A Plant Alkaloid Handbook

Metabolic engineering of plant alkaloid biosynthesis.

Plant alkaloids, one of the largest groups of natural products, provide many pharmacologically active compounds. Several genes in the biosynthetic pathways for scopolamine, nicotine, and berberine have been cloned, making the metabolic engineering of these alkaloids possible. Expression of two branching-point enzymes was engineered: putrescine N-methyltransferase (PMT) in transgenic plants of A...

Synthesis of unnatural alkaloid scaffolds by exploiting plant polyketide synthase.

HsPKS1 from Huperzia serrata is a type III polyketide synthase (PKS) with remarkable substrate tolerance and catalytic potential. Here we present the synthesis of unnatural unique polyketide-alkaloid hybrid molecules by exploiting the enzyme reaction using precursor-directed and structure-based approaches. HsPKS1 produced novel pyridoisoindole (or benzopyridoisoindole) with the 6.5.6-fused (or ...

Ultrastructural changes inducible with the plant alkaloid camptothecin.

The fine structural effects of camptothecin, a plant alkaloid with known antitumor activity, have been examined in ME-180 tissue culture cells. The drug has recently been shown to inhibit ribosomal RNA synthesis; nucleolar changes were therefore expected to occur. As shown here, camptothecin induces nucleoli to segregate but, in addition, it produces microspherules and perichromatin-type granul...

Alkaloid Constituents of the Amaryllidaceae Plant Amaryllis belladonna L.

The plant family Amaryllidaceae is well-known for its unique alkaloid constituents, which exhibit a wide range of biological activities. Its representative, Amaryllis belladonna, has a geographical distribution covering mainly southern Africa, where it has significant usage in the traditional medicine of the native people. In this study, A. belladonna samples collected in Brazil were examined f...

A Handbook