Alkaloids Research Articles

Cloning and functional characterization of the caffeine oxidase gene CsCDH from Camellia sinensis.

Theacrine, a purine alkaloid with pharmacological effects such as calming and anti-depressive activities, is biosynthesized through a key rate-limiting enzyme, caffeine oxidase. Despite its importance, the caffeine oxidase gene (CsCDH) in Camellia sinensis has not been cloned to date. We successfully isolated the full-length CsCDH cDNA, which contains a 501-bp open reading frame (ORF) encoding a 166-amino-acid protein with a calculated molecular weight of 18.7 kDa. Molecular docking and dynamics simulations showed that CsCDH binds tightly and stably to caffeine, indicating its catalytic potential in converting caffeine to 1,3,7-trimethyluric acid. The CsCDH fusion protein was expressed in Escherichia coli and purified through affinity chromatography. In vitro enzymatic assays verified that CsCDH catalyzes the conversion of caffeine into 1,3,7-trimethyluric acid. Furthermore, transient expression in tobacco confirmed its caffeine oxidase activity in planta. Finally, antisense oligonucleotide (asODN) interference experiments confirmed that CsCDH exhibits caffeine oxidase activity in tea plants. This study lays the groundwork for unraveling the theacrine biosynthesis pathway and offers new insights into breeding low-caffeine or high-theacrine tea cultivars.

Cardioprotective Potential of Bioactive Compound from Methanolic Extract of Asparagus racemosus: An In Silico Study Utilizing GC–MS Analysis

Background Historical accounts suggest that, throughout antiquity, medicinal plants and their constituent parts have been used to treat a variety of ailments. Asparagus racemosus, this plant exhibits a wide range of potential uses in medicine. Purpose The purpose of this study is to identify any potentially bioactive ingredients in the methanolic extract of A. racemosus. Methods A variety of compounds were detected using gas chromatography, and their molecular structures were confirmed by Fourier transform infrared (FTIR) analysis and mass spectrometry. Using in silico approaches, the molecule’s potential as a therapeutic candidate, biological activity, and projected targets were carefully examined. Results The molecule 4-(((9-(5-(ethylcarbamoyl)-3,4-dihydroxy tetrahydrofuran-2-yl)-9 H-purin-6-yl)amino)methyl)benzoic acid was found in the highest concentration (27.37%). The identified molecule is purine alkaloid in nature. The promising drug-like properties and therapeutic efficacy for the investigated molecule. Conclusion It could serve as a viable therapeutic option for addressing cardiovascular disorders.

Electrochemical Synthesis of Purine Alkaloid Metabolites from Caffeine

AbstractThe development of electrochemical approaches to the valorization of abundant natural products into high value medications and metabolites is of pharmaceutical interest. In this study, we explored the electrosynthetic behavior of the abundant legal psychoactive, caffeine, a representative member of the purine alkaloid class. Initial screening of the cyclic voltammetric behavior of eleven exemplar purine alkaloids revealed a structure electroactivity relationship (SeAR) for determining the initial oxidation site of caffeine. Optimization of the current controlled electrochemical (CCE) reaction enabled the dialing‐in/out of differential oxidative metabolic products using both undivided and divided cells. Sequential desmethylation around the purine ring was observed both by isolation and comparison to authentic metabolite reference standards via HPLC measurements. Amide, imide, and a novel N‐methyl heteroaryl oxidation mechanism were observed. Tractable quantities of the high‐value medication, theophylline, and the dietary supplement, paraxanthine, were isolated in 17 % and 8 % b.r.s.m. This approach offers a marked improvement compared to the best‐in‐class techniques (chemical 0.8 % and enzymatic 0.97 % yields) and may have potential in other natural product and drug discovery settings to prepare valuable metabolites.

Evolution of the biochemistry underpinning purine alkaloid metabolism in plants.

Purine alkaloids are naturally occurring nitrogenous methylated derivatives of purine nucleotide degradation products, having essential roles in medicine, food and various other aspects of our daily lives. They are generated through convergent evolution in different plant species. The pivotal reaction steps within the purine alkaloid metabolic pathways have been largely elucidated, and the convergent evolution of purine alkaloids has been substantiated through bioinformatic, biochemical and other research perspectives within S-adenosyl-ʟ-methionine-dependent N-methyltransferases. Currently, the biological and ecological roles of purine alkaloids, further refinement of the purine alkaloid metabolic pathways and the investigation of purine alkaloid adaptive evolutionary mechanisms continue to attract widespread research interest. The exploration of the purine alkaloid metabolic pathways also enhances our comprehension of the biochemical mechanism, providing insights into inter-species interactions and adaptive evolution and offering potential value in drug development and agricultural applications. Here, we review the progress of research in the distribution, metabolic pathway elucidation and regulation, evolutionary mechanism and ecological roles of purine alkaloids in plants. The opportunities and challenges involved in elucidating the biochemical basis and evolutionary mechanisms of the purine alkaloid metabolic pathways, as well as other research aspects, are also discussed. This article is part of the theme issue 'The evolution of plant meta-bolism'.

Exploration of the mechanism of temperature influence on bitter taste of theacrine by activating human bitter taste receptor hTAS2R14

Theacrine, a purine alkaloid derived from Camellia assamica var. kucha, has a distinct bitter taste. Our previous study found the lower recognition threshold of theacrine at 25 °C than 45 °C. This study aims to investigate the bitterness characterizations of theacrine at aforementioned temperatures and its taste perception mechanism. Sensory analysis exhibited higher bitterness intensity for theacrine at 25 °C than 45 °C. Subsequently, flow cytometry was performed to verify the above characterization at the cellular level. It revealed that theacrine could activated the bitter receptor hTAS2R14 and the calcium signal at 25 °C was higher than 45 °C. Ultimately, the interaction mechanism was studied by molecular dynamics simulations, indicating that the conformation of theacrine-hTAS2R14 had a higher binding capacity and better stability at 25 °C. Overall, temperature affected the binding of theacrine to the bitter receptor hTAS2R14, resulting in the stronger bitterness intensity of theacrine at 25 °C than 45 °C.

Recording of hippocampal activity on the effect of convulsant doses of caffeine

Seizures occur when there is a hyper-excitation of the outer layer of the brain, with subsequent excessive synchrony in a group of neurons. According to the World Health Organization (WHO), an estimated 50 million people are affected by this disease, a third of whom are resistant to the treatments available on the market. Caffeine (1,3,7-trimethylxanthine), which belongs to the purine alkaloid family, is the most widely consumed psychoactive drug in the world. It is ingested by people through drinks containing this substance, such as coffee, and as an adjuvant in analgesic therapy with non-steroidal antiflammatory drugs. The present study evaluated the electrocorticographic changes observed in the hippocampus of Wistar rats subjected to acute doses of caffeine (150 mg/kg i.p), which represents a toxic dose of caffeine corresponding to an estimated acute intake of more than 12 cups of coffee to record its convulsant activity. Our results showed, for the first time, that the administration of high doses of caffeine (150 mg/kg i.p.) in rats caused an increase in the spectral distribution of power in all frequency bands and suggested the appearance of periods of ictal and interictal peaks in the electrocorticogram (ECog). We have also shown that the anticonvulsants phenytoin, diazepam and phenobarbital have a satisfactory response when associated with caffeine.

Biosystematic Studies, Distribution and Conservation Status of Guaiacum officinale L. in Karnataka State

Guaiacum L. is an evergreen tree indigenous to South America, West Indies and USA. It was introduced during British period. The stem is hard, abundant resin wood, ash- grey-green bark and paripinnate leaves. The flowers are blue-purple in colour and occur in axillary clusters. The fruit is a capsule. Anomocytic, Paracytic and tertacytic types of stomata present only on abaxial surface of the leaf, trichomes absent on both surface. Pollen monad, radialy sysmmetric, tricolporate. The secondary veins are joined to form a loop at the margin. Phenolic test, alkaloid test etc. gave positive results. This plant is having commercial as well as medicinal value. In Karnataka state this plant found only in two places, one in Lalbagh, Bangalore and another in Karnataka College, Dharwad. Silviculture experiments were conducted but not succeeded. In both the places flowers are many, but fruit setting is negligible. It inhibits the spreading of the species in Karnataka.

Role of Drug Remedies in Attention Deficit Hyperactivity Disorder (ADHD): A Case Series

Introduction: ADHD is the most common neurobe havioral disorder in children which comprises of 3 types: inattentive/hyperactive-impulsive/combined type. There are varied drugs in homoeopathy belong ing to narcotic groups which seems to be effective in these type of cases. These groups have various alka loids whose main sphere of action is on CNS or PNS as stimulant, depressor or hypnotic. Case summary: Here, 3 cases are presented with different types of ADHD as diagnosed by Vanderbilt Diagnostic Scale. In all these cases homoeopathic drug remedies were prescribed on the basis of totality of symptoms. Marked improvement in all the cases substantiate the effectiveness of homoeopathy especially drug remedies in these type of behavioural problems when given constitutionally.

Natto alleviates hyperlipidemia in high-fat diet-fed mice by modulating the composition and metabolic function of gut microbiota

Natto has long been considered as a medical-food dual-use product with a hypolipidemic effect. Our study showed that natto was effective in reducing the levels of total cholesterol (TC), triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), and increasing the level of high-density lipoprotein cholesterol (HDL-C) in the serum of hyperlipidemic mice. Metabolism analysis showed that natto could improve the levels of amino acid metabolites, reduce the contents of acylcarnitines, and reverse the levels of purine alkaloids, mainly involving the tricarboxylic acid (TCA) cycle and metabolism of amino acids. Moreover, natto increased beneficial gut microbiota (e.g., Lactobacillus, Faecalibaculum and Oscillibacter) and reduced pathogenic gut microbiota (e.g., Alistipes and Prevotellaceae-UCG-003). In conclusion, our findings suggest that natto-mediated changes in the gut microbiota and its related metabolites can support the prevention of high-fat diet (HFD)-induced hyperlipidemia, laying the theoretical foundation for the continued development of natto as a functional food.

Exploring toxicological interactions in a changing sea: The case of the alkaloids caffeine and caulerpin

The bisindolic alkaloid caulerpin (CAU) is a bioactive compound isolated from green algae of the genus Caulerpa that are highly invasive in the Mediterranean Sea. On the other side, the purine alkaloid caffeine (CAF) is one of the most globally consumed psychoactive substances and a widespread anthropogenic water pollutant. Both compounds display a large panel of biological properties and are well known to accumulate in the tissues of aquatic organisms and, in certain circumstances, co-occur in the human diet. On this premise, the present study aimed to investigate possible synergistic interactions between CAU and CAF by using the bivalve Mytilus galloprovincialis as a model organism. Mussels were exposed to CAF via medium while they were fed with food enriched with CAU. After treatments, biochemical analysis confirmed the toxic potential of CAF, with increased AChE activity and lipid peroxidation. Also, histopathological alterations were observed in the gills and digestive tubules. The NMR-based metabolomics analysis detected higher levels of free amino acids under CAF treatments. Conversely, the food administration of CAU did not affect the above toxicological biomarkers. In addition, we did not observe any cumulative effect between CAF and CAU toward increased cellular damage and neurotoxicity. On the other hand, a possible action of CAU in decreasing CAF toxicity could be hypothesized based on our results. This hypothesis is supported by the activity of CAU as an agonist of peroxisome proliferator-activated receptors (PPARs). PPARs mediate xenobiotic detoxification via cytochromes P450, which is involved in CAF metabolism. Overall, the results obtained not only rule out any cumulative adverse effects of CAF and CAU but also encourage further research to evaluate the possible use of CAU, a compound easily obtained through the valorization of biomass from invasive species, as a food additive to improve the clearance of xenobiotics.

Multidimensional exploration of the bitterness amelioration effect of roasting on Wuyi Rock tea

The influence of roasting on tea bitterness remains unclear. With Wuyi Rock tea (WRT) as an example, this study investigated the impact of roasting on WRT's bitterness, utilizing an integrated approach involving sensory evaluation, bitter compound profiling, and cell-based calcium imaging. Sensory analysis revealed that roasting effectively reduced the perceived bitterness of WRT. This reduction was supported by decreases in various bitter compounds, including 19 flavanols, 11 flavonols, 12 phenolic acids, 2 purine alkaloids, and 9 bitter amino acids, which diminished by 16%, 26%, 19%, 2%, and 70%, respectively. Furthermore, we established two heterogeneous bitter receptor expression systems: TAS2R39/Gα15-HEK293T and TAS2R14/Gα15-HEK293T cell lines. These systems quantitatively confirmed the reduction in bitterness, demonstrating 51% and 62% decreases in intracellular calcium mobilization within the transfected cells, respectively. These findings provide compelling evidence for the bitterness-ameliorating effect of roasting, expanding our knowledge of the role of roasting in shaping the flavor of tea.

Synthesis, structure and high-resolution X-ray studies of purine alkaloid cocrystals with benzene-1,2,4,5-tetracarboxylic acid as a coformer

Synthesis, structure and high-resolution X-ray studies of purine alkaloid cocrystals with benzene-1,2,4,5-tetracarboxylic acid as a coformer

Quantitative Analysis of Caffeine in different commercial kinds of coffee in Iraq

Caffeine is a widely consumed pharmacologically active substance around the world, Caffeine is a purine alkaloid derived from methylxanthine that is readily permeable through the blood-brain barrier and stimulates the adenosine receptors in the brain leading to its central nervous system stimulant activity. Most people regulate their caffeine consumption in accordance with the objective and subjective effects produced from the methylxanthine, However, individual response to caffeine varies greatly from person to person due to the variation in metabolism, age, sex, hormones, clearance, weight, genes, medicine intake and smoking behavior, therefore the amount of caffeine required to achieve the desired effect also varies greatlyand Since that the coffee beans are the world's primary sources of dietary caffeine this study was designed to determine the percent of the caffeine in different commercial coffee brands, the isolated caffeine was identified by different qualitative methods like TLC, and FTIR.

Camellia sinensis, un producto natural de apoyo al tratamiento de afecciones médicas y estomatológicas - Revisión Sistemática

Introduction: The tea plant, Camellia sinensis, is one of the most popular non-alcoholic beverages in the world. The main components of Camellia sinensis include amino acids, fatty acids, phenolic compounds, flavins and purine alkaloids (xanthines). For this reason, in the field of medicine, Camellia sinensis has been used as an anticancer, anxiolytic, antidiabetic, antiobesity, anti-inflammatory, analgesic, antipyretic, chemopreventive, cytotoxic and apoptogenic, genoprotective, hepatoprotective, nephroprotective, hemato-protective, and in wound healing, among other uses. Objective: To carry out a systematic review of the use of C. sinensis as supportive therapy in the treatment of oral disorders. Materials and Methods: This systematic review was carried out following the PRISMA guidelines. The search was carried out in the PubMed, ScienceDirect and Google Academic databases. Articles from studies of Camellia sinensis were reviewed and those from a secondary source, such as literature review articles, were excluded Results: A total of 12 full-text articles were selected for review, in which the properties of Camellia sinensis are detailed. Conclusions: According to the bibliography reviewed, C. sinensis exhibits anticariogenic properties, applications in the treatment of dental erosion, applications in the treatment of gingivitis and bacterial plaque, and applications in the prevention of oral cancer; however, more controlled clinical trials are needed to confirm its effectiveness and safety of use. Keywords: Camellia sinensis; Botany; Functional claim; Therapeutics; Dentistry; Systematic Review.

New Purine Alkaloid from Gleditsia triacanthos and Its Effect on the CNS

New Purine Alkaloid from Gleditsia triacanthos and Its Effect on the CNS

A Determination of the Caffeine Content in Dietary Supplements According to Green Chemistry Principles.

Caffeine is a natural psychoactive substance that belongs to a group of chemical compounds called purine alkaloids. Caffeine is found in various plants such as coffee, tea, cocoa, guarana, and yerba mate. It is often added to dietary supplements for its ability to increase metabolism and aid in weight loss. To determine the caffeine content in dietary supplements, a novel UHPLC method was developed, compatible with the rules of green analytical chemistry. The developed method used only water and ethanol for sample preparation and chromatographic separation on a short C18 column. The obtained method confirmed that caffeine may be analyzed using only environmentally friendly solvents, ethanol, and water. The developed method is characterized by its low limit of quantitation, equal to 0.047 µg/mL, and good reproducibility (a relative standard deviation lower than 1.1%). The obtained results show that the caffeine content in tested dietary supplements is 4-35% higher than the declared amount in most cases. In comparison, the caffeine content of the drug determined using this method was performed with an accuracy of 0.4% RSD.

The total alkaloids of Sophora alopecuroides L. improve depression-like behavior in mice via BDNF-mediated AKT/mTOR signaling pathway

Ethnopharmacological relevanceDepression has become a global public health problem and the development of new highly effective, low-toxicity antidepressants is imminent. Sophora alopecuroides L. is a common medicinal plant, which has therapeutic effect on central nervous system diseases. Aim of the studyIn this study, the antidepressant effect of total alkaloids (ALK) isolated from Sophora alopecuroides L. was explored and the mechanism was further elucidated. Materials and methodsA primary neuronal injury model was established in vitro by corticosterone. ICR mice were then selected to construct an in vivo model of chronic unpredictable mild stress (CUMS)-induced depression, and the ameliorative effects of ALK on depression were examined by various behavioral tests. The antidepressant molecular mechanism of ALK was subsequently revealed by ELISA, Western blot, immunohistochemistry and Golgi staining. ResultsBDNF secretion as well as TrkB and ERK phosphorylated protein levels were found to be improved in primary cortical neurons, along with improved dendritic complexity of neurons. The results of in vivo showed that the depression-like behavior of CUMS-induced mice was reversed after 2 weeks of continuous gavage administration of ALK, and the neurotransmitter levels in the plasma of mice were increased. Moreover, the expression levels of key proteins of BDNF-AKT-mTOR pathway and the complexity of neuronal dendrites were improved in the prefrontal cortex of mice. ConclusionsThese findings indicate that ALK of Sophora alopecuroides L. can effectively improve the depressive phenotype of mice, possibly by promoting the expression of BDNF in prefrontal cortex, activating the downstream AKT/mTOR signal pathway, and ultimately enhancing neuronal dendritic complexity.

Phosphodiester Stationary Phases as Universal Chromatographic Materials for Separation in RP LC, HILIC, and Pure Aqueous Mobile Phase.

Modern analytical chemistry techniques meet the need for greater attention to ecological and economic aspects. It is becoming necessary to seek solutions to reduce harmful waste production, especially in large quantities. High-performance liquid chromatography is a technique widely used in many industries, including mainly pharmaceuticals, and requires an approach to reduce the significant amount of organic solvent waste. One of the green chemistry solutions is using environmentally benign substitutes, such as pure water, supercritical dioxide, and ethanol. Our work focuses on the preparation and application of new stationary phases with embedded hydrophilic groups for separations using pure water in liquid chromatography. Polar-embedded stationary phases are obtained by attaching a phosphodiester group and 4 different hydrophobic molecules. The studies consisted of hydrophobicity measurements, concentration dependence of retention of the organic additive to the mobile phase, and chromatographic separations of polar and non-polar substance mixtures in RP-LC and HILIC systems. Three mixtures were studied: purine alkaloids, benzene, and polycyclic aromatic hydrocarbons and nucleosides. The stationary phases interact differently with the analytes depending on the attached hydrophobic group. It is possible to use pure water to separate each mixture under study. It is also significant that it has been possible to separate a mixture of completely non-polar compounds using pure water for the first time. The research being carried out is crucial in synthesizing new polar-embedded stationary phases, providing work versatility and high environmental performance.

Alkaloids in food: a review of toxicity, analytical methods, occurrence and risk assessments.

Alkaloids have been utilized by humans for years. They have diverse applications in pharmaceuticals. They have been proven to be effective in treating a number of diseases. They also form an important part of regular human diets, as they are present in food items, food supplements, diet ingredients and food contaminants. Despite their obvious importance, these alkaloids are toxic to humans. Their toxicity is dependent on a range of factors, such as specific dosage, exposure time and individual properties. Mild toxic effects include nausea, itching and vomiting while chronic effects include paralysis, teratogenicity and death. This review summarizes the published studies on the toxicity, analytical methods, occurrence and risk assessments of six major alkaloid groups that are present in food, namely, ergot, glycoalkaloids, purine, pyrrolizidine, quinolizidine and tropane alkaloids.

Investigation and dynamic changes of phenolic compounds during a new-type fermentation for ripened Pu-erh tea processing

At present, several novel pile-fermentation styles have been developed for ripened Pu-erh tea (RPT) processing. In this study, tea pigments, phenolic compounds, purine alkaloids and amino acids in six RPTs produced through three various fermentation styles were determined by using HPLC and amino acid analyzer to reveal chemical differences caused by fermentation style, respectively. Additionally, dynamic changes of phenolic compounds and purine alkaloids were explored during a whole new-type fermentation. Despite three various fermentation styles, these RPTs demonstrated consistent sensory and major quality components including three tea pigments, two flavonoids and three purine alkaloids. However, RPTs of the new-type fermentation had relatively higher contents of seven catechins, gallic acid, two flavonols (i.e. quercetin and kaempferol), two other flavonoids (i.e. rutin and luteolin) and 10 amino acids such as l-theanine and l-arginine. The new-type fermentation decelerated the degradation of four galloylated catechins, rutin, amino acids and soluble sugars, but contributed to the accumulations of three non-galloylated catechins, two flavonols, luteolin and gallic acid. Therefore, the new-type fermentation could be a potential style for RPT processing with a shorter fermentation cycle.