Glycoalkaloids and phenolic compounds in three commercial potato cultivars grown in Hebei,China

In order to investigate the food nutrition and safety of potato,the objective of the present study is to quantify glycoalkaloids(-chaconine and-solanine)and phenolic compounds in three potato cultivars,namely,Russet Burbank,Atlantic,and Shepody,grown in Hebei,China,and these two classes of biologically active compounds in commercial dehydrated potato flakes were also investigated.The total glycoalkaloid levels in whole potatoes ranged from 4.72 mg/kg for Shepody potatoes to 34.45 mg/kg for Russet Burbank potatoes.The ratio of-chaconine to-solanine in whole potatoes ranged from 0.41 for Russet Burbank potatoes to 3.61 for Atlantic potatoes.The removal rate of total glycoalkaloids in Russet Burbank potatoes during dehydrated potato flake processing is 90.0%.Chlorogenic acid is the dominant phenolic compound in Russet Burbank potatoes.By contrast,Atlantic and Shepody potatoes contain considerable caffeic acid.The loss rate of phenolic compounds in Russet Burbank during dehydrated potato flake processing is 50.47%.

6-O-Sulfated Modification of Natural Glycoalkaloids Chaconine and Solanine

Glycoalkaloids（GAS） have important biological and pharmaceutical activities, in order to study the relationship between the structures and the activities of carbohydrate chains, two natural glycoalkaloids, chaconine （compound 1 ） and solanine（ compound 2） , were isolated from potato stems and leaves（ Solanum tuberosum L. ）. The selective sulfation to the 6-hydroxy groups of chaeonine and solanine was carried out in a strategy by the use of protective groups. The 6-hydroxyl groups of the sugar chains in chaconine and solanine were protected with 4,4＇-dimethoxytrityl（DMT） while the other hydroxyl groups were acetylated. The protective group DMT was removed by using 0. 5% TFA in dichloromethane, The free 6-hydroxyl groups were sulfated by chlorosulfonic acid pyridine to give 6-O-sulfated products. After the acetyl groups were removed, the final products obtained were sulfated chaconine and sulfated solanine.^ 13C NMR spectra confirmed that chaconine and solanine were sulfated at O6 of the carbohydrate moiety.

Inheritance of steroidal glycoalkaloids in potato tuber flesh

Potato (Solanum tuberosum L.) is the third most important food crop worldwide after wheat and rice in terms of human consumption. A critical domestication trait for potato was the decrease of toxic steroidal glycoalkaloids (SGAs) in tuber flesh. Here, we used a diploid F2 segregating population derived from a cross between S. tuberosum and the wild potato species Solanum chacoense to map the quantitative trait loci (QTLs) associated with the regulation of SGAs content in tuber flesh. In a three-year study, we identified two QTLs on chromosomes 2 and 8 affecting SGAs content in tuber flesh. The QTL on chromosome 8 harbors 38 genes that are co-expressed with the GLYCOALKALOID METABOLISM genes. These findings lay the foundation for exploiting the genes controlling SGAs content in tuber flesh and they provide a theoretical basis for the use of wild germplasm in potato breeding.

Unique Clinical Features of Curaderm when Treating Skin Cancers

Basal cell carcinoma is the most common form of skin cancer and the most frequently occurring form of all cancers. Conventional treatments to remove or destroy basal cell carcinoma are indiscriminate and also remove or destroy normal skin cells resulting in compromised cosmetic outcomes. Consequences of these treatments include body-image issues, anxiety, post-traumatic stress disorder, depression, and poorer quality of social and family life. A progressive topical cream formulation, Curaderm, containing the natural BEC glycoalkaloids, have shown to have advantages over conventional treatments. However, comprehensive clinical features of the skin cancer lesions during treatment with Curaderm have to date not been reported. This report shows that using unpublished data from a large number of patients with varying sizes, types and locations of basal cell carcinomas when treated with Curaderm in a phase 3 trial, an initial increase in size of the lesions occur, followed by a reverse course, leading to complete removal of the skin cancer. The specificity and mode of action of Curaderm explains the superior cosmetic outcomes when compared with conventional therapies.

Three previously undescribed steroidal glycoalkaloids from Solanum lyratum and their anti-tumor activities

In the present study,three previously undescribed steroidal glycoalkaloids(compounds 1–3)were isolated from Solanum lyratum.Their structures were elucidated based on comprehensive spectroscopic data.Their anti-angiogenesis and anti-metastatic activities were evaluated by MTT and wound-healing assays,respectively.Tumor-derived vascular endothelial cells(TdECs),obtained by co-culture of A549 and human umbilical vein endothelial cells(HUVECs),were treated with compounds 1–3.Results showed that compounds 1–3 significantly inhibited the migration of TdECs at 25μM despite the weak cytotoxic activities,which indicated that the compounds exerted anti-tumor activities by inhibiting metastasis,rather than directly inhibiting the proliferation of TdECs.

Two new glycoalkaloids from Solanum lyratum Thunb.

To study the alkaloids of Solanum lyratum Thunb.ODS and silica gel column chromatography combined with HPLC were used to separate and purify the alkaloids.Seven alkaloids were identified via UHPLC-ESI-Q-TOF-MS,1 D and 2 D NMR,respectively 15β-ethoxy-(3β,5α,25 R)-16,23-epoxy-23,24-imino-cholestan-16,20,23(N)-triene-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyran-oside(1),15β-hydroxyl-(3β,25 R)-16,23-epoxy-23,24-imino-cholestan-5,16,20,23(N)-tetraene-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactop-yranoside(2),Solalyraine A(3),Solalyraine B(4),16,23-epoxy-22,26-imino-cholest-22(N),23,25(26)-trien-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside(5),N-(4-amino-butyl)-3-(3-hydroxy-4-methoxy-phenyl)-E-acrylamide(6)and magnoflorine(7).Among them,compounds 1 and 2 were two new steroidal glycoalkaloids that has not been reported in the literature,and compound 7 was isolated from S.lyratum for the first time.

Cardioactive properties of Solanaceae plant extracts and pure glycoalkaloids on Zophobas atratus

Glycoalkaloids, the biologically active secondary metabolites produced by Solanaceae plants, are natural defenses against animals, insects and fungi. In this paper, the effects of glycoalkaloids present in extracts of Solanaceae plants （potato, tomato and black nightshade） or pure commercial glycoalkaloids on the coleopteran Zophobas atratus E were evaluated by in vitro and in vivo bioassays using heart experimental models. Each tested extract induced a dose-dependent cardioinhibitory effect. The perfusion of Zophobas atratus semi-isolated heart using the highest potato and tomato extract concentration （1 mmol/L） caused irreversible cardiac arrests, while extract from black nightshade pro- duced fast but reversible arrests. Pure commercial glycoalkaloids caused similar but less evident effects compared with extracts. Our results showed that the bioactivity of tested compounds depended on their structure and suggested the existence of synergistic interac- tions when combinations of the main glycoalkaloids of potato and black nightshade were used for trials. Surprisingly, injection of tomato and potato extracts in 1-day-old pupae of Zophobas atratus induced reversible positive chronotropic effects and decreased the duration of the both phases （anterograde and retrograde） of the heart contractile activity. Furthermore, these extracts affected the amplitude of the heart contractions.

Alpha-Tomatin against Witches’Broom Disease

Several plants use secondary metabolites against insects and pathogens attack. Among such metabolites known glycoalkaloids are the most studied. Plants from Solanaceae Family are the most abundant on those alkaloids. Despite alfa-tomatine is a known glycoalkaloid, its specific action against Moniliophthora perniciosa, fungi responsible for witches broom disease in cocoa plantations was obtained in this work. Alfa-tomatine was infusion-extracted from Solanum lycopersicum leaves, and its action against the fungi growth was shown on the bioassays. In these tests, M. perniciosa growth was totally inhibited but other fungus tested, the inhibition was not totally, or did not present effect on growth, showing in this way, the specificity of alfa-tomatine to M. perniciosa. The advantages of work with a natural molecule for the fungi control is the stability of the molecule, its resistance to high temperature and pressure and for its use, the simple method of extraction used. The confirmation of the alfa-tomatine molecule was done by High Performance Liquid Chromatography and Mass Spectrometry in comparison to the Sigma standard.

Steroidal scaffold decorations in Solanum alkaloid biosynthesis

Steroidal glycoalkaloids(SGAs)are specialized metabolites produced by hundreds of Solanum species,including important vegetable crops such as tomato,potato,and eggplant.Although it has been known that SGAs play important roles in defense in plants and“anti-nutritional"effects(e.g.,toxicity and bitterness)to humans,many of these molecules have documented anti-cancer,anti-microbial,antiinflammatory,anti-viral,and anti-pyretic activities.Among these,α-solasonine andα-solamargine isolated from black nightshade(Solanum nigrum)are reported to have potent anti-tumor,anti-proliferative,and anti-inflammatory activities.Notably,α-solasonine andα-solamargine,along with the core steroidal aglycone solasodine,are the most widespread SGAs produced among the Solanum plants.However,it is still unknown how plants synthesize these bioactive steroidal molecules.Through comparative metabolomictranscriptome-guided approach,biosynthetic logic,combinatorial expression in Nicotiana benthamiana,and functional recombinant enzyme assays,here we report the discovery of 12 enzymes from S.nigrum that converts the starting cholesterol precursorto solasodine aglycone,and the downstreamα-solasonine,α-solamargine,and malonyl-solamargine SGA products.We further identified six enzymes from cultivated eggplant that catalyze the production ofα-solasonine,α-solamargine,and malonyl-solamargine SGAs from solasodine aglycone via glycosylation and atypical malonylation decorations.Our work provides the gene tool box and platform for engineering the production of high-value,steroidal bioactive molecules inheterologoushosts usingsyntheticbiology.

Metabolomics-assisted refinement of the pathways of steroidal glycoalkaloid biosynthesis in the tomato clade

Steroidal glycoalkaloids（SGAs） are nitrogen-containing secondary metabolites of the Solanum species,which are known to have large chemical and bioactive diversity in nature.While recent effort and development on LC/MS techniques for SGA profiling have elucidated the main pathways of SGA metabolism in tomato,the problem of peak annotation still remains due to the vast diversity of chemical structure and similar on overlapping of chemical formula.Here we provide a case study of peak classification and annotation approach by integration of species and tissue specificities of SGA accumulation for provision of comprehensive pathways of SGA biosynthesis.In order to elucidate natural diversity of SGA biosynthesis,a total of 169 putative SGAs found in eight tomato accessions（Soianum lycopersicum, S.pimpinellifolium, S.cheesmaniae, S.chmielewskii, S.neorickii,S.peruvianum,S.habrochaites,S.pennellii） and four tissue types were used for correlation analysis.The results obtained in this study contribute annotation and classification of SGAs as well as detecting putative novel biosynthetic branch points.As such this represents a novel strategy for peak annotation for plant secondary metabolites.