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Background: Cordia myxa L. (CM) is a valuable ethnomedicinal plant from Boraginaceae family. Traditionally, CM parts especially fruits and leaves are used in chest and urinary tract infections, diarrhoea, dysentery, tuberculosis, liver and spleen disorders, chronic fever, malaria etc. Objective: Despite of known importance and uses, CM has gained relatively less attention of researchers and concise reviews revealing the medicinal potential of CM are scanty. The present review summarizes the chemical constituents and biological activities of CM and aims to stimulate future research to develop it as a functional health food. Results: Analysis of literature on CM showed that its fruits are a rich source of nutrients and are frequently employed in wide ailments such as urinary and respiratory tract infections, chronic fever, liver disorders, asthma, used as anthelmintic, diuretic, expectorant and purgative. Scientific studies have shown the antidiabetic, analgesic, anti-inflammatory, anti-cancer, antioxidant, antiplasmodial, hepatoprotective, hypotensive, antiulcer and antimicrobial activities of CM. More than 45 compounds belonging to carbohydrates, steroids, carotenoids, phenols, flavonoids and alkaloids have been reported from various parts of CM. Conclusion: Systematic preclinical studies support the traditional claims of CM. The analysis of available literature showed that CM could be developed as a drug. Further, studies such as detailed pharmacological and toxicological evaluation, isolation of bioactive compounds, quantitative phytochemistry and structure activity relationship are scanty and thus, crucial to be addressed for uplifting the scientific value of this revered medicinal plant.

Herein, synthesis, spectroscopic studies, single-crystal X-ray diffraction, aggregation-induced emission enhancement (AIEE) and sensing application of water-stable organotin(IV) compounds (4a-6a and 4b-6b) obtained from 3-hydroxy-4H-chromen-4-one ligands is reported. All the synthesized organotin(IV) compounds were characterized using elemental analysis, FT-IR spectroscopy, multi-nuclei NMR (1H, 13C, and 119Sn) spectroscopy, UV-VIS, fluorescence spectroscopy, mass spectrometry, and single-crystal X-ray diffraction. The 119Sn NMR signal of compounds in the range δ –144.92 to –190.68 ppm indicated the formation of hexacoordinated organotin species. The spectroscopic and single-crystal X-ray diffraction studies confirmed the formation of [L2SnR2] type compounds (where L is bidentate ligand and R is an alkyl group) with ‘skew-trapezoidal bipyramidal’ geometry. Further, DFT calculations (of compound 4b) based on DGDZVP basis set fully supported the stability of structure where two short bonds Sn–O(C-O) are cis positioned rather than acquiring trans position. Single-crystal X-ray diffraction analysis of the crystals grown in the presence of water confirmed the stability of 4a in water. Moreover, the water stability of a test compound 4a was established by 119Sn NMR data and spectrofluorimetric data. The spectrofluorimetric scan at different time intervals revealed the stability and constant emission response upto 24 h. The compounds were found fluorescent and exhibited aggregation-induced emission enhancement in MeOH/H2O mixtures, which was confirmed by HRTEM analysis. The test compound 4a showed selective spectrofluorimetric recognition of Pb2+ ions in an aqueous medium by displaying an enhanced emission signal at 478 nm and offered the detection upto 22.66 M. A mechanism of interaction is also proposed by spectroscopic experiments, spectrofluorimetric experiments and computational studies.

Benzothiophenes are valuable heterocycles that are widely used in medicines, agrochemicals, and materials science. Herein, we report a general method for the synthesis of enantioenriched 2,3-disubstituted benzothiophenes via a transition-metal-free C2-alkylation of benzothiophenes with boronic esters. The reactions utilize benzothiophene S -oxides in lithiation–borylations to generate intermediate arylboronate complexes, and subsequent Tf 2 O-promoted S−O bond cleavage to trigger a Pummerer-type 1,2-metalate shift, which gives the coupled products with complete enantiospecificity. Primary, secondary and tertiary alkyl boronic esters and aryl boronic esters are successfully coupled with a range of C3-substituted benzothiophenes. Importantly, this transformation does not require the use of C3 directing groups, therefore it overcomes a major limitation of previously developed transition-metal-mediated C2 alkylations of benzothiophenes.

Radical-induced 1,2-metallate rearrangements of boronate complexes are an emerging and promising class of reactions that allow multiple new bonds to be formed in a single, tuneable reaction step. These reactions involve the addition of an alkyl radical, typically generated from an alkyl iodide under photochemical activation, to a boronate complex to produce an α-boryl radical intermediate. From this α-boryl radical, there are two plausible reaction pathways that can trigger the product forming 1,2-metallate rearrangement: iodine atom transfer (IAT) or single electron transfer (SET). Previous steady state techniques have struggled to differentiate these pathways. Here we apply state-of-the-art time-resolved infrared absorption spectroscopy to resolve all the steps in the reaction cycle, by mapping production and consumption of the reactive intermediates over picosecond to millisecond timescales. We apply this technique to a recently reported reaction involving the addition of an electron-deficient alkyl radical to the strained σ‑bond of a bicyclo[1.1.0]butyl boronate complex to form a cyclobutyl boronic ester. We show that the previously proposed SET mechanism does not adequately account for the observed spectral and kinetic data. Instead, we demonstrate that IAT is the preferred pathway for this reaction and is likely to be operative for other reactions of this type.

Benzoxazolyl linked meta- and para-substituted new chemical entities (5a–5h) featuring thiazolidinedione, rhodanine, hydantoin, and thiohydantoin moieties were synthesized and characterized by 1H NMR, 13C NMR, FT-IR, and HRMS spectral studies. In addition, all compounds were screened for α-glucosidase inhibitory activity and further supported by molecular docking studies carried out at the active site of α-glucosidase (PDB code: 3TOP) in comparison to acarbose used as a standard drug. Out of eight tested compounds, 5d was found as the most active inhibitor of α-glucosidase (IC50 = 9.48 ± 0.36 µM), having rhodanine moiety substituted at meta-position of the phenyl ring.

Dysoxylactam A is a 17-membered macrocyclic lipid which has been found to dramatically reverse multidrug resistance in cancer cells. Three previous syntheses have been reported in 15-17 steps. Using iterative lithiation-borylation reactions as the key C−C bond forming and stereocontrolling steps, we now describe an 11-step synthesis of dysoxylactam A. The complete sequence only required a total of five chromatographic purifications and used minimal protecting groups making it both rapid and efficient.

Our earlier work showed that hydromethanol extract (HME) of Pleurotus florida had antioxidant and anti-cholinesterase potential. This study aimed at isolating the constituent responsible for the activities. HME was subjected to bioactivity guided fractionation using in vitro anti-acetylcholinesterase (Ellman method) and antioxidant (DPPH scavenging assay). The most active constituent was evaluated in vivo employing i.c.v. streptozotocin (STZ) induced dementia in mice. Morris water maze test was used for evaluating memory, followed by biochemical estimations and histopathological studies. Bioactivity guided fractionation resulted in isolation of resveratrol (identified by IR, NMR and MS) and its content in P. florida fruiting bodies was 0.0098% (m/m, by a validated TLC densitometric method). It improved STZ induced dementia and neurodegeneration in mice by reducing brain acetylcholinesterase action and oxidative stress. The observed effects might be the presence of resveratrol. Our results further endorse that P. florida derived resveratrol can be a promising therapy for Alzheimer's disease.

Allylboration of carbonyl compounds is one of the most widely used methods in the stereoselective synthesis of natural products. However, these powerful transformations are so far limited to allyl- or crotylboron reagents; ring-strained substituents in the α-position have not been investigated. Such substrates would lead to an increase in strain energy upon allylboration and as such cause a significant increase in the activation barrier of the reaction. Indeed, no reaction was observed between an α-cyclopropyl allylboronic ester and an aldehyde. However, by converting the boronic ester into the much more reactive borinic ester, the allylboration proceeded well giving alkylidenecyclopropanes in high yield. This process was highly diastereoselective and gives rapid access to versatile alkylidenecyclopropanes and alkylidenecyclobutanes. The chemistry shows a broad substrate scope in terms of both the range of vinylcycloalkyl boronic esters and aldehydes that can be employed. The intermediate boronate complexes were also found to be potent nucleophiles, reacting with a range of non-carbonyl-based electrophiles and radicals, leading to an even broader range of alkylidenecyclopropanes and alkylidenecyclobutanes. Using 11B NMR experiments, we were able to track the intermediates involved, and DFT calculations supported the experimental findings.

A highly diastereoselective, visible-light-induced [3 + 2] cycloaddition between N-sulfonyl cyclopropylamines and electron-deficient olefins is reported. The reactions proceed via the oxidation of a sulfonamide aza-anion by an organic photocatalyst to generate a nitrogen-centered radical. Strain-induced ring opening and intermolecular addition to the olefin generate an intermediate carbon-centered radical that is reduced to an anion prior to 5-exo cyclization. This enables a highly diastereoselective construction of trans-cyclopentanes possessing synthetically useful functional groups.

SrFe12O19 samples were initially prepared using sol-gel auto-combustion method and calcined from 500 to 1100°C (for 6 h). XRD data established the phase formation temperature of SrM phase to be ≈1000°C. Thereafter, the effect of Zn2+-Zr4+ co-dopant on magnetic and structural properties of SrZnxZrxFe12-2xO19 (x = 0.00–1.00) samples calcined between 900–1100°C was investigated. XRD data shows that the cell volume increases (from 690.45Å3 (x = 0.00) to 705.72Å3 (x = 1.00)) while crystallite size decreases (from 123.9 nm (x = 0.00) to 62.3nm (x = 1.00)) calcined at 1000°C. The Rietveld refinement of XRD data confirms a) x = 0.00 sample to be phase pure and b) the presence of ZnFe2O4 (≈2.25) & SrZrO3 (≈2.93%) impurity phases in x = 1.00 sample, calcined at 1000°C. FESEM micrographs revealed that a) grain size decreases for x > 0.20 with `x’ at 900°C and b) increases from 122 nm at 900°C to 443 nm at 1100°C, for x = 0.00. Broadening of Raman bands reveals generation of strain in the lattice with enhancement of Zn2+-Zr4+ concentration. The magnetic studies reveal that the coercivity monotonically decreases (from 5358(x = 0.00) Oe to 690(x = 1.00) Oe at 1000°C) with enhancement of Zn2+-Zr4+ concentration. A maximum Ms value ≈ 70.89 emu/g was observed in x = 0.20 sample at 1100°C. Ms value also decreases for x > 0.20 at each calcination temperature.

Underground coal fires (UCFs) cause remarkable loss of energy resources and significant environmental pollution. Due to the limited capacity of oxygen transport, the inception and development of UCFs represent a very unique mode of coal–oxygen reactions. Therefore, a high-volatile flammable coal sample is thermally analyzed with the combined TGA–DSC approach under four oxygen concentrations (21%, 15%, 9% and 3%) and three heating rates (1 °C min−1, 2 °C min−1 and 5 °C min−1). It is found that the oxygen concentration does not significantly influence the early (low-temperature) stage of coal–oxygen reactions. With the decrease in oxygen concentration, the intensity of the exothermic reactions is reduced and the duration of reactions is extended. Based on the experimental results, the apparent activation energy is calculated. The variation of the apparent activation energy reflects the different reaction stages: volatiles burning and char oxidation, which is verified by the TGA–DSC results. Under the extreme condition of 3% oxygen concentration, a very distinct macroscopic thermochemical behavior is observed, and the limited oxygen supply controls the reaction rate throughout the entire process, which qualitatively explains the persistency of the burning phenomena in most UCFs.

Phytochemicals and naturally occurring antioxidants in grapefruits (Citrus paradisi Macf.) prevent oxidative damage and reduce the risk of chronic diseases such as obesity, diabetes, cancer, and cardiovascular diseases in humans. In the present study, the antioxidant activities and phenolic compounds in the juice, peel, and pulp of four grapefruit varieties (Marsh Seedless, Flame, Rio Red, and Red Blush) were analyzed in relation to fruit maturity. The fruit peel exhibited higher antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC) than the fruit juice and pulp. The antioxidant activities in juice unveiled an increasing trend with fruit development. However, the hydroxyl scavenging activity declined at 180 days after fruit set (DAFS), whereas the TPC and TFC decreased with fruit maturity. The antioxidant activities, TPC, and TFC (except superoxide anion radical scavenging activity) in the fruit peel increased with fruit maturity. With progression of fruit maturity, the antioxidant activities and TFC in fruit pulp decreased, whereas the TPC increased. The Rio Red and Red Blush varieties exhibited more TPC, superoxide activity, and hydroxyl activity at commercial maturity, whereas the Flame variety displayed more TFC. The Red Blush grapefruit variety was most desirable for table purpose use because it demonstrated the highest antioxidant activity, TPC, and TFC in the juice and pulp. However, the peels of Flame and Rio Red varieties were also rich sources of antioxidant compounds that could be used for industrial products. The findings would be helpful for both the nutraceutical industry and crop improvement programs.

Onosma bracteata Wall. (Boraginaceae), commonly known as “gaozaban” is a highly valuable medicinal herb, useful in the treatment of body swellings, abdominal pain, eye-related problems, fever, and urinary calculi. The present study was performed to investigate the antioxidant properties of extract/fractions, viz. ethanol (Obeth) extract, hexane (Obhex) fraction, chloroform (Obcl) fraction, ethyl acetate (Obea) fraction, butanol (Obbu) fraction, and aqueous (Obaq) fraction isolated from O. bracteata. Obea fraction showed stronger free radical quenching ability in various antioxidant assays, as compared to the other fractions. Obea fraction with effective free radical-scavenging properties was further evaluated for the antiproliferative activity against human osteosarcoma MG-63, human neuroblastoma IMR-32, and human lung cancer A549 cell lines using MTT assay. Obea fraction showed strong cytotoxicity with GI50 value of 88.56, 101.61, and 112.7 μg/ml towards MG-63, IMR-32, and A549 cells respectively. Mechanistic studies revealed that Obea fraction in osteosarcoma MG-63 cells increased reactive oxygen species (ROS) level and reduced mitochondrial membrane potential. In the presence of Obea, the cells were found to be arrested in the G0/G1 phase in a dose-dependent manner which is also confirmed by the enhancement in the early apoptotic cell population in flow cytometer analysis. Western blotting demonstrated the decrease in expression of p-NFκB, COX-2, p-Akt, and Bcl-xL, whereas upregulation was observed in the expression of GSK-3β, p53, caspase-3, and caspase-9 proteins. RT-qPCR studies revealed downregulation of Bcl-2, cyclin E, CDK2, and mortalin gene expression and upregulation in the expression of p53 genes. The antioxidant and cytotoxic potential of Obea was attributed to the presence of catechin, kaempferol, onosmin A, and epicatechin, as revealed by HPLC analysis. This is the first report regarding the antiproliferative potential of O. bracteata against osteosarcoma.

The reaction of bicyclo[1.1.0]butyl pinacol boronic ester (BCB‐Bpin) with nucleophiles has been studied. Unlike BCBs bearing electron‐withdrawing groups, which react with nucleophiles at the β‐position, BCB‐Bpin reacts with a diverse set of heteroatom (O, S, N)‐centred nucleophiles exclusively at the α‐position. Aliphatic alcohols, phenols, carboxylic acids, thiols and sulfonamides were found to be competent nucleophiles, providing ready access to α‐heteroatom‐substituted cyclobutyl boronic esters. In contrast, sterically hindered bis‐sulfonamides and related nucleophiles reacted with BCB‐Bpin at the β’‐position leading to cyclopropanes with high trans‐selectivity. The origin of selectivity is discussed.

The synthetically versatile pinacol boronic ester group (Bpin) is generally thought of as a bulky moiety because of the two adjacent quaternary sp3 -hydribized carbon atoms in its diol backbone. However, recent diastereoselective reactions reported in the literature have cast doubt on this perception. Reported herein is a detailed experimental and computational analysis of Bpin and structurally related boronic esters which allows determination of three different steric parameters for the Bpin group: the A-value, ligand cone angle, and percent buried volume. All three parameters suggest that the Bpin moiety is remarkably small, with the planarity of the oxygen-boron-oxygen motif playing an important role in minimising steric interactions. Of the three steric parameters, percent buried volume provides the best correlation between steric size and diastereoselectivity in a Diels-Alder reaction.

The exploration of an anthranilic acid based Schiff base SB as a "Turn-ON" fluorescent probe for the detection of highly toxic selenite (SeIV) and arsenite (AsIII) species in an aqueous medium is described. The selectivity of SB towards SeIV and AsIII in the presence of other ions was investigated by some spectrofluorimetric and 1H NMR spectroscopic experiments. The studies revealed the interaction between SB and AsIII via the deprotonation of phenolic -OH, which enhanced the conjugation in phenolate ion and in turn enhanced the emission response. The SB has analytical prospects for the quantification of AsIII and SeIV with good sensitivity (LODs; 5.15 ppb for SeIV and 3.12 ppb for AsIII calculated by S/N = 3σ/K). Furthermore, it can be used to evaluate real and synthetic samples for the presence of SeIV and AsIII species as well as the fabrication of on-spot recognition devices (in the form of silica gels SB@SiO2 and silica coated TLC aluminium strips SB@SiO2@Al).

A visible-light photoinduced fragmentation borylation of O-phthalimido cycloalkanols with bis(catecholato)diboron is described. Structurally diverse keto and formyloxy alkyl boronic esters are shown to be conveniently prepared by radical-mediated ring opening of cyclic alcohols and hemiacetals, respectively. The reactions proceed under mild conditions in the absence of additives or photocatalysts, display excellent functional group tolerance, and are shown to allow cleavage of 4-, 5-, 6-, and 7-membered ring substrates. The mechanism proceeds via sequential homolytic N–O and C–C bond cleavages, the latter of which involves β-scission of an alkoxy radical, generating a carbonyl and an alkyl radical that is trapped by the diboron reagent. Spectroscopic studies suggest direct photoexcitation of either the phthalimide or diboron substrates with blue light can initiate a radical chain mechanism.

The synthetic protocols, structural aspects, and spectroscopic aspects of mononuclear pseudostannatranes possessing a [4.4.3.01,5]tridecane cage have been reported. A tripodal ligand N(CH2CH2OH){CH...

An experiment was carried out to appraise the effect of seed priming treatment with Mg(NO3)2 against various levels of externally imposed moisture stress by polyethylene glycol-6000 on phytotoxicity in shoot and root and chlorophyll content in maize plant under laboratory conditions. The phytotoxicity of shoot and root was increased as the elevated levels of PEG-6000 towards T1 to T4 (i.e. 1.5 to 4.5 %, Set-I) as compared to control set (T0, i.e. without treated set), while the least values of phytotoxicity were recorded in T5 and onwards increased slowly up to T8 (i.e. 1.5 to 4.5 % of PEG-6000 + primed seed, Set-II). The same trend of phytotoxicity was recorded for both the plant parts at both the times of observations, i.e. shoot and root 120 and 240 hours. The chlorophyll content of shoot was recorded in decreasing trend onwards from T1 to T4 in treatment set-I as compared to T0, i.e. control. While the highest amount of chlorophyll content was recorded in T5 followed by T6 as compared to the rest of the treatments.

A 12-step asymmetric synthesis of thromboxane B2 (TxB2) from 2,5-dimethoxytetrahydrofuran is described. The synthesis employs our organocatalytic aldol reaction of succinaldehyde to give a key bicyclic enal intermediate. From here, the synthetic strategy involves a conjugate addition of an alkenyl side chain to the bicyclic enal, Baeyer–Villiger oxidation, and a highly Z-selective Wittig olefination of a hemiacetal. Key to success was minimizing redox operations and the manipulation of functional groups in the correct order.

A novel series of N-methyl/benzyl-substituted benzimidazolyl-linked para-substituted benzyl-based compounds containing 2,4-thiazolidinediones, dimethyl malonate (DMM), and diethyl malonate (DEM) 17–27 were designed, docked, synthesized, and evaluated for their antidiabetic activity studies. Structures of all the synthesized compounds were confirmed through 1H NMR, 13C NMR, FTIR, and mass spectrometry. Four targeted compounds (17–18 and 22–23) showed good inhibitory potential in the range of 4.10 ± 0.01 to 9.12 ± 0.06 µM. Furthermore, synthesized compounds 17–27 were evaluated for their antioxidant potential and compared with standard ascorbic acid and results showed that compound 18 (EC50 = 0.176 ± 0.002 mM) being the most active. Compounds 17–18 and 22–23 exhibited prominent antidiabetic as well as antioxidant activity. Compound 18 was considered a promising candidate for this series. The designed molecules were docked into α-glucosidase protein (PDB Code. 3TOP) to develop a correlation with the α-glucosidase inhibition studies and were also additionally docked into PPARγ proteins (PDB ID: 2PRG) with rosiglitazone (standard drug) to study their PPARγ binding affinity in comparison with rosiglitazone and to classify these compounds for their PPARγ agonistic behavior.

The genome of Mycobacterium tuberculosis encode for several hypothetical proteins that needed to be characterized. Rv2037c, a hypothetical protein, was 25 and 4 folds upregulated under acidic and nutritive stress, respectively in M. tuberculosis H37Ra. The protein demonstrated lipolytic activity with pNP-decanoate with optimum pH 8.0 and temperature 40 °C. In addition, the protein demonstrated phospholipase activity. To understand the effect of rv2037c on mycobacterium physiology, the gene was cloned and expressed in M. smegmatis. The protein was found in membrane and extracellular fraction. The expression of rv2037c in M. smegmatis (MS_Rv2037c) altered colony morphology and cell surface features like enhanced biofilm and pellicle formation. MS_Rv2037c decreased cell-wall permeability, enhanced TDM content, resistance against various stresses and antibiotics. MS_Rv2037c demonstrated better infection and intracellular survival capability in infected THP-1 macrophage. Macrophages treated with Rv2037c demonstrated irregular cell membrane. Mice infected with MS_Rv2037c had higher bacterial load in lung, liver and spleen compared to control. Rv2037c induced the production of pro-inflammatory cytokines TNFα and IL12, suggesting its role in immune-modulation. Recombinant protein also generated humoral response in EPTB and MDR-TB patients. The results pointed towards the crucial role of this enzyme in cell-wall modulation, infection and intracellular survival of mycobacterium.

Platelet activation results in the generation of thromboxane A2 (TxA2), which promotes thrombus formation by further amplifying platelet function, as well as causing vasoconstriction. Due to its role in thrombus formation and cardiovascular disease, its production is the target of antiplatelet drugs such as aspirin. However, the study of TxA2-stimulated cellular function has been limited by its instability (t1/2 = 32 s, pH = 7.4). Although more stable analogues such as U46619 and difluorinated 10,10-F2-TxA2 have been prepared, we targeted a closer mimic to TxA2 itself, monofluorinated 10-F-TxA2, since the number of fluorine atoms can affect function. Key steps in the synthesis of F-TxA2 included α-fluorination of a lactone bearing a β-alkoxy group, and a novel synthesis of the strained acetal. F-TxA2 was found to be 105 more stable than TxA2, and surprisingly was only slightly less stable than F2-TxA2. Preliminary biological studies showed that F-TxA2 has similar potency as TxA2 toward inducing platelet aggregation but was superior to F2-TxA2 in activating integrin αIIbβ3.

Background: The study was aimed to determine the mechanism of antioxidant effects of Glycyrrhiza glabra L. (GG) roots using in-vitro assays.Methods: The various extracts of GG roots were prepared and evaluated for DPPH scavenging, reducing effects and nitric oxide inhibiting activities. Prepared extracts were screened for the presence of various phytochemicals and quantified on the basis of phytochemical present therein.Results: The results showed that all the prepared extracts contained phenolic compounds. Also, extract showed appreciable antioxidant effects in all three assays employed. However, among prepared extracts, ethylacetate extract was found to have strong free radical inhibition, ferric reducing potential and nitric oxide inhibitory effects. The reason for high antioxidant activity in ethylacetate extract could be attributed to the significant amount phenol compounds present in it. Conclusion: Evidently, GG’s capacity to scavenge free radicals, reducing potential and inhibit nitric oxide contributes to its antioxidant effects and thus, could be a strong candidate for developing antioxidant based drug therapy.

Soil properties can be significantly influenced by the addition of biochar and are known to enhance plant productivity and soil quality. Berseem acts as a good phytoaccumulator. The main aim of this study was to evaluate the effect of different concentrations of biochar on plant height, biomass, and chlorophyll content and on PAHs adsorption capacity at different time intervals. Sixteen treatment combinations were designed in three replicates for a total 144 pots. A soil/biochar (w/w) mixture and poly-aromatic hydrocarbon (PAH) content (50 mg kg−1 naphthalene and 100 mg kg−1 phenanthrene) of suitable ratio for each application was used for filling different pots, having dimensions of 19.6 cm diameter × 20.6 cm height. Various qualitative and quantitative methods were followed for further analysis of soil, plant, and biochar samples. Maximum plant height and plant biomass were observed at 5% and 10% biochar level in the soil as compared to control. Total available nutrients increased with biochar application rate. Increase in biochar concentration resulted in increased PAH adsorption capacity, thereby making it less available to cause the negative effect on plant growth parameters. Bio-concentration factor significantly decreased with increased biochar concentration in soil, i.e., from 92.5 to 5.31 in phenanthrene-contaminated soil and from 17.4 to 1.36 in mixed contaminated soil as compared to control. These results significantly prove that biochar enhanced the PAHs adsorption capacity as well as removal efficiency and crop yield. This study also shows the effectiveness of biochar on contaminant remediation with the help of Trifolium alexandrinum.

The C-terminus fragment (Val-Val-Ile-Ala) of amyloid-β is reported to inhibit the aggregation of the parent peptide. In an attempt to investigate the effect of sequential amino-acid scan and C-terminus amidation on the biological profile of the lead sequence, a series of tetrapeptides were synthesized using MW-SPPS. Peptide D-Phe-Val-Ile-Ala-NH2 (12c) exhibited high protection against β-amyloid-mediated-neurotoxicity by inhibiting Aβ aggregation in the MTT cell viability and ThT-fluorescence assay. Circular dichroism studies illustrate the inability of Aβ42 to form β-sheet in the presence of 12c, further confirmed by the absence of Aβ42 fibrils in electron microscopy experiments. The peptide exhibits enhanced BBB permeation, no cytotoxicity along with prolonged proteolytic stability. In silico studies show that the peptide interacts with the key amino acids in Aβ, which potentiate its fibrillation, thereby arresting aggregation propensity. This structural class of designed scaffolds provides impetus towards the rational development of peptide-based-therapeutics for Alzheimer's disease (AD).

Tin(IV) tricycles form a class of structurally unique and topologically attractive molecules with challenging synthetic attributes. Particularly, “stannatranes and pseudostannatranes” are among the most intensively studied representatives of tin(IV) tricycles. In light of recent research perspectives, this review discusses the progress of stannatranes and pseudostannatranes over the past decades. Herein, stannatranes and pseudostannatranes are arranged into various groups based on their cage skeletons. The synthetic aspects of stannatranes are summarized for different categories of ligating systems, viz. stannatranes with nitrilotriethanolate cages, aminotricarboxylate cages, and substituted nitrilotriethanolate cages. Likewise, detailed synthetic discussions of pseudostannatranes are presented in subsequent sections, comprising [3.3.3.01,5], [4.3.3.01,5], [4.4.3.01,5] and [4.4.4.01,6] cages. Further, intriguing features of stannatranes and pseudostannatranes, such as variation in the Sn–N transannular bond, oligomerization, extended exocyclic bonds, aqueous chemistry and unique spectroscopic aspects, are explained with appropriate examples. Stannatranes possess interesting structural topologies and physical features which can be tuned by controlling the rigidity/flexibility of the ligating system. The choice of the rigid skeleton mitigates oligomerization effects and allows access to highly stable monomeric frameworks. The stability of these systems in aqueous systems facilitates the formation of new hydrolytic species and allows chemical reactivity of the exocyclic bond to obtain new stannatranes.

Stereogenic trifluoromethyl-substituted carbon centers are highly sought-after moieties in pharmaceutical and agrochemical discovery. Here, we show that lithiation–borylation reactions of 2-trifluoromethyl oxirane give densely functionalized and highly versatile trifluoromethyl-substituted α-tertiary boronic esters. The intermediate boronate complexes undergo the desired 1,2-rearrangement of the carbon-based group with complete retentive stereospecificity, a process that was only observed in non-polar solvents in the presence of TESOTf. Although the trifluoromethyl group adversely affects subsequent transformations of the α-boryl group, Zweifel olefinations provide trifluoromethyl-bearing quaternary stereocenters substituted with alkenes, alkynes and ketones.

The identification of spiro N-heterocycles as scaffolds that display structural novelty, three-dimensionality, beneficial physicochemical properties, and enable the controlled spatial disposition of substituents has led to a surge of interest in utilizing these compounds in drug discovery programs. Herein, we report the strain-release-driven Friedel-Crafts spirocyclization of azabicyclo[1.1.0]butane-tethered (hetero)aryls for the synthesis of a unique library of azetidine spiro-tetralins. The reaction was discovered to proceed through an unexpected interrupted Friedel-Crafts mechanism, generating a highly complex azabicyclo[2.1.1]hexane scaffold. This dearomatized intermediate, formed exclusively as a single diastereomer, can be subsequently converted to the Friedel-Crafts product upon electrophilic activation of the tertiary amine, or trapped as a Diels-Alder adduct in one-pot. The rapid assembly of molecular complexity demonstrated in these reactions highlights the potential of the strain-release-driven spirocyclization strategy to be utilized in the synthesis of medicinally relevant scaffolds.

A broad range of acyclic primary and secondary 2,4,6‐triisopropylbenzoate (TIB) esters have been used in lithiation‐borylation reactions, but cyclic TIB esters have not. We have studied the use of cyclic TIB esters in lithiation‐borylation reactions and looked at the effect of ring size (3‐ → 6‐membered rings) on the three key steps of the lithiation‐borylation protocol: deprotonation, borylation and 1,2‐metalate rearrangement. Although all rings sizes could be deprotonated, the cyclohexyl case was impractically slow, and the cyclopentyl example underwent α‐elimination faster than deprotonation at −78 °C and so could not be used. Both cyclobutyl and cyclopropyl cases underwent rapid borylation, but only the cyclobutyl substrate underwent 1,2‐metalate rearrangement. Thus, the cyclobutyl TIB ester occupies a “Goldilocks zone,” being small enough for deprotonation and large enough to enable 1,2‐migration. The generality of the reaction was explored with a broad range of boronic esters., A series of O‐cycloalkyl benzoates were studied to understand their ability to undergo a lithiation–borylation reaction. Ring size was the key feature: too large and the system could not be lithiated; too small and the system could not undergo 1,2‐migration. The cyclobutyl system occupies a “Goldilock's zone” where the lithiation–borylation reaction works well and shows broad substrate scope.

Peptic ulcer is a condition which results from an imbalance between offensive and defensive factors of gastrointestinal system. The investigation was designed to evaluate the antiulcer activity of Symplocos racemosa whole plant methanol extract (MESR) in rat model of indomethacininduced gastric ulceration. The total acidity, gastric volume, pH and free acidity were measured to determine the anti-ulcer activity of MESR. Pretreatment with MESR (125-500 mg/kg) markedly reduced the indomethacin-induced increase in gastric ulcer index and score. These results revealed that antisecretory effects MESR were responsible for antiulcer activity of MESR.

Alkenyl boronic esters are important reagents in organic synthesis. Herein, we report that these valuable products can be accessed by the homologation of boronic esters with lithiated epoxysilanes. Aliphatic and electron-rich aromatic boronic esters provided vinylidene boronic esters in moderate to high yields, while electron-deficient aromatic and vinyl boronic esters were found to give the corresponding vinyl silane products. Through DFT calculations, this divergence in mechanistic pathway has been rationalized by considering the stabilization of negative charge in the C-Si and C-B bond breaking transition states. This vinylidene homologation was used in a short six-step stereoselective synthesis of the proposed structure of machillene, however, synthetic and reported data were found to be inconsistent.

Objectives: Depression is a common neuropsychiatric disorder. The available pharmacotherapy is ineffective for a substantial proportion of patients and has numerous side effects. Therefore, finding safer drugs for the management of depression is of paramount importance. The present study was aimed to identify the compound responsible for anti-depressant like effects of Allium cepa outer scale extract (ACE) and to elucidate its mechanism of action. Methods:The anti-depressant compound from ACE was separated using bioactivity guided fractionation. Furthermore, mouse model of unpredictable chronic mild stress (UCMS) induced depressive behaviour was employed to investigate the anti-depressant like activity and potential mechanism of bioactive compound using behavioural tests (forced swim test (FST), sucrose preference test (SPT), open field test (OFT)) as well as by assessing brain oxidative stress, monoamine oxidase A and serotonin levels. Results:ACE and its ethylacetate fraction (EF) showed marked anti-depressant like effects in mice in the FST model. Chromatographic and spectroscopic studies of EF lead to the isolation of quercetin and quercetin 4'-O-glucoside (QG). Of these, QG (20 mg/kg) treated animals showed activity similar to that shown by fluoxetine in mice using FST. Thus, QG was tested for anti-depressant like activity against UCMS induced depressive behaviour in mice. Treatment of UCMS- exposed mice with QG (20 mg/kg) improved UCMS induced behaviour anomalies and restored brain biochemical parameters (oxidative stress, MAO-A activity and serotonin levels). Discussion:QG is responsible for anti-depressant like effects of ACE possibly via prevention of brain oxidative stress and restoring serotonin levels by inhibiting MAO-A activity.

Pearl millet (PM) starch was reacted with acetic anhydride at different concentrations (1.25, 2.5, 3.75 & 5.0%) and its physicochemical, rheological, morphological and in vitro digestibility properties were compared with native starch. The acetyl (%) and degree of substitution (DS) of acetylated starches ranged between 1.07 and 2.15% and 0.040-0.081, respectively. Swelling power and solubility of acetylated PM starch increased progressively upto 3.75% level of acetylation, however, further increase in acetylation levels resulted in a decrease. Peak, setback and final viscosities of acetylated PM starches were higher than their native counterpart starch. Both native and acetylated PM starches showed similar A-type X-ray diffraction patterns. During heating, storage modulus (G') and loss modulus (G″) of acetylated starches ranged between 753 and 1177Pa and 96-129Pa, respectively. G' was much higher than G'' at all the values of angular frequency studied. Both native and acetylated PM starch pastes showed flow behaviour index value of

While radical additions to π-bonds are well established, additions to σ-bonds are far less explored. We have found that electron deficient radicals derived from alkyl iodides under visible light irradiation add to the central strained bond of bicyclobutyl (BCB)-boronate complexes and lead to 1,3-alkyl disubstituted cyclobutyl boronic esters in high yields, with full stereospecificity and high levels of stereoselectivity. Novel cyclobutyl-substituted structures, including peptide and steroid boronic ester derivatives can be accessed. Additionally, although the use of electron-rich alkyl iodides as radical precursors was found to be ineffective, an alternative route involving alkylsulfonylation of the BCB-boronate followed by reductive desulfonylation provided access to simple alkyl substituted cyclobutane products.

The use of pyridinium‐activated primary amines as photoactive functional groups for deaminative generation of alkyl radicals under catalyst‐free conditions is described. By taking advantage of the visible light absorptivity of electron donor–acceptor complexes between Katritzky pyridinium salts and either Hantzsch ester or Et3N, photoinduced single‐electron transfer could be initiated in the absence of a photocatalyst. This general reactivity platform has been applied to deaminative alkylation (Giese), allylation, vinylation, alkynylation, thioetherification, and hydrodeamination reactions. The mild conditions are amenable to a diverse range of primary and secondary alkyl pyridiniums and demonstrate broad functional group tolerance.

The dyeing of wool fabric using a natural dye extracted from Dacryodes macrophylla has been studied using both conventional as well as ultrasonic dyeing methods. Natural dye was extracted using water as solvent by Soxhlet extraction method. The extracted color was characterized by spectroscopic studies like UV/Visible and further tested for antimicrobial activity (against Vibrio cholerae (MTCC3906), Salmonella enterica serotype typhi (MTCC733), Shigella flexneri (MTCC1457), Escherichia coli (MTCC119), Listeria monocytogenes (MTCC657) and Staphylococcus aureus (MTCC 96). It was observed that the water extract of D. macrophylla showed antimicrobial activities against S. enterica. The effect of mordants on the dyeing outcome in terms of colour depth as well as fastness properties of the dyeing was investigated. It has been found that employing all the three techniques of dyeing i.e., conventional dyeing at 100 oC and 80 oC as well as ultrasonicated dyeings conducted at 80 oC, the mordanted samples were deeper in depth than their unmordanted counterparts. The results of fastness properties of the dyed fabrics were fair to good. Depths of the shade and fastness properties in case of ultrasonic dyeing were found to be better compared to conventional dyeing. Dacryodes macrophyllaextract was found to enhance microbial resistance of wool as well as was itself as a good source of coloration. These textiles dyed with the natural dyes can be very useful in developing clothing for infants, elderly and infirm people to protect them against common infections.

Herein, the prospect of using a silatranyl derivative of dye for dyeing purpose is discussed. Firstly, a silatranyl derivative of methyl red was synthesized and characterized by spectroscopic and elemental analysis. Then, a comparative examination on the fixation of methyl red and its silatranyl derivative on cotton cloth was done after optimizing various parameters. Dye fixation studies, FT-IR, and scanning electron microscopic studies revealed better fixation of silatranyl dye derivative as compared to parent dye. Silanized methyl red was fixed on fiber via covalent interactions whereas methyl red exhibited physical sorption. Covalent fixation of dye on the cotton cloth prevented leaching of dye from cloth even after water and soap treatment for longer periods. Moreover, hydrolysis of silatranyl cage of silanized dye in excessive water (i.e. water fraction fw = 50% v/v in methanol–water mixture) to form dye incorporated silica offers an advantage for pretreatment of dye remains. Thus, the silatranyl derivative of methyl red has prospects as a dyeing agent in the future as it offers benefits to improve colour impression and treatment of dye effluent.

The one-pot sequential coupling of benzylamines, boronic esters, and aryl iodides has been investigated. In the presence of an N-activator, the boronate complex formed from an ortho-lithiated benzylamine and a boronic ester undergoes stereospecific 1,2-metalate rearrangement/anti-SN 2' elimination to form a dearomatized tertiary boronic ester. Treatment with an aryl iodide under palladium catalysis leads to rearomatizing γ-selective allylic Suzuki-Miyaura cross-coupling to generate 1,1-diarylalkanes. When enantioenriched α-substituted benzylamines are employed, the corresponding 1,1-diarylalkanes are formed with high stereospecificity.