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Elucidation of the photophysical and biochemical properties of small molecules can facilitate their applications as prospective therapeutic imaging (theragnostic) agents. Herein, we demonstrate the luminescence behavior of a strategically designed potential therapeutic thiosemicarbazone derivative, ( more...

Climate change affects nitrogen dynamics in crops and diazotrophic microorganisms with carbon dioxide (CO

Herbal medicines have been used for the treatment of various health-related problems since immemorial times. However, Indian Pharmaceuticals Act 1948 states that still there is no special group for herbal drugs. Thus, the expansion of the Indian medicinal systems such as Ayurveda, Siddha, and Unani require scientific validation and documentation of indigenous knowledge to work on patenting and research based on literature. At present, various governmental organizations are actively playing a significant role in the promotion and development of medicinal plants such as the Ministry of Ayush, CDSCO (Central Drugs Standard Control Organization), and D&C Act 1940 & 1945 (amendment) are used to regulate the processing, branding and marketing of herbal medicines. A total of 8000 herbal medicines have been recognized by the Ministry of Ayush to treat various ailments in India. This chapter illustrated various approaches of regulatory bodies for plant-based herbal drugs discovery and validation. more...

Two different chemical methods, TEMPO-oxidation and nitro-oxidation, were used to extract carboxyl cellulose nanofibers (CNFs) from non-wood biomass sources (i.e., jute, soft and hard spinifex grasses). The combined TEMPO-oxidation and homogenization approach was very efficient to produce CNFs from the cellulose component of biomass; however, the nitro-oxidation method was also found to be effective to extract CNFs directly from raw biomass even without mechanical treatment. The effect of these two methods on the resulting cross-section dimensions of CNFs was investigated by solution small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The UV-Vis spectroscopic data from 0.1 wt% TEMPO-oxidized nanofiber (TOCNF) and nitro-oxidized nanofiber (NOCNF) suspensions showed that TOCNF had the highest transparency (> 95%) because of better dispersion, resulted from the highest carboxylate content (1.2 mmol/g). The consistent scattering and microscopic results indicated that TOCNFs from jute and spinifex grasses possessed rectangular cross-sections, while NOCNFs exhibited near square cross-sections. This study revealed that different oxidation methods can result in different degrees of biomass exfoliation and different CNF morphology. more...

The main aim of this work was production and optimization of lipase from Fusarium incarnatum KU377454 by central composite design (CCD) based response surface methodology (RSM). The maximum lipase activity (37.80 ± 0.55 IU/mL) was obtained within 5 d of incubation. The produced lipase was partially purified by salting out technique. Then purified lipase was immobilized using Fe3O4 NPs and further nanoparticles immobilized lipase was evaluated by different characterization study (FTIR, XRD, FESEM, EDX, Zeta potential, UV-spectroscopy, and BET). Then, Fe3O4 immobilized lipase was applied for waste cooking oil (WCO) degradation. It showed 90% biodiesel product yield with major fatty acid yields of linoleic acid, oleic acid, palmitic acid, and linolenic acid. The reusability study of immobilized lipase showed that it could retain 75% of its activity after 5 cycle of waste cooking oil degradation. more...

The principal intent of this work is to explore whether the site-specific binding of a newly synthesized quinoline-appended anthracenyl chalcone, (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ), with an extracellular protein of the human circulatory system, human serum albumin (HSA), can control the rotamerization of its sole tryptophan residue, Trp-214. With this aim, we have systematically studied the binding affinity, interactions, and localization pattern of the title compound inside the specific binding domain of the transport protein and any conformation alteration caused therein. Multiple spectroscopic experiments substantiated by an in silico molecular modeling exercise provide evidence for the binding of the guest ADMQ in the hydrophobic domain of HSA, which is primarily constituted by residues Trp-214, Arg-218, Arg-222, Asp-451, and Tyr-452. Rotationally restricted ADMQ prefers to reside in Sudlow site I (subdomain IIA) of HSA in close proximity (2.45 nm) to the intrinsic fluorophore Trp-214 and is interestingly found to control its vital rotamerization process. The driving force for this rotational interconversion is predominantly found to be governed by the direct interaction of ADMQ with Trp-214. However, the role of induced conformational perturbation in the biomacromolecule itself upon ADMQ adoption cannot be ruled out completely, as indicated by circular dichroism, 3D fluorescence, root-mean-square deviation, root-mean-square fluctuation, and secondary structure element observations. The comprehensive spectroscopic study outlined herein provides important information on the biophysical interaction of a chalcone-based potential therapeutic candidate with a carrier protein, exemplifying its utility in having a regulatory effect on the microconformations of Trp-214. more...

In the development of small-molecule drug candidates, naphthalimide-based compounds hold a very important position as potent anticancer agents with considerable safety in drug discoveries. Being synthetically and readily accessible, naphthalimide compounds with planar architecture have been developed mostly as DNA-targeting intercalators. However, in this article, it is demonstrated, for the first time, that an unfused naphthalimide-benzothiazole bichromophoric compound 2-(6-chlorobenzo[ d] thiazol-2-yl)-1 H-benzo[ de] isoquinoline-1,3(2 H)-dione (CBIQD), seems to expand the bioactivity of naphthalimide as anti-mitotic agent also. Preliminary studies demonstrate that CBIQD interferes with human lung cancer (A549) cell proliferation and growth and causes cellular morphological changes. However, the underlying mechanism of its antitumor action and primary cellular target in A549 cells remained skeptical. Confocal microscopy in A549 cells revealed disruption of interphase microtubule (MT) network and formation of aberrant multipolar spindle. Consistent with microscopy results, UV-vis, steady-state fluorescence, and time-resolved fluorescence (TRF) studies demonstrate that CBIQD efficiently binds to tubulin ( K more...

Enzymes are also known natural catalysts. Lipases are flexible enzymes that are mostly used. These enzymes are found extensively all over the animal and plant kingdoms, likewise in molds and bacteria. Among all identified enzymes, lipases have concerned the mainly biotechnological attention. This review paper discusses the characteristic, microbial origin and application of lipases. The present review discussed about different characteristics and sources (fungal, bacteria’s) of lipase. The present article also discussed about different bioreactors used for lipase production and different biotechnological applications (food, detergent, paper and pulp, biofuels etc) of lipases. An observation to considerate lipases and their applications as bulk enzymes and high-value of production, these enzymes are having huge impact in different bioprocesses. more...

Azapodophyllotoxin (AZP) derivatives, the alternative scaffolds to podophyllotoxins, are intriguing class of small molecules with high anti-proliferative activity against several cancer cell lines. The physicochemical factors associated with or responsible for, anticancer activity which change as a function of the intrinsic molecular nature and its interaction with environment encouraged us to study the detailed photophysics of structurally simplest AZP, 4-(2-Hydroxyethyl)-10-phenyl-3,4,6,7,8,10-hexahydro-1H-cyclopenta[g]furo[3,4-b]quinoline-1-one (HPFQ), for the first time for this class, using steady-state absorption, emission and time-resolved fluorescence (TRF) spectroscopy and TRF anisotropy in solvents of diverse polarity. HPFQ exhibits (i) primary emission originating from a mixed contribution of locally excited (LE) and pure charge transfer (CT) states and (ii) a red shifted excimer emission. The presence of more than one emitting species is confirmed by the wavelength dependent TRF studies. HPFQ shares compatible H-bonding motifs with all solvents: the H-bond acceptor solvents interact with −OH functionality while H-bond donor solvents interact with both −OH and carbonyl oxygen in cyclic ester (ring D). It is demonstrated that the H-bond interactions causes a small change in dipole moment (Δμ ∼3.52D) and directly affect the extent of HPFQ fluorescence quantum yield (ϕf). This cartel of substantial H-bond network and the weak electron acceptor nature of ring D serve as protagonist for the photophysical conduct and impressive fluorescence in all solvents, which is a very rare phenomenon and has been difficult to achieve across the entire polarity scale. Additionally, ϕf and fluorescence lifetime of CT state illustrate high sensitivity to solvent polarity, proticity and viscosity. The lower viscosity of water propels a faster deactivation and a sudden decrease in CT state lifetime in aqueous medium. The lower ϕf in water when compared to alcohols is possibly due to entrapment of water solvent molecules within the cavity formed by close proximity of flexible CH2CH2OH and phenyl (ring E) groups. Thus, the knowledge provided herein can prove momentous for decoding the fluorescence behaviour of other compounds in this category, and even the parent podophyllotoxins! Overall, the magnificent emission showcased by the antitumor HPFQ is important as it can act as a dual therapeutic and imaging agent without the use of co-staining for determining the impact of environmental factors in cancer pathophysiology in future. more...

To reduce crude oil pollution and their environmental impacts, the production of biofuels is the inimitable pathway. Biofuels can be utilized as fuel with significant features like low cetane number and octane number and high heat of vaporization. The major drawbacks of these fuels are corrosiveness, low flame luminosity, water miscibility, ecological toxicity, and lower vapor pressure. The critical problems in biofuels are the availability of raw materials and their dependence on the geographic locations because the availability of feedstocks can vary every season. The utmost feedstock for biofuel production is forestry residues, agricultural residues, and municipal waste due to their low cost and high availability that are known as lignocellulosic biomass, though the large-scale production has still not been recognized. Additionally, the considerable use of microbes and their supply that turn into the production of biofuel process is exceedingly unusual. For the production of biomass-based biofuels, different procedures and renovation technologies are under development and anticipated to be established. This chapter will discuss the types of lignocellulosic biomass, biofuels, and different processes of efficient biofuel production. Biofuels are being a feasible alternative to fossil fuels. The use of lignocellulosic biomass has attracted considerable attention in various engineering and science disciplines to produce biofuels. On the earth, it is the utmost abundant renewable bioresource. The hemicellulose and cellulose are bound with lignin and other molecules (ash) in lignocellulosic biomass to form a complex structure, which is difficult to access for microbial degradation. This chapter highlights some technologies using biorefineries for the production of biofuels, for example, genetic and metabolic engineering, and their present status and future prospect in the production of biofuels production from lignocellulosic biomass. more...

Production of biofuels is the unique way to reduce environmental impact and crude oil pollution. Biofuels can be used as fuel with considerable features like high heat of vaporization and low cetane number and octane number. Their major weaknesses are lower vapor pressure, corrosiveness, water miscibility, low flame luminosity, and environmental toxicity. The availability of raw materials is the critical problem in biofuels, and depending upon the geographic locations, the availability of feedstocks can differ season to season. Agricultural residues, forestry residues, and municipal waste are lignocellulosic biomass, which is well-known feedstock for bioethanol reason of its low cost and high availability, although the marketable production has still not been recognized. Additionally, the supply and the considerable use of microbes make the biofuel production process highly uncharacteristic. Different methods for biomass-based biofuel production and renovation technologies are under improvement and expected to be established. In this chapter, we will discuss about the lignocellulosic, different biomass, and different process of efficient biofuel production. more...

The reduction in size through top-down and bottom-up approaches causes difference in the physical, chemical, and biological properties as compared to original particle.

In the present study, lipase production from mutated strain of Fusarium incarnatum KU377454 was optimized through central composite design (CCD) based response surface methodology (RSM). The maximum lipase production (4.01 IU/mL) was obtained within 4 days of incubation using 0.1% CaCl2 concentration and 8% wheat bran concentration. Further, salting out technique was applied for partial purification of lipase. The partially purified lipase was immobilized using Au@Ag bimetallic nanoshell. The characterization of immobilized lipase was carried out by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transformed infrared (FTIR), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The immobilized lipase could retain its 95% of activity after 15 days of storage at 4 °C. Subsequently, Au@Ag immobilized lipase was used for the degradation of waste cooking oil (WCO), which showed higher WCO degradation (85%) compared to the free lipase mediated waste cooking oil degradation (71%). The immobilized lipase could be reused for five times without any loss of its activity. more...

In the present study, lipase production from mutated strain of Fusarium incarnatum KU377454 was optimized through central composite design (CCD) based response surface methodology (RSM). The maximum lipase production (4.01 IU/mL) was obtained within 4 days of incubation using 0.1% CaCl(2) concentration and 8% wheat bran concentration. Further, salting out technique was applied for partial purification of lipase. The partially purified lipase was immobilized using Au@Ag bimetallic nanoshell. The characterization of immobilized lipase was carried out by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transformed infrared (FTIR), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The immobilized lipase could retain its 95% of activity after 15 days of storage at 4 °C. Subsequently, Au@Ag immobilized lipase was used for the degradation of waste cooking oil (WCO), which showed higher WCO degradation (85%) compared to the free lipase mediated waste cooking oil degradation (71%). The immobilized lipase could be reused for five times without any loss of its activity. more...

Amyloid-β peptides and their metal-associated aggregated states have been implicated in the pathogenesis of Alzheimer's disease. The present paper epitomises the design and synthesis of a small, neutral, lipophilic benzothiazole Schiff base (E)-2-((6-chlorobenzo[d]thiazol-2-ylimino)methyl)-5-diethylamino)phenol (CBMDP), and explores its multifunctionalty as a potential metal chelator/fluorophore using UV-visible absorption, steady-state fluorescence, single molecule fluorescence correlation spectroscopic (FCS) techniques which is further corroborated by in silico studies. Some pharmaceutically relevant properties of the synthesized compound have also been calculated theoretically. Steady-state fluorescence and single molecule FCS reveal that the synthesized CBMDP not only recognizes oligomeric Aβ40, but could also be used as an amyloid-specific extrinsic fluorophore as it shows tremendous increase in its emission intensity in the presence of Aβ40. Molecular docking exercise and MD simulation reveal that CBMDP localizes itself in the crucial amyloidogenic and copper-binding region of Aβ40 and undergoes a strong binding interaction via H-bonding and π-π stacking. It stabilizes the solitary α-helical Aβ40 monomer by retaining the initial conformation of the Aβ central helix and mostly interacts with the hydrophilic N-terminus and the α-helical region spanning from Ala-2 to Val-24. CBMDP exhibits strong copper as well as zinc chelation ability and retards the rapid copper-induced aggregation of amyloid peptide. In addition, CBMDP shows radical scavenging activity which enriches its functionality. Overall, the consolidated in vitro and in silico results obtained for the synthesized molecule could provide a rational template for developing new multifunctional agents. more...

The present study epitomizes the identification of ground state geometry, determination of X-ray structure and solvent dependent excited state intramolecular proton transfer (ESIPT) process of a potential bioactive benzothiazole Schiff base ligand viz (E)-2-((6-chlorobenzo[d]thiazol-2-ylimino)methyl)-5-(diethylamino)phenol (CBMDP) using 1H and 13C NMR, FTIR, single crystal XRD, electronic absorption, steady state emission, time resolved and 3D-fluorescence spectroscopic techniques. The experimental observations have further been corroborated with quantum chemical calculations using Density Functional Theory (DFT) and Time Dependent DFT (TDDFT) methods. Single crystal X-ray structure confirms the existence of enol-imine (N) form of CBMDP in the ground state due to strong intramolecular hydrogen bond between phenolic hydrogen and azomethine nitrogen. The photophysical studies reveal that on photoexcitation, the molecule undergoes structural changes via ESIPT reaction. Dual emission have been identified from the excited enol-imine (N*) and tautomeric keto-amine (T*) species in non-polar heptane. The redistribution of the electron density in the photoexcited CBMDP molecule is visualised from DFT and TDDFT calculations. This electronic redistribution enhances the in basic character of azomethine nitrogen which is reflected in the Mulliken partial atomic charges increases from −0.21 to −0.56, which ultimately leads to an intramolecular hydroxyl proton transfer in the excited state. The simultaneous emission from two states are also theoretically supported by the low energy difference (0.66 kcal/mol) between the N* and T* form in the potential energy surface diagram. The consolidated spectroscopic research, described herein, provides enormous information to open up the new avenues in designing and synthesizing potential bioactive benzothiazole Schiff bases for medicinal chemistry research. more...

The use of bio-based nanoparticles is getting importance due to their ecofriendly and economic nature. Bio-based nanoparticles mainly synthesized from bottom-up approach and mother protein, secondary metabolite, extract, etc. act as stabilizing and capping agent. It helps to synthesize more stable and uniform nanoparticles as compared to chemical methods. High catalytic activity, more surface area, ion exchange capacity, fluorescence activity, and presence in different dimension such as metals, ceramics, and magnetic form allowed use of nanoparticles and their formulation in the field of agriculture such as soil nutrients, crop protectants, environment cleanup, contaminant detection, and reduction of post-harvest losses. Further, nano formulation approaches for controlled delivery of pesticides, nutrients, genetic materials, and growth stimulator can act as an another boon in the agriculture sector. more...

Molecular switches are valuable tools for the detection of many chemical and biological processes. On the other hand, Schiff bases are known for their simplicity in synthesis and their enormous biochemical applications. In this scenario, when a strategically designed Schiff base acts as a molecular switch in biomimetic environments drags inevitable attention. In this article, we hereby demonstrate an interesting behavior of a strategically designed bioactive benzothiazole based Schiff base (E)-2-(((6-chlorobenzo[d]thiazol-2-ylimino)methyl)-5-diethylamino) phenol (CBMDP) whose fluorescence characteristics dramatically modulate as consequence of its structural modification in aqueous and biomimetic environments individually. Electronic absorption, steady state and time resolved fluorescence spectroscopic techniques along with DFT based quantum chemical calculation evidence that in pure organic solvents CBMDP exists in highly fluorescent enol-imine (N) form which transform into feebly fluorescent hydrated species (H) in bulk aqueous media. Contrariwise, on interaction with the ionic and non-ionic micellar media or with liposome, a structural restoration occurs from less fluorescent hydrated (H) species into a highly fluorescent normal (N) one. This molecular flipping of the title compound upon micellar compartmentalization is possibly caused by the micropolarity of the local environment and further supported by its spectral behavior in different polarity gradient solvent mixture of water-dioxane (protic-aprotic) and water-methanol (protic –protic). Usually, Schiff bases are prone to hydrolysis in aqueous media, interestingly, the structural framework of this strategically designed molecule only allow the first step of hydrolysis, which is hydration of azomethine linkage whereas it withstand the second step, and that possibly helps the structural restoration process. Hence the article described herein may emphasize how a systematically designed Schiff base framework can be used as ‘turn off- turn on' fluorescent molecular switch which may be extremely useful for its applications in the area of biochemical sensors. more...

Aluminum phthalocyanine tetrasulphonate (AlPcS 4 ) is a well characterized water soluble phthalocyanine dye having structural similarities with porphyrin and has immense applications as a photosensitizer in photodynamic therapy (PDT). The present article embodies the exploration of physicochemical properties of PDT active AlPcS 4 and its interaction with DNA alkylating quinone in biomimicking micellar microenvironments to overcome the limitation of PDT that is caused by the hypoxic nature of solid tumor. UV–vis absorption, steady state emission and time resolved fluorescence spectroscopy reveal that the AlPcS 4 does not undergo considerable interaction with anionic SDS as well as uncharged Triton X-100 micelle, whereas in case of the series of a cationic surfactant (DTAB, TTAB, CTAB) it shows a significant columbic attraction toward the positively charged head group of the surfactant molecule. In premicellar concentration, surfactant induced aggregation of the probe molecule is observed, which subsequently disaggregates into its monomeric form above critical micellar concentration. The anionic dye localizes itself in the Stern layer of cationic micelles. The escalation of the fluorescence anisotropy value ( r ) with increase in the surfactant concentration is explained by the rise in compactness around the probe with increasing chain length of the cationic surfactant. However, the compactness has a reverse effect on the extent of water penetration or micellar hydration, which in turn decreases the polarity of microenvironment in the Stern layer. The fully micellized PDT active AlPcS 4 experiences stronger interaction with DNA alkylating quinone in confined medium as compared to the aqueous solution and the above said interaction intensifies with decrease in the micellar hydration. This spectroscopic research described herein may provide relevant addition to the usefulness of this bioactive dye–quinone system for the application in photodynamic therapy. more...

The legacy of phosphorescence from expensive organometallic compounds has inspired researchers to develop efficient metal-free organic phosphors. Although organic phosphors offer a cheaper alternative, the long-lived triplets of organic phosphors that are primarily consumed by vibrational dissipation need to be adequately suppressed, and this provides an opportunity to design new organic entities, at par with the organometallic compounds, based on conformational control and incorporation of useful functional groups to alter their emissive properties, especially phosphorescence. Here, we have achieved a proficient dual state emission, underlining the key design rule of conformational control in an organic molecular platform for 2-(6-chlorobenzo[d]thiazol-2-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (CBIQD). In contrast to other known naphthalimides, the system limiting access to non-radiative triplet states is achieved by steric encumbrance which exhibits strong phosphorescence. Here, in addition to strong fluorescence (from planar conformer), phosphorescence is unlocked by suppression of non-radiative channels from the non-planar conformer in glassy solvents (77 K) and when embedded in a polymer matrix of poly(methyl methacrylate) (PMMA) at RT. The spectroscopic delineation of adopted geometry and optical property relationship is sought by a steric approach, extent of intramolecular charge transfer (ICT), presence of carbonyl groups, directed heavy atom effect and the spin-orbit coupling (SOC) invoked by -S- and -Cl atoms. Time dependent density functional theory (TD-DFT) is used to explain the favourable mechanistic path for the decay of excited states (ESs) leading to phosphorescence from a non-planar conformer and fluorescence from a planar conformer. The spectacular access to the radiative singlet and triplet states suggests that there is less scope for loss channels. The phosphorescence of the CBIQD-PMMA system may find use in other biomedical applications due to the biocompatibility of each component. more...

The hypoxic nature of solid tumours and the aggregation of photosensitizers in physiological environments are two governing limiting factors in photodynamic therapy (PDT). This article describes the effect of sensitivity to polarity and the central metal ion on the aggregation–disaggregation pattern of the PDT-active metallophthalocyanine ZnPcS4 and its relevant interaction with a DNA alkylating quinone in an aqueous medium, as well as in a biomimicking micellar microenvironment, under hypoxic conditions to overcome the limitations of PDT. Steady-state absorption and emission, time-resolved fluorescence (TRF), fluorescence anisotropy and dynamic light scattering (DLS) techniques were employed for this purpose. Similarly to AlPcS4, the spectral behaviour of ZnPcS4 remains immune to anionic SDS and also displays a significant interaction with the positively charged head group of cationic surfactants (DTAB, TTAB, and CTAB). In the premicellar region, surfactant-induced aggregation of the probe molecules is dominant. Above the critical micellar concentration (CMC), AlPcS4 fully disaggregates into monomers but the tendency of ZnPcS4 to undergo monomerization increases with a decline in the compactness of cationic micelles. The increase in the fluorescence anisotropy of ZnPcS4 in a fully micellized system upon reducing the compactness of the micelles confirms deeper penetration of the dye inside the micelles, a behaviour which is the reverse of that of AlPcS4. The latter remained resistant in neutral micelles, whereas ZnPcS4 substantially monomerized on an increase in the TX-100 concentration and distributed itself at the shear surface and in the deeper hydrophobic core of a fully micellized system. Dye-induced formation of micellar clusters was identified by DLS measurements, especially in cationic micelles. The interaction of PDT-active ZnPcS4 with DNA alkylating 2,5-dichlorodiaziridinyl-1,4-benzoquinone (AZDCIQ) was studied in an aqueous medium, as well as in all the micellar microenvironments under study, and found to be more prominent in cationic micelles compared with the other systems. However, the association constants (Ka) thus obtained in the cationic micelles were found to be greater for ZnPcS4 than for AlPcS4. Our findings may prove instrumental in expanding the effectiveness and applicability of metallophthalocyanines in terms of understanding their aggregation pattern and interaction with DNA alkylating quinones in a hypoxic micellar microenvironment. more...

Inhibition of Angiotensin Converting Enzyme (ACE) is identified as a main therapeutic target in controlling hypertension. The principal intent of this work is to investigate the ACE inhibitory property of a quinoline appended chalcone derivative (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ), and its binding mechanism with model transport protein BSA by employing steady state and time resolved fluorescence, Circular Dichroism (CD), in silico molecular docking, Induced Fit Docking (IFD) and Molecular Dynamics (MD) simulation. Incubation of ADMQ with kidney cortex plasma membrane shows considerable antihypertensive effect by the inhibition of ACE. ADMQ undergoes strong interaction with ACE both in the absence and presence of BSA. Comparable ACE inhibitory mechanistic profile of ADMQ with standard drug captopril has been identified in terms of the ligand interaction pattern, changes in secondary structural elements and protein RMSF. The steady state emission of BSA undergoes a remarkable decrement via ground state complex formation upon addition of ADMQ in an aqueous buffer solution of BSA at a physiological pH of 7.4 contrary to the time resolved and FRET measurement where both the static and energy transfer mechanism co-exists. The rotationally restricted ADMQ molecule shows strong binding affinity towards subdomain IIA of site I with a close proximity (2.45 nm) to the Trp 213 residue. The minor decrease of α-helical content as calculated from CD spectral measurement and 1–3 A change in protein RMSD during MD simulation clearly indicate that the polypeptide chain is partially destabilized due to the above site specific accommodation of the host (ADMQ). A slight diminution in the ACE inhibitory profile is observed in the presence of BSA; however BSA shows lesser binding towards ADMQ in the presence of the target enzyme. The spectroscopic research described herein may provide enormously important information for ACE inhibition of the chalcone derivative and its detailed binding interaction with a carrier protein for chalcone based drug designing in medicinal chemistry research. more...

The present paper epitomizes the detailed physicochemical behaviour of photodynamic active chlorin e6 (Ce6) and its interaction with the DNA alkylating quinone; 2,5-dichloro diaziridinyl-1,4-benzoquinone (AZDCIQ) in different bio-mimicking micellar microenvironments using steady state absorption, fluorescence, time resolved fluorescence and fluorescence anisotropy studies. Dramatic modulation in the photophysics of Ce6 has been observed in two types of surfactant assemblies namely premicellar and postmicellar assemblies of cationic CTAB, anionic SDS and nonionic TX-100. In water at pH 7.4, Ce6 exists as monomeric (73%, 4.91 ns) and dimeric (27%, 2.49 ns) forms, but with increasing concentration of CTAB in the premicellar region, the absorption and emission intensity decreases significantly due to the formation of surfactant induced higher aggregates. Interestingly further addition of CTAB (at critical micellar concentration and above) leads to disaggregation of those higher aggregates into its subsequent monomeric and dimeric form. In the case of TX-100 and SDS, the dye does not form higher aggregates in the premicellar region, rather it remains as monomeric–dimeric forms throughout the concentration range until the critical micellar concentration (CMC). After micellization, the percentage of Ce6 monomer increases in the case of TX-100, whereas the reverse case is observed in SDS, which may be explained by the forced dimerisation caused by repulsive interactions between anionic Ce6 and SDS micelles. The copper induced fluorescence quenching, solvation dynamics, and fluorescence anisotropy shows that the dye is localised in the Stern layer of CTAB, in the palisade layer of TX-100 and in the outer Gouy–Chapman layer or in aqueous bulk phase in the case of SDS micelles. The interaction of fully micellized PDT active Ce6 with DNA alkylating AZDCIQ is found to be more in CTAB as compared to TX-100 and water. The solvation dynamics of Ce6 in the presence of the quinone reveals the dynamic nature of the interaction between these two partners. The spectroscopic research described herein may provide numerous effective information for the use of chlorin(s) and alkylating quinones together to overcome the limitation of PDT, especially in the hypoxic environment of solid tumors. more...

Of the many forms of above- and below-ground stresses facing agriculture production, physical soil limitations are generally among the most persistent and least amenable to amelioration. Fine textured heavy soils have physical constraints that severely affect soil and plant health and yield parameters and there is a need to study the problems of these type of soils and find possible measures to ameliorate these problems. Reasons for these problems along with possible preventing measures have been discussed. These soils have severe soil aeration problem due to restricted soil water movement within the profile. The affects of these constraints on crop growth and productivity were highlighted. For efficient crop production, it is important to understand the soil environment in which plants grow, to recognize the limitations of that environment and to ameliorate where possible without damaging the soil quality. For satisfactory plant growth, it is essential that the soil provides a favourable physical environment for root development that can exploit the soil sufficiently to provide the plants needs for water, nutrients and anchorage. more...

A comparative biophysical study on the individual conformational adaptation embraced by two homologous serum albumins (SA) (bovine and human) towards a potential anticancer bioorganic compound 2-(6-chlorobenzo[d] thiazol-2-yl)-1H-benzo[de] isoquinoline-1,3(2H)- dione (CBIQD) is apparent from the discrimination in binding behavior and the ensuing consequences accomplished by combined in vitro optical spectroscopy, in silico molecular docking and molecular dynamics (MD) simulation. The Sudlow site I of HSA although anion receptive, harbors neutral CBIQD in Sudlow site I (subdomain IIA, close to Trp) of HSA, while in BSA its prefers to snugly fit into Sudlow site II (subdomain IIIA, close to Tyr). Based on discernable diminution of HSA mean fluorescence lifetime as a function of biluminophore concentration, facile occurrence of fluorescence resonance energy transfer (FRET) is substantiated as the probable quenching mechanism accompanied by structural deformations in the protein ensemble. CBIQD establishes itself within HSA close to Trp214, and consequently reduces the micropolarity of the cybotactic environment that is predominantly constituted by hydrophobic amino acid residues. The stronger association of CBIQD with HSA encourages an allosteric modulation leading to slight deformation in its secondary structure whereas for BSA the association is comparatively weaker. Sudlow site I of HSA is capable to embrace a favorable conformation like malleable gold to provide room for incoming CBIQD, whereas for BSA it behaves more like rigid cast-iron which does not admit any change thus forcing CBIQD to occupy an altogether different binding location i.e. the Sudlow site II. The anticancer CBIQD is found to be stable within the HSA scaffold as vindicated by root mean square deviation (RMSD) and root mean square fluctuation (RMSF) obtained by MD simulation. A competitively inhibited esterase-like activity of HSA upon CBIQD binding to Lys199 and Arg257 residues, plausibly envisions that similar naphthalimide based prodrugs, bearing ester functionality, can be particularly activated by Sudlow site I of HSA. The consolidated spectroscopic research described herein may encourage design of naphthalimide based pro-drugs for effective in vivo biodistribution using HSA-based drug delivery systems. more...

A simple approach was developed to prepare carboxycellulose nanofibers directly from untreated biomass using nitric acid or nitric acid-sodium nitrite mixtures. Experiments indicated that this approach greatly reduced the need for multichemicals, and offered significant benefits in lowering the consumption of water and electric energy, when compared with conventional multiple-step processes at bench scale (e.g., TEMPO oxidation). Additionally, the effluent produced by this approach could be efficaciously neutralized using base to produce nitrogen-rich salts as fertilizers. TEM measurements of resulting nanofibers from different biomasses, possessed dimensions in the range of 190–370 and 4–5 nm, having PDI = 0.29–0.38. These nanofibers exhibited lower crystallinity than untreated jute fibers as determined by TEM diffraction, WAXD and 13C CPMAS NMR (e.g., WAXD crystallinity index was ∼35% for nanofibers vs 62% for jute). Nanofibers with low crystallinity were found to be effective for removal of heavy metal... more...

The present study epitomizes the design, synthesis, photophysics, solvation, and interaction with calf-thymus DNA of a potential antitumor, anticancer quinoline-appended chalcone derivative, (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ) using steady state absorption and fluorescence spectroscopy, molecular modeling, molecular docking, Fourier-transform infrared spectroscopy (FTIR), molecular dynamics (MD) simulation, and gel electrophoresis studies. ADMQ shows an unusual photophysical behavior in a variety of solvents of different polarity. The dual emission has been observed along with the formation of twisted intramolecular charge transfer (TICT) excited state. The radiationless deactivation of the TICT state is found to be promoted strongly by hydrogen bonding. Quantum mechanical (DFT, TDDFT, and ZINDO-CI) calculations show that the ADMQ is sort of molecular rotor which undergoes intramolecular twist followed by a complete charge transfer in the optimized excited state. FTIR studies reveals that ADMQ undergoes important structural change from its native structure to a β-hydroxy keto form in water at physiological pH. The concentration-dependent DNA cleavage has been identified in agarose gel DNA electrophoresis experiment and has been further supported by MD simulation. ADMQ forms hydrogen bond with the deoxyribose sugar attached with the nucleobase adenine DA-17 (chain A) and result in significant structural changes which potentially cleave DNA double helix. The compound does not exhibit any deleterious effect or toxicity to the E. coli strain in cytotoxicity studies. The consolidated spectroscopic research described herein can provide enormous information to open up new avenues for designing and synthesizing chalcone derivatives with low systematic toxicity for medicinal chemistry research. more...

The present study embodies design, in silico DNA interaction, synthesis of benzothiazole containing naphthalimide derivative, 2-(6-chlorobenzo[d]thiazol-2-yl)-1H-benzo[de] isoquinoline-1,3(2H)-dione (CBIQD) along with its systematic photophysics, solvatochromic behavior, and solvation dynamics using an experimental and theoretical spectroscopic approach. Steady-state dual emission and biexponential fluorescence decay reveals the formation of two different excited species. Ground- and excited-state optimized geometry and the potential-energy curve obtained from DFT and TD-DFT calculation ascertained the existence of nonplanar and planar conformation. When the solvent polarity is changed from nonpolar to protic polar, the feebly emissive emission band highly intensifies probably due to the reversal of n, π*-π, π* emissive state along with consequent modulation of their energy gap that is induced by H-bonding. Excluding nonpolar solvents, in all other solvents, the Stokes shift correlates linearly with orientation polarizability, whereas in water, the story remains intriguing. With photoexcitation, intermolecular H-bonding stimulates the pyramidalization tendency of imide "N" with subsequent conformational change of GS nonplanar geometry to a coplanar one through acceptor rehybridization generating a rehybridized intramolecular charge transfer (RICT) state that caused a dramatic fluorescence upsurge. This allosteric modulation is promoted by excited-state H-bonding dynamics especially in strong H-bond donor water. A close interplay between preferential solvation and the proximity effect is evident in the emission behavior in a benzene (Bn)-ethanol (EtOH) binary mixture. Molecular docking analysis delineates considerable noncovalent sandwiched π-π stacking interactions of CBIQD with the pyrimidine rings as well as with imidazole rings of dG 6 and dG 2 base pairs of B-DNA double helix, which probably suffices the design strategy adopted. Overall, a strategic design to synthesize a highly fluorescent and potential bioactive agent is executed to revolutionize the fluorophore field due its enormous progressive importance in biochemical applications. more...

Optimism is a part of positive psychology which leads to better adaptive and coping skills and reduced stress level in an individual. The aim of the present research was to study the association of optimism and perceived stress among young adults. The sample consisted of 170 young adults (79 males and 91 females) within the age range of 18 to 25 years. Purposive sampling technique was employed for collecting the data. The Perceived stress scale-10 (PSS; Cohen, Kamarack & Marmelstein, 1983) and Life Orientation Test- Revised (Scheir, Carver, & Bridges, 1994) was used for measuring perceived stress and optimism respectively. Correlation and t-test was found using IBM SPSS software. Findings suggested that optimism was negatively correlated with perceived stress. Females were found to score significantly higher on perceived stress levels than males. While the gender difference in optimism level was reported to be insignificant. Future research needs to be conducted on the relationship between gender and levels of optimism. more...

Rice (Oryza sativa L.) is grown in alluvial irrigated tract of north-west India due to high productivity and profitability. Rice is the major source of calories for half the world'spopulation as well as in our country (Roy and Bisht, 2012). However, large amount of water input in rice culture has led to over-exploitation of groundwater as indicated by alarming fall in water table. Average fall in water table in Punjab and Haryana state has been more than 0.75 m year-1 in the last decade (Minhas et al. and Humphreys et al. 2010). Thus, there is a need to explore alternate techniques that can sustain rice production and are resource conservative. On the face of global water scarcity and escalating labour rates, when the future of rice production is under threat, direct seeded rice offers an attractive alternative. In this regard, dry-seeded rice (DSR) is one option that can help in saving water, energy, labor and time. Management interventions that reduce irrigation water and increase water productivity (WP) are required in dry-seeded rice. Irrigation scheduling, tillage and short duration cultivars are some of the interventions in this regard. Irrigation scheduling aimed at eliminating over or under irrigation and ensures optimum yields with high water productivity. Tillage affects crop growth by altering soil edaphic environment. Rice plants are unable to utilize soil water in the deeper layers because of shallow root system. Deep tillage has emerged as a better option to improve deep root growth (advantageous for water extraction during drought in upland rice) of rice cultivars. Based on the existing evidence, present paper reviews the management interventions to enhance water productivity in dry-seeded rice. more...