Modification Of Chemical Structure Research Articles

Naphthoindole-2-carboxamides as a lipophilic chemotype of hetarene-anthraquinones potent against P-gp resistant tumor cells

The acquisition of multidrug resistance (MDR) to chemotherapy is a major obstacle to successful cancer treatment. Aiming to improve the potency of anthraquinone-derived antitumor compounds against MDR cancer cells, we employed a rational design approach to develop new heteroarene-fused anthraquinones. Shifting the carboxamide group in the naphtho[2,3-f]indole scaffold from the 3-position to 2 increased the lipophilicity and P-glycoprotein (P-gp) binding of the derivatives, potentially enhancing their ability to circumvent P-gp-mediated MDR. To validate the computations, we developed a scheme for heterocyclization into esters of naphtho[2,3-f]indole-2-carboxylic acid, based on the 5-endo-dig cyclization of 2-alkynyl-3-amino-1,4-dimethoxyanthraquinone under mild basic conditions using tetra-n-butylammonium fluoride (TBAF). The synthesized naphthoindole-2-carboxamides, particularly compound 1a bearing (S)-3-aminopyrrolidine in the carboxamide fragment, demonstrated the highest antiproliferative activity. Most importantly, 1a suppressed the growth of the P-gp-positive K562/4 leukemia tumor cell line (resistance index = 2.4), while its 3-isomer LCTA-2640 and Dox did not (RI = 125 and 140, respectively). Studies of intracellular uptake and distribution showed that 1a, unlike its 3-substituted isomer, effectively accumulated in resistant tumor cells, confirming the correlation between in silico and experimental data. The lead compound 1a interacts with DNA duplex and inhibits topoisomerase 1 but does not induce oxidative stress. Treatment with 1a increases the population of apoptotic cells in both K562 and K562/4 sublines, regardless of the cell cycle phase. Taken together, this work provides an interesting example of how a little modification in chemical structure can lead to striking differences in antitumor properties. In conclusion, we have identified a potent class of compounds that offer distinct advantages in combating resistant tumor cells.

Exploring the Potential of Cyclic Peptidyl Antitumor Agents Derived from Natural Macrocyclic Peptide Phakellistatin 13.

The exploration of novel anticancer compounds based on natural cyclopeptides has emerged as a pivotal paradigm in the contemporary advancement of macrocyclic pharmaceuticals. Phakellistatin 13 is a cycloheptapeptide derived from the brown snubby sponge and exhibits remarkable antitumor activity. In this study, we have designed and synthesized a series of chiral cyclopeptides incorporating the rigid isoindolinone moiety at various sites within the natural cycloheptapeptide Phakellistatin 13, with the aim of investigating conformationally constrained cyclopeptides as potential antitumor agents. Cyclopeptide 3, comprising alternating l-/d-amino acid residues, exhibited promising antihepatocellular carcinoma effects. Detailed biological experiments have revealed that Phakellistatin 13 analogs effectively inhibit the proliferation of tumor cells and induce apoptosis and autophagy, while also causing cell cycle arrest through the modulation of the p53 and mitogen-activated protein kinase (MAPK) signaling pathway. This study not only provides valuable insights into chemical structural modifications but also contributes to a deeper understanding of the biological mechanisms underlying the development of natural cyclopeptide-based drugs.

Chemical structure modification of Brazilin-based natural dye with TiO2 nanostructure improves photovoltaic properties for maximum simulated PCE for DSSCs application

Brazilin has been explored as a photosensitizer in dye-sensitized solar cells (DSSCs) owing to its easy extraction, abundance, and environmental friendliness. However, its narrow solar spectrum absorption and weak interaction with the semiconductor hamper its wide application, highlighting the need for developing novel dyes for enhanced DSSC performance. This study reports eight designed dyes (Braz 01 ‒ Braz 02tb) obtained via introducing the π-bridges such as benzene, thiophene, and benzene-thiophene linked to thieno[3,2-b]thiophene, alongside a cyanoacrylic acceptor into the sites of two hydroxyl (OH) groups of brazilin dye. The density functional theory (DFT) and time-dependent density functional theory (TD- DFT) methods were employed to examine the free dyes' photoelectrical, optoelectronic and structural properties. The results show that the absorption spectra of the designed dyes redshifted by 183.22 nm 239.43 nm regarding the brazilin dye. The energy gap was reduced from 5.074 to 2.46 eV. The reorganization energy decreased from 0.951 eV to 0.528 eV, indicating that the designed dyes exhibited better intramolecular charge transfer (ICT). Notably, the electron affinity, electron accepting power, and maximum charge transfer increased from 1.021 3.472 eV, 1.024 8.387 eV and 1.447 4.780, respectively, signifying improved ICT. The exciton binding energy was lowered from 0.591 0.137 eV, implying that all designed dyes possess minimum charge recombination. The amount of charge transfer of the designed dyes (0.286219.051 au) was observed to be greater than brazilin, signifying enhanced ICT. Moreover, the theoretical DSSCs sensitized with designed dyes demonstrated higher PCE than brazilin dye. The greatest PCE of 13.1 % was attained by Braz 01tb dye. Generally, the improved optoelectronic and photovoltaic characteristics observed in all the designed dyes indicate that modifying the hydroxyl group on the brazilin's R1 or R2 location enhances its photoelectrical properties. Therefore, the designed dyes are regarded as superior candidates for utilization as photosensitizers in DSSCs.

Analysis of Aspergillus niger isolated from ancient palm leaf manuscripts and its deterioration mechanisms

Palm leaf manuscripts (PLMs), venerable historical artefacts containing Buddhist scriptures, history, mathematics and literature, which are carried by palm leaves (Corypha umbraculifera) and are highly susceptible to microbial degradation during prolonged storage. This degradation results in significant alterations to both the appearance and material properties of PLMs, but the precise mechanism underlying this deterioration remains a mystery. To this end, the present study focused on ancient PLMs from Xishuangbanna Dai Autonomous Prefecture in Yunnan Province, China. The objective of present study was to isolate, culture and identify the microorganisms typically found in these manuscripts and to use them to biodegrade the carriers of PLMs. Detailed observations of the biodegradation behavior of these microorganisms on the carriers of PLMs were carried out, together with characterizations of the hierarchical structure and mechanical properties of the leaf fiber cell walls. This comprehensive analysis provided insights into the deterioration mechanisms of the carriers of PLMs. The study revealed the presence of the common fungus Aspergillus niger on ancient PLMs. Aspergillus niger can secrete cellulase, lipase, and acidic substances after colonizing on the carriers of PLMs. These substances sequentially damage the carrier's epidermal cells, mesophyll cells, and leaf fibers, leading to the separation of different tissue structures. At the molecular level, the lipids on the surface of the leaves were degraded initially, and sequential depolymerization of hemicellulose, amorphous cellulose, and crystalline cellulose occurred. Additionally, this study firstly applied nanoindentation technology in the research of PLMs. The mechanical properties of the cell walls underwent notable alterations due to the modifications in chemical and crystalline structure of the carriers of PLMs upon the biodegradation of Aspergillus niger. Specifically, the hardness and elastic modulus of leaf fiber cell walls showed an initial increasing and then decreasing trend, consistent with the trend of cellulose crystallinity, which also provided a new reference for assessing the degree of deterioration of PLMs.

Exploring Synthesis and Medicinal Applications of Andrographolide Derivatives: A Review

Abstract: Andrographolide, derived from the plant Andrographis paniculata (AP), exhibits a diverse range of biological activities, encompassing anti-bacterial, anti-tumor, antiinflammatory, anti-obesity, anti-viral, anti-fibrotic, hypoglycemic, and immunomodulatory properties. Notably, numerous analogues of andrographolide have been synthesized, incorporating significant chemical structural modifications to enhance bioavailability and druggability. A comprehensive exploration into their molecular and cellular mechanisms of action has also been undertaken, enriching our understanding. The investigation highlights the potential of related terpenoid analogues from Andrographis paniculata, beyond the diterpene lactone andrographolide, to hold promise in disease treatment due to structural similarities and diverse pharmacological effects. This review offers insights into the anticipated synthesis and therapeutic applications of andrographolide derivatives across a spectrum of disorders.

Bioremoval of lead ion from the aquatic environment using lignocellulosic (Zea mays), thermodynamics modeling, and MC simulation

Lead (Pb+2) ions considered a crucial neurotoxic heavy metal result in serious troubles in the live biological environment including poisoning, and liver and kidney shortage, in addition to anemia, hepatitis, encephalopathy, and renal syndrome. In the current study, the biomass of Zea mays (ZMS) was prepared as a biosorbent for the elimination of Pb+2 ions from the aquatic environment in batch mode relevant to contact time, pH solution, biosorbent dose, and temperature. The Zea mays biomass was characterized using an SEM microscope coupled with EDX, FTIR, XRD, and BET surface area analysis to investigate the modification of chemical structure for the biosorption system. According to the biosorption experiments, the supreme biosorbent capability of ZMS approaches 16.9 mg/g for 180 min at pH = 5.5. The evaluation of kinetics analysis reveals that the (Pb+2) biosorption by ZMS was better described with pseudo-second-order kinetics. In addition, the nonlinear regression of Freundlich, Langmuir, Temkin, and Elovich isothermal models was modeled to the equilibrium data, and it was deduced that the Langmuir isotherm provides a better fit than Langmuir based on the correlation coefficient values. The thermodynamic factors were calculated for this biosorption process in which the lead ions are sequestered by the ZMS. According to these factors, it was elucidated that the (Pb+2) ions biosorption onto the Zeamays sponge is exothermic and spontaneous. In addition, Monte Carlo (MC) simulations were conducted to screen the adsorption competence of pigments and ligands in Zea mays for Pb+2 ions adsorption. The outputs of experimental and simulation studies proved the potentiality of Zea mays sponge (ZMS) as a promising biosorbent for eliminating heavy metallic elements from aqueous media.

Modification of the polymer PETG by 16 MeV Au ions

Commercial poly(ethylene glycol-co-1,4 cyclohexanedimethanol terephthalate) (PETG) foils were irradiated with 16 MeV Au7+ ions and the resulting modifications in the polymer chemical structure, optical properties, and surface hydrophobicity were analyzed. Under irradiation, PETG displays a redshift in the optical absorbance edge, accompanied by a decrease in the optical gap from 3.8 eV to 2.4 eV. An overall decrease of characteristic functional groups is observed with damage cross sections varying from (1–2) × 10-13 cm2. New bands are formed linked mainly to oxidation and formation of conjugated carbon–carbon double bonds. The hydrophilicity of the irradiated surfaces increases possibly due to surface oxidation.

Recent advances in the synthesis of pyrazoline derivatives from chalcones as potent pharmacological agents: A comprehensive review

The pyrazoline scaffold plays a vital role in heterocyclic chemistry as a fundamental building block in both organic and medicinal chemistry. A pyrazoline scaffold is composed of an endocyclic double bond, two nitrogen atoms, and five different types of bonds. It is a significant chemical fragment and exhibits various bioavailabilities, allowing the synthesis of a range of diverse compounds with promising biological potential. Over the past decade, extensive research efforts have been devoted to investigating the therapeutic potentials of pyrazoline scaffolds, encompassing their antibacterial, anti-inflammatory, analgesic, cytotoxic, and anti-tumor activities. Moreover, in the presence of a unique chemical structure, pyrazolines have made it easier to produce new substitutions with low toxicity as compared to their natural analogue. The current review focuses on the recent progress in the synthesis of pyrazoline scaffolds from chalcones, with an emphasis on their possible biological functions. The study identifies a diverse range of pyrazoline derivatives that exhibit promising biological properties and have been successfully reported in various studies. The primary objective is to determine the chemical groups and structural modifications that enhance their bioactivity, low toxicity, and handling. Furthermore, the review explores the bioavailability, synthetic challenges, and progress made in utilising pyrazoline derivatives in pharmaceutical and synthetic chemistry from 2017 to 2023. The different biological potentials of various substituted pyrazolines are reported here such as 1,4-dimethylpiperazine, 2-(2-methyl-1H-benzo[d]imidazol-1-yl)acetohydrazide, 1-methyl-4-phenylpiperazine, 4,5-dihydrooxazole, 2H-chromen-2-one, 2-(4-chlorophenyl)-5-methyl-4,5-dihydrooxazole, benzo[d]thiazole, ethoxybenzene, and 1-bromo-4N,N-dimethylaniline. The review also discusses the effects of different functional groups, such as OCH3, OH, NO2, CF3, and halogens, added to different positions of the pyrazoline scaffold.

Rational design of adjuvants boosts cancer vaccines.

Cancer vaccines are expected to be next breakthrough in cancer immunotherapy. In cancer vaccines, adjuvants play an important role by enhancing and reshaping tumor antigen-specific immune responses. Failures in previous cancer vaccine clinical trials can be attributed to inappropriate selection and design of tumor antigens and adjuvants. Using basic theories of tumor immunology, the development of sequencing technology and nanotechnology enables the creation of cancer vaccines through appropriate selection of tumor antigens and adjuvants and their nanoscale assembly based on the specific characteristics of each tumor. In this chapter, we begin by discussing the various types of cancer vaccines and categories of tumor antigens. Then, we summarize the classification of adjuvants for cancer vaccines, including immunostimulatory molecules and delivery systems, and clarify the various factors that influence the properties of adjuvants, such as chemical composition, structure, and surface modification. Finally, we provide perspectives and insights on rational design of adjuvants in cancer vaccines to enhance their efficacy.

Machine Learning Model Training and Practice: A Study on Constructing a Novel Drug Detection System

Drugs, AIDS and terrorism are the three major public hazards in the world. Drug abuse seriously endangers social security and human life and health. The World Drug Report 2023 shows that the continued record supply of illicit drugs and increasingly flexible trafficking networks are exacerbating the global crisis and posing challenges for health services and law enforcement responses. The number of people injecting drugs worldwide in 2021 is estimated to be 13.2 million, 18% higher than previous estimates. At present, the world drug control situation is very serious, and it is necessary to increase the means to solve the drug problem and curb the spread of drugs, and efficient and accurate drug detection technology plays a very important role in drug control work. NPS, also known as "planning drugs" or "laboratory drugs", is a drug analogue obtained by the chemical structure modification of controlled drugs by criminals in order to evade the crackdown. It has similar or stronger excitatory, hallucinogenic, narcotic and other effects with controlled drugs, and has become a third-generation drug popular in the world after traditional drugs and synthetic drugs. Therefore, through the drug detection technology based on artificial intelligence machine learning technology, the current development of AI as a "drug detector" and the future space are analyzed.

Embrittlement of PFSA Reinforced Membrane Interfaces after Ex-Situ Chemical-Mechanical Aging

Perfluorosulfonic acid (PFSA) membrane degradation has been identified as one of the main factors responsible for the short lifetime of PEMFCs [1,2]. The aging mechanisms of these membranes are complex due to mechanical fatigue combined to chemical aggressions. Mechanical fatigue results from the wetting/drying cycles while the chemical aggressions are induced by radicals formed during fuel cell operation. Although it is commonly accepted that chemical and mechanical stresses can interact to accelerate membrane degradation [3], coupled studies are rarely conducted. Thus, an original experimental set-up to perform ex-situ aging tests combining membrane exposure to cyclic mechanical stresses to a free radical environment under conditions close to those observed during cell operation has been developed [4]. Ex-situ aging was performed on PFSA membranes reinforced (Nafion™ XL) with a cyclic compression oscillating between 0 - 10 MPa (0.1 Hz frequency) and a Fenton solution containing 1 ppm Fe2+ and 3 %vol H2O2. Such stresses revealed a significant morphological alteration with the appearance of “bubbles” close to the surface membrane (Figure 1, left). No chemical structure modification was detected within the three different layers. Nevertheless, SEM-EDX, FTIR and Raman microscopic analyses highlight delamination close to the reinforcement/PFSA interface (Figure 1, rigth). Additional peeling tests argued this failure point in the Nafion™ XL membrane. Figure 1

Identification of degradation products of brivaracetam using liquid chromatography quadrupole time-of-flight tandem mass spectrometry: Degradation pathway elucidation.

Pyrrolidone-based drugs find widespread use in treating conditions such as epilepsy and Alzheimer's disease, and in various other medical applications. Brivaracetam, the latest generation of pyrrolidone drugs, has exhibited significant promise owing to chemical structure modifications. Its affinity to the SV2A receptor is double that of the previous-generation drug, levetiracetam. Consequently, brivaracetam holds substantial potential for diverse applications. As a novel drug not yet included in the pharmacopeias of developed nations, comprehensive analysis and research are necessary to guarantee its safe utilization in clinical settings. A liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC/QTOFMS) method has been developed to effectively separate, identify and characterize both the degradation products and process-related substances of brivaracetam. Stress testing of the sample was carried out following the guidelines outlined in ICH Q1A(R2). The structures of these impurities were identified through positive electrospray ionization QTOF high-resolution MS and NMR spectroscopy. Additionally, the formation mechanism of each degradation product is thoroughly discussed. Under the analytical conditions outlined in this paper, brivaracetam and its degradation products were effectively separated. Thirteen degradation products were detected and characterized, shedding light on their origins and degradation pathways. Among these, three degradation products align with previously reported impurities, and two unreported degradation products were synthesized and confirmed through NMR spectroscopy. The stress testing results revealed the instability of brivaracetam under acidic, alkaline, oxidative and thermal stress conditions, while it exhibited relative stability under photolytic stress conditions. The study developed an analytical method for brivaracetam that enabled the effective detection and separation of brivaracetam and its 13 degradation products. This method addresses a gap in both current domestic and foreign drug standards. The structures of all the major degradation products were characterized by high-resolution LC/QTOFMS, which is essential for quality control during the drug production process, stability evaluation and the establishment of proper storage conditions.

Oral Delivery of Gemcitabine-Loaded Glycocholic Acid-Modified Micelles for Cancer Therapy.

The clinical utility of gemcitabine, an antimetabolite antineoplastic agent applied in various chemotherapy treatments, is limited due to the required intravenous injection. Although chemical structure modifications of gemcitabine result in enhanced oral bioavailability, these modifications compromise complex synthetic routes and cause unexpected side effects. In this study, gemcitabine-loaded glycocholic acid-modified micelles (Gem-PPG) were prepared for enhanced oral chemotherapy. The in vitro transport pathway experiments revealed that intact Gem-PPG were transported across the intestinal epithelial monolayer via an apical sodium-dependent bile acid transporter (ASBT)-mediated pathway. In mice, the pharmacokinetic analyses demonstrated that the oral bioavailability of Gem-PPG approached 81%, compared to less than 20% for unmodified micelles. In addition, the antitumor activity of oral Gem-PPG (30 mg/kg, BIW) was superior to that of free drug injection (60 mg/kg, BIW) in the xenograft model. Moreover, the assessments of hematology, blood chemistry, and histology all indicated the hypotoxicity profile of the drug-loaded micelles.

Synergistic Use of All-Acceptor Strategies for the Preparation of an Organic Semiconductor and the Realization of High Electron Transport Properties in Organic Field-Effect Transistors.

The development of n-type organic semiconductor materials for transporting electrons as part of logic circuits is equally important to the development of p-type materials for transporting holes. Currently, progress in research on n-type materials is relatively backward, and the number of polymers with high electron mobility is limited. As the core component of the organic field-effect transistor (OFET), the rational design and judicious selection of the structure of organic semiconductor materials are crucial to enhance the performance of devices. A novel conjugated copolymer with an all-acceptor structure was synthesized based on an effective chemical structure modification and design strategy. PDPPTT-2Tz was obtained by the Stille coupling of the DPPTT monomer with 2Tz-SnMe3, which features high molecular weight and thermal stability. The low-lying lowest unoccupied molecular orbital (LUMO) energy level of the copolymer was attributed to the introduction of electron-deficient bithiazole. DFT calculations revealed that this material is highly planar. The effect of modulation from a donor-acceptor to acceptor-acceptor structure on the improvement of electron mobility was significant, which showed a maximum value of 1.29 cm2 V-1 s-1 and an average value of 0.81 cm2 V-1 s-1 for electron mobility in BGBC-based OFET devices. Our results demonstrate that DPP-based polymers can be used not only as excellent p-type materials but also as promising n-type materials.

Performance of polycarboxylate superplasticisers in seawater-blended cement: Effect from chemical structure and nano modification

Abstract The performance of polycarboxylate superplasticisers (PCE) in cement blended with seawater (SW) depends on its molecular structure since large ions in SW significantly influenced its mechanism. The aim of this study was to investigate the effect of the molecular structure of PCE on the fresh properties of SW-blended cement pastes. A series of six PCEs with different charge densities, side chain lengths, and anchor groups were modified by introducing nanosilica and their physicochemical properties were characterised, and the performance was evaluated by determined by minislump, rheological behaviour and setting time. Finally, the potential mechanism was proposed via measurement of adsorption amount and layer thickness, and water film thickness (WFT). The results showed that the PCE with longer side chains and higher AA:HEPG ratio provided a significant improvement in the workability of cement pastes mixed with SW. According to the flow curves from the rheology experiments, analysis of the rheological behaviour of polycarboxylate superplasticisers in SW-blended cements paste by three rheological models. By adsorption measurement and WFT testing, high higher AA:HPEG ratio exhibits high sorption and WFT indicating less inhibition by ions in SW.

A sodium-dependent split DNAzyme fluorescent sensor under butanol acceleration for ultrasensitive detection of PIWI-interacting RNAs and microRNAs

Split DNAzymes have been designed as multifunctional biosensors. However, their limited sensitivity and low resistance to nuclease hinder their applications in biological samples. Herein, we developed a sodium-dependent and butanol accelerated split DNAzyme fluorescent sensor named Na+-BAS DNAzyme which has an ultra-sensitivity for quantifying PIWI-interacting RNAs/microRNAs and can be directly applied in blood biopsy to detect nucleic acids within the extracellular vesicles (EVs). The Na+-BAS DNAzyme consists of two split DNA strands based on NaA43 DNAzyme, a starting hairpin DNA for binding target to initiate the combining of the split enzymes, and a hairpin RNA-embedded DNA substrate labeled a quencher and a fluorophore for signal readout after its cleavage by the assembled DNAzyme complex. To achieve ultra-sensitivity, we employed a simple but key approach of butanol dehydration to highly accelerate the measuring reaction. The sensor has achieved an ultra-low detection limit of 12 × 10−18 M miR-21 after 30 min reaction, and 3.98 or 2.69 particles μL−1 MCF-7 EVs through miR-21 or piR-20365 detection. With these high performances, the sensor can detect extremely trace abundance of miR-21 in a single MCF-10a or MCF-7 EV, quantifying it as 5.93 × 10−3 or 0.12 copies per EV. Without any chemical structure modification, the sensor can be directly used in the plasma sample for breast cancer diagnosis which has obtained both 100% sensitivity and specificity using the biomarker of piR-20365. The Na+-BAS DNAzyme sensor’s ultra-sensitivity, high efficiency, universality, and simplicity make it a great potential in the clinical diagnostic application.

Polymer Electrolytes Based on Polybenzimidazole, Poly(Vinylidene Fluoride-co-Hexafluoropropylene), and Ionic Liquids

Ionic liquids, salts with melting temperature below 100°C, have continuously attracted research interest. Introduction of ionic liquids in a polymer matrix affords polymer electrolytes exhibiting extremely high electroconductivity and electrochemical stability, membranes on their basis possessing good mechanical properties. Diversity of the polymers/copolymers suitable as the matrix as well as practically unlimited variety of ionic liquids (obtained via variation of the anion-cation composition and additional modification of the ions chemical structure) have afforded the polymer electrolytes with a wide range of the physico-chemical properties. In this study, the attention has been primarily focused on the results published over the recent decades and related to investigation of electrolytes for electrochemical devices, in which the membranes based on polybenzimidazole (meta-PBI), the poly(vinylidene fluoride-со-hexafluoropropylene) (PVdF-HFP) copolymer, and ammonium or imidazolium ionic liquids have been used. Various types of polymer electrolytes differing in the composition and the application range have been considered in this study: polymer + ionic liquid, polymer + ionic liquid + acid, and polymer + ionic liquid + lithium/sodium salt. Moreover, the influence of the fillers, introduced in the above-said polymer electrolytes to improve the properties and resolve the issue of the ionic liquid retention in the membrane, has been discussed. This report presents vast data sets (tables) on the electroconductivity and thermal stability of more than 100 polymer electrolytes, which are demanded by the broad journal audience.

New approaches to the modification of chemical structure and photophysical properties of BODIPY dyes

New approaches to the modification of chemical structure and photophysical properties of BODIPY dyes

Molecular Recognition Study toward the Mitochondrial Electron Transport Chain Inhibitor Mubritinib and Human Serum Albumin.

The ability to bind plasma proteins helps in comprehending relevant aspects related to the pharmacological properties of many drugs. Despite the vital role of the drug mubritinib (MUB) in the prophylaxis of various diseases, its interaction with carrier proteins still needs to be clarified. The present work focuses on the interaction between MUB and Human serum albumin (HSA), investigated by employing multispectroscopic, biochemical, and molecular docking approaches. The results reveal that MUB has quenched HSA intrinsic fluorescence (following a static mechanism) by attaching very close (r = 6.76 Å) and with moderate affinity (Kb ≈ 104 M-1) to the protein site I (mainly by H-bonds, hydrophobic and Van der Waals forces). On one side, the HSA-MUB interaction has been accompanied by a slight disturbance in the HSA chemical environment (around the Trp residue) and protein secondary structure modifications. On another side, MUB competitively inhibits HSA esterase-like activity, which is very similar to other Tyrosine kinase inhibitors, and evidence that protein functional alterations have been triggered by MUB interaction. In summary, all of the presented observations can shed light on diverse pharmacological factors associated with drug administration.

Acetic acid bacteria in agro-wastes: from cheese whey and olive mill wastewater to cellulose

In this study, cheese whey and olive mill wastewater were investigated as potential feedstocks for producing bacterial cellulose by using acetic acid bacteria strains. Organic acids and phenolic compounds composition were assayed by high-pressure liquid chromatography. Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction were used to investigate modifications in bacterial cellulose chemical and morphological structure. Cheese whey was the most efficient feedstock in terms of bacterial cellulose yield (0.300g of bacterial cellulose/gram of carbon source consumed). Bacterial cellulose produced in olive mill wastewater presented a more well-defined network compared to pellicles produced in cheese whey, resulting in a smaller fiber diameter in most cases. The analysis of bacterial cellulose chemical structure highlighted the presence of different chemical bonds likely to be caused by the adsorption of olive mill wastewater and cheese whey components. The crystallinity ranged from 45.72 to 80.82%. The acetic acid bacteria strains used in this study were characterized by 16S rRNA gene sequencing, allowing to assign them to Komagataeibacter xylinus and Komagataeibacter rhaeticus species. This study proves the suitability to perform sustainable bioprocesses for producing bacterial cellulose, combining the valorisation of agro-wastes with microbial conversions carried out by acetic acid bacteria. The high versatility in terms of yield, morphology, and fiber diameters obtained in cheese whey and olive mill wastewater contribute to set up fundamental criteria for developing customized bioprocesses depending on the final use of the bacterial cellulose. KEY POINTS: • Cheese whey and olive mill wastewater can be used for bacterial cellulose production. • Bacterial cellulose structure is dependent on the culture medium. • Komagataeibacter strains support the agro-waste conversion in bacterial cellulose.