Two Different Clar's Sextets: Clar's Rule Does Not Necessarily Contradict the Global Pathway of Conjugated Macrocycles.

Two contradictory theories, Clar's sextet and resonance theory, explain the stability of conjugated macrocycles using localized and delocalized models, respectively. To reconcile these theories and gain better insights, PAH-containing porphyrinoids were chosen as a representative class of conjugated macrocycles. Two types of Clar's sextets were identified and proposed for the first time based on their interaction with global conjugated pathways: (i) shared sextets that integrate with and perturb the global resonance pathway, and (ii) independent sextets that are separate from the pathway and potentially stabilize or do not perturb it.

Effects of Electron-Withdrawing and Electron-Donating Groups on Aromaticity in Cyclic Conjugated Polyenes.

Determining the aromaticity of various fluorinated benzenes is challenging as easily obtained experimental aromaticity [Δδ( - )] necessitates the chemical shifts of inner and outer protons. This issue was addressed in porphyrinoids by replacing the electron-withdrawing (E.W.

Synthesis of Dioxa-1,7-naphthicorrole and Its Oxidized Porphyrinoid as a Potential Built-In Linker for Biomolecules.

The first aromatic benzicorrole termed naphthicorrole was synthesized with a carbon donor containing more than six members. Its oxidized (enedione-embedded) porphyrinoid was also obtained using different meso-aryl substitutions under sequential oxidation conditions. The resulting enedione motif of the nonaromatic porphyrinoid was regioselective to the C2 position for S or N nucleophiles.

-(2-Thienyl)vinylarene as an Alternative Synthetic Motif for Porphyrinoids: -Arene-Connected Porphyrinoids.

-Arene-connected porphyrinoids were synthesized with -(2-thienyl)vinylarene motif as a new building block for porphyrinoids. This motif can replace meso-aryl-substituted dipyrromethene and serve as a command key arranging -connectivity of porphyrinoid. While (benzene version) is very weak, (pyridine version) shows a substantial amount of diatropic ring current due to reduced steric hindrance (without H23) and rigidified became more aromatic than .

Isolation of a Melanoblast Stimulator from , Its Structural Modification, and Structure-Activity Relationships for Vitiligo.

A novel melanoblast stimulator () was isolated from . Its analogs were also synthesized to support a new furan-based melanoblast stimulator scaffold for treating vitiligo. Isolated 5-(hydroxymethyl)furfural (HMF, ) is a well-known compound in the food industry.

Carbaporphyrin Dimers That Bear a Rigid Naphthalene Motif as an Internal Strap.

The first fully connected aromatic carbaporphyrin dimer () and its bis-Pd complex () that bear a rigid naphthalene motif as an internal strap were synthesized. These dimers consisted of two aromatic carbaporphyrins that shared a naphthalene motif. The π-electron conjugation of the obtained macrocycles was proposed to have two separated local 22 π-electron pathways and a 34 π-electron pathway.

Tuned Cd Selectivity: Showcase of Electronic and Regio-Effect of π-Extended Di-2-Picolylamine-Substituted Quinoline-Based Tolans.

π-Extended di-2-picolylamine (DPA)-substituted 8-hydroxyquinoline (8-HQ) tolans () were synthesized for testing electronic and regio-effects. The electron-poor CN-tolan () showed clear selectivity for Cd (>>Zn) over other metal ions via turn-on fluorescence, while the electron-rich MeO-tolan () displayed no clear metal selectivity. Furthermore, considering that there was no significant energy difference between the Cd complexes of and , the intended regio-effect (7- vs.

Anastral Spindle 3/Rotatin Stabilizes Sol narae and Promotes Cell Survival in .

Apoptosis and compensatory proliferation, two intertwined cellular processes essential for both development and adult homeostasis, are often initiated by the mis-regulation of centrosomal proteins, damaged DNA, and defects in mitosis. Fly Anastral spindle 3 (Ana3) is a member of the pericentriolar matrix proteins and known as a key component of centriolar cohesion and basal body formation. We report here that is a suppressor of lethality induced by the overexpression of Sol narae (Sona), a metalloprotease in a disintegrin and metalloprotease with thrombospondin motif (ADAMTS) family.

Systematic Modifications of a Simple Tolan: Another Category of Viscosity Sensor.

The first tolan derivative-based viscosity sensor () has been synthesized, and its fluorescence intensity and lifetime increase when the viscosity of the solvent increases in methanol-glycerol mixtures. Phthalide () was selected among structurally diverse tolan derivatives through systematic modifications of a simple tolan. To test as a viscosity sensor, fluorescence lifetime imaging (FLIM) images of HeLa cells were obtained upon treatment with 5 μM of to map the viscosity of the HeLa cells.

Synthetic Anion Transporters as Endoplasmic Reticulum (ER) Stress Inducers.

Cl-ion transporters (-) were synthesized based on the binding motifs of prodigiosin. Transporter clearly displays Cl-ion transportation activity across both model and live cell membranes. Furthermore, can disrupt Ca homeostasis and increase the intracellular concentration of Ca in the DLD-1 cell.

ADAMTS Sol narae cleaves extracellular Wingless to generate a novel active form that regulates cell proliferation in Drosophila.

Wnt/ Wingless (Wg) is essential for embryonic development and adult homeostasis in all metazoans, but the mechanisms by which secreted Wnt/Wg is processed remain largely unknown. A Drosophila Sol narae (Sona) is a member of A Disintegrin And Metalloprotease with ThromboSpondin motif (ADAMTS) family, and positively regulates Wg signaling by promoting Wg secretion. Here we report that Sona and Wg are secreted by both conventional Golgi and exosomal transports, and Sona cleaves extracellular Wg at the two specific sites, leading to the generation of N-terminal domain (NTD) and C-terminal domain (CTD) fragments.

Trochlear nerve palsy associated with Moyamoya disease.

A 48-year-old woman with intracranial hemorrhage at the right hemisphere and the right midbrain was diagnosed as Moyamoya disease (MMD). While restoring consciousness, she complained of diplopia. The left hypertropia with a compensatory right head tilt was noted.

Bond Rotation in an Aromatic Carbaporphyrin: Allyliporphyrin.

Allyliporphyrin is a carbaporphyrin that has replaced one pyrrole with an allyl group. Dynamic behavior (bond rotation) was observed by variable temperature H NMR and 2D-NOESY NMR spectroscopy and theoretically examined by DFT calculations. These studies revealed that well-defined bond rotation was first observed in the limited space of the carbaporphyrin from 2 through cis-2 and the calculated rotational barrier was low enough, with the relative energy level of cis-2 only 0.

Synthesis of a Phlorin from a Meso-Fused Anthriporphyrin by a Diels-Alder Strategy.

An anthracene-containing meso-fused carbaporphyrin, which has extended π-conjugation pathways as compared to the corresponding naphthalene-containing carbaporphyrin, has been synthesized. The weak global aromaticity of the anthriporphyrin also allowed its use as the diene for a Diels-Alder reaction with dimethyl acetylenedicarboxylate (DMAD). The resulting phlorin contains an interesting bicyclic structure.

Fluorescent and cooperative ion pair receptor based on tolan for Na (or Li) and HSO: logic AND gate.

A tolan derivative was synthesized as a fluorescent and cooperative ion pair receptor. As both Na and HSO ions were complexed to the receptor, only substantial fluorescence was quenched. Thus, it also acts as a logic AND gate.

Accelerated hydration reaction of an unsymmetrical tolan evidenced by a Hg(ii)-trapped macrocycle and its application as a Hg(ii)-selective indicator.

Hg(ii)-mediated hydration reactions of unsymmetrical quinoline type tolans were studied. The observed accelerated reactions of the tolans rely on the additional binding motifs of the tolan, as supported by the X-ray structure of the macrocycle (2b). The analyte-specific reaction allows us to detect Hg(ii) in buffered media.

2-(Naphthalen-1-yl)thiophene as a New Motif for Porphyrinoids: Meso-Fused Carbaporphyrin.

The first synthesis of meso-fused carbaporphyrin via a premodification method was accomplished by substituting two pyrrole moieties and one meso-carbon with 2-(naphthalen-1-yl)thiophene. The obtained global π-conjugation pathway of the macrocycle noticeably disturbs the 10π local aromaticity of naphthalene, and its aromatic nature was supported by NMR spectroscopy together with nucleus-independent chemical shift, anisotropy of the induced current density, and harmonic oscillator stabilization energy calculations. In addition, the meso-fused carbaporphyrin also allowed the formation of a square planar Pd(II) complex.

Conformationally Locked Tolans, β-Sheet Structures, and Photophysical Properties.

Conformationally locked tetrasubstituted tolans were synthesized by introducing a tether on the tolan. To demonstrate the utilities of these motifs, a β-hairpin structure (15) was synthesized, and its additional stabilizing effects were evaluated. Moreover, the photophysical properties of cyclic tolans and their β-sheet structure were investigated.

Synthetic anion transporters that bear a terminal ethynyl group.

Cl(-) transporters that bear a terminal ethynyl group were synthesized; they consist of non-pyrrolic hydrogen bond motifs such as phenolic OH, amide NH, and triazole CH. The ethynyl group of these non-pyrrolic analogs plays an important role in chloride efflux and they exhibit no significant cytotoxic activity.

Bis-ureidoquinoline as a selective fluoride anion sensor through hydrogen-bond interactions.

Bis-ureidoquinoline shows a characteristic UV-vis absorbance and turn-on fluorescence changes in the presence of the fluoride anion. Such selective changes probably originate from the hydrogen-bond interactions, as shown by the (1)H NMR titration and DFT calculations. Bis-ureidoquinoline can be used as a fluoride-selective sensor for the detection of fluoride anions under illumination from a laboratory hand-held UV lamp.

Hg(II)-mediated intramolecular cyclization reaction in aqueous media and its application as Hg(II) selective indicator.

The Hg(II)-specific intramolecular cyclization reaction of ethynyl phenols was carried out for the first time in semiaqueous media at ambient temperature. The reaction unit (ethynyl phenol) was coupled with a malononitrile derivative (signal unit), which afforded the chromogenic Hg(II) indicator 7. The reaction of the chromogenic Hg(II) indicator 7 was further optimized in DMSO/water (3:7, v/v) (10 mM PBS buffer, pH = 7.

A calix[2]phenol[2]pyrrole and a fused pyrrolidine-containing derivative.

The hybrid calix[2]phenol[2]pyrrole 4 and the fused pyrrolidine-containing macrocycle 9 were synthesized from two different isomeric starting materials, namely dimethyl 2-hydroxyisophthalate and 5-hydroxyisophthalate, respectively. The fused species 9 is devoid of obvious substrate binding properties. In contrast, the heterocalix system 4 displays the fluoride-induced conformational changes characteristic of the parent system.

N-Tosylpyrrolidine calix[4]pyrrole: synthesis and ion binding studies.

The synthesis and preliminary solution phase ion binding properties of the N-tosylpyrrolidine calix[4]pyrrole 2 are reported. This β-octaalkyl-substituted calix[4]pyrrole, the first to be prepared via a direct condensation reaction, was obtained by reacting the 3,4-alkyl-functionalized pyrrole 8 with acetone in the presence of an acid catalyst. On the basis of (1)H NMR spectroscopic analyses and isothermal titration calorimetry, it was concluded that, compared with the parent, β-unsubstituted calix[4]pyrrole (1), compound 2 possesses significantly enhanced binding ability for halide anions in chloroform.