Cynoglossum australe

Cynoglossum australe R.Br. C. amabile Stapf and Drummond (Borraginaceae)... 

Trachelanthamidine as well as isoretronecanol can be generated from the imminium salt. There exists evidence that the saturated necine rosmarinecine is generated via isoretronecanol and that trachelanthamidine is the precursor for retronecine as well as heliotridine [61]. Isoretronecanol has been shown to be also the precursor of those PAs which have the unt)q)ical stereochemistry (instead of 8a) as found in the PAs from Cynoglossum australe [62] (Scheme 13.1). 

Hagan DB, Robins DJ (1990) Biosynthesis of the pyrrolizidine alkaloids cynaustraline and cynaustine in Cynoglossum australe. J Chtan Res (S) 9 292—293... 

All four stereoisomeric forms of 1-hydroxymethylpyrrolizidine have been found as part of pyrrolizidine alkaloids. The final member of the series was discovered by Brandange et al. 53,56). Phalaenopsine Is (Table 3 F) is an ester derivative of (—)-isoretronecanol (1), present in Phalaenopsis equestris. Both forms of supinidine also occur naturally. An ester derivative of (+)-supinidine (2), cynaustine (Table 3H) has been found in Cynoglossum australe by Culvenor and Smith. 91). 

---