Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C-H functionalization and their photophysical properties

A series of α- and β-ethynyl-substituted BODIPY derivatives (3a, 4a, 5a, 5b, 6a, 6b) were synthesized by gold(I)-catalyzed direct C-H alkynylation reactions of dipyrromethane and BODIPY, respectively, with ethynylbenziodoxolone (EBX) in a regioselective manner. Depending on the position of the ethynyl substituent in the BODIPY skeleton, the photophysical properties of the resulting α- and β-substituted BODIPYs are notably altered. The lowest S0-S1 transition absorbance and fluorescence bands are both bathochromically shifted as the number of substituents increases, while the emission quantum yields of the β-ethynylated derivatives are significantly lower than those of α-ethynylated ones. The current method should be useful for fine-tuning of the photophysical properties of BODIPY dyes as well as for constructing BODIPY-based building cores for functional π-materials.

Tungsten(VI) Complex of N-Fused Porphyrin Absorbing Near-Infrared Light beyond 1000 nm

Incorporating tungsten into the N3 core of a N-fused porphyrin (NFP; 1) affords high-valent tungsten(VI)-NFP complexes, WClO₂ -1 and 21-chlorinated WClO₂ -3. The X-ray structure of WClO₂ -1 reveals a distorted octahedral geometry with sitting atop metal coordination. The absorption spectrum of WClO₂ -1 displays bathochromically shifted Q-like bands beyond 1000 nm, indicating an inherently narrow HOMO-LUMO energy gap. DFT calculations show that the degeneracy of the LUMO and LUMO+1 pair of 1 is significantly resolved by the tungsten(VI) coordination. Conclusively, magnetic circular dichroism (MCD) spectroscopy and cyclic voltammetry provide a rationale for the narrow HOMO-LUMO energy gap in the "16-electron" d⁰ tungsten(VI)-NFP complexes.

Synthesis of azulitriphyrin(2.1.1)

A ring-contracted carbaporphyrin, azulitriphyrin(2.1.1), was synthesized via intramolecular McMurry coupling reaction. Absorption, NMR spectra and NICS calculations of protonated azulitriphyrin(2.1.1) revealed its Hückel aromatic character as a 14[Formula: see text] porphyrinoid.

Chrysene-Bridged Porphyrin Tweezers: Chiral Receptors for Fullerenes

Bis(bicyclic) molecules dimethanochrysene and diethanochrysene were prepared by Diels-Alder reaction of the naphthodiyne equivalent with cyclopentadiene and 1,3-cyclohexadiene, respectively. Reaction of dimethanochrysene and 7,9-diphenyl-8H-cyclopent[a]acenaphthylen-8-one resulted in the generation of a fluorescent hydrocarbon in unexpected multistep pericyclic reactions. Syn-oriented diethanochrysene-connected bisporphyrin tweezers was prepared from the reaction of chrysene-bridged syn-dipyrrole with tripyrranedicarbaldehyde. The structure of the receptor and its 1 : 1 complex with C₆₀ or C₇₀ was determined by X-ray diffraction analysis. The dihedral angles of the bicyclo[2.2.2]octadiene moieties were narrowed by complexation of the receptor with the fullerenes. The binding affinities of the tweezers with C₆₀ and C₇₀ were calculated to be 2.7(4)×10⁴ and 8.01(7)×10⁴  M^-1 , respectively by UV-vis and fluorescence spectroscopy.

Oxidative nitration reaction of antiaromatic 5,15-dioxaporphyrin

Upon oxidation of 20[Formula: see text]-electron antiaromatic 5,15-dioxaporphyrin (DOP) using nitrosonium ions as oxidants, a tetrakis-[Formula: see text]-nitrated compound was formed instead of the expected 18[Formula: see text]-electron aromatic dication species via an oxidative nitration reaction mechanism. Compared with the original DOP, this tetranitro DOP product exhibited a blue shift of absorption and downfield shifts of the [Formula: see text]-pyrrolic proton signals. The unique antiaromatic electronic structure of the tetranitro DOP was disclosed experimentally by electrochemistry and theoretically by DFT and NICS calculations.

P5022Dual-energy CT was effective to evaluate of microvasculopathy in chronic thromboembolic pulmonary hypertension

Background

The existence of microvasculopathy in patients with chronic thromboembolic pulmonary hypertension (CTEPH) had been suggested. However, the impact of microvasculopathy for pathophysiology had been unknown. Recently dual-energy CT (DECT) can produce a sensitive iodine distribution map as blood perfusion in lung fields to quantify lung perfusion, also can suggest the existence of microvasculopathy according to poor subpleural perfusion which was published previously.

Methods

We retrospectively reviewed poor subpleural perfusion (defined as subpleural spaces either not or minimally perfused in all segments) and hemodynamics of 83 treatment-naïve CTEPH patients who underwent DECT from February 2014 to Jan 2019. Patients were divided according to poor subpleural perfusion: a microvasculopathy group (n=44) or a non-microvasculopathy group (n=39).

We assessed cardiopulmonary exercise test, right heart catheterization and DECT parameters as quantitative evaluation of pulmonary blood volume (PBV). PBV was calculated as the average of entire lung iodine density.

Results

PBV value in non-microvasculopathy group showed significant inverse correlation with pulmonary vascular resistance (PVR) (y = 14236 x-1.028 r=−0.530, p<0.01).

PBV, SvO2, and %DLCO/VA were significantly lower (22.0 vs. 26.4, p<0.01, 61.3 vs. 66.0, p<0.01, and 59.2 vs 75.9 p<0.01), and systolic pulmonary arterial pressure, PVR, VE/VCO2 slope, BNP were higher (69.3 vs 60.6 p=0.04, 834 vs 586 p<0.01, 45.5 vs. 37.8, p=0.02, and 440 vs 122 p=0.04) in microvasculopathy group, while the other parameters were similar between the two groups.

Multivariate analysis revealed that %DLCO/VA was the only predictor of microvasculopathy (OR,0.895 [95% CI, 0.835 - 0.960]; P<0.01).

Conclusion

Pulmonary blood flow of patients in non-micorvasculopathy group showed inverse correlation with PVR. DECT was effective to assess the microvasculopathy in CTEPH. In our experience, less than 60% of non-operable CTEPH patients have microvasculopathy.

Mechanical regulation of bone homeostasis through p130Cas-mediated alleviation of NF-κB activity

Mechanical loading plays an important role in bone homeostasis. However, molecular mechanisms behind the mechanical regulation of bone homeostasis are poorly understood. We previously reported p130Cas (Cas) as a key molecule in cellular mechanosensing at focal adhesions. Here, we demonstrate that Cas is distributed in the nucleus and supports mechanical loading-mediated bone homeostasis by alleviating NF-κB activity, which would otherwise prompt inflammatory processes. Mechanical unloading modulates Cas distribution and NF-κB activity in osteocytes, the mechanosensory cells in bones. Cas deficiency in osteocytes increases osteoclastic bone resorption associated with NF-κB-mediated RANKL expression, leading to osteopenia. Upon shear stress application on cultured osteocytes, Cas translocates into the nucleus and down-regulates NF-κB activity. Collectively, fluid shear stress-dependent Cas-mediated alleviation of NF-κB activity supports bone homeostasis. Given the ubiquitous expression of Cas and NF-κB together with systemic distribution of interstitial fluid, the Cas-NF-κB interplay may also underpin regulatory mechanisms in other tissues and organs.

Bis(1,3-dithiol-2-ylidene)-Substituted Subtriazachlorin: A Subphthalocyanine Analogue with Redox Properties

Bis(1,3-dithiol-2-ylidene)-substituted subtriazachlorin was formed because of an unusual reaction of a 1,3-dithiole-2-one-fused subphthalocyanine in a triethylphosphite-mediated tetrathiafulvalene synthesis. In this novel molecule, the bis(1,3-dithiol-2-ylidene)ethane moiety and subtriazachlorin structure are fused, resulting in an electron-donating ability and broad absorption in the near-infrared region.

Immunogenomic profiles associated with response to neoadjuvant chemoradiotherapy in patients with rectal cancer

BACKGROUND

Accumulating evidence suggests that radiotherapy success has an immune-associated component. The immunogenomic profiles associated with responses to chemoradiotherapy (CRT) were assessed in patients with locally advanced rectal cancer in this study.

METHODS

CD8+ tumour-infiltrating lymphocyte (TIL) and stromal lymphocyte densities were assessed by immunohistochemistry using pretreatment biopsies from patients with advanced rectal cancer who had preoperative CRT. Whole-exome sequencing and gene expression microarray analysis were conducted to investigate the genomic properties associated with the response to CRT and CD8+ TIL density. Response to CRT was determined based on Dworak tumour regression grade (TRG); tumours with complete (TRG 4) or near-complete (TRG 3) regression were grouped as good responders, and those with TRG 1 as non-responders.

RESULTS

Immunohistochemical examinations (275 patients) showed that pre-CRT CD8+ TIL density was associated with better response to CRT and improved recurrence-free survival, whereas pre-CRT stromal CD8+ cell density was not associated with either response to CRT or recurrence-free survival. Whole-exome sequencing (74 patients) showed that the numbers of single-nucleotide variations (SNVs) and neoantigens predicted from SNVs were higher in good responders than in non-responders, and these correlated positively with CD8+ TIL density (r_S  = 0·315 and r_S  = 0·334 respectively). Gene expression microarray (90 patients) showed that CD8A expression correlated positively with the expression of programmed cell death 1 (PDCD1) (r_S  = 0·264) and lymphocyte-activation gene 3 (LAG3) (r_S  = 0·507).

CONCLUSION

Pre-CRT neoantigen-specific CD8+ T cell priming may be a key event in CRT responses where immune checkpoint molecules could be useful targets to enhance tumour regression.