tazettine and hemanthamine

Seventy alkaloids of galanthamine, lycorine, homolycorine, tazettine, haemanthamine, narciclasine, and tyramine types were detected by GC/MS in 25 Galanthus elwesii and seven Galanthus nivalis populations, collected from different locations in Bulgaria. Intraspecies diversity in the alkaloid profiles regarding the main alkaloid types (chemotypes) was observed. Tyramine-type protoalkaloids (namely, hordenine and its derivatives) were dominant in 19 populations of G. elwesii. In other populations of G. elwesii, the plants accumulated mainly homolycorine-, lycorine-, and galanthamine-type alkaloids. The alkaloid profiles of G. nivalis were dominated by narciclasine-, galanthamine-, lycorine-, haemanthamine-, or tazettine-type compounds. Geographical distribution of chemotypes indicated a relationship between populations, since adjacent populations often displayed similar alkaloid profiles. The results from year-to-year sampling and transplantation experiments imply genetic determination of alkaloid synthesis in the two studied species of Galanthus.

Topics: Alkaloids; Amaryllidaceae Alkaloids; Galantamine; Galanthus; Gas Chromatography-Mass Spectrometry; Phenanthridines

Fifteen Amaryllidaceae alkaloids (1-15) were evaluated for their antiproliferative activities against six distinct cancer cell lines. Several of these natural products were found to have low micromolar antiproliferative potencies. The log P values of these compounds did not influence their observed activity. When active, the compounds displayed cytostatic, not cytotoxic activity, with the exception of pseudolycorine (3), which exhibited cytotoxic profiles. The active compounds showed similar efficacies toward cancer cells irrespective of whether the cell lines were responsive or resistant to proapoptotic stimuli. Altogether, the data from the present study revealed that lycorine (1), amarbellisine (6), haemanthamine (14), and haemanthidine (15) are potentially useful chemical scaffolds to generate further compounds to combat cancers associated with poor prognoses, especially those naturally resistant to apoptosis, such as glioblastoma, melanoma, non-small-cell lung, and metastatic cancers.

Topics: Amaryllidaceae Alkaloids; Antineoplastic Agents, Phytogenic; Apoptosis; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Humans; Molecular Structure; Phenanthridines

Seven alkaloids were isolated from Sprekelia formosissima, and five from Hymenocallis x festalis. Tazettine, lycorine, haemanthidine and haemanthamine were evaluated for antiproliferative and multidrug resistance (mdr) reversing activity on mouse lymphoma cells. Lycorine, haemanthidine and haemanthamine displayed pronounced cell growth inhibitory activities against both drug-sensitive and drug-resistant cell lines, but did not significantly inhibit mdr-1 p-glycoprotein. Thus, the tested alkaloids are apparently not substrates for the mdr efflux pump. Assays for interactions with DNA and RNA revealed that the antiproliferative effects of lycorine and haemanthamine result from their complex formation with RNA.

Topics: Alkaloids; Amaryllidaceae Alkaloids; Aniline Compounds; Animals; Antineoplastic Agents, Phytogenic; Dioxoles; DNA; Drug Resistance, Multiple; Leukemia L5178; Magnoliopsida; Mice; Molecular Structure; Nucleic Acid Denaturation; Phenanthridines; Plant Stems; RNA, Transfer; Tumor Cells, Cultured; Verapamil

Topics: Alkaloids; Amaryllidaceae Alkaloids; Galantamine; Humans; Neuromuscular Junction; Parasympathomimetics; Phenanthridines

Topics: Alkaloids; Amaryllidaceae Alkaloids; Galantamine; Phenanthridines