1.Molecular Docking and Binding Mode Analysis of Plant Alkaloids as in vitro and in silico Inhibitors of Trypanothione Reductase from Trypanosoma cruzi.
Argüelles AJ, Cordell GA, Maruenda H. Nat Prod Commun. 2016 Jan;11(1):57-62.
Trypanothione reductase (TryR) is a key enzyme in the metabolism of Trypanosoma cruzi, the parasite responsible for Chagas disease. The available repertoire of TryR inhibitors relies heavily on synthetic substrates of limited structural diversity, and less on plant-derived natural products. In this study, a molecular docking procedure using a Lamarckian Genetic Algorithm was implemented to examine the protein-ligand binding interactions of strong in vitro inhibitors for which no X-ray data is available. In addition, a small, skeletally diverse, set of natural alkaloids was assessed computationally against T. cruzi TryR in search of new scaffolds for lead development. The preferential binding mode (low number of clusters, high cluster population), together with the deduced binding interactions were used to discriminate among the virtual inhibitors. This study confirms the prior in vitro data and proposes quebrachamine, cephalotaxine, cryptolepine, (22S,25S)-tomatidine, (22R,25S)-solanidine, and (22R,25R)-solasodine as new alkaloid scaffold leads in the search for more potent and selective TryR inhibitors.
2.Chemistry and anticarcinogenic mechanisms of glycoalkaloids produced by eggplants, potatoes, and tomatoes.
Friedman M1. J Agric Food Chem. 2015 Apr 8;63(13):3323-37. doi: 10.1021/acs.jafc.5b00818. Epub 2015 Mar 30.
Inhibition of cancer can occur via apoptosis, a genetically directed process of cell self-destruction that involves numerous biomarkers and signaling pathways. Glycoalkaloids are nitrogen-containing secondary plant metabolites found in numerous Solanaceous plants including eggplants, potatoes, and tomatoes. Exposure of cancer cells to glycoalkaloids produced by eggplants (α-solamargine and α-solasonine), potatoes (α-chaconine and α-solanine), and tomatoes (α-tomatine) or their hydrolysis products (mono-, di-, and trisaccharide derivatives and the aglycones solasodine, solanidine, and tomatidine) inhibits the growth of the cells in culture (in vitro) as well as tumor growth in vivo. This overview comprehensively surveys and consolidates worldwide efforts to define the following aspects of these natural compounds: (a) their prevalence in the three foods; (b) their chemistry and structure-activity relationships; (c) the reported factors (biomarkers, signaling pathways) associated with apoptosis of bone, breast, cervical, colon, gastric, glioblastoma, leukemia, liver, lung, lymphoma, melanoma, pancreas, prostate, and squamous cell carcinoma cell lines in vitro and the in vivo inhibition of tumor formation and growth in fish and mice and in human skin cancers; and (d) future research needs.
3.Electromyographic and laboratory findings in acute Solanum torvum poisoning.
Glover RL1, Connors NJ2, Stefan C3, Wong E3, Hoffman RS4, Nelson LS4,5, Milstein M1, Smith SW4,5, Swerdlow M1. Clin Toxicol (Phila). 2016;54(1):61-5. doi: 10.3109/15563650.2015.1110749. Epub 2015 Nov 18.
CONTEXT: Solanum torvum berries, known as susumber or turkey berries, are prepared as part of traditional Jamaican dishes usually served with cod and rice. Poisoning is rare. Although toxic compounds have never been definitively isolated, previous reports suggest toxicity results from inhibition of acetylcholinesterases. We present a case of susumber berry poisoning with detailed electromyographic studies and laboratory analysis.
4.Impact of light-exposure on the metabolite balance of transgenic potato tubers with modified glycoalkaloid biosynthesis.
Shepherd LV1, Hackett CA2, Alexander CJ2, McNicol JW2, Sungurtas JA3, McRae D3, McCue KF4, Belknap WR4, Davies HV3. Food Chem. 2016 Jun 1;200:263-73. doi: 10.1016/j.foodchem.2015.12.095. Epub 2015 Dec 31.
Metabolite profiling (liquid chromatography-mass spectrometry (LC-MS) and gas chromatography (GC-MS)) was used to assess the impact of light on the composition of transgenic potato (Solanum tuberosum L. cv. Desirée) with reduced glycoalkaloid content via the down-regulation of the SGT1 gene. Transgenic tubers exhibited an almost complete knock-out of α-solanine production and light had little impact on its accumulation. Levels of α-chaconine increased significantly in the peel of both the control and transgenic lines when exposed to light, particularly in the transgenic line. Major differences in metabolite profiles existed between outer and inner tuber tissues, and between light and dark-treated tubers. Many of the light-induced changes are explicable in terms of pathways known to be affected by stress responses. The impact of transgenesis on profiles was much less than that of tissue type or light and most differences were explicable in terms of the modification to the glycoalkaloid pathway.