Alkaloid Profiles Research Articles

Endophyte mixture effects on ryegrass staggers in sheep

Epichloë endophytes protect ryegrass from insect pests, but no strain provides both the highest level of insect protection and lowest risk to livestock health. This study examined mixtures of endophytes to find combinations that could mitigate ryegrass staggers in sheep. At Barenbrug NZ, Courtenay, pastures varying widely in sown proportions of perennial ryegrass infected with nea3, nea12 and standard endophyte (SE) were sown in May 2019 and tested with lambs in summer and hoggets in spring 2020. In summer, sown proportions of >65% nea3, <35% nea12 and no SE delayed severe staggers (score 4–5) by 1 week. Alkaloid profiles of these pastures included the tremorgens epoxyjanthitrem I (<0.28 ppm) of nea12 and paxilline (<0.15 ppm) and terpendole C (<1.37 ppm) of nea3. In spring, sown proportions of >65% nea3 and <35% nea12 and/or SE did not induce staggers (score 0–0.1). Those pastures had low concentrations of the potent tremorgen lolitrem B (<0.30 ppm) of SE, epoxyjanthitrem I (<0.39 ppm) of nea12 and paxilline (<0.09 ppm) and terpendole C (<0.41 ppm) of nea3 and SE. The optimal endophyte formulations that minimised staggers across summer and spring were >65% nea3, <35% nea12 and no SE.

Characterising the Nutritional and Alkaloid Profiles of Tarwi (Lupinus mutabilis Sweet) Pods and Seeds at Different Stages of Ripening

Tarwi (Lupinus mutabilis Sweet) is a key crop for Andean indigenous communities, offering proteins and fats. Both the pods and seeds of tarwi are consumed, either in their tender (immature) state or as dried, fully ripe seeds. Tarwi, like other Lupinus species, contains high alkaloid levels in its fruits and seeds that must be removed before consumption. This study evaluated the fat, protein, fibre, and alkaloid contents of four cultivars at five maturity stages ranging from 180 to 212 days after sowing. Samples of the pods and the seeds were analysed to determine their colour and protein, crude fibre, fat, and alkaloid contents. The results showed that while the protein concentration in the pods decreased as the fruits matured, the protein content in the seeds increased, reaching approximately 41%. Moreover, the pods exhibited a significant decrease in alcohol content, with the values dropping below 1% at the senescent (dry) stage for all the cultivars. In contrast, the alkaloid levels in the seeds remained stable from 196 days after sowing in the Guaranguito, Andean, and Ecuadorian cultivars, with concentrations around 4%. The present study showed that as the pods matured, their overall protein content decreased, while their seed protein content increased to around 41%. The alkaloid levels in the pods dropped below 1% in the dry stage, while the seed alkaloid levels remained stable at around 4% in the Guaranguito, Andean, and Ecuadorian cultivars after 196 days. However, in the Peruvian cultivar, the alkaloid content remained constant starting from 188 days after sowing, with concentrations just over 3%. This result suggests that as the pods mature, their alkaloid content decreases, while the alkaloid levels in the seeds stabilise from around 188 to 196 days after seeding. Consequently, the alkaloid contents found in the seeds likely originate from other aerial parts of the plant and are not significantly increased by the pods.

Pyrrolizidine alkaloid contents and profiles in Borago officinalis leaves, flowers and microgreens: Implications for safety

Borago officinalis (borage) is widely consumed as a herb or vegetable, however, it produces toxic pyrrolizidine alkaloids (PA). In 2020, the European Union (EU) established maximum levels for the PA content in certain foodstuffs, including borage leaves.This study aimed to evaluate PA contents and profiles in borage originating from different cultivation conditions and developmental stages. A total of 106 borage leaf samples, including borage microgreens, leaves from commercial producers, and plants from various home gardens at pre-flowering, flowering and end-of-flower stages, as well as 33 flower samples from plants grown in home gardens, were analyzed.The microgreens exhibited strikingly high PA contents, exceeding the maximum level set by Commission Regulation (EU) 2023/915 by an average factor of 130. PA contents in the leaves of pre-flowering plants exceeded the maximum level by an average factor of 5, whereas PA contents in the leaves of flowering plants were below the maximum level in most cases. The PA contents in flowers were higher than those of the corresponding leaves, suggesting increased accumulation of PA in flowers compared to leaves. Additionally, the occurrence of acetylated PA, especially 7-acetyl-lycopsamine-N-oxide, which are not listed in the EU regulation, was shown to be significant in borage.In summary, our results indicate that the PA contents in borage leaves are highest in emerging plants and decrease with the progression of plant or leaf maturity. The findings suggest that borage microgreens may not be suitable for human consumption and that further regulatory consideration of acetylated PA is warranted.

Impact of External Sources of Indole Acetic Acid and 2,3,5-Triiodobenzoic Acid on Alkaloid Production and Their Relationships with Primary Metabolism and Antioxidant Activity in Annona emarginata (Schltdl.) H. Rainer.

Annona emarginata is a native Brazilian species capable of producing at least ten alkaloids of ecological, agronomic, and pharmacological importance. Some studies have explored the effect of external phytoregulators on the production of alkaloids, including the effect of auxins, which, like alkaloids, derive from the shikimic acid pathway. Thus, this study aimed to evaluate how indole acetic acid (IAA) and its inhibitor 2,3,5-triiodobenzoic acid (TIBA) impact the production of alkaloids and the primary metabolism of A. emarginata, which brings advances in the understanding of the mechanisms of alkaloid synthesis and can aid in the bioprospection of molecules of interest in Annonaceae. The design was completely randomized, with three treatments (control, IAA [10-6 M] and TIBA [10-6 M]) and five collection times (12, 36, 84, 156, and 324 h). The following variables were analyzed: total alkaloids, alkaloid profile, nitrate reductase activity, gas exchange in photosynthesis, chlorophyll a fluorescence, sugars, starch, and antioxidant activity. Of the twelve alkaloids analyzed, discretine and xylopine were not detected in the control plants; however, both were detected when IAA was applied (in roots and leaves) and xylopine (in roots) when the inhibitor was applied. The alkaloid asimilobine was not detected with the use of TIBA. Variations in alkaloid concentrations occurred in a punctual manner, without significant variations in photosynthesis and nitrate reductase activity, but with variations in the antioxidant system and sugar concentrations, mainly at 156 h, when the highest alkaloid concentrations were observed with the use of TIBA. It could be concluded that IAA is capable of selectively modulating the production of alkaloids in A. emarginata, either due to an external source or by the application of its inhibitor (TIBA).

Fingerprinting alkaloids for traceability: Semi-untargeted UHPLC-MS/MS approach in raw lupins as a case study

Lupin seeds are recognized for their nutritional value and potential health benefits, but they contain also a significant amount of alkaloids, an anti-nutritive class of compounds, which vary significantly in composition within and between species due to environmental factors. In this study, we developed a predictive multi-experiment approach using ultra-high performance liquid chromatography coupled with triple quadrupole with linear ionic trap tandem mass spectrometry (UHPLC-QqQ-LIT-MS/MS) for comprehensive alkaloid profiling and geographical classification of Lupinus albus L. samples originating from four different Italian regions. Six targeted quinolizidine alkaloids were detected and 21 other alkaloids were putatively identified. Hierarchical Cluster Analysis (HCA) and partial least squares discriminant analysis (PLS-DA) were applied to explore the data structure and successfully classify samples according to their geographical origin. The data demonstrate the efficacy of the developed approach in providing valuable insights in alkaloid profiles of lupin seeds and their potential as markers for geographical traceability.

Phytochemical Profile, Antioxidant, Anti-Alzheimer, And α-Glucosidase Inhibitory Effect Of Algerian Peganum harmala Seeds Extract.

Peganum harmala seeds crude hydro-methanolic extract and their fractions (obtained with ethyl acetate and butan-1-ol) were analyzed and compared for their chemical profiles of alkaloids and polyphenols content. Moreover, their antioxidant, a-glucosidase, acetylcholinesterase, and butyrylcholinesterase inhibitory activities were evaluated. The butan-1-ol fraction revealed the highest total phenolic content and exhibited the highest antioxidant capacity. From the inhibitory enzyme evaluations, it should be highlighted the butan-1-ol fraction inhibitory potential of ɑ-glucosidase (the IC50= 141.18±4μg/mL), which was better than the acarbose inhibitory effect (IC50= 203.41±1.07 μg/mL). The extracts' chemical profile analysis revealed several compounds, in which quercetin dimethyl ether, harmine and harmaline emerged as the major compounds. The different solvents used impacted Peganum harmala seed contents and biological responses. Statistical analysis showed a significant correlation between bioactive compounds and biological activities. Thus, Peganum harmala seeds could be a promising natural source of bioactive compounds at the crossroads of many human diseases, and its cultivation may be encouraged.

Characterization of active alkaloids and metabolites in rats after oral administration of Zuojin Pill using UHPLC-Q-TOF-MS combined with bioinformatics and molecular docking analyses

Zuojin Pill (ZJP), a traditional Chinese medicine prescription composed of Rhizoma Coptidis and Euodiae Fructus in the ratio of 6:1 (w/w), has been widely used for the treatment of gastric disorders. However, an in-depth understanding of in vivo metabolism and distribution profiles of protoberberine alkaloids (PBAs) and indole alkaloids (IDAs) in ZJP is lacking. In this study, a method using ultra-high performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was developed to systematically screen the alkaloids and their metabolites in rat plasma and various tissues after oral administration of ZJP. Furthermore, bioinformatics and molecular docking analyses were conducted to elucidate the contribution of the alkaloids and metabolites enriched in the stomach to the therapeutic effect of ZJP on gastritis. A total of 33 compounds, including 7 prototype alkaloids and 26 metabolites, were chemically defined or tentatively identified in this work. The metabolic pathways of PBAs (hydroxylation, oxidation, reduction, demethylation, demethylenation, glucuronide conjugation, sulfate conjugation) and IDAs (hydroxylation, glucuronide conjugation) were revealed. Notably, 7 prototype alkaloids and 18 metabolites were detected in the stomach, indicating their propensity for gastric distribution. These alkaloids and metabolites showed strong affinities with the 7 hub targets associated with gastritis, such as CCR7, CXCR4, IL6, IFNG, CCL2, TNF, and PTPRC, and could be considered the potential active substances of ZJP for treating gastritis. In conclusion, this study clarified the gastric distribution propensity of PBAs and IDAs and their metabolites, as well as their favorable binding interactions with gastritis-related targets, which could provide essential data for the further study of the pharmacodynamic material basis and gastroprotective mechanism of ZJP.

Implications of high PsSAD expression and oleic acid content in defining the Sujata phenotype of Papaver somniferum

Papaver somniferum L. produces therapeutically-useful alkaloids like morphine, codeine, papaverine, and thebaine that accumulate in the latex of its capsule. Apart from its alkaloids, the edible seeds of the plant have high nutritional value and culinary use, with the seed oil being rich in the health-promoting unsaturated fatty acids. Sujata is low alkaloid-producing latex-less culinary variety of P. somniferum developed from an alkaloid-rich gum harvest parent (Sampada) for curtailing the narcotic menace of morphine and opium (dried latex). Earlier, it has been shown that the expression of stearoyl-acyl-carrier protein desaturase (PsSAD) in the young capsule and the proportion of unsaturated fatty acids in the seeds are higher in Sujata as compared to Sampada. Here, we studied bacterial endophytes isolated from Sujata tissues for their role in defining the fatty acid (saturated stearic versus unsaturated oleic) profile in its leaves and seeds. Besides, a potyvirus infecting P. somniferum was characterized through its coat protein gene sequencing and transmission electron microscopy and the two genotypes (Sujata and Sampada) contrasting in their phenotypes (oil/fatty acid, alkaloid and latex profiles) were compared for their susceptibility towards it through indicator plant- and qRT-PCR-based virus infectivity assays. In both the assays, Sujata was found to have higher susceptibility to the potyvirus, as compared to Sampada. The most plausible reason for this could be the higher PsSAD expression in the leaves of Sujata, which resulted in higher relative levels of oleic acid and lower relative levels of stearic acid in its leaves as compared to that of Sampada.

Discovery of Epichloë as novel endophytes of Psathyrostachys lanuginosa in China and their alkaloid profiling

The Epichloë genus represents a significant group of above-ground endophytes extensively researched for their potential applications in agriculture and ecology. Additionally, Epichloë species synthesize bioactive alkaloids, which generally cause health problems in livestock and have detrimental effects on the performance of insect herbivores. Psathyrostachys lanuginosa serves as a valuable forage grass for livestock owing to its high nutritional value and resilience in adverse environmental conditions. Nevertheless, to date, no reports have documented Epichloë as endophytes of P. lanuginosa. In this study, four strains (PF5, PF9, QG2, and QG4) were isolated and identified through morphological, molecular, and phylogenetic analyses as endophytes of P. lanuginosa. Morphological analysis indicated colony characteristics and conidia features consistent with symbiotic Epichloë, with no significant differences observed in growth rates or conidia dimensions among the four strains. Phylogenetic analysis confirmed all strains as E. bromicola. Additionally, alkaloid biosynthetic genes were detected, revealing differences in the potential synthesis of peramine and indole diterpenoid alkaloids among strains from different geographic origins. However, all four E. bromicola strains exhibited similar potential for synthesizing ergot alkaloids, but not loline alkaloids. Overall, this study identified P. lanuginosa as a novel host for E. bromicola and provided insights into the alkaloid profiles of these strains, laying a solid foundation for the scientific and rational utilization of Epichloë resources.

Consequences of pollen defense compounds for pollinators and antagonists in a pollen-rewarding plant.

Plants produce an array of defensive compounds with toxic or deterrent effects on insect herbivores. Pollen can contain relatively high concentrations of such defense compounds, but the causes and consequences of this enigmatic phenomenon remain mostly unknown. These compounds could potentially protect pollen against antagonists but could also reduce flower attractiveness to pollinators. We combined field observations of the pollen-rewarding Lupinus argenteus with chemical analysis and laboratory assays to test three hypotheses for the presence of pollen defense compounds: (1) these compounds are the result of spillover from adjacent tissues, (2) they protect against pollen thieves, and (3) they act as antimicrobial compounds. We also tested whether pollen defense compounds affect pollinator behavior. We found a positive relationship between alkaloid concentrations in pollen and petals, supporting the idea that pollen defense compounds partly originate from spillover. However, pollen and petals exhibited quantitatively (but not qualitatively) distinct alkaloid profiles, suggesting that plants can adjust pollen alkaloid composition independently from that of adjacent tissues. We found no relationship between pollen alkaloid concentration and the abundance of pollen thieves in Lupinus flowers. However, pollen alkaloids were negatively associated with bacterial abundance. Finally, plants with more alkaloids in their pollen received more pollinator visits, but these visits were shorter, resulting in no change in the overall number of flowers visited. We propose that pollen defense compounds are partly the result of spillover from other tissues, while they also play an antimicrobial role. The absence of negative effects of these compounds on pollinator visitation likely allows their maintenance in pollen at relatively high concentrations. Taken together, our results suggest that pollen alkaloids affect and are mediated by the interplay of multiple interactions.

Environmental conditions affect the nutritive value and alkaloid profiles of Lupinus forage: Opportunities and threats for sustainable ruminant systems

The identification of crops that simultaneously contribute to the global protein supply and mitigate the effects of climate change is an urgent matter. Lupins are well adapted to nutrient-poor or contaminated soils, tolerate various abiotic stresses, and present relevant traits for acting as ecosystem engineers. Lupins are best studied for their seeds, but their full foraging potential needs further evaluation. This study evaluated the effects of location and sowing date on forage production, proximate composition, and the detailed mineral and alkaloid profiles of three species of Lupinus (L. albus cv. Estoril, L. angustifolius cv. Tango, and L. luteus cv. Cardiga). Sowing date and location and their interaction with the plant species significantly affected the vast majority of measured parameters, emphasizing the effects of climate and soil conditions on these crops. The relatively high crude protein and in vitro digestibility support the potential of the lupin species studied as sustainable forage protein sources in diets for ruminant animals. The content of individual essential macro and trace elements was below the maximum tolerable levels for cattle and sheep. Lupanine, smipine, and sparteine were the most abundant quinolizidine alkaloids in L. albus cv. Estoril, lupanine, and sparteine in L. angustifolius cv. Tango, and lupinine, gramine, ammodendrine, and sparteine in L. luteus cv. Cardiga. Based on the maximum tolerable levels of total quinolizidine alkaloid intake, the dietary inclusion of forages of L. albus cv. Estoril and L. angustifolius cv. Tango does not pose a risk to the animals, but the high alkaloid content of L. luteus cv. Cardiga may compromise its utilization at high levels in the diet. Overall, the results reveal a high potential for lupins as protein forage sources well adapted to temperate regions and soils with lower fertility, with a relevant impact on livestock sustainability in a climate change era.

Variability of Isoquinoline Alkaloid Profiles and Anticholinesterase Activities with Binding-Mode Predictions of Glaucium flavum Population.

In this study, phytochemical and biological activity studies supported by docking were carried out on a species of the genus Glaucium, a repository of isoquinoline alkaloids. The GC-MS (Gas Chromatography-Mass Spectrometry) method is used to characterize the isoquinoline alkaloids of Glaucium flavum Crantz. (Papaveraceae). G. flavum was collected from seven different regions of Türkiye (Antalya, Urla-Izmir, Mordogan-Izmir, Mugla, Assos-Canakkale, Karabiga-Canakkale, Giresun) and totally 17 compounds were detected by GC-MS. Glaucine was found to be the major constituent in the sample collected from Mugla, whereas isocorydine was recorded to be the principal alkaloid in other samples. Further fractionation studies on G. flavum collected from Antalya province in Southwestern Türkiye, yielded five major alkaloids (isocorydine 1, dihydrosanguinarine 2, glaucine 3, dehydroglaucine 4, protopine 5) which were characterized by spectroscopic methods. Anticholinesterase activities of the extracts and isolated alkaloids were also tested by in vitro Ellman method. The isolated compounds were also analyzed by a molecular docking technique to determine the binding orientations in the gorge of the active site of acetylcholinesterase (AChE) and a homology model of butyrylcholinesterase (BuChE). This is the first comparative investigation of the phytochemical composition and biodiversity of Glaucium flavum species growing in Türkiye.

Epichloë fungal endophyte strains and their Lolium hosts affect resistance to Listronotus bonariensis (Coleoptera: Curculionidae)

ABSTRACT Both adults and larvae of Listronotus bonariensis damage ryegrass (Lolium spp.), a dominant component of New Zealand pasture. Damage can be reduced by Epichloë festucae var. lolii, a biotrophic fungal symbiont of ryegrass, through the production of alkaloids with deterrent and/or toxic effects to insect herbivores including L. bonariensis. Here we report results from two pot trials and a field trial comparing endophyte strains with different alkaloid profiles that have been introduced to reduce or eliminate adverse effects on stock. Adult L. bonariensis feeding scars, number of eggs and the proportion of tillers with larval damage and the severity of that damage were recorded. Samples of pseudostem and leaf blades were analysed for alkaloids. AR1 endophyte reduced adult feeding, oviposition, and larval damage whereas AR37 had no effect on adults but was highly effective in reducing larval damage. Reduction in adult feeding and oviposition by different NEA strains was governed by concentrations of peramine and ergovaline. For plants infected with AR37, alkaloid concentrations that determined the extent of larval damage were influenced by host species and ploidy; tetraploid L. perenne was more severely damaged than its diploid equivalent; L. multiflorum cultivars were more susceptible than the L. hybridum and L. perenne cultivars.

Molecular Docking and GC/MS-Based Approach for Identification of Anxiolytic Alkaloids from Griffinia (Amaryllidaceae) Species in a Zebrafish Model.

Griffinia gardneriana Ravenna, Griffinia liboniana Morren and Griffinia nocturna Ravenna (Amarillydaceae) are bulbous plants found in tropical regions of Brazil. Our work aimed to determine the alkaloid profiles of Griffinia spp. and evaluate their anxiolytic potential through in vivo and in silico assays. The plants grown in greenhouses were dried and their ground bulbs were subjected to liquid-liquid partitions, resulting in alkaloid fractions that were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). Anxiolytic activity was evaluated in zebrafish (Danio rerio) through intraperitoneal injection at doses of 40, 100 and 200 mg/kg in light-dark box test. GC-MS analyses revealed 23 alkaloids belonging to different skeleton types: lycorine, homolychorine, galanthamine, crinine, haemanthamine, montanine and narcisclasine. The chemical profiles were relatively similar, presenting 8 alkaloids common to the three species. The major component for G. gardneriana and G. liboniana was lycorine, while G. nocturna consisted mainly of anhydrolycorine. All three alkaloid fractions demonstrated anxiolytic effect. Furthermore, pre-treatment with diazepam and pizotifen drugs was able to reverse the anxiolytic action, indicating involving the GABAergic and serotonergic receptors. Molecular docking showed that the compounds vittatine, lycorine and 11,12-dehydro-2-methoxyassoanine had high affinity with both receptors, suggesting them to be responsible for the anxiolytic effect.

Differential Tolerance of Primary Metabolism of Annona emarginata (Schltdl.) H. Rainer to Water Stress Modulates Alkaloid Production

Annona emarginata produces alkaloids of ecological and pharmacological interest and is tolerant to water and biotic stress, so it is used as rootstock for other Annonaceae fruits. There are few reports in the literature on how contrasting water stress impacts the production of specialized metabolites in Annonaceae and how primary metabolism adjusts to support such production. The objective of this investigation was to evaluate how drought and flooding stress affect alkaloid concentration and the primary metabolism of young A. emarginata plants. Three water levels (flooding, field capacity, and drought) were studied at two moments (stress and recovery). Variables analyzed were gas exchange levels, chlorophyll a fluorescence, leaf sugars, total alkaloid content, alkaloid profile, and Liriodenine concentration. The photosynthetic metabolism of A. emarginata was affected by water stress, with plants having a greater ability to adapt to drought conditions than to flooding. During the drought, a reduction in photosynthetic efficiency with subsequent recovery, higher starch and trehalose concentrations in leaves, and total alkaloids in roots (480 µg.g−1) were observed. Under flooding, there was a reduction in photochemical efficiency during stress, indicating damage to the photosynthetic apparatus, without reversal during the recovery period, as well as a higher concentration of total sugars, reducing sugars, sucrose, glucose, and fructose in leaves, and Liriodenine in roots (100 µg.g−1), with a lower concentration of total alkaloids (90 µg.g−1). It could be concluded that there is differential tolerance of A. emarginata to water stress, inducing the modulation of alkaloid production, while drought promotes a higher concentration of total alkaloids and flooding leads to an increase in the Liriodenine concentration.

High-performance liquid chromatography analysis of alkaloids in various parts of lotus extracts with ion mobility spectrometry and mass spectrometry dual detection.

Using high-performance liquid chromatography coupled with electrospray ionization-ion mobility spectrometry and mass spectrometry, we proposed a dual-detection method for the identification and profiling of alkaloids in various lotus parts including leaf, plumule, stem, seed epicarp, and receptacle. The eluent from high-performance liquid chromatography was split and conducted to electrospray ionization-ion mobility spectrometry and time-of-flight mass spectrometry separately to facilitate the compound identification. In total, 23 kinds of alkaloids were identified based on m/z, drift time, and retention time, including alkaloid isomers such as lirinidine, N-nornuciferine, and O-nornuciferine with identical m/z that are difficult to differentiate using mass spectrometry alone. Using this method, we investigated the changing dynamics of alkaloid accumulation in lotus leaves and lotus stems at different harvesting periods. The total alkaloid content showed an increasing trend with the growth and development of leave and stem. Overall, the developed dual detection method has the advantages of high peak capacity and high sensitivity compared with the conventional detection method and facilitates the identification of detected compounds.

Phytochemical Profile of Alkaloid Extract from Dendrobium huoshanense and Inhibitory Effects against Oxidative Stress in H2 O2 -Induced PC12 Cells.

This study aimed to explore the alkaloid profile of Dendrobium huoshanense and determine the potential protective effect against oxidative damage. The crude D. huoshanense alkaloid extract (DHAE) was obtained by 70 % ethanol extraction and liquid-liquid partition. DHAE contained specific alkaloid components with abundant 6-hydroxynobiline (58.15 %) and trace dendrobine (3.23 %) in the preliminary HPLC fingerprint and GC-MS analysis, which was distinguished from D. officinale or D. nobile. Subsequently, six alkaloids including 6-hydroxynobiline, 2-hydroxy dendrobine, nobilonine, dendrobine, Findlayines D and trans-dendrochrysanine were identified in the purified DHAE (namely DHSAE-3, DHSAE-3') via further solid phase extraction coupled with UPLC-MS/MS analysis. Meanwhile, pretreatment with DHAE or DHSAE (0.5, 5 μg/mL) increased cell viability by 14.0-57.4 % compared to that of H2 O2 -induced PC12 Model cells. Among them, 5 μg/mL DHSAE-3-treated cells displayed a pronounced reversion than the positive vitamin E (p<0.01). Furthermore, a clear cellular morphological restoration and 38.4 % reduction in intracellular reactive oxidative species level were achieved. Our findings suggest that D. huoshanense has a characteristic alkaloid profile represented by abundant 6-hydroxynobiline, and DHAEs exhibit obvious protection against oxidative neuronal damage. Overall, this study indicates that DHAEs might be used to inhibit oxidative stress and provide a source to develop novel neuroprotective drugs.

The leaf idioblastome of the medicinal plant Catharanthus roseus is associated with stress resistance and alkaloid metabolism.

Catharanthus roseus leaves produce a range of monoterpenoid indole alkaloids (MIAs) that include low levels of the anticancer drugs vinblastine and vincristine. The MIA pathway displays a complex architecture spanning different subcellular and cell type localizations, and is under complex regulation. As a result, the development of strategies to increase the levels of the anticancer MIAs has remained elusive. The pathway involves mesophyll specialized idioblasts where the late unsolved biosynthetic steps are thought to occur. Here, protoplasts of C. roseus leaf idioblasts were isolated by fluorescence-activated cell sorting, and their differential alkaloid and transcriptomic profiles were characterized. This involved the assembly of an improved C. roseus transcriptome from short- and long-read data, IDIO+. It was observed that C. roseus mesophyll idioblasts possess a distinctive transcriptomic profile associated with protection against biotic and abiotic stresses, and indicative that this cell type is a carbon sink, in contrast to surrounding mesophyll cells. Moreover, it is shown that idioblasts are a hotspot of alkaloid accumulation, suggesting that their transcriptome may hold the key to the in-depth understanding of the MIA pathway and the success of strategies leading to higher levels of the anticancer drugs.

Mexican argemone (Argemone mexicana L.) CYP719A14 protein bioinformatic analysis

CYP719A14 structure analysis and its interaction with ligands via bioinformatic methods. Methods. Homologous modeling of three-dimensional structure of enzyme. Molecular docking. Results. CYP719A14 enzyme, which shows cheilanthifoline synthase activity, model was build based on results of homologous modeling. Interaction of built model with possible substrates – benzylisoquinoline compounds: (S)-Scoulerine, (S)-Cheilanthifoline, (S)-Tetrahydrocolumbamine, (S)-Reticuline was investigated using molecular docking method, thermodynamic characteristics of interaction were calculated. Potential Ligand Access Chanel – potential active center was identified. Conclusions. Potential Ligand Access Chanel CYP719A14 enzyme, which is formed by aminoacids residues PHE57-GLY69, ALA285-ARG310, THR369-HSD390 researched, allowing to use discovered data in alkaloid engineering research with aim to improve Mexican argemone alkaloid profile.

LC-MS/MS Evaluation of Pyrrolizidine Alkaloids Profile in Relation to Safety of Comfrey Roots and Leaves from Polish Sources.

Comfrey (Symphytum officinale L.) has a long tradition of use in the treatment of musculoskeletal disorders. However, due to hepatotoxic pyrrolizidine alkaloids (PAs), the EMA restricts the use of comfrey root (CR) to external use only and for short periods of time. Recent studies indicate a low permeability of PAs across the skin, calling into question the safety of topical application of products containing comfrey preparations. The aim of our work was to develop and validate an HPLC method enabling the separation of isomeric PAs from comfrey and, on this basis, to assess the potential toxicity of CR and comfrey leaf (CL) obtained from various Polish sources. The qualitative and quantitative analysis of PAs via HPLC-MS/MS was performed in MRM mode. The results obtained confirmed a lower content of PAs in CL than in CR and showed a wide variation in the composition of PAs in CR, with a much more stable profile of PAs in CL. Factor analysis confirmed that CRs and CLs differ in PA content, which is influenced by the growth conditions and geographical origin. The determined concentrations of PAs prove that in some CRs available on the Polish herbal market, the content of PAs may exceed the daily dose considered safe.