alpha-chaconine and solanidine

This review shall attempt to summarize the significance of glycoalkaloids in potato products. Specific areas that are discussed include the types and distribution of glycoalkaloids identified in potatoes, facts affecting their rates of formation and biosynthesis, control measures to minimize their formation, methods of analysis, and the health implications of such compounds along with their flavor properties.

Topics: Diosgenin; Food Preservation; Models, Biological; Plants, Edible; Solanaceous Alkaloids; Solanine; Species Specificity; Vegetables

Potato (Solanum tuberosum) is the fourth culture in the world and is widely used in the agri-food industries. They generate by-products in which α-chaconine and α-solanine, the two major solanidine-based glycoalkaloids of potato, are present. As secondary metabolites, they play an important role in the protection system of potato and are involved in plant protection against insects. To add value to these by-products, we described here new glycoalkaloids that could have phytosanitary properties.. Solanidine, as a renewable source, was modified with an azido linker and coupled by copper-catalyzed alkyne azide cycloaddition to alkynyl derivatives of the monosaccharides found in the natural potato glycoalkakoids: D-glucose, D-galactose and L-rhamnose. The efficacy of our compounds was evaluated on the potato aphid Macrosiphum euphorbiae. The synthetic compounds have stronger aphicidal properties against nymphs than unmodified solanidine. They also showed strong aphicidal activities on adults and a negative impact on fecundity.. Our synthetic neoglycoalkaloids affected Macrosiphum euphorbiae survival at the nymphal stage as well as at the adult stage. Furthermore, they induced a decrease in fecundity. Our results show that chemical modifications of by-products may afford new sustainable compounds for crop and plant protection. © 2018 Society of Chemical Industry.

Topics: Animals; Aphids; Diosgenin; Fertility; Insecticides; Nymph; Solanine; Solanum tuberosum

Steroidal glycoalkaloids (SGAs) are plant secondary metabolites known to be toxic to animals and humans and that have putative roles in defense against pests. The proposed mechanisms of SGA toxicity are sterol-mediated disruption of membranes and inhibition of cholinesterase activity in neurons. It has been suggested that phytopathogenic microorganisms can overcome SGA toxicity by enzymatic deglycosylation of SGAs. Here, we have explored SGA-mediated toxicity toward the invasive oomycete Phytophthora infestans, the causative agent of the late blight disease in potato and tomato, as well as the potential for SGA deglycosylation by this species. Our growth studies indicate that solanidine, the nonglycosylated precursor of the potato SGAs α-chaconine and α-solanine, has a greater physiological impact than its glycosylated forms. All of these compounds were incorporated into the mycelium, but only solanidine could strongly inhibit the growth of P. infestans in liquid culture. Genes encoding several glycoside hydrolases with potential activity on SGAs were identified in the genome of P. infestans and were shown to be expressed. However, we found no indication that deglycosylation of SGAs takes place. We present additional evidence for apparent host-specific adaptation to potato SGAs and assess all results in terms of future pathogen management strategies.

Topics: Carbohydrate Sequence; Diosgenin; Fungal Proteins; Glycoside Hydrolases; Glycosylation; Host-Pathogen Interactions; Molecular Structure; Mycelium; Phytophthora infestans; Plant Diseases; Solanaceous Alkaloids; Solanine; Solanum lycopersicum; Solanum tuberosum; Steroids

The estimation of glycoalkaloids in the flesh of different types of decayed potatoes was evaluated. The results showed that turned green and also sprouting or rotting potato flesh contain high amounts of toxic solanine and chaconine, exceeding by 2-5-fold the recommended limit, and ranging from 2578±86mg/kg to 5063±230mg/kg of dry weight potato flesh. For safety consideration, these decayed potatoes should be systematically set aside. To avoid a net economic loss and encourage the removal of this hazardous food, a recycling process was investigated to generate added-value compounds from the toxic glycoalkaloids. A simple chemo-enzymatic protocol comprising a partial acidic hydrolysis followed by an enzymatic treatment with the β-glycosidase from Periplaneta americana allowed the efficient conversion of α-chaconine to solanidine.

Topics: Animals; beta-Glucosidase; Chromatography, High Pressure Liquid; Diosgenin; Hydrogen-Ion Concentration; Periplaneta; Solanine; Solanum tuberosum

To study the antifungal effects of the potato secondary metabolites α-solanine, α-chaconine, solanidine and caffeic acid, alone or combined.. Resistance to glycoalkaloids varied among the fungal species tested, as derived from minimum inhibitory concentrations assays. Synergistic antifungal activity between glycoalkaloids and phenolic compounds was found. Changes in the fluidity of fungal membranes caused by potato secondary plant metabolites were determined by calculation of the generalized polarization values. The results partially explained the synergistic effect between caffeic acid and α-chaconine and supported findings on membrane disruption mechanisms from previous studies on artificial membranes. LC/MS analysis was used to determine variability and relative amounts of sterols in the different fungal species. Results suggested that the sterol pattern of fungi is related to their resistance to potato glycoalkaloids and to their taxonomy.. Fungal resistance to α-chaconine and possibly other glycoalkaloids is species dependent. α-Chaconine and caffeic acid show synergistic antifungal activity. The taxonomic classification and the sterol pattern play a role in fungal resistance to glycoalkaloids.. Results improve the understanding of the antifungal mode of action of potato secondary metabolites, which is essential for their potential utilization as antifungal agents in nonfood systems.

Topics: Antifungal Agents; Caffeic Acids; Diosgenin; Fungi; Microbial Sensitivity Tests; Phenols; Solanine; Solanum tuberosum

A higher yield of glycoalkaloids was recovered from potato peels using pressurized liquid extraction (1.92 mg/g dried potato peels) compared to conventional solid-liquid extraction (0.981 mg/g dried potato peels). Response surface methodology deduced the optimal temperature and extracting solvent (methanol) for the pressurized liquid extraction (PLE) of glycoalkaloids as 80 °C in 89% methanol. Using these two optimum PLE conditions, levels of individual steroidal alkaloids obtained were of 597, 873, 374 and 75 µg/g dried potato peel for α-solanine, α-chaconine, solanidine and demissidine respectively. Corresponding values for solid liquid extraction were 59%, 46%, 40% and 52% lower for α-solanine, α-chaconine, solanidine and demissidine respectively.

Topics: Alkaloids; Diosgenin; Methanol; Phytochemicals; Solanaceous Alkaloids; Solanine; Solanum tuberosum; Solid Phase Extraction

An ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) method was developed for the determination of alpha-solanine, alpha-chaconine and solanidine in plasma and urine. The sample was acidified with aqueous solution containing 2% (v/v if not specified) formic acid, and then cleaned-up by solid-phase extraction with a mixed-mode cation exchange (MCX) cartridge. The analysis of the glycoalkaloids was carried out on an Acquity UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) with gradient elution of acetonitrile (containing 0.1% formic acid) and H2O (containing 0.05% formic acid and 5.0 mmol/L ammonium acetate). The analytes were detected by positive electrospray ionization tandem mass spectrometry in MRM mode, and quantified by external matrix-matched standard calibration. The cycle time of each analysis was 5.5 min. The calibration curves were linear in the range of 0.3-100 ng/mL of the glycoalkaloids in plasma and urine. The correlation coefficients were 0.997-0.999. The limits of detection (S/N = 3) and quantitation (S/N = 10) were 0.1 ng/mL and 0.3 ng/mL. The average recoveries were 82%-112% and 96%-114% for the glycoalkaloids spiked in plasma and urine, respectively, with relative standard deviations of 4.0%-16% and 2.7%-17% (n = 6). The method is simple, accurate and sensitive to detect the glycoalkaloids in plasma and urine for both clinical and forensic purposes.

Topics: Chromatography, High Pressure Liquid; Diosgenin; Humans; Solanine; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

The potato glycoalkaloids, α-chaconine, α-solanine and solanidine, along with potato peel extracts were investigated for potential anti-inflammatory effects in vitro. Their potential to reduce two biomarkers of inflammation, cytokine and nitric oxide (NO) productions, were assessed in the stimulated Jurkat and macrophage models, respectively.. Cytokine and nitric oxide productions were stimulated in Jurkat and Raw 264.7 macrophages with Concanavalin A (Con A; 25 μg/ml) and lipopolysaccaride (LPS; 1 μg/ml), respectively. Selective concentrations of glycoalkaloids and potato peel extracts were added simultaneously with Con A or LPS for 24h to investigate their potential to reduce inflammatory activity.. α-Chaconine and solanidine significantly reduced interleukin-2 (IL-2) and interleukin-8 (IL-8) productions in Con A-induced Jurkat cells. The potato peel extracts did not influence cytokine production. In LPS-stimulated Raw macrophages, α-solanine, solanidine and two potato peel extracts significantly reduced induced NO production.. Our findings suggest that sub-cytotoxic concentrations of potato glycoalkaloids and potato peel extracts possess anti-inflammatory effects in vitro and with further investigation may be useful in the prevention of anti-inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents; Cell Line; Concanavalin A; Diosgenin; Humans; Interleukin-2; Interleukin-8; Jurkat Cells; Lipopolysaccharides; Macrophages; Mice; Nitric Oxide; Plant Extracts; Solanine; Solanum tuberosum

alpha-Solanine and alpha-chaconine are two naturally occurring steroidal glycoalkaloids in potatoes (Solanum tuberosum), and solanidine-N-oxide is a corresponding steroidal aglycone. The objective of this research was to screen potential cyto-toxicity of these potato glycoalkaloids using bovine oocyte maturation, in vitro fertilization techniques and subsequent embryonic development as the in vitro model. A randomized complete block design with four in vitro oocyte maturation (IVM) treatments (Experiment 1) and four in vitro embryo culture (IVC) treatments (Experiment 2) was used. In Experiment 1, bovine oocytes (n=2506) were matured in vitro in medium supplemented with 6 microM of alpha-solanine, alpha-chaconine, solanidine-N-oxide or IVM medium only. The in vitro matured oocytes were then subject to routine IVF and IVC procedures. Results indicated that exposure of bovine oocytes to the steroidal glycoalkaloids during in vitro maturation inhibited subsequent pre-implantation embryo development. Potency of the embryo-toxicity varied between these steroidal glycoalkaloids. In Experiment 2, IVM/IVF derived bovine embryos (n=2370) were cultured in vitro in medium supplemented with 6 microM of alpha-solanine, alpha-chaconine, solanidine-N-oxide or IVC medium only. The results showed that the pre-implantation embryo development is inhibited by exposure to these glycoalkaloids. This effect is significant during the later pre-implantation embryo development period as indicated by fewer numbers of expanded and hatched blastocysts produced in the media containing these alkaloids. Therefore, we conclude that in vitro exposure of oocytes and fertilized ova to the steroidal glycoalkaloids from potatoes inhibits pre-implantation embryo development. Furthermore, we suggest that ingestion of Solanum species containing toxic amounts of glycoalkaloids may have negative effects on pre-implantation embryonic survival.

Topics: Animals; Cattle; Diosgenin; Embryonic Development; Fertilization in Vitro; Solanaceous Alkaloids; Solanine; Solanum tuberosum; Tissue Culture Techniques

Reduced liver weight was used to evaluate the potential toxicity in mice of four naturally occurring steroidal glycoalkaloids: alpha-chaconine and alpha-solanine, alpha-tomatine and solasonine. Increased liver weights was used to evaluate the three corresponding steroidal aglycones: solanidine, tomatidine, and solasodine and the non-alkaloid adrenal steroid dehydroepiandrosterone (DHEA). Adult female Swiss-Webster mice were fed diets containing test compound concentrations of 0 (control), 1.2, 2.4 or 4.8 mmol/kg diet for 7, 14 or 28 d. Absolute liver weights (LW) and relative liver weights (liver weight/body weight x 100, %LW/BW) were determined at autopsy. The %LW/BW was lower than that of controls in mice fed the potato glycoalkaloid alpha-chaconine (-10%, P < or = 0.05) for 7 d with the 2.4 mmol/kg diet dose. Under these same conditions, %LW/BW was greater than that of controls in mice fed two aglycones: solanidine (27%, P < or = 0.001) and solasodine (8%, P < or = 0.01). Relative liver weight increases induced by the aglycones were determined under time and dose conditions in which differences in body weight and food consumption were not significant (2.4 mmol/kg diet for 28 d). Under these conditions, the observed %LW/BW increases relative to the controls were as follows: solanidine (32%, P < or = 0.001), solasodine (22%, P < or = 0.001) and DHEA (16%, P < or = 0.001). Solanidine, solasodine and DHEA were equally potent and were more potent than tomatidine. We also observed that the greater %LW/BW in mice fed 2.4 mmol/kg diet solasodine or solanidine for 14 d declined to near control values if they were fed control diets for another 14 d. The increase in relative liver weight induced by solanidine and solasodine is a reversible adaptive response. These findings and the apparent effects of structure on biological activity should serve as a guide for the removal of the most toxic ++compounds from plant foods. The implications of the results for food safety and health are discussed.

Topics: Alkaloids; Animals; Body Weight; Dehydroepiandrosterone; Diosgenin; Eating; Female; Liver; Mice; Organ Size; Plants, Edible; Solanaceous Alkaloids; Solanine; Solanum lycopersicum; Solanum tuberosum; Structure-Activity Relationship; Tomatine; Vegetables

Impregnated CD2 transgenic mice, which contain multiple copies of a lambda gt10lacZ construct integrated into the genome of each cell, were given a predetermined estimated maximum tolerated dose of several steroidal alkaloids: Solanum glycoalkaloids from potato, alpha-chaconine and alpha-solanine; aglycones, solanidine and solasodine, and a Veratrum alkaloid, jervine. Observations were made of dams and foetuses for indications of toxicity and/or terata; some dam livers and foetuses were assayed for mutagenicity using the lacZ gene. Other dams were gavaged with a single dose of 75 mg all-trans-retinol/kg to serve as a reference teratogen. Unexpectedly, this level of retinol was not clearly teratogenic. The results of both positive and non-positive selection systems showed that the mutation frequencies in the livers of the dams dosed with alpha-chaconine, alpha-solanine and solanidine were three to four times higher than historically normal in the livers of this transgenic mouse strain.

Topics: Alkaloids; Animals; Diosgenin; Embryonic and Fetal Development; Female; Gene Expression Regulation, Developmental; Lac Operon; Liver; Mice; Mice, Inbred BALB C; Mice, Transgenic; Mutation; Pregnancy; Solanaceous Alkaloids; Solanine; Solanum tuberosum; Teratogens; Tretinoin; Veratrum Alkaloids

In this study the effects of the glycoalkaloids alpha-solanine, alpha-chaconine, alpha-tomatine and the aglycone solanidine on model membranes composed of PC in the absence and presence of sterols have been analysed via permeability measurements and different biophysical methods. The main result is that glycoalkaloids are able to interact strongly with sterol containing membranes thereby causing membrane disruption in a way which is specific for the type of glycoalkaloid and sterol. For this dual specificity both the sugar moiety of the glycoalkaloid and the side-chain of the sterol on position 24 turned out to be of major importance for the membrane disrupting activity. The order of potency of the glycoalkaloids was alpha-tomatine > alpha-chaconine > alpha-solanine. The plant sterols beta-sitosterol and fucosterol showed higher affinity for glycoalkaloids as compared to cholesterol and ergosterol. The mode of action of the glycoalkaloids is proposed to consist of three main steps: (1) Insertion of the aglycone part in the bilayer. (2) Complex formation of the glycoalkaloid with the sterols present. (3) Rearrangement of the membrane caused by the formation of a network of sterol-glycoalkaloid complexes resulting in a transient disruption of the bilayer during which leakage occurs.

Topics: Calorimetry, Differential Scanning; Carbohydrate Sequence; Cell Membrane; Diosgenin; Freeze Fracturing; Lipid Bilayers; Microscopy, Electron; Molecular Sequence Data; Solanaceous Alkaloids; Solanine; Sterols; Substrate Specificity; Tomatine

To assess whether reported toxicities of potato-derived glycoalkaloids could be the result of interactions with cellular DNA, the genotoxic effects of alpha-solanine, alpha-chaconine and solanidine were studied, using the Ames test (Salmonella strains TA98 and TA100), the mouse peripheral blood micronucleus test and the mouse transplacental micronucleus test. The Ames test for mutagenicity with alpha-solanine was weakly positive in TA100 with S-9 activation (29 revertants per millimole per plate). However, pooled data from duplicate tests gave a negative effect. Pooled data from two experiments with alpha-chaconine gave a weak positive response in TA98 without microsomes (17 revertants per millimole per plate). The micronucleus tests for clastogenicity using male mouse and foetal blood were negative. The absence of mutagenicity and clastogenicity suggests lack of damage to intracellular DNA for potato alkaloid toxicity.

Topics: Animals; Diosgenin; Female; Fetus; Injections, Intraperitoneal; Male; Mice; Micronucleus Tests; Mortality; Mutagenicity Tests; Mutagens; Salmonella typhimurium; Solanaceous Alkaloids; Solanine; Solanum tuberosum

The development of a high-performance liquid chromatography (HPLC) method for the separation and quantification of potato glycoalkaloids and their aglycone solanidine in blood serum is reported. High selectivity was obtained by using solid-phase extraction followed by off-line dual-column HPLC. Injections were made via a sample enrichment column to achieve maximum sensitivity in the assay. The potato alkaloids in the HPLC effluents were detected by ultraviolet absorption at 200 nm. The detection limits were estimated to be 0.3 ng/ml of serum for each of the alkaloids. The method was used to study the pharmacokinetics of potato glycoalkaloids in humans. alpha-Solanine and alpha-chaconine were detected in all blood serum samples collected from seven volunteers 1-25 h after a meal of potatoes. Solanidine was detected in some samples, but there were no traces of the mono- or diglycosides. The average apparent biological half-lives for alpha-solanine and alpha-chaconine were 11 and 19 h, respectively.

Topics: Adult; Alkaloids; Chromatography, High Pressure Liquid; Diosgenin; Half-Life; Humans; Male; Solanaceous Alkaloids; Solanine; Solanum tuberosum; Spectrophotometry, Ultraviolet

Potatoes frequently contain growth inhibitors and toxic compounds including digestive enzyme inhibitors, lectins and glycoalkaloids. The literature suggests that Solanum alkaloids have the ability to induce neurological damage such as spina bifida and other malformations. As part of a programme of improvement in the safety of potatoes using molecular plant genetics and parallel food safety evaluation, we evaluated the effect of several potato glycoalkaloids and aglycones in the frog embryo teratogenesis assay--Xenopus (FETAX) with and without metabolic activation by Aroclor 1254-induced rat liver microsomes. The data suggest that the glycoalkaloid alpha-chaconine is teratogenic and more embryotoxic than alpha-solanine, in terms of the median lethal concentration (LC50) after 96 hr of exposure, the concentration inducing gross terata in 50% of the surviving frog embryos (96-hr EC50, malformation), and the minimum concentration needed to inhibit the growth of the embryos. Since these two compounds differ only in the nature of the carbohydrate side chain attached to the 3-OH group of solanidine, the side chain appears to be an important factor in governing teratogenicity. The aglycones demissidine, solanidine and solasodine were less toxic than the glycosides alpha-chaconine and alpha-solanine. The in vitro teratogenesis assay should be useful for: (a) predicting the teratogenic potential of solanaceae alkaloids, glycoalkaloids and related natural products; and (b) facilitating experimental approaches to suppress plant genes and enzymes that control the biosynthesis of the most toxic compounds.

Topics: Abnormalities, Drug-Induced; Animals; Diosgenin; Embryo, Nonmammalian; Lethal Dose 50; Microsomes, Liver; Rats; Solanaceous Alkaloids; Solanine; Solanum tuberosum; Teratogens; Xenopus

The induction of hepatic ornithine decarboxylase (ODC) activity in rat livers by the potato glycoalkaloids alpha-solanine, alpha-chaconine, and their aglycone solanidine, has been studied. Ip administration of alpha-solanine at 7.5, 15 and 30 mg/kg body weight produced markedly elevated enzyme activity at 4 hr after treatment, with a linear dose response. The increase was four-fold at the lowest dose administered to 12-fold at the highest. ODC activity was measured at 1, 2, 3, 4, 5, 6, 8, and 24hr after alpha-solanine was given. A statistically significant increase in enzyme activity was evident at 3 hr after treatment; maximal activity occurred at 5 hr and was approximately 12 times greater than the dimethylsulphoxide (DMSO) control level. Elevated activities persisted for several hours, decreasing to about one-third of the maximal level at 8 hr. The relative effects of alpha-solanine, alpha-chaconine and solanidine on ODC activities were studied at 4 hr using an equimolar dose of 17 mM/kg body weight. ODC activity induced by alpha-chaconine was higher than that induced by alpha-solanine; the latter activity was two-thirds that of the former. The aglycone solanidine did not induce any increase in activity compared with the DMSO control. ODC activity with dexamethasone, a glucocorticoid, at 4 mg/kg body weight, followed a pattern similar to that of alpha-solanine. However, maximal activity occurred slightly earlier at 4 hr after treatment. The results show that the extent of induced ODC activity depends on the structure of the potato alkaloid.

Topics: Animals; Diosgenin; Enzyme Induction; Injections, Intraperitoneal; Liver; Male; Ornithine Decarboxylase; Rats; Rats, Inbred Strains; Solanaceous Alkaloids; Solanine; Solanum tuberosum

The infectivity of herpes simplex virus Type I in tissue culture was inhibited by prior incubation with aqueous suspensions of glycoalkaloids in order of activity alpha-chaconine greater than alpha-tomatine greater than alpha-solasonine but not by the corresponding aglycones, solanidine, tomatidine and solasodine. However, inhibition was not only dependent on the presence of a sugar moiety since the glycone alpha-solanine was inactive under the conditions used. The glycones, but not the aglycones, showed cytopathic effects on cellular membranes of Vero cells and erythrocytes; therefore, it is suggested that inactivation of virus results from insertion of the glycones into the viral envelope.

Topics: Animals; Cell Line; Cell Membrane; Cell Survival; Chlorocebus aethiops; Diosgenin; Erythrocyte Membrane; Monosaccharides; Sheep; Simplexvirus; Solanaceous Alkaloids; Solanine; Structure-Activity Relationship; Tomatine