soldier Springs off Hwy 40; 40º10'40.3", 111º01’19.0”, 2338 m.  Sagebrush bordering aspen along Strawberry River. SPJ-16419, 6 Aug 2014

Boros C.A.; Stermitz F.R.; Harris G.H., 1990: Iridoid glycosides and a pyridine monoterpene alkaloid from orthocarpus new artifactual iridoid dienals.Journal Of Natural Products (lloydia). 53(1): 72-80. Euphroside [1] was found to be the major iridoid of Orthocarpus purpureoalbus, Orthocarpus luteus, Orthocarpus tolmei, and Orthocarpus tenuifolius, all species of the Section Orthocarpus in the genus Orthocarpus (Scrophulariaceae). Small amounts of plantarenaloside, adoxoside, ixoroside, geniposidic acid, and mussaenosidic acid were encountered in some of the species. Two closely related new iridoid glucoside dienals, 2 and 3, which appeared to be the MeOH adducts from a bisdehydration process on euphroside [1], were isolated from extracts of all species. Attempts to prepare the dienals by dehydration of euphroside [1] were unsuccessful and yielded a monodehydrated MeOH adduct 6 rather than the isolated dienals. Euphrosine [16], a new pyridine monoterpene alkaloid, was isolated from O. luteus. It was synthesized from 1 through the intermediacy of 6.