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The two ZnII atoms in the crystal structure of the title complex, [Zn(NO3)2(C10H24N4)]·CH3OH, have a distorted octahedral coordination sphere, defined by 1,4,8,11-tetraazacyclotetradecane (cyclam) N atoms in the equatorial plane and nitrate O atoms in the axial sites. The conformation of the cyclam is trans-III (R, R, S, S), which is typical for metal–cyclam complexes. Nitrate anions are involved in intra- and intermolecular hydrogen bonding with the N–H groups of the ZnII–cyclam unit. Together with the methanol solvent molecule, the hydrogen-bonding network connects the ZnII–cyclam units into ribbons running parallel to the a axis.

The two Zn

Lower urinary tract symptoms (LUTS) induced by anticholinergic drug action impair the QOL of patients and are associated with a poor prognosis. Therefore, it is expedient to develop methods of predicting the anticholinergic side effects of drugs, which we aimed to achieve in this study using a quantitative structure-activity relationship (QSAR) and docking study with molecular operations environment (MOE; Molecular Simulation Informatics Systems [MOLSIS], Inc.) In the QSAR simulation, the QSAR model built using the partial least squares regression (PLS) and genetic algorithm-multiple linear regression (GA-MLR) methods showed remarkable coefficient of determination (R2) and XR2 values. In the docking study, a specific relationship was identified between the adjusted docking score (-S) and bioactivity (pKi) values. In conclusion, the methods developed could be useful for in silico risk assessment of LUTS, and plans are potentially applicable to numerous drugs with anticholinergic activity that induce serious side effects, limiting their use.

Staphylococcus aureus produces a variety of exoproteins that interfere with host immune systems. We attempted to purify cytotoxins against human leukocytic cells from the culture supernatant of S. aureus by a combination of ammonium sulfate precipitation, ion-exchange chromatography on a CM-cellulose column and HPLC on a Mono S 5/50 column. A major protein possessing cytotoxicity to HL60 human promyelocytic leukemia cells was purified, and the protein was identified as α-hemolysin (Hla, α-toxin) based on its molecular weight (34 kDa) and N-terminal amino acid sequence. Flow cytometric analysis suggested differential cytotoxicity of Hla against different human peripheral blood leukocyte populations. After cell fractionation with density-gradient centrifugation, we found that peripheral blood mononuclear cells (PBMCs) were more susceptible to Hla than polymorphonuclear leukocytes. Moreover, cell surface marker analysis suggested that Hla exhibited slightly higher cytotoxicity against CD14-positive PBMCs (mainly monocytes) than CD3- or CD19-positive cells (T or B lymphocytes). From these results, we conclude that human leukocytes have different susceptibility to Hla depending on their cell lineages, and thereby the toxin may modulate the host immune response.

Fluorescence labeling of the target molecules using a small molecule-based probe is superior than a method using genetically expressed green fluorescence protein (GFP) in terms of convenience in its preparation and functionalization. Fluorophore-nitrilotriacetic acid (NTA) conjugates with several ester protecting groups were synthesized and evaluated for their cell membrane permeability by fluorescence microscopy analysis. One of the derivatives, acetoxymethyl (AM)-protected NTA conjugate is hydrolyzed, resulting in intracellular accumulation, thus providing localized fluorescence intensity in cells. This modification is expected as an effective method for converting a non-cell membrane permeable NTA-BODIPY conjugates to a cell membrane permeable derivatives.

Novel compounds bearing acetal groups in their biphenylmethane skeletons were synthesized in moderate yields from benzophenone derivative. Compound 1 did not exhibit antagonistic activity against the ERα estrogen receptor; however, compounds 2, 3, and 4 exhibited potent ERα antagonistic activities. A small difference in the ERα antagonistic activities of the stereoisomers was observed. It was suggested that the methyl groups on the acetal moieties were responsible for the observed ERα antagonistic activities of the compounds. These results could be attributed to interactions of the methyl groups of the acetal functional groups with the hydrophobic binding residues of the binding site.

We report the synthesis of a peptide nucleic acid (PNA) monomer containing preQ

Targeted protein degradation using chimeric small molecules such as proteolysis-targeting chimeras (PROTACs) and specific and nongenetic inhibitors of apoptosis protein [IAP]-dependent protein erasers (SNIPERs) is an emerging modality in drug discovery. Here, we expand the repertoire of E3 ligases capable of ubiquitylating target proteins using this system. By incorporating β-naphthoflavone (β-NF) as a ligand, we developed a novel class of chimeric molecules that recruit the arylhydrocarbon receptor (AhR) E3 ligase complex. β-NF-ATRA, a chimeric degrader directed against cellular retinoic acid binding proteins (CRABPs), induced the AhR-dependent degradation of CRABP-1 and CRABP-2 via the ubiquitin-proteasome pathway. A similar compound ITE-ATRA, in which an alternative AhR ligand was used, also degraded CRABP proteins. Finally, we developed a chimeric compound β-NF-JQ1 that is directed against bromodomain-containing (BRD) proteins using β-NF as an AhR ligand. β-NF-JQ1 induced the interaction of AhR and BRD proteins and displayed effective anticancer activity that correlated with protein knockdown activity. These results demonstrate a novel class of chimeric degrader molecules based on the ability to bring a target protein and an AhR E3 ligase into close proximity.

We report the synthesis of a peptide nucleic acid (PNA) monomer containing preQ1, a positively charged guanine analogue. The new monomer was incorporated into PNA oligomers using standard Fmoc-chemistry-based solid-phase synthesis. The preQ1 unit-containing PNA oligomers exhibited improved affinity for their complementary DNA through electrostatic attraction, and their sequence specificity was not compromised. It could be beneficial to incorporate preQ1 into PNA oligomers instead of guanine when creating antisense/antigene agents or research tools.

l?Leu-based heteropeptides having (R)- or (S)-chiral five-membered carbocyclic ring amino acids (Ac5c3EG) with an ethylene acetal moiety were prepared. A conformational analysis using FT-IR absorption, 1H NMR, and circular dichroism (CD) spectra revealed that l?Leu-based hexapeptides and nonapeptides having (R)- or (S)-Ac5c3EG formed right-handed (P) helical structures in solution. An X-ray crystallographic analysis of nonapeptides 5 a and 5 b showed similar right-handed (P) α-helical structures, without an intramolecular hydrogen bond of the peptide N?H????O? (acetal) type., ChemistrySelect, 2(26), pp.8108-8114; 2017

Lysine-based amphipathic nonapeptides, including homochiral peptides [Ac-(l-Lys-l-Lys-Xaa)3-NH2 (Xaa=Gly, Ala, Aib, Ac5c, or Ac6c) and Ac-(d-Lys-d-Lys-Aib)3-NH2], a heterochiral peptide [Ac-(l-Lys-d-Lys-Aib)3-NH2], and a racemic mixture of diastereomeric peptides [Ac-(rac-Lys-rac-Lys-Aib)3-NH2] were designed and synthesized to investigate the relationship between their preferred secondary structures and their antimicrobial activity. Peptide 5, [Ac-(l-Lys-l-Lys-Ac6c)3-NH2] formed a stable α-helical structure and exhibited strong activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa).

We developed a novel methodology using cyclic α,α-disubstituted α-amino acids (dAAs) with an acetal-side chain to control peptide secondary structures. The introduction of cyclic dAAs into peptides contributed to the stabilization of peptide secondary structures as a helix, while an acidic treatment of peptides resulted in a marked conformational change., Organic and Biomolecular Chemistry, 15(30), pp.6302-6305; 2017

Here we report the synthesis of new PNA monomers for pseudocomplementary PNA (pcPNA) that are fully compatible with standard Fmoc chemistry. The thiocarbonyl group of the 2-thiouracil (sU) monomer was protected with the 4-methoxy-2-methybenzyl group (MMPM), while the exocyclic amino groups of diaminopurine (D) were protected with Boc groups. The newly synthesized monomers were incorporated into a 10-mer PNA oligomer using standard Fmoc chemistry for solid-phase synthesis. Oligomerization proceeded smoothly and the HPLC and MALDI-TOF MS analyses indicated that there was no remaining MMPM on the sU nucleobase. The new PNA monomers reported here would facilitate a wide range of applications, such as antigene PNAs and DNA nanotechnologies.

The fluorescent labeling of target proteins is useful for analyzing their functions and localization in cells, and several fluorescent probes have been developed. However, the fusion of tags such as green fluorescent protein (GFP) to target proteins occasionally affects their functions and/or localization in living cells. Therefore, an imaging method that uses short peptide tags such as hexa-histidine (the His tag) has been attracting increasing attention. Few studies have investigated ON/OFF switchable fluorescent probes for intracellular His-tagged proteins. We herein developed a novel ON/OFF switchable probe for imaging targeted intracellular proteins fused with a CH6 tag, which is composed of one cysteine residue and six histidine residues.

Steroids are important components of cell membranes and are involved in several physiological functions. A diphenylmethane (DPM) skeleton has recently been suggested to act as a mimetic of the steroid skeleton. However, difficulties are associated with efficiently introducing different substituents between two phenyl rings of the DPM skeleton, and, thus, further structural development based on the DPM skeleton has been limited. We herein developed an efficient synthetic method for introducing different substituents into two phenyl rings of the DPM skeleton. We also synthesized DPM-based estrogen receptor (ER) modulators using our synthetic method and evaluated their ER transcriptional activities.

In recent years, the induction of target-protein degradation via the ubiquitin-proteasome system (UPS) mediated by small molecules has attracted attention, and this approach has applications in pharmaceutical development. However, this technique requires a ligand for the target protein that can be incorporated into tailor-made molecules, and there are many proteins for which such ligands have not been found. In this study, we developed a protein-knockdown method that recognizes a His-tag fused to a protein of interest. This strategy theoretically allows comprehensive targeting of proteins of interest by a particular molecule recognizing the tag. As expected, our hybrid molecule 10 [SNIPER(CH6)] efficiently degraded His-tagged CRABP-II and Smad2 in cells. This system provides an easy method to determine the susceptibility of proteins of interest to UPS-mediated degradation. Furthermore, we hope that this method will become an efficient tool to analyze the function of the UPS.

A dodecapeptide, Boc-(L-Leu-L-Leu-Aib-L-Leu-D-Leu-Aib)2-OMe (2), was designed and synthesized to investigate the influence of L-Leu to D-Leu residue replacement on the helical secondary structure of L-Leu-Aib-based dodecapeptides. Its preferred conformation was analyzed based on its Fourier transform infrared spectra, CD spectra, and X-ray diffraction. It was revealed that peptide 2 formed a mixture of right-handed (P) 310- and α-helical structures in solution, and eight helical molecules were assembled in the crystalline state.

Nanoimprint lithography, NIL, is an attractive low cost lithography technique especially for a non-volatile memory device application. The advantages of NIL are simpler exposure system with no coat/dev track, single process step without SADP/SAQP, less design rule restriction, lower cost-of-ownership, compared with other lithography technologies. NIL working templates are made by the replication of the EB written high quality master templates. Fabrication of high resolution master templates is one of the key items, so as to realize high quality replica templates by carefully controlled replication process. Application of multi-beam mask writer, MBMW, to the NIL master template fabrication is very attractive for the coming generation of the new memory devices. For a fine feature master template such as 1z nm node, shot counts for writing with single beam tool will increase drastically and the writing time is estimated more than days. On the other hand, because of the parallel exposure principle, MBMW can write a master in a certain time for any feature size. In addition, MBMW is suitable for high resolution low sensitivity EB resist, which is evitable for fine feature master fabrication of lines and holes. We applied MBMW for the fabrication sub-15nm feature size templates. A full-field 1x master template was fabricated. In this presentation, we will be discussing master template fabrication process with MBMW and the performance of the template. We will also discuss the replication process with a high resolution master.

Non-secosteroidal VDR ligands without any assymmetric carbon were designed and synthesized based on the structure of the previously reported non-secosteroidal VDR agonist LG190178. The VDR-agonistic activity of all synthesized compounds was evaluated, and 7b emerged as a potent agonist activity with an EC50 value of 9.26 nM. Moreover, a docking simulation analysis was also performed to determine the binding mode of 7b with VDR-LBD.

The chiral deuterium- and 13C-isotope-labeled α-aminoisobutyric acids CD3-Aib and 13CH3-Aib were enantioselectively synthesized from L-Ala aldimine using simplified Maruoka chiral phase-transfer catalysts. Homo-chiral (S)-CD3-Aib homopeptides, up to decamers, were prepared. A (R)-CD3-Aib polymer and (S)-13CH3-Aib polymer were also prepared. Conformational studies on homopeptides using CD spectra and an X-ray crystallographic analysis revealed that the preferred conformations were 310-helical structures comprising equal amounts of right-handed (P) and left-handed (M) helical-screw structures. The α-carbon chiral centers induced by the D- or 13C-isotope substitution of Aib were incapable of controlling the helical-screw directions of their oligopeptides and short polymers., Tetrahedron, 72(39), pp.5864-5871; 2016

A single chiral cyclic α,α-disubstituted amino acid with side-chain methoxymethyl (MOM) protecting groups, (3S,4S)-1-amino-(3,4-dimethoxymethoxy)cyclopentanecarboxylic acid [(S, S)-Ac5 c(dOMOM) ], or side-chain hydroxy groups, (3S,4S)-1-amino-(3,4-dihydroxy)cyclopentanecarboxylic acid [(S, S)-Ac5 c(dOH) ], was attached to the N-terminal or C-terminal position of α-aminoisobutyric acid (Aib) tetrapeptide segments; i.e., we designed and synthesized four pentapeptides, Cbz-[(S, S)-Ac5 c(dOMOM) ]-(Aib)4 -OEt (1), Cbz-[(S, S)-Ac5 c(dOH) ]-(Aib)4 -OEt (2), Cbz-(Aib)4 -[(S, S)-Ac5 c(dOMOM) ]-OMe (3), and Cbz-(Aib)4 -[(S, S)-Ac5 c(dOH) ]-OMe (4). We then analyzed the peptides' structures in the crystalline state. The four peptides all folded into 310 -helical structures; 1 formed a left-handed (M) 310 -helix, 2 formed a mixture of right-handed (P) and (M) 310 -helices, 3 formed a mixture of (P) and (M) 310 -helices, and 4 formed a (P) 310 -helix, respectively. In packing mode, the molecules of peptides 1 and 3, which both possessed an Ac5 c(dOMOM) residue, were connected by intermolecular hydrogen bonds along the peptide backbone (NH···O type). On the other hand, the packing of peptides 2 and 4, which both contained an Ac5 c(dOH) residue, was based on intermolecular hydrogen bonds derived from both the peptide backbone and the side-chain hydroxy groups of the amino acid Ac5 c(dOH) (OH···O type). © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 757-768, 2016.

mTEC progenitors differentiate to mature Aire+ mTECs through a pathway that initiates with RANK and LtβR signaling via the nonclassical NF-κB, followed by TRAF-6–driven maturation., Medullary thymic epithelial cells (mTECs) expressing autoimmune regulator (Aire) are critical for preventing the onset of autoimmunity. However, the differentiation program of Aire-expressing mTECs (Aire+ mTECs) is unclear. Here, we describe novel embryonic precursors of Aire+ mTECs. We found the candidate precursors of Aire+ mTECs (pMECs) by monitoring the expression of receptor activator of nuclear factor-κB (RANK), which is required for Aire+ mTEC differentiation. pMECs unexpectedly expressed cortical TEC molecules in addition to the mTEC markers UEA-1 ligand and RANK and differentiated into mTECs in reaggregation thymic organ culture. Introduction of pMECs in the embryonic thymus permitted long-term maintenance of Aire+ mTECs and efficiently suppressed the onset of autoimmunity induced by Aire+ mTEC deficiency. Mechanistically, pMECs differentiated into Aire+ mTECs by tumor necrosis factor receptor-associated factor 6-dependent RANK signaling. Moreover, nonclassical nuclear factor-κB activation triggered by RANK and lymphotoxin-β receptor signaling promoted pMEC induction from progenitors exhibiting lower RANK expression and higher CD24 expression. Thus, our findings identified two novel stages in the differentiation program of Aire+ mTECs.

Chiral five-membered carbocyclic ring amino acids bearing various diol acetal moieties were synthesized starting from l-malic acid, and homo-chiral homopeptides composed of cyclic amino acid (S)-Ac5 c(3EG) bearing an ethylene glycol acetal, up to an octapeptide, were prepared. A conformational analysis revealed that (S)-Ac5 c(3EG) homopeptides formed helical structures. (S)-Ac5 c(3EG) homopeptides, up to hexapeptides, formed helical structures without controlling the helical screw direction, while (S)-Ac5 c(3EG) hepta- and octapeptides formed helical structures with a preference for the left-handed (M) helical-screw direction. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 555-562, 2016.

A peptide-based protein knockdown system for inducing nuclear receptors degradation via the ubiquitin-proteasome system was developed. Specifically, the designed molecules were composed of two biologically active scaffolds: a peptide that binds to the estrogen receptor α (ERα) surface and an MV1 molecule that binds to cellular inhibitors of apoptosis proteins (IAP: cIAP1/cIAP2/XIAP) to induce ubiquitylation of the ERα. The hybrid peptides induced IAP-mediated ubiquitylation followed by proteasomal degradation of the ERα. Those peptides were also applicable for inducing androgen receptor (AR) degradation.

Cell-penetrating peptides (CPPs) have been developed as drug, protein, and gene delivery tools. In the present study, arginine (Arg)-rich CPPs containing unnatural amino acids were designed to deliver plasmid DNA (pDNA). The transfection ability of one of the Arg-rich CPPs examined here was more effective than that of the Arg nonapeptide, which is the most frequently used CPP. The transfection efficiencies of Arg-rich CPPs increased with longer post-incubation times and were significantly higher at 48-h and 72-h post-incubation than that of the commercially available transfection reagent TurboFect. These Arg-rich CPPs were complexed with pDNA for a long time in cells and effectively escaped from the late endosomes/lysosomes into the cytoplasm. These results will be helpful for designing novel CPPs for pDNA delivery.

We investigated the preferred conformations of l-Leu-Aib-alternating peptides, Boc-(l-Leu-Aib)n-OMe (n = 1: 1, 2: 2, 3: 3, 4: 4, 5: 5), in solution and in the crystalline state. Peptides that contain more than six amino acid residues fold into right-handed (P) helical structures. Specifically, hexapeptide 3 forms a (P) 310-helix, and octapeptide 4 and decapeptide 5 form (P) α-helices as their preferred conformations in solution. In the crystalline state, both octapeptide 4 and decapeptide 5 fold into (P) α-helices.

Copper–indium–gallium–sulfide–selenide (CIGSSe) is used in photovoltaic cells and photocathodes, because of its tunable optoelectronic properties, but the fabrication of CIGSSe samples usually requires a multistage process under vacuum. Herein we used a flux growth technique for the sulfide system and achieved efficient flux growth of idiomorphic copper–indium–sulfide CuInS2 crystals of size ∼5 μm from a NaCl–InCl3 flux under mild conditions at ambient pressures. We first examined the flux growth conditions such as holding temperature, solute concentration, and holding time for growing highly crystalline CuInS2 crystals. A moderate holding temperature (∼550 °C) and high solute concentration (∼70 mol %) yielded idiomorphic pure CuInS2 crystals. High-resolution transmission electron microscopy showed clear electron diffraction spots, indicating that the resultant CuInS2 crystals had a highly crystalline, intrinsic tetragonal crystal structure. Thermogravimetry-differential thermal analysis showed that the C...

A homochiral L-Leu-L-Leu-Aib segment was incorporated into the N- or C-termini of left-handed (M) helical peptides (D-Leu-L-Leu-Aib)n. We then investigated the preferred conformations of two sets of three peptides; i.e., Boc-L-Leu-L-Leu-Aib-(D-Leu-L-Leu-Aib)n-OMe (n = 1: 1; 2: 2; 3: 3) and Boc-(D-Leu-L-Leu-Aib)n-L-Leu-L-Leu-Aib-OMe (n = 1: 4; 2: 5; 3: 6), in solution and in the crystalline state. Nonapeptide 2 and dodecapeptide 3, each containing an N-terminal L-Leu-L-Leu-Aib segment, formed left-handed (M) helices as the preferred secondary structures in solution. In the crystalline state, nonapeptide 2 folded into an (M) -helical structure. Peptides 4–6, each containing a C-terminal L-Leu-L-Leu-Aib segment, formed roughly equivalent amounts of right-handed (P) and (M) helices.

Cu–In–Ga–S–Se (CIGSSe) is a promising light-absorber in thin-film photovoltaic cells, as well as a photocathode for solar H2 production, but the fabrication of layers of CIGSSe crystals on substrates is both time- and cost-intensive. Here, we report the fabrication of CuInS2 crystal layers on various precursor-loaded Mo/soda-lime glass (SLG) substrates using a flux coating method. X-ray diffraction analysis indicated that the main phase was CuInS2, while MoS2 which formed through the sulfurization of the Mo substrate was present as a minor phase. Top-surface field-emission scanning electron microscopy (FE-SEM) images indicated that the CuInS2 crystals were sparsely formed on the bare Mo/SLG, In/Mo/SLG, and Cu/Mo/SLG substrates. In contrast, closely packed CuInS2 crystals were formed on Cu2S/Mo/SLG. Smaller CuInS2 crystals 0.5–1 μm in size were grown on Cu2S/Mo/SLG compared to those on other substrates. This sharp difference in crystal population and size could be attributed to the pre-loading effect of the precursors. Cross-sectional FE-SEM analysis with energy-dispersive X-ray spectroscopy mapping revealed the homogenous fabrication of idiomorphic CuInS2 crystals on the partially sulfurized Mo substrate, yielding a CuInS2/MoS2/Mo heterostructure amenable to photovoltaic applications. The formation mechanism of this unique heterostructure was discussed based on the experimental results.

Targeted protein degradation using small chimeric molecules, such as proteolysis-targeting chimeras (PROTACs) and specific and nongenetic inhibitors of apoptosis protein [IAP]-dependent protein erasers (SNIPERs), is a promising technology in drug discovery. We recently developed a novel class of chimeric compounds that recruit the aryl hydrocarbon receptor (AhR) E3 ligase complex and induce the AhR-dependent degradation of target proteins. However, these chimeras contain a hydrophobic AhR E3 ligand, and thus, degrade target proteins even in cells that do not express AhR. In this study, we synthesized new compounds in which the AhR ligands were replaced with a hydrophobic adamantane moiety to investigate the mechanisms of AhR-independent degradation. Our results showed that the compounds, 2, 3, and 16 induced significant degradation of some target proteins in cells that do not express AhR, similar to the chimeras containing AhR ligands. However, in cells expressing AhR, 2, 3, and 16 did not induce the degradation of other target proteins, in contrast with their response to chimeras containing AhR ligands. Overall, it was suggested that target proteins susceptible to the hydrophobic tagging system are degraded by chimeras containing hydrophobic AhR ligands even without AhR.

Targeted protein degradation using chimeric small molecules is an emerging modality in drug discovery. These compounds termed proteolysis-targeting chimeras (PROTACs) and specific and nongenetic inhibitors of apoptosis protein [IAP]-dependent protein erasers (SNIPERs) contain two ligands connected with a linker: one ligand is specific for an E3 ubiquitin ligase, and the other ligand is specific for the target protein, and cross-link the E3 ligase and the target protein within the cell, thereby inducing the poly-ubiquitylation and proteasomal degradation of the target. Currently only a limited number of the E3 ligases, including IAPs, VHL and CRBN, can be recruited to the target proteins by this technology. Here, we expand the repertoire of E3 ligases capable of ubiquitylating target proteins using this system. By incorporating β-naphthoflavone (β-NF) as a ligand for E3 ubiquitin ligase, we developed a novel class of chimeric molecules that recruit the aryl-hydrocarbon receptor (AhR) E3 ligase complex. β-NF-ATRA, a chimeric degrader directed against cellular retinoic acid binding proteins (CRABPs), induced the AhR-dependent degradation of CRABP-1 and CRABP-2 via the ubiquitin-proteasome pathway. A similar compound ITE-ATRA, in which an alternative AhR ligand was used, also degraded CRABP proteins. We also developed a chimeric compound b-NF-JQ1 that is directed against bromodomain-containing (BRD) proteins using b-NF as an AhR ligand. β-NF-JQ1 induced the interaction of AhR and BRD proteins and displayed effective anticancer activity that correlated with protein knockdown activity. These results demonstrate a novel class of chimeric degrader molecules based on the ability to recruit AhR E3 ligase to the target proteins. Citation Format: Nobumichi Ohoka, Genichiro Tsuji, Takuji Shoda, Takuma Fujisato, Masaaki Kurihara, Yosuke Demizu, Mikihiko Naito. Development of small molecule chimeras that recruit aryl-hydrocarbon receptor (AhR) E3 ligase to induce degradation of target proteins [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C125. doi:10.1158/1535-7163.TARG-19-C125

Nanoimprint lithography, NIL, is gathering much attention as one of the most promising candidates for the next generation lithography for semiconductor. The advantages of NIL are simpler exposure system with no coat/dev track, single process step without SADP/SAQP, less design rule restriction, lower cost-of-ownership, compared with other lithography technologies. NIL working templates are made by the replication of the EB written high quality master templates. Fabrication of high resolution master templates is one of the key items. Since NIL is 1:1 pattern transfer process, master templates have to have 4 times higher resolution compared with conventional photomasks. Another key is to maintain the quality of the master templates in replication process. NIL process is applied for the template replication and this imprint process determines most of the performance of the replicated templates. Application of multi-beam mask writer, MBMW, to the NIL master template fabrication is very attractive. For a fine feature master template such as 1z nm node, shot count for writing with single beam tool will drastically increase and the writing time is estimated more than days. On the other hand, because of the parallel exposure principle, MBMW can write a master in a certain time for any feature size. In addition, MBMW is suitable for high resolution low sensitivity EB resist, which is evitable for fine feature master fabrication. We applied MBMW for the fabrication of full-field master of 1z nm node. In this presentation, we will be discussing master template fabrication process with MBMW and the performance of the template. We will also discuss the replication process with a high resolution master.

We designed and synthesized two dodecapeptides, Boc-(l-Leu-l-Leu-Aib-d-Leu-d-Leu-Aib)2-OMe (5) and Boc-l-Leu-l-Leu-Aib-(d-Leu-d-Leu-Aib)2-l-Leu-l-Leu-Aib-OMe (6), that contain equal amounts of l-Leu, d-Leu, and achiral Aib residues. The conformations of peptides 5 and 6 in the crystalline state were studied using X-ray crystallographic analysis. Peptide 5 formed a left-handed (M) α-helical structure, whereas peptide 6 was composed of a combination of fused (M) α-helical and right-handed (P) 310-helical structures. In solution, roughly equivalent amounts of (P) and (M) helices were present in 5, whereas the (M) α-helix was present in 6 as its dominant conformation.

Arginine (Arg)-rich peptides exhibit an effective cell-penetrating ability and deliver membrane-impermeable compounds into cells. In the present study, three types of Arg-rich peptides, R9 containing nine Arg residues, (RRG)3 containing six Arg and three glycine (Gly) residues, and (RRU)3 containing six Arg and three α-aminoisobutyric acid (Aib) residues, were evaluated for their plasmid DNA (pDNA) delivery and cell-penetrating abilities. The transfection efficiency of R9/pDNA complexes was much higher than those of (RRG)3 and (RRU)3/pDNA complexes, and was derived from the enhanced cellular uptake of R9/pDNA complexes. The replacement of three Arg residues with the neutral amino acid Gly and hydrophobic amino acid Aib drastically changed the cell-penetrating ability and physicochemical properties of peptide/pDNA complexes, resulting in markedly reduced transfection efficiency. A comparison of the R9 peptide administration forms between a peptide alone and peptide/pDNA complex revealed that the uptake of R9 peptides was more efficient for the complex than the peptide alone, but occurred through the same internalization mechanism. The results of the present study will contribute to the design of novel Arg-rich cell-penetrating peptides for pDNA delivery., Bioorganic & Medicinal Chemistry, 23(15), pp.4911-4918; 2015

Estrogen receptors (ERs) play a major role in the growth of human breast cancer cells. An antagonist that acts as not only an inhibitor of ligand binding but also an inducer of the down-regulation of ER would be useful for the treatment for ER-positive breast cancer. We previously reported the design and synthesis of a selective estrogen receptor down-regulator (SERD), (E/Z)-4-(1-{4-[2-(dodecylamino)ethoxy]phenyl}-2-phenylbut-1-en-1-yl)phenol (C12), which is a tamoxifen derivative having a long alkyl chain on the amine moiety. This compound induced degradation of ERα via a proteasome-dependent pathway and showed an antagonistic effect in MCF-7 cells. With the aim of increasing the potency of SERDs, we designed and synthesized various tamoxifen derivatives that have various lengths and terminal groups of the long alkyl side chain. During the course of our investigation, C10F having a 10-fluorodecyl group on the amine moiety of 4-OHT was shown to be the most potent compound among the tamoxifen derivatives. Moreover, computational docking analysis suggested that the long alkyl chain interacted with the hydrophobic region on the surface of the ER, which is a binding site of helix 12 and coactivator. These results provide useful information to develop promising candidates as SERDs.

Chiral cyclic α,α-disubstituted α-amino acids with four chiral centers at their acetal moieties were synthesized. An X-ray crystallographic analysis of homo-chiral tripeptide with (2R,3R)-butane-2,3-diol acetal moieties revealed that the tripeptide formed both (P) and (M) helical structures, and all peptide main-chain N(i)-H were intramolecularly hydrogen-bonded with the side-chain acetal -O- of the same amino acid residues (i). The effect of the four chiral centers in the amino acid residue on the peptide backbone helical-screw control was very weak., Tetrahedron, 71(23), pp.3909-3914; 2015

Two diastereomeric six-membered ring α,α-disubstituted α-amino acids (1R,3R)- and (1S,3R)-1-amino-3-methylcyclohexanecarboxylic acids (Ac6c3M); side-chain restricted leucine analogs, were stereoselectively synthesized from (3R)-3-methylcyclohexanone by a Bucherer–Bergs or Strecker reaction. Two series of homo-chiral homopeptides Cbz-[(1R,3R)- and (1S,3R)-Ac6c3M]n-OMe, up to hexapeptides (n=6), were prepared, respectively, and the preferred conformations of cyclohexane rings of amino acid residues and the peptide-backbones were studied. In solution, these peptides formed helical structures, but the helical-screw control to one-handedness was not possible for the hexapeptide length. In the crystal state, all (1R,3R)-Ac6c3M residues formed cyclohexane chair form conformations with a 3-methyl substituent at equatorial orientation and an amino group at the axial position, whereas all (1S,3R)-Ac6c3M residues assumed cyclohexane chair forms with the 3-methyl and amino groups at equatorial orientations. The preferred peptide-backbone structure of (1R,3R)-Ac6c3M hexapeptide had (P) and (M) 310-helices, and that of (1S,3R)-Ac6c3M hexapeptide had (P) and (M) α-helices in the crystal state.

A new bis-cationic cyclic amino acid, 9-amino-3,7-diazabicyclo[3.3.1]nonane-9-carboxylic acid (9- a mino- b is p idine-9-carboxylic acid; Abp), which is available for both solution phase and solid phase peptide synthesis, was designed and synthesized. Furthermore, a heterotripeptide Cbz-Leu-Abp-Ala-OMe (9) containing Abp was prepared, and its dominant conformation was analyzed by examining its nuclear magnetic resonance and infrared spectra and performing molecular modeling. The tripeptide 9 formed a β-turn structure as its preferred conformation in solution.

We developed several stabilized helical heptapeptides (DPI-01-10) composed of l-leucine residues, an α,α-disubstituted α-amino acid (α-aminoisobutyric acid [Aib] or hydroxymethylserine [Hms]), and a stapled side chain as inhibitors of vitamin D receptor (VDR)-coactivator interactions. The inhibitory activity of these peptides against VDR-coactivator interactions was evaluated using a receptor cofactor assay system, and DPI-08 demonstrated strong activity (IC50: 3.2μM).