Light Induced Proton Coupled Charge Transfer Triggers Counterion Directional Translocation.

We demonstrate directed translocation of ClO anions from cationic to neutral binding site along the synthetized BPym-OH dye molecule that exhibits coupled excited-state intramolecular proton-transfer (ESIPT) and charge-transfer (CT) reaction (PCCT). The results of steady-state and time-resolved spectroscopy together with computer simulation and modeling show that in low polar toluene the excited-state redistribution of electronic charge enhanced by ESIPT generates the driving force, which is much stronger than by CT reaction itself and provides more informative gigantic shifts of fluorescence spectra signaling on ultrafast ion motion. The associated with ion translocation red-shifted fluorescence band (at 750 nm, extending to near-IR region) appears at the time ~83 ps as a result of electrochromic modulation of PCCT reaction.

From Terminal to Spiro-Phosphonium Acceptors, Remarkable Moieties to Develop Polyaromatic NIR Dyes.

Phosphonium-based compounds gain attention as promising photofunctional materials. As a contribution to the emerging field, we present a series of donor-acceptor ionic dyes, which were constructed by tailoring phosphonium (A) and extended π-NR (D) fragments to an anthracene framework. The alteration of the π-spacer of electron-donating substituents in species with terminal - PPh Me groups exhibits a long absorption wavelength up to λ =527 nm in dichloromethane and shifted the emission to the near-infrared (NIR) region (λ=805 nm for thienyl aniline donor), although at low quantum yield (Φ<0.

Exogenous insulin-like growth factor 1 accelerates growth and maturation of follicles in human cortical xenografts and increases ovarian output in mice.

Objective: To measure the influence of exogenous insulin-like growth factor 1 (IGF1) on follicle growth and maturation in human ovarian cortical xenografts.

Design: Xenotransplantation model.

Setting: University-based research laboratory.

Chronic superphysiologic AMH promotes premature luteinization of antral follicles in human ovarian xenografts.

Anti-Müllerian hormone (AMH) is produced by growing ovarian follicles and provides a diagnostic measure of reproductive reserve in women; however, the impact of AMH on folliculogenesis is poorly understood. We cotransplanted human ovarian cortex with control or AMH-expressing endothelial cells in immunocompromised mice and recovered antral follicles for purification and downstream single-cell RNA sequencing of granulosa and theca/stroma cell fractions. A total of 38 antral follicles were observed (19 control and 19 AMH) at long-term intervals (>10 weeks).

Multiple Emission of Phosphonium Fluorophores Harnessed by the Pathways of Photoinduced Counterion Migration.

In the emerging field of intramolecular charge transfer induced counterion migration, we report the new insights into photophysical features of luminescent donor-acceptor phosphonium dyes (D-π-) A [X ] (π=-(C H ) -). The unique connectivity of the phosphorus atom affords multipolar molecules with a variable number of arms and the electronic properties of the acceptor group. In the ion-paired form, the transition from dipolar to quadrupolar configuration enhances the low energy migration-induced band by providing the additional pathways for anion motion.

Counterion Migration Driven by Light-Induced Intramolecular Charge Transfer.

A series of D-π- pyridinium compounds, in which D = -NPh and A = -PyMe are linked by various amounts of linear phenyl spacers, were strategically designed and synthesized. Their characterization revealed the presence of excited-state intramolecular charge transfer (ESICT) that triggers a corresponding response from the counterion. In medium and strong polar solvents, the fast solvent relaxation occurring after ESICT overwhelms the counterion effect, showing typical emission solvatochromism.

Chapter Open for the Excited-State Intramolecular Thiol Proton Transfer in the Room-Temperature Solution.

We report here, for the first time, the experimental observation on the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton in room-temperature solution. This phenomenon is demonstrated by a derivative of 3-thiolflavone (), namely, 2-(4-(diethylamino)phenyl)-3-mercapto-4-chromen-4-one (), which possesses an -S-H···O═ intramolecular H-bond (denoted by the dashed line) and has an S absorption at 383 nm. Upon photoexcitation, exhibits a distinctly red emission maximized at 710 nm in cyclohexane with an anomalously large Stokes shift of 12 230 cm.

Correlation between Kinetics and Thermodynamics for Excited-State Intramolecular Proton Transfer Reactions.

Finding the relation between thermodynamics and kinetics for a reaction is of fundamental importance. Here, the thermodynamics and kinetics correlation of excited-state intramolecular proton transfer (ESIPT) was investigated by the TD-DFT calculation under the CAM-B3LYP/6-311+G** level. We choose the family 2-(2'-aminophyenyl)benzothiazole and its amino derivatives as paradigms, which all possess the NH-type intramolecular hydrogen bond (H-bond), and investigate the corresponding ESIPT reaction.

Excited-state intramolecular proton transfer in the kinetic-control regime.

A new series of molecules bearing a 2,11-dihydro-1H-cyclopenta[de]indeno[1,2-b]quinoline (CPIQ) chromophore with the N-HN type of intramolecular hydrogen bond are strategically designed and synthesized, among which CPIQ-OH, CPIQ-NHAc and CPIQ-NHTs in solution exhibit a single emission band with an anomalously large Stokes shift, whereas CPIQ-NH2 and CPIQ-NHMe show apparent dual-emission property. This, in combination with time-resolved spectroscopy and the computational approach, leads us to conclude that CPIQ-OH, CPIQ-NHAc and CPIQ-NHTs undergo ultrafast, highly exergonic excited-state intramolecular proton transfer (ESIPT), while a finite rate of ESIPT is observed for CPIQ-NH2 and CPIQ-NHMe with a time constant of 117 ps and 39 ps, respectively, in acetonitrile at room-temperature. Further temperature-dependent studies deduce an appreciable ESIPT barrier for CPIQ-NH2 and CPIQ-NHMe.

Diversified Excited-State Relaxation Pathways of Donor-Linker-Acceptor Dyads Controlled by a Bent-to-Planar Motion of the Donor.

Herein, we introduce the cyclic 8π-electron (C8π) molecule N,N'-diaryl-dihydrodibenzo[a,c]phenazine (DPAC) as a dual-functional donor to establish a series of new donor-linker-acceptor (D-L-A) dyads DLA1-DLA5. The excited-state bent-to-planar dynamics of DPAC regulate the energy gap of the donor, while the acceptors A1-A5 are endowed with different energy gaps and HOMO/LUMO levels. As a result, the rate and efficiency of the excited-state electron transfer vs.

Substituted benzothiophene and benzofuran derivatives as a novel class of bone morphogenetic Protein-2 upregulators: Synthesis, anti-osteoporosis efficacies in ovariectomized rats and a zebrafish model, and ADME properties.

The bone morphogenetic protein (BMP) pathway is a promising new target for the design of therapeutic agents for the treatment of low bone mass. This study optimized the structure of the anti-osteoporosis compound 38 by balancing its lipophilicity and improving its stability. Twenty derivatives which were not reported in the literature were designed and synthesized.

A Facile Molecular Machine: Optically Triggered Counterion Migration by Charge Transfer of Linear Donor-π-Acceptor Phosphonium Fluorophores.

The D-π-A type phosphonium salts in which electron acceptor (A=- PR ) and donor (D=-NPh ) groups are linked by polarizable π-conjugated spacers show intense fluorescence that is classically ascribed to excited-state intramolecular charge transfer (ICT). Unexpectedly, salts with π=-(C H ) - and -(C H C H )- exhibit an unusual dual emission (F and F bands) in weakly polar or nonpolar solvents. Time-resolved fluorescence studies show a successive temporal evolution from the F to F emission, which can be rationalized by an ICT-driven counterion migration.

Sulfur-Based Intramolecular Hydrogen-Bond: Excited-State Hydrogen-Bond On/Off Switch with Dual Room-Temperature Phosphorescence.

We report O-H----S hydrogen-bond (H-bond) formation and its excited-state intramolecular H-bond on/off reaction unveiled by room-temperature phosphorescence (RTP). In this seminal work, this phenomenon is demonstrated with 7-hydroxy-2,2-dimethyl-2,3-dihydro-1 H-indene-1-thione (DM-7HIT), which possesses a strong polar (hydroxy)-dispersive (thione) type H-bond. Upon excitation, DM-7HIT exhibits anomalous dual RTP with maxima at 550 and 685 nm.

Intramolecular Phosphacyclization: Polyaromatic Phosphonium P-Heterocycles with Wide-Tuning Optical Properties.

Rationally designed cationic phospha-polyaromatic fluorophores were prepared through intramolecular cyclization of the tertiary ortho-(acene)phenylene-phosphines mediated by Cu triflate. As a result of phosphorus quaternization, heterocyclic phosphonium salts 1 c-3 c, derived from naphthalene, phenanthrene, and anthracene cores, exhibited very intense blue to green fluorescence (Φ =0.38-0.

Improvement of the Photophysical Performance of Platinum-Cyclometalated Complexes in Halogen-Bonded Adducts.

Three groups of luminescent platinum complexes [Pt(C^N)(L)(Y)] [C^N=benzothienyl-pyridine (1), bezofuryl-pyridine (2), phenyl-pyridine (3); L/Y=DMSO/Cl (a), PPh /Cl (b), PPh /CN (c)] have been probed as halogen-bond (XB) acceptors towards iodofluorobenzenes (IC F and I C F ). Compounds 1 a and 2 a (L/Y=DMSO/Cl) afford the adducts 1 a⋅⋅⋅I C F and 2 a⋅⋅⋅I C F , which feature I⋅⋅⋅S /I⋅⋅⋅π and I⋅⋅⋅O /I⋅⋅⋅Cl short contacts, respectively. The phosphane-cyanide derivatives 1 c and 2 c (L/Y=PPh /CN) co-crystallise with both IC F and I C F .

Synthesis of a novel class of substituted benzothiophene or benzofuran derivatives as BMP-2 up-regulators and evaluation of the BMP-2-up-regulating effects in vitro and the effects on glucocorticoid-induced osteoporosis in rats.

The BMP pathway is a promising new target for the design of therapeutic agents for the treatment of low bone mass. To enrich our understanding of SAR and based on our previously concluded structure-effect relationship, 23 derivatives were prepared in this work. The synthesis, up-regulating activities on BMP-2 expression, and bone loss prevention efficacies of these compounds in rats with glucocorticoid-induced osteoporosis are presented.

Synthesis and antiparasitic activity of new bis-arylimidamides: DB766 analogs modified in the terminal groups.

Fifteen novel bis-arylimidamide derivatives with various 6-membered (7a-c) and 5-membered (7d-o) heterocyclic rings replacing the terminal pyridyl rings of the lead compound DB766{(2,5-bis[2-i-propoxy-4-(2-pyridylimino)aminophenylfuran]}, were prepared and evaluated versus Trypanosoma cruzi, Leishmania amazonensis, Trypanosoma brucei rhodesiense and Plasmodium falciparum. Compound 7a with pyrimidine replacing the pyridine rings showed good activity versus T. cruzi, T.

Synthesis and antitumor activity of novel 3,4-diaryl squaric acid analogs.

A series of novel 3,4-diaryl squaric acid analogs 4a-r related to combretastatin A-4 (CA4) using squaric acid as the cis-restricted linker were prepared and studied for their anticancer activity against selected human cancer cell lines. New compounds 4g, 4k, 4m, 4n, 4p, 4q and 4r exhibit strong activities against human leukemia cells with IC50 values of ≤20 nM and compounds 4k, 4n, 4p, 4q and 4r showed potent activities against a panel of human tumor cell lines. Compounds 4n and 4p arrest tumor cell cycle in G2-M phase.

Substituted benzothiophene or benzofuran derivatives as a novel class of bone morphogenetic protein-2 up-regulators: synthesis, structure-activity relationships, and preventive bone loss efficacies in senescence accelerated mice (SAMP6) and ovariectomized rats.

In this work, substituted benzothiophene and benzofuran compounds were found to be a new class of potential anabolic agents by enhancing BMP-2 expression. A series of benzothiophene and benzofuran derivatives have been synthesized, and their activities of up-regulating BMP-2 and bone loss prevention efficacies in SAMP6 mice and OVX rats have been studied. Benzothiophenes 1, 3, 14, 4a, 7a, 8a, and benzofuran analogue 2 showed higher BMP-2 up-regulation rates in vitro.

Synthesis and anticancer activity of novel 3,4-diarylthiazol-2(3H)-ones (imines).

A series of 3,4-diarylthiazol-2(3H)-ones and three 3,4-diarylthiazol-2(3H)-imines were synthesized and evaluated for their cytotoxicity in a panel of human cancer cell lines. Compounds 21 and 22 showed potential anticancer activity against human CEM cells with IC50 values of 0.12 and 0.

The effect of substituted thiophene and benzothiophene derivates on PPARgamma expression and glucose metabolism.

Eighteen substituted thiophene and benzothiophene derivatives were studied for their effects on peroxisome proliferator-activated receptor gamma (PPARgamma) in HepG2 cells. Three derivatives (compounds 5, 120.97%; 15, 102.

Synthesis and evaluation of 1-(benzo[b]thiophen-2-yl)ethanone analogues as novel anti-osteoporosis agents acting on BMP-2 promotor.

A novel series of 1-(benzo[b]thiophen-2-yl)ethanone analogues were prepared and evaluated for enhancing BMP-2 expression. Compounds 1-5, 7, 8, 12, 13 and 16, with upregulation rate values of 35.6%, 27.

Some new acyclic nucleotide analogues as antiviral prodrugs: synthesis and bioactivities in vitro.

A series of ester analogues of acyclic nucleotide PMPA and PMEA were synthesized as potent antiviral agents. The antiviral evaluation results indicated that bis benzyl ester prodrug of PMPA 5f and bis allyl ester prodrug of PMEA 5g exhibited potent antiviral activities. The IC(50) of 5f for HBV was 2.

Synthesis and anti-influenza activities of carboxyl alkoxyalkyl esters of 4-guanidino-Neu5Ac2en (zanamivir).

Three alkoxyalkyl 2-carboxylate ester derivatives related to zanamivir were synthesized. All of the analogs of zanamivir modified at carboxylic moiety with alkoxyalkyl esters 1a-c showed higher activities than ribavirin on influenza A and B virus in the MDCK cells. Oral treatment or intraperitoneal administration of compound 1c showed significantly protective effects in mice infected with influenza A virus with low toxicities.