ISSN:0958-0344    

DOI:10.1002/pca.2800040102

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractAn optimized high performance liquid chromatographic (HPLC) procedure for the analysis and quantitation of piperidino‐chromone alkaloids has been developed, featuring short retention times, high and adequate resolution. The HPLC system uses a C‐18 reversed phase column eluted with methanol:20 mM potassium dihydrogen phosphate (50:50) with UV detection at λ=254 nm. Comparative studies on the content of chromone alkaloids in the root, stem‐ and root‐bark ofSchumanniophyton magnificumandS. problematicumwere carried out using thi

ISSN:0958-0344    

DOI:10.1002/pca.2800040103

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractA normal phase, isocratic, analytical high performance liquid chromatographic (HPLC) method has been developed for the analysis of toxic methylsuccinimidoanthranoyllycoctonine (MSAL) norditerpenoid alkaloids occurring in poisonous larkspurs (Delphiniumsp.). The method has good sensitivity, specificity for MSAL norditerpenoid alkaloid and rapid analysis times. The technique employs 5 μm neutral alumina as the stationary phase and utilizes a mixture of hexane: 95% isopropyl alcohol as the mobile phase. Accurate and reproducible analyses can be performed on 1 g samples of plant material. The method has been applied to the analysis of the chemical phenology of the MSAL norditerpenoid alkaloids methyllycaconitine and 14‐deacetylnudicauline in three species of tall larkspurs (Delphinium barbeyi, D. occidentale, D. glaucescens). Analytical results confirm the primary occurrence of these toxic alkaloids in early vegetative tissues of these plants, their concentration in reproductive plant tissues and their reduction in level with plant maturation. The chemical phenology results further confirm the observed difference in the toxicity of the three tall larkspurs (D. barbeyi>D. glaucescens>D. occidentale) to livestock. Intraspecies differences of toxic alkaloid occurrence associated with site were also demonstrat

ISSN:0958-0344    

DOI:10.1002/pca.2800040104

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe13C nuclear magnetic resonance (NMR) spectral data for nineent‐kaurenes, 12ent‐beyeranes and fourent‐atisene derivatives, isolated fromElaeoselinumspecies, are discussed. The assignments of the13C signals were based on DEPT sequences, two‐dimensional (2D) δH/δC NMR spectra and comparison with known compounds. The assignments of some knownent‐kaurenes

ISSN:0958-0344    

DOI:10.1002/pca.2800040105

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

ISSN:0958-0344    

DOI:10.1002/pca.2800040106

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

ISSN:0958-0344    

DOI:10.1002/pca.2800040107

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe Annonaceous acetogenins are an exciting new class of bioactive natural products whose antitumour, pesticidal and other bioactivities are due to inhibition of electron transport in mitochondria. This paper tabulates the 61 compounds in this class which have been published in the period of 1990–1992 and reviews recent progress with the chemistry and biology of these potent compounds. (Appendices will be published in the next issue

ISSN:0958-0344    

DOI:10.1002/pca.2800040108

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

ISSN:0958-0344    

DOI:10.1002/pca.2800040101

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY