Functional implications of NHR-210 enrichment in C. elegans cephalic sheath glia: insights into metabolic and mitochondrial disruptions in Parkinson's disease models.

Glial cells constitute nearly half of the mammalian nervous system's cellular composition. The glia in C. elegans perform majority of tasks comparable to those conducted by their mammalian equivalents. The cephalic sheath (CEPsh) glia, which are known to be the counterparts of mammalian astrocytes, are enriched with two nuclear hormone receptors (NHRs)-NHR-210 and NHR-231. This unique enrichment makes the CEPsh glia and these NHRs intriguing subjects of study concerning neuronal health. We endeavored to assess the role of these NHRs in neurodegenerative diseases and related functional processes, using transgenic C. elegans expressing human alpha-synuclein. We employed RNAi-mediated silencing, followed by behavioural, functional, and metabolic profiling in relation to suppression of NHR-210 and 231. Our findings revealed that depleting nhr-210 changes dopamine-associated behaviour and mitochondrial function in human alpha synuclein-expressing strains NL5901 and UA44, through a putative target, pgp-9, a transmembrane transporter. Considering the alteration in mitochondrial function and the involvement of a transmembrane transporter, we performed metabolomics study via HR-MAS NMR spectroscopy. Remarkably, substantial modifications in ATP, betaine, lactate, and glycine levels were seen upon the absence of nhr-210. We also detected considerable changes in metabolic pathways such as phenylalanine, tyrosine, and tryptophan biosynthesis metabolism; glycine, serine, and threonine metabolism; as well as glyoxalate and dicarboxylate metabolism. In conclusion, the deficiency of the nuclear hormone receptor nhr-210 in alpha-synuclein expressing strain of C. elegans, results in altered mitochondrial function, coupled with alterations in vital metabolite levels. These findings underline the functional and physiological importance of nhr-210 enrichment in CEPsh glia.

Hesperidin: Enrichment, forced degradation, and structural elucidation of potential degradation products using spectral techniques.

RATIONALE: Hesperidin (HES) is a well-known citrus bioflavonoid phyto-nutraceutical agent with polypharmacological properties. After 2019, HES was widely used for prophylaxis and COVID-19 treatment. Moreover, it is commonly prescribed for treating varicose veins and other diseases in routine clinical practice. Pharmaceutical impurities and degradation products (DP) impact the drug's quality and safety and thus its effectiveness. Therefore, forced degradation studies help study drug stability, degradation mechanisms, and their DPs. This study was performed because stress stability studies using detailed structural characterization of hesperidin are currently unavailable in the literature. METHODS: In the HES enrichment method crude HES was converted to its pure form (98% purity) using column chromatography and then subjected to forced degradation under acid, base, and neutral hydrolyses followed by oxidative, reductive, photolytic, and thermal stress testing (International Conference on Harmonization guidelines). The stability-indicating analytical method (SIAM) was developed to determine DPs using reversed-phase high-performance liquid chromatography (C18 column with methanol and 0.1% v/v acetic acid in deionized water [70:30, v/v] at 284 nm). Further, structural characterization of DPs was performed using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy. In addition, in silico toxicity predictions were performed using pKCSM and DataWarior freeware. RESULTS: HES was found to be susceptible to acidic and basic hydrolytic conditions and yielded three DPs in each, which were detected using designed SIAM. Of six DPs, three were pseudo-DPs (short lived), and the remaining were characterized using LC-MS/MS and NMR spectroscopy. The tentative mechanism of the formation of proposed DPs was explained. The proposed DPs were found inactive from in silico toxicity predictions. CONCLUSIONS: Hesperidin was labile under acidic and basic stress conditions. The potential DPs were characterized using LC-ESI-MS/MS and NMR spectral techniques. The proposed mechanism of formation was hypothesized. In addition, to identify and characterize the DPs, a SIAM, which has broad biomedical applications, was successfully developed.

Design and synthesis of N-acyl and dimeric N-Arylpiperazine derivatives as potential antileishmanial agents.

The current regime for leishmaniasis is associated with several adverse effects, expensive, parenteral treatment for longer periods and the emergence of drug resistance. To develop affordable and potent antileishmanial agents, a series of N-acyl and homodimeric aryl piperazines were synthesized with high purity, predicted druggable properties by in silico methods and investigated their antileishmanial activity. The in vitro biological activity of synthesized compounds against clinically validated intracellular amastigote and extracellular promastigote form of Leishmania donovani parasite showed eight compounds inhibited 50% amastigotes growth below 25 µM. The half maximal inhibitory concentration (IC50) and cytotoxicity assessment of eight active compounds, 4a, 4d and 4e demonstrated activity with an IC50 2.0 - 9.1 µM and selectivity index 10 - 42. Compound 4d (IC50 2.0 µM, SI = 42) found to be the best among them with four-folds more potent and eight-folds less toxic than the control drug miltefosine. Overall, results demonstrated that compound 4d is a promising lead candidate for further development as antileishmanial drug.

A Tandem Semipinacol Rearrangement/Aldehyde Arylation or Alkylation of Trisubstituted 2,3-Epoxy Alcohols with Grignard Reagents for Functionalized 1,3-Diols.

A tandem semipinacol rearrangement/aldehyde arylation or alkylation reaction leading to formation of functionalized 1,3-diols bearing three consecutive tertiary stereocenters is identified from the reaction of various new trisubstituted 2,3-epoxy alcohols with numerous Grignard reagents. This reaction is useful for stereoselective construction of three consecutive tertiary stereocenters. The observed 1,3-diols exist in the anti configuration, which is confirmed by two-dimensional nuclear Overhauser effect spectroscopy, the crystal structure of acetonide of 1,3-diol analogue 3ai, and further density functional theory studies.

Regioselective synthesis of functionalized pyrazole-chalcones via a base mediated reaction of diazo compounds with pyrylium salts.

A base-mediated reaction of triaryl/alkyl pyrylium tetrafluoroborate salts with α-diazo-phosphonates, sulfones and trifluoromethyl compounds affords the corresponding functionalized pyrazole-chalcones as 5-P-5 and 3-P-3 tautomeric mixture. The reaction proceeds through an initial nucleophilic addition of diazo substrates to pyrylium salts followed by a base-mediated pyrylium ring-opening and intramolecular 1,5-cyclization to afford formal 1,3-dipolar cycloaddition products. The products underwent a Nazarov-type cyclization upon hydride reduction followed by acidic-workup, furnishing the corresponding indenyl-pyrazoles in high yields.

Quantitative Analysis of Bioactive Carbazole Alkaloids in Murraya koenigii (L.) from Six Different Climatic Zones of India Using UPLC/MS/MS and Their Principal Component Analysis.

Murraya koenigii (L.) Spreng (Curry leaf) is a commercially important medicinal plant in South Asia, containing therapeutically valuable carbazole alkaloids (CAs). Thus, the quantitative evaluation of these compounds from different climatic zones of India are an important aspect for quality assessment and economic isolation of targeted compounds from the plant. In this study, quantitative estimation of CAs among 34 Indian natural populations of M. koenigii was assessed using UPLC/MS/MS. The collected populations represent the humid subtropical, tropical wet & dry, tropical wet, semi-arid, arid, and montane climatic zones of India. A total of 11 CAs viz. koenine-I, murrayamine A, koenigine, koenimbidine, koenimbine, O-methylmurrayamine A, girinimbine, mahanine, 8,8''-biskoenigine, isomahanimbine, and mahanimbine were quantified using multiple reaction monitoring (MRM) experiments within 5.0 min. The respective range for natural abundance of CAs were observed as 0.097-1.222, 0.092-5.014, 0.034-0.661, 0.010-1.673, 0.013-7.336, 0.010-0.310, 0.010-0.114, 0.049-5.288, 0.031-1.731, 0.491-3.791, and 0.492-5.399 mg/g in leaves of M. koenigii. The developed method shown linearity regression coefficient (r2 >0.9995), LOD (0.003-0.248 ng/mL), LOQ (0.009-0.754 ng/mL), and the recovery was between 88.803-103.729 %. The bulk of these CAs were recorded in their highest concentrations in the humid subtropical zone, followed by the tropical wet & dry zones of India. Further, principal component analysis (PCA) was performed which differentiated the climatic zones according to the dominant and significant CAs contents within the populations. The study concludes that the method established is simple, rapid, with high sample throughput, and can be used as a tool for commercial purposes and quality control of M. koenigii.

Metal- and Phenol-Free Synthesis of Biaryl Ethers: Access to Dibenzobistriazolo-1,4,7-oxadiazonines and Vancomycin-Like Glyco-Macrocycles as Antibacterial Agents.

An efficient synthesis of biaryl ethers, from electron-deficient aryl halides using NaH/DMSO under metal- and phenol-free conditions, has been achieved to access dibenzo-bistriazolo-1,4,7-oxadiazonines and vancomycin-like glyco-macrocycles. A 44-membered glyco-macrocycle showed promising activity against vancomycin-resistant Staphylococcus aureus (VRSA).

One-Pot Copper(I)-Catalyzed Ligand/Base-Free Tandem Cyclooxidative Synthesis of Quinazolinones.

A novel and efficient Cu(I)-catalyzed ligand- and base-free multipathway domino strategy has been developed for the synthesis of 2-substituted quinazolinones. The reaction utilizes 2-bromobenzamide and multiform substrates such as aldehydes, alcohols, and methyl arenes for a one-pot protocol, whereas TMSN3 is used as a nitrogen source. A wide range of substrate scope, functional group tolerance, and operational simplicity are synthetically useful features.

Synthesis of S-(-)-5,6-Dihydrocanthin-4-ones via a Triple Cooperative Catalysis-Mediated Domino Reaction.

An enantioselective synthesis of S-(-)-5,6-dihydrocanthin-4-ones via a triple cooperative catalysis-mediated domino reaction having a broad substrate scope is reported. The reaction between substituted 1-formyl-9H-ß-carbolines and terminal alkynes in the presence of catalytic amounts of Jorgensen-Hayashi catalyst, copper iodide, and Hunig base proceeded via a multicascade route, affording the title compounds in good yields and excellent ees with interesting mechanistic features. These compounds were assessed for in vitro antiplasmodial activity against P. falciparum strains. Additionally, 5,6-dihydrocanthin-4-ones are demonstrated to be a versatile precursor to different fused ß-carboline derivatives via simple synthetic transformations.

Identification of gallic acid based glycoconjugates as a novel tubulin polymerization inhibitors.

A novel class of gallic acid based glycoconjugates were designed and synthesized as potential anticancer agents. Among all the compounds screened, compound 2a showed potent anticancer activity against breast cancer cells. The latter resulted in tubulin polymerization inhibition and induced G2/M cell cycle arrest, generation of reactive oxygen species, mitochondrial depolarization and subsequent apoptosis in breast cancer cells. In addition, ultraviolet-visible spectroscopy and fluorescence quenching studies of the compound with tubulin confirmed direct interaction of compounds with tubulin. Molecular modeling studies revealed that it binds at the colchicine binding site in tubulin. Further, 2a also exhibited potent in vivo anticancer activity in LA-7 syngeneic rat mammary tumor model. Current data projects its strong candidature to be developed as anticancer agent.

Naturally Occurring Carbazole Alkaloids from Murraya koenigii as Potential Antidiabetic Agents.

This study identified koenidine (4) as a metabolically stable antidiabetic compound, when evaluated in a rodent type 2 model (leptin receptor-deficient db/db mice), and showed a considerable reduction in the postprandial blood glucose profile with an improvement in insulin sensitivity. Biological studies were directed from the preliminary in vitro evaluation of the effects of isolated carbazole alkaloids (1-6) on glucose uptake and GLUT4 translocation in L6-GLUT4myc myotubes, followed by an investigation of their activity (2-5) in streptozotocin-induced diabetic rats. The effect of koenidine (4) on GLUT4 translocation was mediated by the AKT-dependent signaling pathway in L6-GLUT4myc myotubes. Moreover, in vivo pharmacokinetic studies of compounds 2 and 4 clearly showed that compound 4 was 2.7 times more bioavailable than compound 2, resulting in a superior in vivo efficacy. Therefore, these studies suggested that koenidine (4) may serve as a promising lead natural scaffold for managing insulin resistance and diabetes.

Transition-Metal-Free C-3 Arylation of Quinoline-4-ones with Arylhydrazines.

A transition-metal-free C-3-arylation of quinolin-4-ones in the presence of base has been achieved by using arylhydrazines as aryl radical source and air as oxidant. The reaction proceeds smoothly at room temperature and does not require any prefunctionalization and N-protection of quinoline-4-ones. The utility of this methodology is further demonstrated in synthesis of quinoline-quinolone hybrid as well as 6-aryl-benzofuro[3,2-c]quinoline scaffold.

Genetic diversity and population structure analysis between Indian red jungle fowl and domestic chicken using microsatellite markers.

The present study was conducted to assess the genetic diversity, population structure, and relatedness in Indian red jungle fowl (RJF, Gallus gallus murgi) from northern India and three domestic chicken populations (gallus gallus domesticus), maintained at the institute farms, namely White Leghorn (WL), Aseel (AS) and Red Cornish (RC) using 25 microsatellite markers. All the markers were polymorphic, the number of alleles at each locus ranged from five (MCW0111) to forty-three (LEI0212) with an average number of 19 alleles per locus. Across all loci, the mean expected heterozygosity and polymorphic information content were 0.883 and 0.872, respectively. Population-specific alleles were found in each population. A UPGMA dendrogram based on shared allele distances clearly revealed two major clusters among the four populations; cluster I had genotypes from RJF and WL whereas cluster II had AS and RC genotypes. Furthermore, the estimation of population structure was performed to understand how genetic variation is partitioned within and among populations. The maximum ▵K value was observed for K = 4 with four identified clusters. Furthermore, factorial analysis clearly showed four clustering; each cluster represented the four types of population used in the study. These results clearly, demonstrate the potential of microsatellite markers in elucidating the genetic diversity, relationships, and population structure analysis in RJF and domestic chicken populations.

Synthesis of triazolo isoquinolines and isochromenes from 2-alkynylbenzaldehyde via domino reactions under transition-metal-free conditions.

We describe two simple straightforward syntheses of triazolo isoquinolines (3) and isochromenes (7) from 2-alkynylbenzaldehydes (1) as a common synthon. The synthetic strategy for 3 involves formation of the (E)-1-(2-nitrovinyl)-2-(alkynyl)benzene species 2 via condensation of synthon 1 with nitromethane followed by a [3 + 2] cycloaddition/extrusion of the nitro group/regioselective 6-endo cyclization domino sequence. In yet another strategy, the synthon 1 was condensed with nitromethane followed by electrophilic iodo cyclization of the resulting 2-nitro-1-(2-(alkynyl)phenyl)ethanol (6) to furnish iodo isochromene derivatives. The salient feature of the above two strategies involves formation of the corresponding heterocycles under metal-free conditions in good yields.

A strategy for the synthesis of anthraquinone-based aryl-C-glycosides.

An efficient and simple strategy for the synthesis of a diverse range of anthraquinone-based aryl-C-glycosides has been developed. It involves the sequential Diels-Alder reaction and oxidative aromatization with the preformed glycosyl diene and dienophiles. The glycosyl dienes were obtained from simple sugars by tandem one-pot substitution and elimination reaction.

Modulation of Neurotransmitter Pathways and Associated Metabolites by Systemic Silencing of Gut Genes in C. elegans.

The gut is now recognized as the "second brain" of the human body due to its integral role in neuronal health and functioning. Although we know that the gut communicates with the brain via immunological factors, microbial metabolites, and neurotransmitters, the interplay of these systems remains poorly understood. To investigate this interplay, we silenced 48 genes that are exclusively or primarily expressed in the C. elegans intestine. We studied the associated effects on various aspects of neurodegeneration, including proteotoxicity induced by α-Syn expression. We also assayed behaviours, such as mobility and cognition, that are governed by various neurotransmitters. We identified nine gut genes that significantly modulated these events. We further performed HR-MAS NMR-based metabolomics to recognize the metabolic variability induced by the respective RNAi conditions of R07E3.1, C14A6.1, K09D9.2, ZK593.2, F41H10.8, M02D8.4, M88.1, C03G6.15 and T01D3.6. We found that key metabolites such as phenylalanine, tyrosine, inosine, and glutamine showed significant variation among the groups. Gut genes that demonstrated neuroprotective effects (R07E3.1, C14A6.1, K09D9.2, and ZK593.2) showed elevated levels of inosine, phenylalanine, and tyrosine; whereas, genes that aggravated neurotransmitter levels demonstrated decreased levels of the same metabolites. Our results shed light on the intricate roles of gut genes in the context of neurodegeneration and suggest a new perspective on the reciprocal interrelation of gut genes, neurotransmitters, and associated metabolites. Further studies are needed to decipher the intricate roles of these genes in context of neurodegeneration in greater detail.

A Cyclic Disulfide Diastereomer From Bioactive Fraction of Bruguiera gymnorhiza Shows Anti-Pseudomonas aeruginosa Activity.

Pseudomonas aeruginosa is an opportunistic pathogen that commonly causes hospital-acquired infection and is of great concern in immunocompromised patients. The quorum sensing (QS) mechanism of P. aeruginosa is well studied and known to be responsible for pathogenicity and virulence. The QS inhibitor derived from the natural product can be an important therapeutic agent for pathogen control. The present study reports the role of Bruguiera gymnorhiza purified fraction (BG138) in inhibiting virulence factor production, biofilm formation, quorum sensing molecules, and expression of QS-related genes of P. aeruginosa. Structural characterization of BG138 by high resolution mass spectrometry, Fourier transform infrared spectroscopy, 1D (1H and 13C NMR) and 2D NMR reveals that the fraction is a mixture of already known cyclic disulfide diastereomer, namely, brugierol and isobrugierol. The minimum inhibitory concentration (MIC) of BG138 against P. aeruginosa was 32 µg/ml. Biofilm formation was significantly reduced at sub-MIC concentrations of BG138. Scanning electron microscopy analysis reports the concentration-dependent biofilm inhibition and morphological changes of P. aeruginosa. Flow cytometry-based cell viability assay showed that P. aeruginosa cells exhibit increased propidium iodide uptake on treatment with 32 and 64 µg/ml of BG138. At sub-MIC concentrations, BG138 exhibited significant inhibition of virulence factors and reduced swimming and swarming motility of P. aeruginosa. Furthermore, the effect of BG138 on the expression of QS-related genes was investigated by qRT-PCR. Taken together, our study reports the isolation and structural characterization of bioactive fraction BG138 from B. gymnorhiza and its anti-biofilm, anti-virulence, anti-quorum sensing, and cell-damaging activities against P. aeruginosa.

Assessment of Tissue Specific Distribution and Seasonal Variation of Alkaloids in Alstonia scholaris.

Alstonia scholaris is a well-known source of alkaloids and widely recognized for therapeutic purposes to treat the ailments in human and livestock. However, the composition and production of alkaloids vary due to tissue specific metabolism and seasonal variation. This study investigated alkaloids in leaves, stems, trunk barks, fruits, and flowers of A. scholaris. The impact of seasonal changes on the production of alkaloids in the leaves of A. scholaris was also investigated. One and two-dimensional Nuclear Magnetic Resonance (NMR) experiments were utilized for the characterization of alkaloids and total eight alkaloids (picrinine, picralinal, akuammidine, 19 S scholaricine, 19,20 E vallesamine, Nb-demethylalstogustine N-Oxide, Nb-demethylalstogustine, and echitamine) were characterized and quantified. Quantitative and multivariate analysis suggested that the alkaloids content is tissue specific, illustrating the effect of plant tissue organization on alkaloidal production in A. scholaris. The results suggest that the best part to obtain alkaloids is trunk barks, since it contains 7 alkaloids. However, the best part for isolating picrinine, picralinal, akuammidine, 19 S scholaricine, and 19,20 E vallesamine is fruit, since it shows highest amount of these alkaloids. Undoubtedly, NMR and statistical methods are very helpful to differentiate the profile of alkaloids in A. scholaris.

Stereodivergent Synthesis of (Z)-/(E)-ß-Sulfonylacrylamides via Tandem Difunctionalization of Alkynes with Sulfinates and Isocyanides.

Stereoselective difunctionalizations of the terminal and internal alkynes with various sulfinates and isocyanides have been achieved to prepare (Z)-/(E)-ß-sulfonylacrylamides. The (Z)-ß-sulfonylacrylamides were generated via a one-pot process that involves the reaction of terminal alkynes with sulfinates and isocyanides in the presence of iodine in sequential manner. The (E)-ß-sulfonylacrylamides were prepared in a two-step synthesis via palladium(II)-catalyzed addition of isocyanide to (E)-ß-iodovinylsulfones synthesized from alkynes.

Furostanol saponins from Asparagus racemosus as potential hypoglycemic agents.

Bioactivity guided phytochemical investigation led to isolation of six undescribed furostanol saponins, furoasparoside A-F along with five known compounds, gallic acid, methyl gallate, quercetin-3-O-ß-glucopyranoside, liquiritigenin 4׳-O-ß-apiofuranosyl-(1 â†’ 2)-ß-glucopyranoside and ß-glucogallin for the first time from the roots of Asparagus racemosus. Isolated saponins were screened for their antidiabetic potential in L6-GLUT4myc myotubes in vitro followed by an in vivo evaluation in streptozocin-induced diabetic rats and db/db mice. Furoasparoside E produced a notable decrease in the postprandial blood glucose profile, in leptin receptor-deficient db/db mice, type 2 diabetes model. The effect of furoasparoside E on GLUT4 translocation was found to be mediated by the AMPK-dependent signaling pathway in L6-GLUT4myc myotubes. Moreover, it emerged as a stable plant metabolite with higher bioavailability and efficacy in in vivo pharmacokinetic studies. Therefore, these studies indicated that furoasparoside E may serve as a propitious lead for the management of type 2 diabetes and its secondary complications from natural source.