Low Polar Surface Research Articles

Ligand-Based Virtual Screening as a Path to New Chemotypes for Candidate PET Radioligands for Imaging Tauopathies.

Ligand-based virtual screening (LBVS) has rarely been tested as a method for discovering new structural scaffolds for PET radioligand development. This study used LBVS to discover potential chemotype leads for developing radioligands for PET imaging of tauopathies. ZINC12, a free database of over 12 million commercially available compounds, was searched to discover novel scaffolds based on similarities to four query compounds. Thirteen high-ranking hits were purchased and assayed for their ability to compete against three tritiated radioligands at their distinct binding sites in Alzheimer's disease brain tissue. Three hits were 2-substituted 6-methoxy naphthalenes. Synthetic elaboration of this new chemotype yielded three new ligands (25, 26, and 28) with high affinity for the [3H]6 (flortaucipur) neurofibrillary tangle binding site. Compound 28 showed remarkably high affinity (Ki, 7 nM) and other desirable properties for a candidate PET radioligand, including low topological polar surface area, moderate computed log D, and amenability for labeling with carbon-11. LBVS appears to be uniquely valuable for discovering new chemotypes for candidate PET radioligands.

Efficient Inhibition of Deep Conversion of Partial Oxidation Products in C-H Bonds' Functionalization Utilizing O2 via Relay Catalysis of Dual Metalloporphyrins on Surface of Hybrid Silica Possessing Capacity for Product Exclusion.

To inhibit the deep conversion of partial oxidation products (POX-products) in C-H bonds' functionalization utilizing O2, 5-(4-(chloromethyl)phenyl)-10,15,20-tris(perfluorophenyl)porphyrin cobalt(II) and 5-(4-(chloromethyl)phenyl)-10,15,20-tris(perfluorophenyl)porphyrin copper(II) were immobilized on the surface of hybrid silica to conduct relay catalysis on the surface. Fluorocarbons with low polarity and heterogeneous catalysis were devised to decrease the convenient accessibility of polar POX-products to catalytic centers on the lower polar surface. Relay catalysis between Co and Cu was designed to utilize the oxidation intermediates alkyl hydroperoxides to transform more C-H bonds. Systematic characterizations were conducted to investigate the structure of catalytic materials and confirm their successful syntheses. Applied to C-H bond oxidation, not only deep conversion of POX-products was inhibited but also substrate conversion and POX-product selectivity were improved simultaneously. For cyclohexane oxidation, conversion was improved from 3.87% to 5.27% with selectivity from 84.8% to 92.3%, which was mainly attributed to the relay catalysis on the surface excluding products. The effects of the catalytic materials, product exclusion, relay catalysis, kinetic study, substrate scope, and reaction mechanism were also investigated. To our knowledge, a practical and novel strategy was presented to inhibit the deep conversion of POX-products and to achieve efficient and accurate oxidative functionalization of hydrocarbons. Also, a valuable protocol was provided to avoid over-reaction in other chemical transformations requiring high selectivity.

DDDR-31. TARGETING CANCER STEM CELLS WITH A CDK2 INHIBITOR IN GLIOBLASTOMA

Abstract Glioblastoma (GB) is the most common and aggressive adult brain tumor with no cure. Brain tumor stem cells (BTSCs) are a rare population of self-renewing multipotent stem cells in GB that contribute to tumorigenesis, therapeutic resistance and tumour recurrence. Here, we report a CDK2 inhibitor that suppresses BTSCs via OSM/OSMR/STAT3 signalling pathway. To begin with we performed high throughput screening (HTS) of ~8400 compounds including FDA-approved drugs in patient derived human BTSCs that naturally harbour EGFRvIII mutation and elevated STAT3 phosphorylation, in search of compounds that can suppress EGFRvIII/OSMR/STAT3 oncogenic pathway. The screen led to the identification of a panel of CDK inhibitors that possessed important characteristics including a) ability to cross the blood-brain barrier with mall molecular weights of 277-566 kDa, b) low Topological Polar Surface Area (TPSA) of 76-115 A°, c) a low number of Hydrogen Bond Donors (HBDs) (1-4), and d) cLogP values ranging from 2-4. Following counter screens, we focused on a CDK2 inhibitor that significantly and most efficiently reduced OSM/OSMR signalling and STAT3 activation. Importantly, we found that the compound inhibited the self-renewal and growth of BTSCs in EGFRvIII subtype of BTSCs. This research has led to future investigation on in vivo assessment of this CDK2 inhibitor in combination with ionizing radiation and chemotherapy in preclinical models of GB.

TARGETING CANCER STEM CELLS WITH A CDK2 INHIBITOR IN GLIOBLASTOMA

Abstract Glioblastoma (GB) is the most common and aggressive adult brain tumor with no cure. Brain tumor stem cells (BTSCs) are a rare population of self-renewing multipotent stem cells in GB that contribute to tumorigenesis, therapeutic resistance, and tumour recurrence. Here, we report a CDK2 inhibitor that suppresses BTSCs via OSM/OSMR/STAT3 signalling pathway. To begin with, we performed high throughput screening (HTS) of ~8400 compounds including FDA-approved drugs in patient derived human BTSCs that naturally harbour EGFRvIII mutation and elevated STAT3 phosphorylation, in search of compounds that can suppress EGFRvIII/OSMR/STAT3 oncogenic pathway. The screen led to the identification of a panel of CDK inhibitors that possessed important characteristics including a) ability to cross the blood-brain barrier with mall molecular weights of 277-566 kDa, b) low Topological Polar Surface Area (TPSA) of 76-115 A°, c) a low number of Hydrogen Bond Donors (HBDs) (1-4), and d) cLogP values ranging from 2-4. Following counter screens, we focused on a CDK2 inhibitor that significantly and most efficiently reduced OSM/OSMR signalling and STAT3 activation. Importantly, we found that the compound inhibited the self-renewal and growth of BTSCs in EGFRvIII subtype of BTSCs. This research has led to future investigation on in vivo assessment of this CDK2 inhibitor in combination with ionizing radiation and chemotherapy in preclinical models of GB.

Polylactic acid/multi-wall carbon nanotubes composite fibrous membrane and their applications in oil-water separation

Because of the rising consumption of oil, the oily pollutants contained in wastewater have caused great damage to the ecological environment. Herein, we report a novel composite PLA fibrous membrane for oil-water separation. First, a series of hydrophobic polylactic acid/multi-wall carbon nanotubes (PLA/CNTs) composite fibrous membranes were fabricated via electrospinning. To modify the membranes’ crystalline structure, the as-prepared PLA/CNTs composite fibrous membranes were subsequently treated by being immersed in an acetone/ethanol mixed solution for 5 min. FTIR and XRD were applied to thoroughly investigate the crystalline modification's mechanism and effects on the oil-water separation capability of the as-prepared composite fibrous membranes. With the introduction of CNTs and the crystalline modification, a low polar, rough and porous surface was endowed to the as-prepared fibrous membranes, enhancing their hydrophobicity and oil-water selectivity. The oil uptake of the as-prepared fibrous membrane could reach 114.01 g/g. The water contact angle in the air could reach 134.2° while the water contact angle under oil can reach 157.3° Therefore, such high separation capability in the oil-water mixture will make the PLA/CNTs composite fibrous membranes promising candidates for oil-water separation applications.

Going Viral: An Investigation into the Chameleonic Behaviour of Antiviral Compounds.

The ability to adjust conformations in response to the polarity of the environment, i.e. molecular chameleonicity, is considered to be important for conferring both high aqueous solubility and high cell permeability to drugs in chemical space beyond Lipinski's rule of 5. We determined the conformational ensembles populated by the antiviral drugs asunaprevir, simeprevir, atazanavir and daclatasvir in polar (DMSO-d6 ) and non-polar (chloroform) environments with NMR spectroscopy. Daclatasvir was fairly rigid, whereas the first three showed large flexibility in both environments, that translated into major differences in solvent accessible 3D polar surface area within each conformational ensemble. No significant differences in size and polar surface area were observed between the DMSO-d6 and chloroform ensembles of these three drugs. We propose that such flexible compounds are characterized as "partial molecular chameleons" and hypothesize that their ability to adopt conformations with low polar surface area contributes to their membrane permeability and oral absorption.

Dependence of the Liquid Polarity in the Wetting of Rough Surface: An Effective Surface Tension Approach.

Liquid and surface polarities play an important role in wetting phenomena, and this should still be true if the surface is rough. We analyze the wetting of high-polar and low-polar liquids on rough low-polar surfaces made of polystyrene. The experimental results are analyzed by the surface tension components (STC) and the equation-of-state (EQS) approaches. Both approaches predicted a clear increase of the contact angle (CA) with the surface roughness for high-polar liquids, but they failed for low-polar liquids: STC calculations produce the wrong tendency in the total solid surface energy, and EQS is not able to fit the data for these liquids. These results show that low-polar liquids show little dependence on the roughness of a low-polar surface, while high-polar liquids are very sensitive to it. As a consequence, the calculated CAs are close to experimental values only for the high-polar liquids, while there are great differences for low-polarity liquids. Both STC and EQS approaches are able to describe the apparent CAs on polystyrene rough surfaces by using effective surface and interfacial tensions, but their effectiveness is limited to high-polarity liquids.

A new perspective to improve the treatment of Lianhuaqingwen on COVID-19 and prevent the environmental health risk of medication.

Lianhuaqingwen (LH), one traditional Chinese medicine (TCM), has been used to treat the coronavirus disease 2019 (COVID-19), but its ecotoxicity with potential human health security has not been well investigated. To overcome such adverse effects and improve its medication efficacy, an intelligent multi-method integrated dietary scheme, screening, and performance evaluation approach was developed. Thirteen LH compounds were selected, and the main protease (Mpro) was used as the potential drug target. Resulted information showed that the more compounds of LH added, the higher medication efficacy obtained using multi-method integrated screening system, expert consultation method, and molecular dynamics simulation. Pharmacodynamic mechanism analysis showed that low total energy and polar surface area of LH active compound (i.e., β-sitosterol) will contribute to the best therapeutic effect on COVID-19 using quantitative structure-activity relationships (QSAR) and sensitivity models. Additionally, when mild COVID-19 patients take LH with the optimum dietary scheme (i.e., β-lactoglobulin, α-lactalbumin, vitamin A, vitamin B, vitamin C, carotene, and vitamin E), the medication efficacy were significantly improved (23.58%). Pharmacokinetics and toxicokinetics results showed that LH had certain human health risks and ecotoxicity. This study revealed the multi-compound interaction mechanism of LH treatment on COVID-19, and provided theoretical guidance for improving therapeutic effect, evaluating TCM safety, and preventing human health risk.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-21125-w.

3-nitroimidazo[1,2-b]pyridazine as a novel scaffold for antiparasitics with sub-nanomolar anti-Giardia lamblia activity

As there is a continuous need for novel anti-infectives, the present study aimed to fuse two modes of action into a novel 3-nitroimidazo[1,2-b]pyridazine scaffold to improve antiparasitic efficacy. For this purpose, we combined known structural elements of phosphodiesterase inhibitors, a target recently proposed for Trypanosoma brucei and Giardia lamblia, with a nitroimidazole scaffold to generate nitrosative stress. The compounds were evaluated in vitro against a panel of protozoal parasites, namely Giardia lamblia, Trypanosoma brucei, T. cruzi, Leishmania infantum and Plasmodium falciparum and for cytotoxicity on MRC-5 cells. Interestingly, selective sub-nanomolar activity was obtained against G. lamblia, and by testing several analogues with and without the nitro group, it was shown that the presence of a nitro group, but not PDE inhibition, is responsible for the low IC50 values of these novel compounds. Adding the favourable drug-like properties (low molecular weight, cLogP (1.2–4.1) and low polar surface area), the key compounds from the 3-nitroimidazo[1,2-b]pyridazine series can be considered as valuable hits for further anti-giardiasis drug exploration and development.

Implications of the Conformationally Flexible, Macrocyclic Structure of the First-Generation, Direct-Acting Anti-Viral Paritaprevir on Its Solid Form Complexity and Chameleonic Behavior.

Direct-acting antiviral regimens have transformed therapeutic management of hepatitis C across all prevalent genotypes. Most of the chemical matter in these regimens comprises molecules well outside the traditional drug development chemical space and presents significant challenges. Herein, the implications of high conformational flexibility and the presence of a 15-membered macrocyclic ring in paritaprevir are studied through a combination of advanced computational and experimental methods with focus on molecular chameleonicity and crystal form complexity. The ability of the molecule to toggle between high and low 3D polar surface area (PSA) conformations is underpinned by intramolecular hydrogen bonding (IMHB) interactions and intramolecular steric effects. Computational studies consequently show a very significant difference of over 75 Å2 in 3D PSA between polar and apolar environments and provide the structural basis for the perplexingly favorable passive permeability of the molecule. Crystal packing and protein binding resulting in strong intermolecular interactions disrupt these intramolecular interactions. Crystalline Form I benefits from strong intermolecular interactions, whereas the weaker intermolecular interactions in Form II are partially compensated by the energetic advantage of an IMHB. Like Form I, no IMHB is observed within the receptor-bound conformation; instead, an intermolecular H-bond contributes to the potency of the molecule. The choice of metastable Form II is derisked through strategies accounting for crystal surface and packing features to manage higher form specific solid-state chemical reactivity and specific processing requirements. Overall, the results show an unambiguous link between structural features and derived properties from crystallization to dissolution, permeation, and docking into the protein pocket.

An investigation on the effect of drug physicochemical properties on the enhancement strength of enhancer: The role of drug-skin-enhancer interactions

The aim of present work was to investigate the influence of drug physicochemical properties on the enhancement effect of enhancers, which guided the application of enhancers in different drug transdermal prescriptions. Firstly, Polyglyceryl-3 dioleate (POCC) was selected as a model enhancer and its enhancement effect on ten drugs was assessed by in vitro skin permeation experiment. Secondly, the correlation analysis of physicochemical properties of drugs was carried out from the aspects of partition and permeation. The interactions of drug-skin-POCC were elucidated by FT-IR, molecular docking, solubility parameters calculation, ATR-FTIR, Raman study, molecular dynamics simulation and confocal laser scanning microscopy (CLSM). The results showed that the enhancement ratio (ER) of drugs was ranging from 2.23 to 7.45. On one hand, the miscibility between drugs with low polar surface area (P.S.A) and donor solution was decreased more pronounced by the addition of POCC because of the drug was difficult to form hydrogen-bond with POCC, facilitating the vehicle/SC partition of drugs. On the other hand, the permeation of drugs with low P.S.A and polarizability was enhanced more significantly by POCC because the drug was less likely to interact with skin lipids compared to others, causing that POCC had more chance to interact with skin lipids to improve permeation drugs across the SC more easily. In conclusion, the different strength of drug-skin-POCC interactions was the main reason for the discrepancy in the enhancement effect of the POCC on ten drugs, which laid a basis for the research on the drug-specific molecular mechanisms of enhancers.

Mechanical and thermal properties of biocomposite films produced from hazelnut husk and polylactic acid

ABSTRACT This study focused on the potential use of hazelnut husk (HH) flour, agricultural by-product, as filler in the PLA biocomposite films. The tensile strength and elongation at break of the biocomposites films decreased with the increasing content of the HH flour. As the amount of the HH flour in the PLA was increased by 10 wt%, the tensile strength decreased from 33 to 26.3 MPa. A sharp decrease in the tensile strength (6.33 MPa) of the specimens was determined as the amount of the HH flour was increased by 20 wt%. There was no significant difference in the tensile strength as the HH content increased from 20 to 40 wt%. The main reason for the lower tensile strength was mainly attributed to them due to the weak interfacial bond between HH flour with higher polar surface and the PLA with lower polar surface. The hydrophilic nature of the HH leads to a tendency for HH fibers to mingle or form agglomerations, which resulted in the lower tensile strength, especially at high HH filler loadings. The increase in the filler content improved the thermal stability of biocomposites.

Synthesis of low surface energy thin film of polyepichlorohydrin-triazole-ols

HypothesisThe dispersive and polar components of surface energy are influenced by the effective molecular size and the intra-molecular configurations of the polar groups, respectively. The surface energy was hypothesized that the surface energy of a polyepichlorohydrin (PECH)-triazole polymer can be reduced by adding an end hydroxyl group (a polar group) which can interact with the nitrogen on the triazole group to reduce the net dipole of the molecule and to reduce the increase in dispersive surface energy by the addition of alkyl chain (dispersive group). ExperimentsThe chlorine atom on PECH rubber was firstly substituted by an azide group, which was then converted to triazole groups linked with alkyl-ol that contained 1–4 carbon atoms. The polymers thus-produced were then spin-coated onto a silicon wafer to form a thin film characterized by static contact angles (30 s contact) and dynamic contact angles for drops of water and diiodomethane. FindingsThe newly synthesized materials have sufficient thin film-formation capacity. Dual interactions that involve interactions between alkyl-ol hydroxyl group and amine nitrogen and the interaction between ether oxygen and imine nitrogen cause the dispersive surface energy to decrease as the alkyl chain length increases. Consequently, a very low polar surface energy of 0.14 mJ/m2 was obtained for PECH-triazole-propyl-ol, a material without any halogen atoms.

What Makes a Compound a Sodium Channel Inhibitor

Voltage-gated sodium channels has been found to be the most promiscuous group of protein drug targets. To develop drugs for this uniquely indiscriminate binding site is a challenge that requires an unconventional approach. A practicable strategy would be to focus on mechanism of action, not affinity. One of the most significant questions regarding mechanism is to distinguish nonspecific and specific binding. We expect that those compounds which bind specifically to the Phe residue of the local anesthetic binding site (F1579 in Nav1.4, F1760 in Nav1.5) will act predominantly by modulation, and therefore will have a preferable therapeutic profile.In this study we identified chemical properties which determine effective binding involving this residue. We used the data from a study (Zheng et al., 2014), where both wild type and binding site mutant channels were screened using the Library of Pharmacologically Active Compounds (LOPAC). We have found that those compounds which are highly potent, but only in the presence of the Phe residue, occupy a remarkably small fraction of the chemical space filled up with compounds of the LOPAC.These are strongly lipophilic compounds, with 2-3 aromatic rings, low polar surface area, containing a positively charged nitrogen, which however is able to deprotonate at physiological pH. Quantitatively, these compound have molecular weight in the range of 250-450, aromatic atom count: 12-18, logP: 3-6, pKa: 7-10, polar surface area: 4-70 Å2. The chemical space delineated by these criteria contains 8 % of all compounds, of which 56 % were potent (IC50 less than 5 µM) and Phe-sensitive (larger than 5x difference in IC50) sodium channel inhibitors. Of the remaining 92 % of all compounds, located outside this restricted section of the chemical space, only 2.8 % were both potent and Phe-sensitive.

Role of wetting agents and disintegrants in development of danazol nanocrystalline tablets.

Poor wetting and/or particle aggregation are the shortcomings of the dried nanocrystalline suspensions, which subsequently might hinder the superior dissolution performance of the nano-crystalline suspensions. The objective of this study was to evaluate the effect of wetting agents and disintegrants on the dissolution performance of dried nanocrystals of an active pharmaceutical ingredient (API) with poor wetting property. Danazol, a BCS Class II compound with high LogP and low polar surface area, was chosen as a model compound for this study. Danazol nanocrystalline suspension was prepared by wet-media milling and converted into powder via spray granulation either with mannitol or microcrystalline cellulose as carriers at a drug: carrier ratio of 1:9 w/w. Danazol nanocrystalline suspension showed a superior dissolution performance compared to an un-milled danazol suspension. Dried danazol nanocrystals suffered from poor wetting leading to hindered dissolution performance i.e.~40% and~15% drug dissolution within 15min for the mannitol and microcrystalline cellulose-based granules, respectively. Addition of a lipophilic surfactant (i.e. docusate sodium) at a surfactant: drug ratio of 0.015: 1 w/w during granulation helped in retaining the superior drug dissolution rates i.e. more than 80% drug dissolution within 15min for mannitol-based granules by enhancing the wettability of dried danazol nanocrystals when compared to a hydrophilic surfactant (i.e. poloxamer 188) or disintegrant (i.e. sodium starch glycolate or croscarmellose sodium). The fast-dissolving mannitol-based granules containing danazol nanocrystals and docusate sodium were compressed into a tablet dosage form. The tablets containing danazol nanocrystals with docusate sodium showed a superior dissolution performance compared to a tablet containing un-milled danazol with docusate sodium.

Distribution of Psychotropic Drugs Into Lipoproteins.

The aim of this pilot study was to investigate whether psychotropic drugs frequently analyzed in a routine therapeutic drug monitoring laboratory bind to low-density lipoproteins/very-low-density lipoproteins (LDL/VLDL) in human serum. Drug concentrations in 20 serum sample pools containing one psychotropic drug each, and in the LDL/VLDL fractions extracted from the same samples, were measured by triple quadrupole liquid chromatography tandem mass spectrometry. The membrane permeability of the drugs was measured using a Parallel Artificial Membrane Permeability Assay. Of the 20 antidepressants, antipsychotics, and antiepileptics examined, 7 drugs were detected in both the pooled serum samples and in the LDL/VLDL fraction. Binding of drugs to LDL/VLDL significantly correlated with high octanol: water partition coefficient (logP), high degree of protein binding, and a low polar surface area. The drugs found in LDL/VLDL, with the exception of aripiprazole, were also characterized by high or intermediate membrane permeability. The present results indicate that psychotropic drugs with certain characteristics bind to LDL/VLDL in blood. This further implies that lipoproteins could play an important role in drug transport.

Anti-Trypanosomal and Antimalarial Properties of Tetralone Derivatives and Structurally Related Benzocycloalkanones.

Background and objectives: Sleeping sickness and malaria alike are insect-borne protozoan diseases that share overlapping endemic areas in sub-Saharan Africa. The causative agent for malaria has developed resistance against all currently deployed anti-malarial agents. In the case of sleeping sickness, the currently deployed therapeutic options are limited in efficacy and activity spectra, and there are very few drug candidates in the development pipeline. Thus, there is a need to search for new drug molecules with a novel mode of actions. Materials and Methods: In the current study, an in vitro screening of a library of tetralone derivatives and related benzocycloalkanones was effected against T. b. brucei and P. falciparum. Results: Several hits with low micromolar activity (0.4–8 µM) against T. b. brucei were identified. Conclusions: The identified hits have a low molecular weight (<280 Da), a low total polar surface area (<50 Ų), and a defined structure activity relationship, which all make them potential starting points for further hit optimization studies.

Solution-processed organic field-effect transistors with cross-linked poly(4-vinylphenol)/polyvinyl alcohol bilayer dielectrics

In bottom-gated organic field-effect transistors (OFETs) carrier transport and device performances show strong dependencies on the dielectric and surface properties of gate insulating materials. A single-layer gate dielectric cannot meet the requirements of large permittivity (k) and low surface polarity for fabricating low-operating-voltage, high-performance OFETs. Here, we have designed a bilayer gate dielectric consisting of a low-k cross-linked poly(4-vinylphenol) (CL-PVP) in contact with an active layer to provide a low polar surface and an underneath high-k polyvinyl alcohol (PVA) layer to ensure a high capacitance. The results show that the CL-PVP/PVA bilayer not only offers a smooth and uniform surface with low polarity and low surface energy as well as good solvent resistance for efficient carrier transport, but also possesses a relatively high capacitance and low leakage current for low threshold and operating voltages. We have utilized this bilayer dielectric to fabricate OFETs based on a conventional semiconducting polymer poly(3-hexylthiophene) (P3HT). High overall device performances have been achieved in the devices with a mobility of 0.1 cm2 V−1 s−1. The maximum density of trap states at the interface between the P3HT film and the CL-PVP/PVA bilayer is estimated to be 7.10 × 1012 cm−2 eV−1, further proving that this bilayer dielectric provides a high quality interface for P3HT. The CL-PVP/PVA bilayer is thus a promising candidate as a gate dielectric for fabricating high-performance organic or even organic-inorganic hybrid perovskite transistors by a solution processing technique.

Design, synthesis and structure−activity relationship studies of GPR40 agonists containing amide linker

Free fatty acid receptor 1 (FFAR1/GPR40) attracted significant attention as a potential target for developing novel antidiabetic drugs because of its unique mechanism in glucose homeostasis. Several reports have expressed concerns about central nervous system (CNS) penetration of GPR40 agonists, which is possibly attributed to their high lipophilicity and low total polar surface area. Herein, we report our efforts to improve the physicochemical properties and pharmacokinetic profiles of LY2881835, a GPR40 agonist that had undergone Phase I clinical trial, through a series of structural optimizations. We identified an orally efficacious compound, 15k, which possessed increased plasma exposure, prolonged half-life and reduced CNS exposure and liver to plasma distribution ratio compared with LY2881835. 15k is a potentially valuable lead compound in the development of safe and efficacious GPR40-targeted drugs to treat type 2 diabetes mellitus.

Renewable, Eugenol-Modified Polystyrene Layer for Liquid Crystal Orientation.

We synthesized a series of plant-based and renewable, eugenol-modified polystyrene (PEUG#) (# = 20, 40, 60, 80, and 100, in which # is the molar content of the eugenol moiety in the side group). Eugenol is extracted from clove oil. We used polymer modification reactions to determine the liquid crystal (LC) orientation properties of the polymer films. In general, the LC cells fabricated using the polymer films with a higher molar content of eugenol side groups exhibited vertical LC orientation behavior. The vertical orientation behavior was well correlated with the surface energy value of the polymer films. The vertical LC orientation could be formed due to the low polar surface energy value on the polymer film generated by the nonpolar carbon group. Electro-optical performances (e.g., voltage holding ratio (VHR), residual DC voltage (R-DC), and thermal orientation stabilities) were good enough to be observed for LC cells using PEUG100 polymer as an eco-friendly LC orientation material.