Podophyllum lignan

Jackson, D.E. and Dewick, P.M. (1984) Biosynthesis of Podophyllum lignans. II. Interconversions of aryltetralin lignans in Podophyllum hexandrum. Phytochemistry, 23, 1037-12. 

Higher plants have yielded many effective, clinically useful anticancer drugs, including those derived from Catharanthus alkaloids, Taxus diterpenes, Camptotheca alkaloids, and Podophyllum lignans. Research in this area has been reviewed extensively (3-13). 

Hashimoto, S, Honda, T, Ikegami, S, A new and general glycosidation method for podophyllum lignan glycosides. Tetrahedron Lett., 32, 1653-1654, 1991. 

In connection with the synthesis of podophyllum lignans, ester (62) was deprotonated and the resulting enolate condensed with 3,4,5-trimethoxybenzaldehyde to give a 1 1 mixture of diastereomeric aldols (equation 68). The structure of (63) was established by X-ray analysis the other diastereomer was assigned the 2,3-anti relative stereochemistry (64) on circumstantial evidence. It was suggested that the 1 1 mixture of isomeric products results from a 1 1 mixture of the ( )- and (Z)-enolate, each of which shows complete simple and diastereofacial selectivity in its reactions with 3,4,5-trimethoxybenzaldehyde. For this to be true, it is also necessary that the ( )-enolate reacts through a non-Zimmerman , boat-like transition state, whereas the (Z)-enolate reacts through the normal chair-like transition state. 

Yoo and Porter [67] developed a sensitive immunoassay for the natural Podophyllum lignan, podophyllotoxin. Reverse-phase HPLC separation followed by radioimmunoassay (RIA) for human plasma samples and immunoaffinity extraction (IAE) followed by RIA for human urine samples were used to investigate a lignan-related hypocholesterolemic agent. This analysis proved to be very useful in quantifying extremely low drug concentrations in body fluids [68],... 

Ishibashi, H., Ito, K., Tabuchi, M. and Ikeda, M. (1991) Synthetic studies on podophyllum lignans tributyltin hydride-induced radical cyclizalion and intramolecular Heck reaction of a-benzylidene-/3-(( -bromobenzyl)-y-lactones. Heterocycles, 32, 1279-82. 

Kuhn and Von Wartburg [131, 230] have chromatographed podophyllum lignans and their glycosides on silica gel G layers, using the solvents ... 

Jackson D E, Dewick P M 1984 Biosynthesis of Podophyllum lignans. I. Cinnamic acid precursors of podophyllotoxin in Podophyllum hexandrum. Phytochemistry 23 1029-1035... 

The newly discovered iridoid glycoside 36 has been made as its hexa-acetate by condensation of the i r( riate 6-triiyl ether with the required 1,2-cyanoethylidene acetal. Condensation of trimethylsilyl 2,3,4,6-tetra-0-acetyl-/3-D-glucopyranoside with the corresponding alcohol in the presence of boron trifluoride resulted in the production in 80% yield of the acetylated glycoside of the podophyllum lignan 37 with an a,/3-ratio of 5 95P ... 

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