Bruce K. Cassels

Kinabaline and the aporphinoid biogenesis-of azaanthracene and azafluorene alkaloids☆

Abstract The new azafluorene alkaloid kinabaline was isolated from Meiogyne virgata, together with liriodenine, cleistopholine and other known substances. The azafluorene onychine and the azaanthracene cleistopholine can be related to the diazafluoranthene eupolauridine through a common hypothetical precursor derived from the oxoaporphine liriodenine.

Revised structures of the azafluorenone alkaloids from guateria dielsiana

Abstract The structures of three alkaloids isolated from Guatteria dielsiana , 6-methoxyonychine, dielsine and dielsinol, originally described as 1-azafluoren-9-ones, are revised to 4-azafluoren-9-ones on the basis of previous synthetic work and current studies on alkaloids of the Annonaceae. Synthetic 6-methoxyonychine (6-methoxy-1-methyl-4-azafluoren-9-one) isshown to be id

Fate of Ingested Aristolochic Acids in Battus archidamas

Key Word Index--Battus archidamas; Papilionidae; Lepidoptera; aristolochic acids; sequestration; excretion; metabolism. Abstract--Battus archidamas larvae reared on Aristolochia chilensis sequester aristolochic acids selectively and independently of lipophilicity. A considerable proportion of the ingested acids can be recovered from the excreta, but the amounts which remain unaccounted for suggest that metabolic detoxification is the principal mean of disposing of these substances by the insects.

Additional alkaloids from Laurelia philippiana and L. novae-zelandiae

Abstract Asimilobine, anonaine, noreorydine, nornantenine, (+)-reticuline and the new alkaloid, 4-hydroxyanonaine, were isolated from Laurelia philippiana bark. The biogenetically related obovanine, oxoputerine and (−)-romneine, not known as a natural product, were obtained from the bark of L. novae-zelandiae . The occurrence of ( R )-norlaudanosoline-derived alkaloids in L. novae-zelandiae is a distinctive feature of this tree. Neither L. novae-zelandiae nor L. philippiana accumulate dimeric benzylisoquinoline alkaloids to any appreciable extent in the trunk bark, differing in this respect from L. sempervirens , the only other Laurelia species.

Heterogeneous catalysts in the preparation of 2-aryl-1,3-dinitropropanes from β-nitrostyrenes or benzaldehydes

The use of heterogeneous basic catalysts (KF, NaHCO3) in the preparation of 2-Aryl-1,3-dinitropropanes from β-nitrostyrenes or benzaldehydes is described, with one example followed kinetically by HPLC analysis of aliquots of the reaction.

Alkaloids of sophora tetraptera sensu reiche

Abstract Sophora tetraptera sensu Reiche seeds were examined for alkaloids. Cytisine, methylcytisine and matrine were isolated, and a fourth alkaloid was detected by TLC. The relative amounts of the three major alkaloids support the segregation of this Chilean species from S. tetraptera J. Mill. and S. microphylla Ait. of New Zealand.

Chapter 1 Alkaloids from Guatteria

Publisher Summary This chapter reviews the azafluorenone alkaloids as completely as possible, discusses a small number of structurally unusual though not unprecedented compounds, and also updates the older contributions on the mainline isoquinoline alkaloids insofar as the genus Guatteria is concerned. Guutteriu alkaloids can be classified into eight main types depending on the structural characteristics of their skeleton, and these eight skeletal types are biosynthetically related, or at least conceivable proposals for their formation in vivo are reported. Aporphinoids are by far the most abundant alkaloids in this genus and also, generally speaking, in the family Annonaceae. Guatteria has proved to be a rich source of unusual structures of this general type. Dehydronornuciferine and O-methyldehydroisopiline are isolated from G. ouregou, where they cooccur with the corresponding noraporphines, and the N-formyl derivatives dehydroformouregine and formouregine.