Plant Growth-Promoting Attributes of Zinc Solubilizing Dietzia maris Isolated from Polyhouse Rhizospheric Soil of Punjab.

Zinc solubilizing rhizobacteria (ZSR) enhance the phyto-availability of Zn by converting its insoluble forms into usable forms that are essential for the growth and nutritional quality of crops. In the present study, a potential ZSR, hereafter referred to as strain N14, was isolated from the polyhouse rhizospheric soil of Punjab, India. The isolated rhizobacteria was found to be Gram-positive, aerobic, rod-shaped, and demonstrated a solubilization index of 63.75 on the Bunt Rovira (BR) medium. The 16S rRNA gene sequence analysis revealed that isolated strain N14 matches substantially with type strain Dietzia maris DSM 43672 T. In its ZnO broth assay, a significant amount of soluble Zn was detected along with a simultaneous decrease in pH of the broth. Ultra-performance liquid chromatography analysis revealed the release of organic acids, specifically, lactic acid and acetic acid by D. maris strain N14 which could be the reason for the decrease in broth pH. The production of indole acetic acid (29.91 µg/ml), gibberellic acid (4.72 µg/ml), ammonia (38.87 µg/ml), siderophore (0.89%), along with the release of HCN and appearance of phosphate solubilization zone (14.4 mm) with this strain suggested its possible plant growth-promoting (PGP) characteristics. Therefore, this strain was employed in the formulation of pellets which were applied for in vivo PGP studies using tomato plants. The developed bioformulated pellets showed a significant enhancement in plant growth as compared to control and vermicompost treated plants. To the best of our knowledge, this is the first report describing the Zn solubilizing and PGP characteristics of D. maris.

Isolation, optimized extraction, and ultra-high performance liquid chromatography with photodiode array method for quantitative analysis of chiratol in Swertia paniculata.

The global natural product-based industry is growing fast with the introduction of new phytochemicals and herbal extract products from different geographical regions. Swertia paniculata is a well-known plant with medicinal properties; however, the quality control for its major phytochemical constituents from the Himalayan geographical region is nevertheless reported. Therefore, the first objective of this investigation was to characterize and optimize the extraction process while the second objective was to validate a quantitative analytical method for chiratol from S. paniculata herbal extract. The chiratol was characterized with spectral analysis. The optimum extraction condition for the highest yield of metabolite was realized in chloroform as a solvent system under ultrasonication. The ultra-high performance liquid chromatography coupled with photodiode array detection method for analytical quantification was validated for specificity, linearity, limits of detection, limits of quantification, precision, repeatability, recovery, and robustness using Eclipse Plus C18 column (100 mm × 4.6 mm × 3.5 µm id). The gradient elution of water/acetonitrile as mobile phase was used at a flow rate of 0.5 ml/min. The recovery percentage was very satisfactory with values within specification. The robustness parameters showed no substantial influence of evaluated parameters by the Youden test. The developed method was ascertained to be appropriate for the proposed purpose.

Mixed organic and inorganic nitrogen sources enhance chitosan yield in novel isolates of Penicillium.

Chitosan, a valuable biopolymer, has traditionally been derived from marine sources. However, exploring fungal alternatives offers a sustainable supply. This research investigates the potential of chitosan production from fungal sources, focusing on the optimization of abiotic factors using two novel Penicillium strains (IITISM-ANK1 and IITISM-ANK2) isolated from dry aged sludge. Box-Behnken model and standard statistical analysis were deployed to develop an equation predicting the effect of carbon and nitrogen sources, pH, and temperature on chitosan production. Batch experiments validate the model's accuracy under optimized conditions. The results indicate that mixed organic and inorganic nitrogen sources in the form of peptone, nitrate, and ammonium salts enhanced chitosan yield in both isolates. At optimal conditions for the chitosan production of IITISM-ANK2 and IITISM-ANK1 were found to be 293.29 mg/L and 325.01 mg/L, with the degree of deacetylation of over 74 % which is a critical parameter for chitosan quality. Thus, these isolates can be used as a potent microbe for industrial chitosan production and contribute to advancing sustainable chitosan production and its potential industrial applications.

Statistical modelling, optimization, and mechanistic exploration of novel ureolytic Enterobacter hormaechei IITISM-SA3 in cadmium immobilization under microbial inclusive and cell-free conditions through microbially induced calcite precipitation.

The study aimed to evaluate the potential of a novel isolated ureolytic Enterobacter hormaechei IITISM-SA3 in cadmium bioremoval through MICP. The optimization and modelling of the biotic and abiotic factors affecting the process of mineralization were also performed. In addition, the underlying mechanism of MICP-driven Cd mineralization under microbial-inclusive and cell-free conditions was revealed and supported through the characterization of the bio-precipitates obtained using various characterization techniques. The results indicated that the isolate could remove 97.18% Cd2+ of 11.4 ppm under optimized conditions of 36.86 h, pH 7.63, and biomass dose of 1.75 ml. Besides, the presence and absence of bacterial cells were found to influence both the morphologies and crystalline structures of precipitates. The precipitates obtained under microbial-inclusive conditions showed typical rhombohedral crystalline structures of the composition comprising CaCO3, CdCO3, and 0.67Ca0.33CdCO3. However, the crystalline nature of the precipitate reduced to a nano-sized granular structure in cell-free media. Unlike the cadmium mineralization process under microbial-inclusive media, where bacterial cells serve as nucleation sites for crystallization, the carbonate precipitation effectively captures Cd2+ through co-precipitation, chemisorption, or alternative mechanisms involving interactions between metal ions and CaCO3 under cell-free conditions. The findings presented suggest that using cell-free culture supernatant enriched with carbonate ions provides an avenue that could be harnessed for sustainable metal remediation.

Cholic Acid-Derived Gemini Amphiphile Can Eradicate Interkingdom Polymicrobial Biofilms and Wound Infections.

Biofilm infections are mainly caused by Gram-positive bacteria (GPB) like Staphylococcus aureus, Gram-negative bacteria (GNB) like Pseudomonas aeruginosa, and fungi like Candida albicans. These infections are responsible for antimicrobial tolerance, and commensal interactions of these microbes pose a severe threat to chronic infections. Treatment therapies against biofilm infections are limited to eradicating only 20-30% of infections. Here, we present the synthesis of a series of bile acid-derived molecules using lithocholic acid, deoxycholic acid, and cholic acid where two bile acid molecules are tethered through 3'-hydroxyl or 24'-carboxyl terminals with varying spacer length (trimethylene, pentamethylene, octamethylene, and dodecamethylene). Our structure-activity relationship investigations revealed that G21, a cholic acid-derived gemini amphiphile having trimethylene spacer tethered through the C24 position, is a broad-spectrum antimicrobial agent. Biochemical studies witnessed that G21 interacts with negatively charged lipoteichoic acid, lipopolysaccharide, and phosphatidylcholine moieties of GPB, GNB, and fungi and disrupts the microbial cell membranes. We further demonstrated that G21 can eradicate polymicrobial biofilms and wound infections and prevent bacteria and fungi from developing drug resistance. Therefore, our findings revealed the potential of G21 as a versatile antimicrobial agent capable of effectively targeting polymicrobial biofilms and wound infections, suggesting that it is a promising antimicrobial agent for future applications.

Xanthone Derivatives Enhance the Therapeutic Potential of Neomycin against Polymicrobial Gram-Negative Bacterial Infections.

Gram-negative bacterial infections are difficult to manage as many antibiotics are ineffective owing to the presence of impermeable bacterial membranes. Polymicrobial infections pose a serious threat due to the inadequate efficacy of available antibiotics, thereby necessitating the administration of antibiotics at higher doses. Antibiotic adjuvants have emerged as a boon as they can augment the therapeutic potential of available antibiotics. However, the toxicity profile of antibiotic adjuvants is a major hurdle in clinical translation. Here, we report the design, synthesis, and biological activities of xanthone-derived molecules as potential antibiotic adjuvants. Our SAR studies witnessed that the p-dimethylamino pyridine-derivative of xanthone (X8) enhances the efficacy of neomycin (NEO) against Escherichia coli and Pseudomonas aeruginosa and causes a synergistic antimicrobial effect without any toxicity against mammalian cells. Biochemical studies suggest that the combination of X8 and NEO, apart from inhibiting protein synthesis, enhances the membrane permeability by binding to lipopolysaccharide. Notably, the combination of X8 and NEO can disrupt the monomicrobial and polymicrobial biofilms and show promising therapeutic potential against a murine wound infection model. Collectively, our results unveil the combination of X8 and NEO as a suitable adjuvant therapy for the inhibition of the Gram-negative bacterial infections.

Small molecules that disrupt RAD54-BLM interaction hamper tumor proliferation in colon cancer chemoresistance models.

RAD54 and BLM helicase play pivotal roles during homologous recombination repair (HRR) to ensure genome maintenance. BLM amino acids (aa 181-212) interact with RAD54 and enhance its chromatin remodeling activity. Functionally, this interaction heightens HRR, leading to a decrease in residual DNA damage in colon cancer cells. This contributes to chemoresistance in colon cancer cells against cisplatin, camptothecin, and oxaliplatin, eventually promoting tumorigenesis in preclinical colon cancer mouse models. ChIP-Seq analysis and validation revealed increased BLM and RAD54 corecruitment on the MRP2 promoter in camptothecin-resistant colon cancer cells, leading to BLM-dependent enhancement of RAD54-mediated chromatin remodeling. We screened the Prestwick small-molecule library, with the intent to revert camptothecin- and oxaliplatin-induced chemoresistance by disrupting the RAD54-BLM interaction. Three FDA/European Medicines Agency-approved candidates were identified that could disrupt this interaction. These drugs bound to RAD54, altered its conformation, and abrogated RAD54-BLM-dependent chromatin remodeling on G5E4 and MRP2 arrays. Notably, the small molecules also reduced HRR efficiency in resistant lines, diminished anchorage-independent growth, and hampered the proliferation of tumors generated using camptothecin- and oxaliplatin-resistant colon cancer cells in both xenograft and syngeneic mouse models in BLM-dependent manner. Therefore, the 3 identified small molecules can serve as possible viable candidates for adjunct therapy in colon cancer treatment.

CD4+ T cell-derived novel peptide Thp5 induces interleukin-4 production in CD4+ T cells to direct T helper 2 cell differentiation.

The differentiation of naïve CD4(+) T cells into T helper 2 (Th2) cells requires production of the cytokine IL-4 in the local microenvironment. It is evident that naïve/quiescently activated CD4(+) T cells produce the IL-4 that drives Th2 cell differentiation. Because early production of IL-4 in naïve T cells leads to preferential Th2 cell differentiation, this process needs to be tightly regulated so as to avoid catastrophic and misdirected Th2 cell differentiation. Here, we show that Thp5, a novel peptide with structural similarity to vasoactive intestinal peptide, regulates production of early IL-4 in newly activated CD4(+) T cells. Induction of IL-4 in CD4(+) T cells by Thp5 is independent of the transcription factor STAT6 but dependent on ERK1/2 signaling. Furthermore, cytokines (IL-12 and TGF-ß) that promote the differentiation of Th1 or Th17 cells inhibit Thp5 induction, thus suppressing Th2 cell differentiation. We further showed that Thp5 enhances Th2 responses and exacerbates allergic airway inflammation in mice. Taken together, our findings reveal that early activated CD4(+) T cells produce Thp5, which plays a critical role as a molecular switch in the differentiation of Th cells, biasing the response toward the Th2 cell phenotype.

Isolation of Food Grade Dye from Flower Petals of Butea monosperma and Determination of Marker Compounds for Its Quantitative Analysis.

Health concerns associated with synthetic dyes/colorants have fostered the use of natural coloring materials for food applications. This study has been carried out to extract a natural dye from the flower petals of Butea monosperma (family Fabaceae) under an eco-friendly and organic solvent-free approach. Hot aqueous extraction of dry B. monosperma flowers followed by lyophilization of the resulting extract furnished an orange-colored dye in ∼35% yield. Silica gel column chromatography of dye powder resulted in the isolation of three marker compounds, viz. iso-coreopsin (1), butrin (2), iso-butrin (3) which were characterized by spectral methods, e.g., ultra violet, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and high-resolution mass spectrometry. The XRD analysis of isolated compounds established an amorphous nature for compounds 1 and 2 while compound 3 showed good crystallinity. The stability of dye powder and the isolated compounds 1-3 was determined by thermogravimetric analysis which showed excellent stability up to 200 °C. In trace metal analysis, the product B. monosperma dye powder exhibited low relative abundance <4% for Hg along with negligible concentrations of Pb, As, Cd, and Na. The detection and quantification of marker compounds 1-3 in the B. monosperma flower extracted dye powder were carried out by a highly selective UPLC/PDA method of analysis.

A localized hydrogel-mediated chemotherapy causes immunogenic cell death via activation of ceramide-mediated unfolded protein response.

Treatment of triple-negative breast cancer (TNBC) is challenging because of its "COLD" tumor immunosuppressive microenvironment (TIME). Here, we present a hydrogel-mediated localized delivery of a combination of docetaxel (DTX) and carboplatin (CPT) (called DTX-CPT-Gel therapy) that ensured enhanced anticancer effect and tumor regression on multiple murine syngeneic and xenograft tumor models. DTX-CPT-Gel therapy modulated the TIME by an increase of antitumorigenic M1 macrophages, attenuation of myeloid-derived suppressor cells, and increase of granzyme B+CD8+ T cells. DTX-CPT-Gel therapy elevated ceramide levels in tumor tissues that activated the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK)-mediated unfolded protein response (UPR). This UPR-mediated activation of apoptotic cell death led to release of damage-associated molecular patterns, thereby activating the immunogenic cell death that could even clear the metastatic tumors. This study provides a promising hydrogel-mediated platform for DTX-CPT therapy that induces tumor regression and effective immune modulation and, therefore, can be explored further for treatment of TNBC.

Cloning, purification, crystallization and preliminary X-ray diffraction studies of Escherichia coli PapD-like protein (EcpD).

Many Gram-negative bacteria are characterized by hair-like proteinaceous appendages on their surface known as fimbriae. In uropathogenic strains of Escherichia coli, fimbriae mediate attachment by binding to receptors on the host cell, often contributing to virulence and disease. E. coli PapD-like protein (EcpD) is a periplasmic chaperone that plays an important role in the proper folding and guiding of Yad fimbrial proteins to the outer membrane usher protein in a process known as pilus biogenesis. EcpD is essential for pilus biogenesis in uropathogenic E. coli and plays an important role in virulence. In the present study, EcpD was cloned, overexpressed, purified and crystallized by the hanging-drop vapour-diffusion method. The crystals diffracted to 1.67 Šresolution and belonged to the orthorhombic space group C222(1), with unit-cell parameters a = 100.3, b = 127.6, c = 45.9 Å. There was a single molecule in the asymmetric unit and the corresponding Matthews coefficient was calculated to be 3.02 Å(3) Da(-1), with 59% solvent content. Initial phases were determined by molecular replacement.

Solvothermal conversion of spent aromatic waste to ethyl glucosides.

On-farm extraction of commercially important essential oil from aromatic crops generates huge spent aromatic waste. This massive waste is often disposed in the unregulated landfills or burned in the open air to vacate the fields. Hence, a new method for processing of aromatic spent waste has been developed to obtain platform chemicals, such as, xylose and ethyl glucosides. The thermochemical liquefaction of acid pre-treated palmarosa (cymbopogon martini) biomass furnished a mixture of ethyl glucopyranosides in good yield (∼17 wt% relative to biomass) and selectivity (∼77%) by heating with p-cymen-2-sulphonic acid (p-CSA) in the presence of ethanol as a solvent. The detection, quantification and isolation of ethyl glucosides may provide a new application of spent aromatic biomass for use as a feed stock in the production of value added chemicals.

Synthesis of deoxy-Andrographolide Triazolyl Glycoconjugates for the Treatment of Alzheimer's Disease.

A new andrographolide-based terminal alkyne 3 was synthesized in good yield from deoxy-andrographolide 2, obtained from a natural compound andrographolide 1, which in turn was isolated from the leaves of the plant Andrographis paniculata. Copper(I)-catalyzed azide-alkyne cycloaddition reaction of alkyne 3 with azido-sugars 4a-f furnished a library of andrographolide-fastened triazolyl glycoconjugates 5a-f in good yields. The structures of these semisynthetic andrographolide derivatives were established by Fourier transform infrared, NMR, and mass spectroscopy. The compounds 5a-f were further evaluated against Alzheimer's disease (AD) using a scopolamine (SCOP)-induced memory impairment mice model. It was observed that antioxidant and anticholinesterase properties of these compounds contribute significantly toward their remarkable potential to improve cognitive functioning.

Click chemistry inspired synthesis of andrographolide triazolyl conjugates for effective fluorescent sensing of ferric ions.

The naturally occurring compound andrographolide 1 was used as a substrate for the synthesis of a novel terminal alkyne 3 which on copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction with azides 4a-l, 7 and 9 furnished a series of regioselective andrographolide triazolyl conjugates 5a-l, 8 and 10, respectively. A free glycoconjugate 6 was also prepared by selective deprotection of compound 5i in good yield. All the compounds were characterized by absorbance, FT-IR, NMR, and HR-MS analyses. The triazolyl conjugate 8 was further investigated as a probe for selective detection of Fe3+ ion in matrix. The mode of attachment of Fe3+ ion to the compound 8 was established by absorbance, fluorescence, infrared (IR), and nuclear magnetic resonance (NMR) spectroscopy, and high resolution mass-spectrometry (HR-MS). The logic gate circuits were constructed for the probe 8 and ethylenediaminetetraacetic acid (EDTA). The environmental perspective of probe 8 was investigated in real water samples.

Click Chemistry Inspired Synthesis of Hydroxyanthracene Triazolyl Glycoconjugates.

Novel hydroxyanthracene-based terminal alkynes 3 and 5a/b were synthesized by the acetylide addition reaction at the 9,10-position of anthraquinone 1 under mild conditions. The developed alkynes 3, 5a, and 5b on Huisgen azide-alkyne cycloaddition reaction with azido-sugars 6 in the presence of Cu(I) catalyst provided a series of triazole fasten hydroxyanthracene glycoconjugates 7, 8, and 9, respectively, in good yields. The representative compounds 9 and 7h were successfully deprotected under room-temperature conditions to liberate the corresponding free glycoconjugates 10 and 11, respectively. Further, structures of a few compounds were unmaliciously evidenced by their single-crystal X-ray.

Structural investigation on SPI-6-associated Salmonella typhimurium VirG-like stress protein that promotes pathogen survival in macrophages.

Enteric microbial pathogenesis, remarkably a complex process, is achieved by virulence factors encoded by genes located within regions of the bacterial genome termed pathogenicity islands. Salmonella pathogenicity islands (SPI) encodes proteins, that are essential virulence determinants for pathogen colonization and virulence. In addition to the well-characterized SPI-1 and SPI-2 proteins, which are required for bacterial invasion and intracellular replication, respectively, SPI-6 (formerly known as Salmonella enterica centisome 7 island [SCI]) encoding proteins are also known to play pivotal role in Salmonella pathogenesis. However, the underlying molecular mechanism of these proteins remained elusive. To gain molecular insights into SPI-6-associated proteins, in this study, a SPI-6 Salmonella typhimurium VirG-like protein (STV) is characterized using interdisciplinary experimental approaches including X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy and infection assays. The high-resolution crystal structure, determined by the single-wavelength anomalous dispersion (SAD) method, reveals that STV belongs to the LTxxQ motif family. Solution-state NMR spectroscopy studies reveal that STV form a dimer involving interconnected helices. Interestingly, functional studies show that STV influence pathogen persistence inside macrophages in vitro at later stages of infection. Altogether, our findings suggest that STV, a member of the LTxxQ stress protein family, modulates bacterial survival mechanism in macrophages through SPI-1 and SPI-2 genes, respectively.

A divergent approach for the synthesis of (hydroxymethyl)furfural (HMF) from spent aromatic biomass-derived (chloromethyl)furfural (CMF) as a renewable feedstock.

Extraction of commercial essential oil from several aromatic species belonging to the genus Cymbopogon results in the accumulation of huge spent aromatic waste which does not have high value application; instead, the majority is burned or disposed of to vacate fields. Open burning of spent aromatic biomass causes deterioration of the surrounding air quality. Therefore, a new protocol has been developed for chemical processing of spent biomass to obtain 5-(chloromethyl)furfural (CMF) with high selectivity (∼80%) and yields (∼26 wt% or ∼76 mol% with respect to pre-treated biomass) via refluxing in aqueous HCl in the presence of NaCl as a cheap catalyst. No black tar formation and gasification were observed in the processing of the spent aromatic biomass. Spent aromatic waste-derived CMF was further converted to 5-(hydroxymethyl)furfural (HMF) in good yields by a novel one pot method using iodosylbenzene (PhIO) as a reagent under mild reaction conditions.

Crystal structure of the usher chaperone YadV reveals a monomer with the proline lock in closed conformation suggestive of an intermediate state.

Cell surface pili assembled by the chaperone-usher (CU) pathway play a crucial role in the adhesion of uropathogenic Escherichia coli. YadV is the chaperone component of the CU pathway of Yad pili. Here, we report the crystal structure of YadV from E. coli. In contrast to major usher chaperones, YadV is a monomer in solution as well as in the crystallographic symmetry, and the monomeric form is a preferred state for interacting with pilus subunits. Moreover, we observed a closed conformation for the proline lock, a crucial structural element for chaperone-pilus subunit interaction. MD simulation shows that the closed state of the proline lock is not energetically stable. Thus, the structure of monomeric YadV with its closed proline lock may serve as an intermediate state to provide suitable access to pilus subunits.

Intraoral salivary duct cyst: Report of rare entity.

Salivary duct cysts (SDCs) are true cysts caused by obstruction of the salivary ducts and are rare in minor salivary glands. A 62-year-old male reported with a painless swelling in the left buccal mucosa for 2 years. Excision of the entire lesion was performed under local anesthesia following which histopathological examination was performed. Microscopically, a dilated salivary gland duct composed of 1-2 layers of cuboidal cells with intraluminal mucous plug was observed. Cystic lumen lined by mucous cells, squamous cells and ciliated cells was seen. Oncocytic metaplasia was also present at various places. Histopathologically, it was consistent with the diagnosis of SDC. Intraoral SDCs and mucoceles clinicopathologically mimic salivary gland neoplasms, making diagnosis difficult and subject to errors in treatment. It is important for oral and maxillofacial surgeons to include SDC in the differential diagnosis of swelling affecting buccal mucosa.