5,6-Dehydrolupanine, a New Alkaloid, and Lupanine from Thermopsis rhombifolia (Nutt.) Richards

Abstract

In addition to the alkaloids originally reported in flowering plants of T. rhombifolia, lupanine (3) and a new major alkaloid were isolated from 6 week old plants. This new alkaloid has been characterized as 5,6-dehydrolupanine (7).

Production of Quinolizidine Alkaloids by Photomixotrophic Cell Suspension Cultures: Biochemical and Biogenetic Aspects1

“…The a-pyridone alkaloids such as anagyrine (XIII) are assumed to derive from lupanine via 5,6-dehydr~lu~anine (XII) as a key intermediate. In recent years 5,6-dehydrolupanine (XII) has been detected in many species in which both lupanine and a-pyridone alkaloids were present [18,21,221. In analogy to the biosynthesis of the alkaloids which derive from lupanine, a similar series may be constructed using anagyrine o r thermopsine as origin.…”

Aphylline, epiaphylline, 10,17-dioxosparteine, gramine, and other unexpected alkaloids from Lupinus hartwegii

“…Whole plants washed free of vermiculite were homogenized and extracted for basic compounds as described earlier. 13 The pale yellow alkaloid residue, 905 mg as acetate salts, was dried and stored under nitrogen at 0 °C. Recovery of all the reference alkaloids by this scheme was greater than 90%.13•15…”

“…Authentic gramine, similarly recrystallized, had mp 132 °C (lit.30 1 34 °C). MS M+ m/e 174 (23), 131 (19), 130 (100), 77 (13), 45 (10), 44 (23) was identical with that of gramine,29 with metastables at m/e 126, 98.6, 81.7, and 57.6; Xmax (EtOH) 218 nm (log e 3.4); pmax 3480 cm-1 (s, NH stretch); NMR 6 2.30 s (6 ), 3.70 s (4 H), 7.2 m (4 H); high-resolution MS m/e 174.1150 (caled for CnHi4N2; 174.1157), 131.0732 (caled for C9H9N, 131.0735), 103.0540 (caled for C8H6N, 103.0547), 77.0392 (caled for C6H6, 77.0391).…”

Biosynthesis of Thermopsis Alkaloids from Carbon-14 Dioxide. Evidence for the Formation of the Pyridone Bases from Lupanine Via 5,6-Dehydrolupanine

“…The 10% QF-1 column, described previously together with its operating conditions (41, was utilized for all analyses from which alkaloid specific activities were determirmed. All authentic reference alkaloids, their purity, identity, and behavior on all the above chromtographic systems have k n described previously (4).…”

“…Alkaloids were extracted from freshly harvested whole plants as previgsusly described (4). Recovery of each of the known alkaloids of T. rhombifolia, as well as sparteine and a-isolupanine (91, was > 90% by this procedure.…”