Physiological and molecular mechanisms of ZnO quantum dots mitigating cadmium stress in Salvia miltiorrhiza.

This study delved into the physiological and molecular mechanisms underlying the mitigation of cadmium (Cd) stress in the model medicinal plant Salvia miltiorrhiza through the application of ZnO quantum dots (ZnO QDs, 3.84 nm). A pot experiment was conducted, wherein S. miltiorrhiza was subjected to Cd stress for six weeks with foliar application of 100 mg/L ZnO QDs. Physiological analyses demonstrated that compared to Cd stress alone, ZnO QDs improved biomass, reduced Cd accumulation, increased the content of photosynthetic pigments (chlorophyll and carotenoids), and enhanced the levels of essential nutrient elements (Ca, Mn, and Cu) under Cd stress. Furthermore, ZnO QDs significantly lowered Cd-induced reactive oxygen species (ROS) content, including H2O2, O2-, and MDA, while enhancing the activity of antioxidant enzymes (SOD, POD, APX, and GSH-PX). Additionally, ZnO QDs promoted the biosynthesis of primary and secondary metabolites, such as total protein, soluble sugars, terpenoids, and phenols, thereby mitigating Cd stress in S. miltiorrhiza. At the molecular level, ZnO QDs were found to activate the expression of stress signal transduction-related genes, subsequently regulating the expression of downstream target genes associated with metal transport, cell wall synthesis, and secondary metabolite synthesis via transcription factors. This activation mechanism contributed to enhancing Cd tolerance in S. miltiorrhiza. In summary, these findings shed light on the mechanisms underlying the mitigation of Cd stress by ZnO QDs, offering a potential nanomaterial-based strategy for enhancing Cd tolerance in medicinal plants.

The use of biofield energy therapy as complementary and alternative medicine in human health care system: a narrative review and potential mechanisms.

INTRODUCTION: There has been accumulating interest in the application of biofield therapy as complementary and alternative medicine (CAM) to treat various diseases. The practices include reiki, qigong, blessing, prayer, distant healing, known as biofield therapies. This paper aims to state scientific knowledge on preclinical and clinical studies to validate its potential use as an alternative medicine in the clinic. It also provides a more in-depth context for understanding the potential role of quantum entanglement in the effect of biofield energy therapy. CONTENT: A comprehensive literature search was performed using the different databases (PubMed, Scopus, Medline, etc.). The published English articles relevant to the scope of this review were considered. The review gathered 45 papers that were considered suitable for the purpose. Based on the results of these papers, it was concluded that biofield energy therapy was effective in treating different disease symptoms in preclinical and clinical studies. SUMMARY: Biofield therapies offer therapeutic benefits for different human health disorders, and can be used as alternative medicine in clinics for the medically pluralistic world due to the growing interest in CAM worldwide. OUTLOOK: The effects of the biofield energy therapies are observed due to the healer's quantum thinking, and transmission of the quantum energy to the subject leads to the healing that occurs spiritually through instantaneous communication at the quantum level via quantum entanglement.

Enhancing Photothermal/Photodynamic Therapy for Glioblastoma by Tumor Hypoxia Alleviation and Heat Shock Protein Inhibition Using IR820-Conjugated Reduced Graphene Oxide Quantum Dots.

We use low-molecular-weight branched polyethylenimine (PEI) to produce cytocompatible reduced graphene oxide quantum dots (rGOQD) as a photothermal agent and covalently bind it with the photosensitizer IR-820. The rGOQD/IR820 shows high photothermal conversion efficiency and produces reactive oxygen species (ROS) after irradiation with near-infrared (NIR) light for photothermal/photodynamic therapy (PTT/PDT). To improve suspension stability, rGOQD/IR820 was PEGylated by anchoring with the DSPE hydrophobic tails in DSPE-PEG-Mal, leaving the maleimide (Mal) end group for covalent binding with manganese dioxide/bovine serum albumin (MnO2/BSA) and targeting ligand cell-penetrating peptide (CPP) to synthesize rGOQD/IR820/MnO2/CPP. As MnO2 can react with intracellular hydrogen peroxide to produce oxygen for alleviating the hypoxia condition in the acidic tumor microenvironment, the efficacy of PDT could be enhanced by generating more cytotoxic ROS with NIR light. Furthermore, quercetin (Q) was loaded to rGOQD through π-π interaction, which can be released in the endosomes and act as an inhibitor of heat shock protein 70 (HSP70). This sensitizes tumor cells to thermal stress and increases the efficacy of mild-temperature PTT with NIR irradiation. By simultaneously incorporating the HSP70 inhibitor (Q) and the in situ hypoxia alleviating agent (MnO2), the rGOQD/IR820/MnO2/Q/CPP can overcome the limitation of PTT/PDT and enhance the efficacy of targeted phototherapy in vitro. From in vivo study with an orthotopic brain tumor model, rGOQD/IR820/MnO2/Q/CPP administered through tail vein injection can cross the blood-brain barrier and accumulate in the intracranial tumor, after which NIR laser light irradiation can shrink the tumor and prolong the survival times of animals by simultaneously enhancing the efficacy of PTT/PDT to treat glioblastoma.

The Sentient Cell: Implications for Osteopathic Medicine.

The Foundation of Osteopathic Research and Clinical Endorsement (FORCE) is an organization that includes various figures involved in clinical and non-profit research and does not depend on any private or government body. To better understand how the human body behaves, we need to observe cellular behavior. Considering the human body as layers, districts, and regions, or just as a machine, is severely limiting to understanding the systemic mechanisms that are implemented to maintain bodily health. For some years, FORCE has contributed several articles to the literature to support the view of a human body as a unit, a fascial continuum (solid and fluid fascia) capable of interacting consciously, and not as a passive mirror, with respect to external stresses. The article reviews the tensegrity theory applied to the cell, trying to bring to light that the mechanistic vision on which this theory is based does not meet biological reality. We review some concepts related to biology, the science that studies life, and quantum physics, the science that studies the invisible physical phenomena that underlie life. Understanding that the cells and tissues are aware of the therapeutic approaches they receive could better guide the decisions of the osteopathic clinician.

Recent Advances in Chemistry, Mechanism, and Applications of Quantum Dots in Photodynamic and Photothermal Therapy.

Semiconductor quantum dots (QD) are a kind of nanoparticle with unique optical properties that have attracted a lot of attention in recent years. In this paper, the characteristics of these nanoparticles and their applications in nanophototherapy have been reviewed. Phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), has gained special importance because of its high accuracy and local treatment due to the activation of the drug at the tumor site. PDT is a new way of cancer treatment that is performed by activating light-sensitive compounds named photosensitizers (PS) by light. PSs cause the destruction of diseased tissue through the production of singlet oxygen. PTT is another non-invasive method that induces cell death through the conversion of near-infrared light (NIR) into heat in the tumor situation by the photothermal agent (PA). Through using energy transfer via the FRET (Förster resonance energy transfer) process, QDs provide light absorption wavelength for both methods and cover the optical weaknesses of phototherapy agents.

Photon Upconversion at Organic-Inorganic Interfaces.

Photon upconversion is a process that combines low-energy photons to form useful high-energy photons. There are potential applications in photovoltaics, photocatalysis, biological imaging, etc. Semiconductor quantum dots (QDs) are promising for the absorption of these low-energy photons due to the high extinction coefficient of QDs, especially in the near infrared (NIR). This allows the intriguing use of diffuse light sources such as solar irradiation. In this review, we describe the development of this organic-QD upconversion platform based on triplet-triplet annihilation, focusing on the dark exciton in QDs with triplet character. Then we introduce the underlying energy transfer steps, starting from QD triplet photosensitization, triplet exciton transport, triplet-triplet annihilation, and ending with the upconverted emission. Design principles to improve the total upconversion efficiency are presented. We end with limitations in current reports and proposed future directions. This review provides a guide for designing efficient organic-QD upconversion platforms for future applications, including overcoming the Shockley-Queisser limit for more efficient solar energy conversion, NIR-based phototherapy, and diagnostics in vivo.

Chelating Effect of Siderophore Desferrioxamine-B on Uranyl Biomineralization Mediated by Shewanella putrefaciens.

In contaminated water and soil, little is known about the role and mechanism of the biometabolic molecule siderophore desferrioxamine-B (DFO) in the biogeochemical cycle of uranium due to complicated coordination and reaction networks. Here, a joint experimental and quantum chemical investigation is carried out to probe the biomineralization of uranyl (UO22+, referred to as U(VI) hereafter) induced by Shewanella putrefaciens (abbreviated as S. putrefaciens) in the presence of DFO and Fe3+ ion. The results show that the production of mineralized solids {hydrogen-uranium mica [H2(UO2)2(PO4)2·8H2O]} via S. putrefaciens binding with UO22+ is inhibited by DFO, which can both chelate preferentially UO22+ to form a U(VI)-DFO complex in solution and seize it from U(VI)-biominerals upon solvation. However, with Fe3+ ion introduced, the strong specificity of DFO binding with Fe3+ causes re-emergence of biomineralization of UO22+ {bassetite [Fe(UO2)2(PO4)2·8(H2O)]} by S. putrefaciens, owing to competitive complexation between Fe3+ and UO22+ for DFO. As DFO possesses three hydroxamic functional groups, it forms hexadentate coordination with Fe3+ and UO22+ ions via these functional groups. The stability of the Fe3+-DFO complex is much higher than that of U(VI)-DFO, resulting in some DFO-released UO22+ to be remobilized by S. putrefaciens. Our finding not only adds to the understanding of the fate of toxic U(VI)-containing substances in the environment and biogeochemical cycles in the future but also suggests the promising potential of utilizing functionalized DFO ligands for uranium processing.

Herbal Medicine-Inspired Carbon Quantum Dots with Antibiosis and Hemostasis Effects for Promoting Wound Healing.

Bleeding and bacterial infections are crucial factors affecting wound healing. The usage of herbal medicine-derived materials holds great potential for promoting wound healing. However, the uncertain intrinsic effective ingredients and unclear mechanism of action remain great concerns. Herein, inspired by the herbal medicine Ligusticum wallichii, we reported the synthesis of tetramethylpyrazine-derived carbon quantum dots (TMP-CQDs) for promoting wound healing. Of note, the use of TMP as the precursor instead of L. wallichii ensured the repeatability and homogeneity of the obtained products. Furthermore, TMP-CQDs exhibited high antibacterial activity. Mechanically, TMP-CQDs inhibited the DNA repair, biosynthesis, and quorum sensing of the bacteria and induced intracellular reactive oxygen species (ROS). Moreover, TMP-CQDs could accelerate blood coagulation through activating factor VIII and promoting platelet aggregation. Effective wound healing was achieved by using TMP-CQDs in the Staphylococcus aureus-infected mouse skin wound model. This study sheds light on the development of herbal medicine-inspired materials as effective therapeutic drugs.

Assembling Ag2S quantum dots onto peptide nanosheet as a biomimetic two-dimensional nanoplatform for synergistic near infrared-II fluorescent imaging and photothermal therapy of tumor.

Fluorescent bioimaging and photothermal therapy (PTT) techniques have potential significance in cancer diagnosis and treatment and have been widely applied in biomedical and practical clinical trials. This study proposes the molecular design and biofabrication of a two-dimensional (2D) nanoplatform, exhibiting promising prospects for synergistic bioimaging and PTT of tumors. First, biocompatible 2D peptide nanosheets (PNSs) were designed and prepared through peptide self-assembly. These served as a support matrix for assembling polyethylene glycol-modified Ag2S quantum dots (PEG-Ag2SQDs) to form a 2D nanoplatform (PNS/PEG-Ag2SQDs) with unique fluorescent and photothermal properties. The designed 2D nanoplatform not only showed improved photothermal efficacy and an elevated photothermal conversion efficiency of 52.46 %, but also demonstrated significant lethality against tumors in both in vitro and in vivo cases. Additionally, it displays excellent imaging effects in the near-infrared II region, making it suitable for synergistic fluorescent imaging-guided PTT of tumors. This study not only provides a facile approach for devising and synthesizing 2D peptide assemblies but also presents new biomimetic strategies to create functional 2D organic/inorganic nanoplatforms for biomedical applications.

The Graphene Quantum Dots Gated Nanoplatform for Photothermal-Enhanced Synergetic Tumor Therapy.

Currently, the obvious side effects of anti-tumor drugs, premature drug release, and low tumor penetration of nanoparticles have largely reduced the therapeutic effects of chemotherapy. A drug delivery vehicle (MCN-SS-GQDs) was designed innovatively. For this, the mesoporous carbon nanoparticles (MCN) with the capabilities of superior photothermal conversion efficiency and high loading efficiency were used as the skeleton structure, and graphene quantum dots (GQDs) were gated on the mesopores via disulfide bonds. The doxorubicin (DOX) was used to evaluate the pH-, GSH-, and NIR-responsive release performances of DOX/MCN-SS-GQDs. The disulfide bonds of MCN-SS-GQDs can be ruptured under high glutathione concentration in the tumor microenvironment, inducing the responsive release of DOX and the detachment of GQDs. The local temperature of a tumor increases significantly through the photothermal conversion of double carbon materials (MCN and GQDs) under near-infrared light irradiation. Local hyperthermia can promote tumor cell apoptosis, accelerate the release of drugs, and increase the sensitivity of tumor cells to chemotherapy, thus increasing treatment effect. At the same time, the detached GQDs can take advantage of their extremely small size (5-10 nm) to penetrate deeply into tumor tissues, solving the problem of low permeability of traditional nanoparticles. By utilizing the photothermal properties of GQDs, synergistic photothermal conversion between GQDs and MCN was realized for the purpose of synergistic photothermal treatment of superficial and deep tumor tissues.

Ultrashort channel MoSe2transistors with selenium atoms replaced at the interface: first-principles quantum-transport study.

Realizing n- and p-type transition metal dichalcogenide (TMD)-based field-effect transistors for nanoscale complementary metal oxide semiconductor (CMOS) applications remains challenging owing to undesirable contact resistance. Quantumtransport calculations were performed by replacing single-sided Se atoms of TMD near the interface with As or Br atoms to further improve the contact resistance. Here, partial selenium replacement produced a novel interface with a segment of metamaterial MoSeX (Pt/MoSeX/MoSe2; X = As, Br). Such stable metamaterials exhibit semi-metallicity, and the contact resistance can be thus lowered. Our findings provide insights into the potential of MoSe2-based nano-CMOS logic devices.

Ochrolines A-C, three new indole diketopiperazines from cultures of endophytic fungi Bionectria ochroleuca SLJB-2.

Three new indole diketopiperazines, ochrolines A-C (1-3), along with three known compounds (4-6), were isolated and identified from the EtOAc extract of the solid fermentation of Bionectria ochroleuca SLJB-2. Notably, compound 1 featured a natural rarely-occurring caged skeleton with a 6/5/6/7 heterotetracyclic bridged ring system. The structures including absolute configurations of 1-3 were fully accomplished by extensive spectroscopic analyses, DFT GIAO 13C NMR and electronic circular dichroism (ECD) calculations. The plausible biogenetic pathways of these new indole diketopiperazines were also proposed. Moreover, the cytotoxic activity screening revealed that compound 2 exhibited moderate inhibitory effect against A549 with inhibition rate of 57.44% at the concentration of 50 µM and compound 1 exhibited mild inhibitory activities against A549, Hela and MCF-7.

Structurally diverse analgesic diterpenoids from the flowers of Rhododendron molle.

Thirteen diterpenoids (1-13), classified into four structurally diverse carbon skeletons, including 1,5-seco-kalmane (1 and 6), grayanane (2-11), kalmane (12), and rhodomollane (13), were isolated from the flowers extract of Rhododendron molle. Among them, rhodomollinols A - E (1-5) were five new diterpenoids and their structures were elucidated by extensive spectroscopic methods including HRESIMS, UV, IR, 1D and 2D NMR, as well as quantum ECD calculations. Rhodomollinol A (1) is the first representative of a 6-deoxy-1,5-seco-kalmane diterpenoid. The abnormal NMR phenomenon of the presence of only 9 carbon resonances instead of 20 carbons in the 13C NMR spectrum of 1 was observed and elucidated by the quantum NMR calculations. All diterpenoids 1-13 showed significant analgesic activities in an acetic acid-induced writhing model. It's the first time to report the analgesic activity of a rhodomollane-type diterpenoid. At a dose of 1.0 mg/kg, diterpenoids 1-3, 6, 8, 9, and 12 reduced the writhe numbers with inhibition rates over 50%, and 9 exhibited stronger analgesic activity with a writhe inhibition rate of 89.7% than that of the positive control morphine. Importantly, even at the lowest dose of 0.04 mg/kg, rhodomollinols A (1) and B (2), rhodomollein X (7), and 2-O-methylrhodojaponin VI (9) still showed more potent analgesic effects than morphine with the writhe inhibition rates of 51.8%, 48.0%, 61.7%, and 60.0%, respectively. A preliminary structure-activity relationship might provide some clues to design potential analgesics on the basis of structurally diverse Ericaceae diterpenoids.

Efficacy and Safety of Quantum Molecular Resonance Electrotherapy in Patients with Aqueous-Deficient, Evaporative and Mixed-Type Dry Eye: A Randomized Interventional Study.

INTRODUCTION: To evaluate the efficacy and safety of Quantum Molecular Resonance (QMR) treatment in patients with severe dry eye disease (DED), as well as its effects on aqueous-deficient (ADDE), evaporative (EDE), and mixed (MDE) dry eye. METHODS: In this prospective, interventional study, 81 patients were randomly allocated to received four treatment sessions of QMR at 1-week intervals (Rexon-Eye®, Resono Ophthalmic, Trieste, Italy) (QRM group) or tear substitute four times daily, containing 0.15% sodium hyaluronate and 3% trehalose (Thealoz Duo®, Thea Pharma, France) (SH-TH group). Outcome measures included ocular surface disease index (OSDI) questionnaire, tear meniscus height (TMH), tear breakup time (TBUT), non-invasive breakup time (NIBUT), corneal fluorescein staining (CFS), lipid layer thickness (LLT), tear film osmolarity (OSM), and meibomian gland dysfunction (MGD) grade, which were assessed at baseline and 1-month and 3-month follow-up. RESULTS: The QMR group achieved better improvements than the SH-TH group in OSDI and SANDE questionnaires, NIBUT, LLT, and CFS. The mean differences between the groups were as follows: OSDI (- 12.4 ± 0.25 points, P = 0.01), SANDE (10.6 ± 1.7 points, P = 0.01), NIBUT (2 ± 0.25 s, P = 0.01), LLT (18.7 ± 0.7 nm, P = 0.01), and CFS (1.2 ± 0.1 points, P = 0.02). In subgroups analysis, QMR treatment demonstrated a beneficial role to improve DED symptoms and signs in ADDE, EDE, and MDE. CONCLUSION: QMR is an effective and well-tolerated treatment that seems to improve DED symptoms and signs in patients with severe DED. However, further studies are needed to confirm this. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT06119386.

Dynamic Covalent Bonds in the Ebselen Class of Antioxidants Probed by X-ray Quantum Crystallography.

Dynamic bonds are essential structural ingredients of dynamic covalent chemistry that involve reversible cleavage and formation of bonds. Herein, we explore the electronic characteristics of Se-N bonds in the organo-selenium antioxidant ebselen and its derivatives for their propensity to function as dynamic covalent bonds by employing high-resolution X-ray quantum crystallography and complementary computational studies. An analysis of the experimentally reconstructed X-ray wavefunctions reveals the salient electronic features of the Se-N bonds with very low electron density localized at the bonding region and a positive Laplacian value at the bond critical point. Bond orders and percentage covalency and ionicity estimated from the X-ray wavefunctions, along with localized orbital locator (LOL) and electron localization function (ELF) analyses show that the Se-N bond is unique in its closed shell-like features, despite being a covalent bond. Time-dependent DFT calculations simulate the cleavage of Se-N bonds in ebselen in the excited state, further substantiating their nature as dynamic bonds.

A literature review of the increased intracellular free calcium concentration by biofield therapy or laser exposure. An explanation by using a theoretical study of hydrated calcium ions.

INTRODUCTION: A revision of several experimental results on cells shows that electromagnetic radiation, either produced by biofield therapy (BFT) or laser, induced an increase in intracellular free calcium concentration. An explanation of this phenomenon is proposed. METHODS: Quantum chemistry calculations were performed on Ca2+ with different degrees of hydration with the DFT/r2SCAN-3c method together with the implicit solvation model SMD. RESULTS: Ca2+ dehydration energy by quantum calculations, in an aqueous medium, coincides with the experimental results of the energy of the photon emitted in biofield therapies and lasers. This strongly suggests that the increased intracellular free calcium concentration is because of calcium ion dehydration upon the application of radiation. The Ca2+ dehydration increases the membrane potential due to an augment of the net charge on Ca2+ and it moves near the membrane by the attraction of its negative ions. The voltage-dependent channels are also activated by this membrane potential. CONCLUSION: The increased intracellular Ca2+ concentration occurs with biofield therapy (BFT) or laser. A novel explanation is given based on resonance-induced Ca2+ dehydration with applied radiation, supported by experimental data and theoretical calculations.

Study on CdSe/ZnS Quantum Dot Fluorescence Immunoprobe for Detection of Aflatoxin B1 in 5 Traditional Chinese Medicines.

Aflatoxin is a highly toxic substance, of which aflatoxin B1 is the most toxic and carcinogenic among aflatoxins. In this paper, the team used homemade CdSe/Zns quantum dots to construct a fluorescent immunoprobe and all-antigen coupling with aflatoxin B1. It used a self-developed fluorescence intensity detector to detect aflatoxin B1 in five traditional Chinese medicines, namely, ginseng, Panax ginseng, Chuanxiong rhizome, rhubarb, and yam. The recoveries were 80.0-102.0%; the relative standard deviations (RSD)were from 2.4 to 9.2.

Galangal-Cinnamon Spice Mixture Blocks the Coronavirus Infection Pathway through Inhibition of SARS-CoV-2 MPro, Three HCoV-229E Targets; Quantum-Chemical Calculations Support In Vitro Evaluation.

Natural products such as domestic herbal drugs which are easily accessible and cost-effective can be used as a complementary treatment in mild and moderate COVID-19 cases. This study aimed to detect and describe the efficiency of phenolics detected in the galangal-cinnamon mixture in the inhibition of SARS-CoV-2's different protein targets. The potential antiviral effect of galangal-cinnamon aqueous extract (GCAE) against Low Pathogenic HCoV-229E was assessed using cytopathic effect inhibition assay and the crystal violet method. Low Pathogenic HCoV-229E was used as it is safer for in vitro laboratory experimentation and due to the conformation and the binding pockets similarity between HCoV-229E and SARS-CoV-2 MPro. The GCAE showed a significant antiviral effect against HCoV-229E (IC50 15.083 µg/mL). Twelve phenolic compounds were detected in the extract with ellagic, cinnamic, and gallic acids being the major identified phenolic acids, while rutin was the major identified flavonoid glycoside. Quantum-chemical calculations were made to find molecular properties using the DFT/B3LYP method with 6-311++G(2d,2p) basis set. Quantum-chemical values such as EHOMO, ELUMO, energy gap, ionization potential, chemical hardness, softness, and electronegativity values were calculated and discussed. Phenolic compounds detected by HPLC-DAD-UV in the GCAE were docked into the active site of 3 HCoV-229E targets (PDB IDs. 2ZU2, 6U7G, 7VN9, and 6WTT) to find the potential inhibitors that block the Coronavirus infection pathways from quantum and docking data for these compounds. There are good adaptations between the theoretical and experimental results showing that rutin has the highest activity against Low Pathogenic HCoV-229E in the GCAE extract.

Theoretical Studies for the Discovery of Potential Sucrase-Isomaltase Inhibitors from Maize Silk Phytochemicals: An Approach to Treatment of Type 2 Diabetes.

A theoretical analysis of the potential inhibition of human sucrase-isomaltase (SI) by flavonoids was carried out with the aim of identifying potential candidates for an alternative treatment of type 2 diabetes. Two compounds from maize silks, maysin and luteolin, were selected to be studied with the structure-based density functional theory (DFT), molecular docking (MDock), and molecular dynamics (MD) approaches. The docking score and MD simulations suggested that the compounds maysin and luteolin presented higher binding affinities in N-terminal sucrase-isomaltase (NtSI) than in C-terminal sucrase-isomaltase (CtSI). The reactivity parameters, such as chemical hardness (η) and chemical potential (µ), of the ligands, as well as of the active site amino acids of the NtSI, were calculated by the meta-GGA M06 functional in combination with the 6-31G(d) basis set. The lower value of chemical hardness calculated for the maysin molecule indicated that this might interact more easily with the active site of NtSI, in comparison with the values of the acarbose and luteolin structures. Additionally, a possible oxidative process was proposed through the quantum chemical calculations of the electronic charge transfer values (∆N) between the active site amino acids of the NtSI and the ligands. In addition, maysin displayed a higher ability to generate more oxidative damage in the NtSI active site. Our results suggest that maysin and luteolin can be used to develop novel α-glucosidase inhibitors via NtSI inhibition.

Theoretical Study of Structure and Photophysics of Homologous Series of Bis(arylydene)cycloalkanones.

Photophysical properties of a series of bis(arylydene)cycloalkanone dyes with various donor substituents are studied using quantum chemistry. Their capacity for luminescence and nonradiative relaxation through trans-cis isomerization is related to their structure, in particular, to the donor capacity of the substituents and the degree of conjugation due to the central cycloalkanone moiety. It is shown that cyclohexanone central moiety introduces distortions and disrupts the conjugation, thus leading to a nonmonotonic change in their properties. The increasing donor capacity of the substituents causes increase in the HOMO energy (rise in the oxidation potential) and decrease in the HOMO-LUMO gap, which results in the red shift of the absorption spectra. The ability of the excited dye to relax through fluorescence or through trans-cis isomerization is governed by the height of the barrier between the Franck-Condon and S1-S0 conical intersection regions on the potential energy surface of the lowest π-π* excited state. This barrier also correlates with the donor capacity of the substituents and the degree of conjugation between the central and donor moieties. The calculated fluorescence and trans-cis isomerization rates are in good agreement with the observed fluorescence quantum yields.