ABSTRACT Background Skeletal muscle atrophy is a frequent comorbidity of metabolic disorders and chronic diseases, and despite its high prevalence, no pharmacological therapy is available, representing a major unmet clinical need. Adiponectin and its receptors are key regulators of skeletal muscle metabolism, mitochondrial function and myogenesis, yet clinical translation has been hindered by the lack of receptor‐selective agonists with favourable pharmacological and safety profiles. Here, we report the identification and characterization of CDRI‐1709S, the first small‐molecule AdipoR1‐selective agonist and evaluate its myogenic and anti‐atrophy efficacy. Methods A PGC‐1α luciferase reporter‐based screen in AdipoR1/AdipoR2‐transfected, AdipoR‐low HEK293T cells identified CDRI‐1709S as an AdipoR1 agonist. Adiponectin‐associated signalling events were evaluated by immunoblotting in AdipoR1/2‐overexpressing HEK293T cells and AdipoR‐abundant C2C12 myotubes, with receptor specificity confirmed using RNA interference. Myogenic potential was assessed by morphometric analysis and immune detection of myogenic factors. Fibre‐type composition and metabolic capacity were evaluated using immunoblotting and extracellular flux analysis. Anti‐atrophy effects were examined in vitro using various assault‐induced models of myotube atrophy, and in vivo using rat models of dexamethasone (Dex) and sciatic nerve denervation‐induced muscle atrophy. Results CDRI‐1709S selectively activated AdipoR1 with high potency (EC50: 414.7pM) and, at a pharmacologically relevant concentration (100 nM), induced rapid adiponectin‐associated signalling, including phosphorylation of AMPK, AKT and p38‐MAPK, along with upregulation of its downstream skeletal muscle metabolic targets PGC‐1α, GLUT4 and UCP3 in an AdipoR1‐dependent manner (p < 0.05). CDRI‐1709S promoted C2C12 myoblast differentiation into mature myotubes, accompanied by increased expression of MyoD and myogenin (p < 0.05). Treated myotubes were protected against cytokine‐, Dex‐ and nutrient‐deprivation‐induced atrophy through suppression of atrogenes Atrogin‐1 and MuRF‐1 (p < 0.01), restoration of myogenic markers (p < 0.05) and prevention of Dex‐induced fibre‐type switching toward glycolytic MyHC‐IIB, with concomitant induction of slow (MyHC‐I) and fast (MyHC‐IIA) oxidative fibres (p < 0.05). CDRI‐1709S also reversed Dex‐mediated impairments in oxidative and glycolytic capacity (p < 0.05). Oral administration of CDRI‐1709S (10 mg/kg/day) in Dex‐ and denervation‐induced rat models restored atrogene expression, myogenic markers, local adiponectin signalling and myofibrillar architecture to normalcy (p < 0.05 to p < 0.0001). CDRI‐1709S prevented Dex‐induced enrichment of glycolytic fibres and preserved oxidative fibre composition (p < 0.05). The structural/molecular improvements translated into significant functional enhancements, including toe‐spread reflex in denervated limbs (p < 0.05) and increased grip strength (p < 0.0001) plus prolonged wire‐hang duration (p < 0.01) in Dex‐treated animals. Conclusion CDRI‐1709S is the first AdipoR1‐selective small‐molecule agonist that induced myogenesis and robustly ameliorated skeletal muscle atrophy, establishing the proof‐of‐concept for AdipoR1‐targeting as a promising therapeutic strategy for sarcopenia and skeletal muscle atrophy.

ABSTRACT Background Skeletal muscle atrophy is a hallmark of ageing and chronic diseases, yet effective pharmacotherapies remain unavailable. Adiponectin signalling through AdipoR1 and AdipoR2 regulates skeletal muscle metabolism, regeneration and oxidative capacity, but the therapeutic use of adiponectin is limited by its large size and complex multimeric structure. Small‐molecule AdipoR agonists, therefore, represent an attractive therapeutic strategy. Methods A PGC‐1α promoter‐luciferase assay was used to screen for AdipoR agonists in HEK‐293T cells overexpressing AdipoR1 or AdipoR2. Receptor specificity was validated through receptor overexpression and RNA‐interference. C2C12 myoblast differentiation was assessed using phase‐contrast microscopy and myosin heavy chain (MyHC) immunostaining followed by morphometric analyses of cross‐sectional area (CSA) and Feret's diameter, along with immunoblotting of MyoD and myogenin. Anti‐atrophy effects were examined in myotubes exposed to dexamethasone, cytokines or nutrient deprivation by evaluating CSA and diameter through morphometry, immunoblotting and qRT‐PCR analysis of atrogenes and myogenic markers. Oxidative metabolism and mitochondrial function were analysed using extracellular flux analysis and immunoblotting of fibre‐type markers, including MyHC‐I, MyHC‐IIA and MyHC‐IIB. In vivo efficacy was evaluated in a dexamethasone‐induced and a sciatic nerve denervation‐induced rat models following oral administration of Med. Muscle histology, molecular signalling and functional performance were analysed. All immunoblots were analysed by densitometry. Results Med activated AdipoR1 and AdipoR2 with EC50 values of 160 and 302 pM, respectively, and stimulated canonical adiponectin signalling pathways, including AMPK, AKT and p38 MAPK. It significantly induced expression of typical adiponectin targets, PGC‐1α, PPARα, Glut4 and UCP3 (p < 0.0001). AdipoR1 knockdown completely abolished Med‐mediated signalling, whereas AdipoR2 depletion caused partial attenuation. Med enhanced myogenic differentiation, evidenced by increasing myotube formation and expression of MyoD, myogenin and MyHC. It protected myotubes against dexamethasone‐, cytokine‐ and nutrient deprivation‐induced atrophy by preserving CSA and Feret's diameter (p < 0.0001), which was accompanied by suppression of Atrogin‐1 and MuRF1, and increased MyoD and myogenin expression (p < 0.05). Med also enhanced oxidative capacity by increasing fatty acid oxidation and Med‐treated cells showed elevated oxidative fibre markers. Oral administration of Med significantly attenuated muscle atrophy in both rat models, evidenced by improved muscle morphology, suppressed atrogenes, enhanced myogenic markers and increased muscle adiponectin expression and corresponding downstream signalling. Med markedly improved muscle function, including grip strength (p < 0.0001), wire hanging (p < 0.01) and rotarod performance (p < 0.01) and toe‐spread ability of denervated limbs (p < 0.01). Conclusion These findings identify Med as a potent small‐molecule orally bioavailable AdipoR agonist and provide proof‐of‐concept for AdipoR agonists as potential therapeutics for sarcopenia and muscle wasting disorders.

In a quest to identify new osteogenic agents, a new series of 3-aryl-2H-chromene derivatives were rationally designed based on natural isoflavonoids and synthesized through ring transformation of 2H-pyran-2-ones with 3-acetyl-2H-chromene derivatives. From primary screening, five compounds were found to be active in osteoblast differentiation. Among these, the most active compound, 3-(7-methoxy-2H-chromen-3-yl)-5-piperidin-1-ylbiphenyl-4-carbonitrile, showed significantly enhanced calcium nodule formation at 1 pM and 100 pM, and increased osteoblast cell viability. Western blotting experiments indicate that this chromene upregulated osteogenic marker genes such as RUNX2, BMP2, and Type 1 col at the transcriptional and translational levels at concentrations of 1 pM and 100 pM. Furthermore, it decreased osteoblast cell apoptosis at 1 pM and 100 pM, while increasing cell survival in serum-deprived conditions. All these results suggested that the compound has great potential as a bone anabolic agent to improve bone health.

A new series of N-phenyl-carbazole (N-phCbz) appended pyranones were designed and synthesized using alpha-oxo-ketene-S,S-acetal under mild reaction conditions in good yields. The reactivity of donor-acceptor (D-A)-based 2H-pyranones was utilized to develop their ring-transformed benzene-cored N-phenyl-carbazole derivatives. All the synthesized carbazole-based pyranones showed aggregation-induced emission (AIE) characteristics in 80-99% water fraction (f (w)) in DMSO. Among all the synthesized compounds, 6-(4-(9H-carbazol-9-yl)phenyl)-4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile exhibited excellent AIE behavior with ca. 70-fold increase in fluorescence in 80% f(w) at 550nm. Furthermore, this compound showed exceptionally high fluorescence in nonpolar solvent (THF) as compared to polar solvents such as DMSO (ca. 200-fold increase in fluorescence). The DFT, DSC, and TGA analyses of the synthesized D-pi-A compounds suggested the strong electron-donor ability of N-phCbz, with good thermal stability in the range of 231-393 degrees C. These N-phenyl-carbazole-appended pyranones with interesting AIE properties have great potential as probes for bioimaging applications as well as for optoelectronic materials.

Guanine-rich DNA/RNA sequences can form Hoogsteen bonds to adopt noncanonical secondary structures called G-quadruplexes, and these have been associated with diverse cellular processes. There has been considerable research interest in the design of G4-interacting ligands for cellular probing of the G4 structure and understanding its associated biological function. Most of the fluorescent G4 ligands either do not have significant selectivity over other nucleic acid structures, have high Stokes shift, or are not in the near-infrared (NIR) region, which limits its cellular visualization. The current work involves the rational design and synthesis of NIR fluorescent probes comprising a (Z)-1-methyl-2-((3-methylbenzo[d]thiazol-2(3H)-ylidene)methyl)quinolin-1-ium scaffold. Among the designed molecules, 4a exhibited far-red fluorescence (lambda max = 680 nm) with large Stokes shift (similar to 182 nm) upon selective binding to human telomeric G-quadruplexes. The dye 4a does not disturb the conformation and stability of G-quadruplexes, thereby making it suitable for nucleic acid research based applications. Interestingly, 4a showed remarkable selectivity over single- and double-stranded structures in contrast to a commercially available quadruplex binding probe, Thiazole orange (TO). The molecular docking studies indicate that 4a binds at the groove region of the telomeric DNA G-quadruplex through pi-pi stacking interactions with the quinoline and amine-substituted phenyl ring and with the phosphate backbone through anion-pi interactions with the benzothiazole ring. The designed molecule 4a has interesting photophysical properties, cell permeability, and biocompatibility with minimal cytotoxicity. Fluorescence imaging studies in live HeLa cells showed that probe 4a binds to the transient population of the DNA G-quadruplex in the nucleus and RNA quadruplexes in the cytoplasm. In brief, G-quadruplex NIR fluorescent probe 4a with a higher signal/noise ratio has significant potential for cellular imaging studies and thus opens avenues to decipher the biological pathways for better understanding of G-quadruplex biology.

Human skeleton requires an adequate supply of many different nutritional factors for optimal growth and development. The role of nutrition in bone growth has piqued interest in recent years, especially in relation to maximizing peak bone mass and reducing the risk of osteoporosis. Protein deficiency-induced bone loss was induced in female growing rats. All experimental rodent diets were prepared as per recommendations for growing animals. 9-Demethoxy-medicarpin (DMM) treatment was given to growing Sprague Dawley (SD) rats at 1 mg and 10 mg dose orally for 30 days. Bones were collected for bone mineral density (BMD). Bone marrow cells were isolated from femur for calcium nodule formation. Serum samples were collected for biochemical pa-rameters. We found that DMM treatment speeds up the recovery of musculoskeletal weakness by replenishing nutrients in proven rodent model. DMM supplementation for four weeks showed significantly increased verte-bral, femur and tibial BMD compared with the untreated PD group. Albumin levels were significantly enhanced in treatment groups, in which 10 mg dose imparted a better effect. We conclude that DMM treatment led to increased BMD and biochemical parameters in protein deficient condition in growing rats and has potential as a bone growth supplement.

Lipid droplets (LDs) have drawn much attention in recent years. They serve as the energy reservoir of cells and also play an important role in numerous physiological processes. Furthermore, LDs are found to be associated with several pathological conditions, including cancer and diabetes mellitus. Herein, we report a new class of teraryl-based donor-acceptor-appended aggregation-induced emission luminogen (AIEgen), 6a, for selective staining of intracellular LDs in in vitro live 3T3-L1 preadipocytes and the HeLa cancer cell line. In addition, AIEgen 6a was found to be capable of staining and quantifying the LD accumulation in the tissue sections of advanced-stage human cervical cancer patients. Unlike commercial LD staining dyes Nile Red, BODIPY and LipidTOX, AIEgen 6a showed a high Stokes shift (195 nm), a good fluorescence lifetime decay of 12.7 ns, and LD staining persisting for nearly two weeks. A new class of D-pi-A teraryl-based AIEgen 6a was designed and synthesized for selective staining of intracellular lipid droplets.

Water contamination due to the presence of lead is one of the leading causes of environmental and health hazards because of poor soil and groundwater waste management. Herein we report the synthesis of functionally modified luminescent carbon quantum dots (CQDs) obtained from watermelon juice as potential nanomaterials for the detection of toxic Pb2+ ions in polluted water and cancer cells. By introducing surface passivating ligands such as ethanolamine (EA) and ethylenediamine (ED) in watermelon juice, watermelon-ethanolamine (WMEA)-CQDs and watermelon-ethylenediamine (WMED)-CQDs exhibited a remarkable ~10-fold and ~6-fold increase in fluorescence intensity with respect to non-doped WM-CQDs. The relative fluorescence quantum yields of WMEA-CQDs and WMED-CQDs were found to be 8% and 7%, respectively, in an aqueous medium. Among various functionally-modified CQDs, only WMED-CQDs showed high selectivity towards Pb2+ ions with a remarkably good limit of detection (LoD) of 190 pM, which is less than that of the permissible limit (72 nM) in drinking water. The functionally altered WMED-CQDs detected Pb2+ metal ions in polluted water and in a human cervical cancer cell line (HeLa), thus advocating new vistas for eco-friendly nanomaterials for their use as diagnostic tools in the environment and biomedical research areas.

4-Pyranone is a six-membered unsaturated oxygen heterocycles with ring oxygen and one carbonyl group linked together with two ethene moieties forming a cyclic system. It is isomeric with 2-pyranone. 4 H -Pyran-4-one is commonly known as 4-pyrone or γ-pyrone. This chapter includes the discussion of natural products embeded with skeleton of 4-pyranones. In addition various synthetic methods has also been dicussed to afford 4-pyranones. Further reactions of this molecules is also discussed.

2-Pyranone derivatives are unsaturated cyclic esters which have been used in organic synthesis as building blocks for several biologically active compounds. 2-Pyranone scaffold constitutes an important class of natural products, which possess diverse array of biological activity. The pharmacological activities of several of the natural products are compiled in Chapter 3.1.1 (Natural isolated pyranones). In this chapter, the biological significance of several synthetic compounds containing pyranone moiety has been described.

This chapter discusse about the characteristics of pyranones. We discuss the spectroscopic analysis of representative of pyranone. To prove the aromatic and aliphatic character different reactions are represented. The aromaticity of the ring possibly arises from the betaine structures 5 and 6 . However, based on various considerations, it is best considered as enol-lactone rather that pyrylium betaine.

Abstract:Bone healing and regeneration is a complex process that recapitulates embryonic skeletal development and is delayed in diseases like osteoporosis. Bone healing therapies like recombinant bone morphogenetic-2 protein (rhBMP-2) and parathyroid hormone (PTH), an approved bone anabolic therapy reduces fracture risks but are fraught with high cost and several side effects. Thus, there is an unmet need for cost-effective bone healing agents. In this study, we have synthesized 3-piperidinylethoxypterocarpan (3-PEP) which is a hybrid of bone supplement ipriflavone and anti-resorptive drug raloxifene and evaluated its bone regeneration and healing potential. Prior to studies in animal models, the potency of 3-PEP was confirmed in calvarial osteoblast cells. Bromodeoxy uridine cell proliferation and cell viability assay revealed that 3-PEP at 100 pM concentration increased the proliferation and survival of osteoblasts simultaneously inhibiting the apoptosis by involving activation of BCL-2 by phosphorylation at Ser70 site through MEK-ERK pathway. In vivo studies were conducted in estrogen-deficient ovariectomized Balb/c mice and drill hole injury was generated in the mid diaphysis of the femur in all the animals. Treatment with 3-PEP commenced the next day onward and terminated at 7 and 15 days. Micro-CT analysis and calcein labeling of newly generated bone at the drill hole injury site showed that 3-PEP promotes bone healing and new bone formation at a dose of 5 mg/kg at the injury site. These data were also corroborated in non-ovariectomized Balb/c mice cortical defect model. Owing to the side effects associated with rhBMP-2 and PTH, along with the expenses involved, our study proposes an alternative therapeutic option for bone healing.

Background: Antimicrobial resistance is a growing menace, claiming millions of lives all over the world. In this context, drug repurposing is one approach gaining interest as a suitable alternative to conventional drug discovery and development. Methods: Whole-cell assays were used to screen FDA-approved drugs to identify novel antimicrobial agents active against bacterial pathogens. Following identification of nitazoxanide, its various characteristics, such as antimicrobial activity against MDR isolates, time-kill kinetics, ability to synergize with approved drugs, antibiofilm activity and ability to generate resistance in Staphylococcus aureus, were determined, followed by determination of its in vivo potential against MDR S. aureus. Results: Nitazoxanide demonstrated a potent in vitro antistaphylococcal profile, including equipotent activity against clinical drug-resistant S. aureus and Enterococcus spp. Nitazoxanide exhibited concentration-dependent killing, significantly eradicated preformed S. aureus biofilm and S. aureus did not generate resistance to it. Nitazoxanide strongly synergized with linezolid both in vitro and in vivo against linezolid-susceptible and -resistant S. aureus, displaying superior activity to untreated control and drug-alone treatment groups. Conclusions: Nitazoxanide can be utilized in combination with linezolid against infections caused by linezolid-resistant S. aureus as it exhibits strong synergism in vitro and in vivo.

An extensive literature survey revealed that the chemistry of 2 H -pyran-3(6 H )-one ( I ) is meagerly developed, while its isomeric counterpart, 2 H -pyran-3(4 H )-one ( II ), is little known and limited to chemical index. Compounds of 2 H -Pyran-3(6 H )-ones ( I ) are of considerable interest as reactive substrates for the construction of racemic monosaccharides, cycloadducts, Michael adducts, and various pharmaceuticals. Optically active 6-hydroxy-( IV ), 6-alkoxy-( V ), and 6-acyloxypyran-3-ones ( VI ) are found as highly useful chiral synthons because of the presence of multiple functionalities for the construction of a variety of natural products. Nucleophilic and electrophilic additions to pyranones basically depend on the type of substituents already present at stereogenic center. Not only this, but the stereochemistry of the newly introduced stereogenic center is also predominantly governed by the substituents present on existing chiral center.

Osteoporosis is a metabolic bone disorder associated with impaired bone microarchitecture leading to fragility fractures. Long-term usage of parathyroid hormone (PTH) enhances bone resorption and leads to osteosarcoma in rats which limits its exposure to maximum 2 years in human. Notably, the anabolic effects of PTH do not endure in the absence of sustained administration. Studies in our lab identified osteogenic and antiresorptive activity in medicarpin, a phytoestrogen belonging to the pterocarpan class. Considering dual-acting property of medicarpin and limitations of PTH therapy, we envisaged that medicarpin sequential treatment after PTH withdrawal could serve as promising therapeutic approach for osteoporosis treatment. As PTH exerts its bone anabolic effect by increasing osteoblast survival, our study aims to determine whether medicarpin amplifies this effect of PTH. Our results show that PTH withdrawal led to reduced bone mineral density and bone parameters, while sequential treatment of medicarpin after PTH withdrawal significantly enhanced these parameters. Remarkably, these effects were more pronounced than 8-week PTH treatment. Sequential therapy also significantly increased P1NP levels and decreased CTX levels and TRAP positive cells compared to PTH 8W group where CTX levels were quite high due to bone resorptive action of PTH. Protein expression studies revealed that medicarpin along with PTH betters the antiapoptotic potential compared to PTH alone, through augmentation of cyclic adenosine monophosphate-PKA-CREB pathway. These results proclaim that medicarpin sequential treatment prevented the reduction in bone accrual and strength accompanying PTH withdrawal and also aided in antiapoptotic role of PTH. The study points toward the potential use of medicarpin as a replacement therapeutic option postdiscontinuation of PTH.

A convenient synthesis of t}lierl'l)lZ,J-b~,PYridines (3), thienol~,l-cj.p>;ridines (4), p.yrazolol3.-4--hlpyridines (6), thienol2,3-dlpyrimidines (9), pyridoll,2-althieno!2,3-dlpyrimidines (11), pyridoll ,2-alpyrimidol4' ,5' : 4,51thieqpl2,3-dlpyrimidines (12), pyridoll,2-alpyrimido!4,5-d!pyrlmidines (13) and pyrazolo!3,4-d!pyrimido!l,2-alpyrimidines (14) has been described starting from the reaction of suitably functionalized pyridines (1, 2), pyrimidines (7), and pyrido!1,2-a.jpyrimidines (10) with different nucleophiles in sequence o.f r~c;tilrns.

AbstractPowdery mildew (PM) caused by the obligate biotrophic fungal pathogen Erysiphe pisi is an economically important disease of legumes. Legumes are rich in isoflavonoids, a class of secondary metabolites whose role in PM resistance is ambiguous. Here we show that the pterocarpan medicarpin accumulates at fungal infection sites, as analysed by fluorescein‐tagged medicarpin, and provides penetration and post‐penetration resistance against E. pisi in Medicago truncatula in part through the activation of the salicylic acid (SA) signalling pathway. Comparative gene expression and metabolite analyses revealed an early induction of isoflavonoid biosynthesis and accumulation of the defence phytohormones SA and jasmonic acid (JA) in the highly resistant M. truncatula genotype A17 but not in moderately susceptible R108 in response to PM infection. Pretreatment of R108 leaves with medicarpin increased SA levels, SA‐associated gene expression, and accumulation of hydrogen peroxide at PM infection sites, and reduced fungal penetration and colony formation. Strong parallels in the levels of medicarpin and SA, but not JA, were observed on medicarpin/SA treatment pre‐ or post‐PM infection. Collectively, our results suggest that medicarpin and SA may act in concert to restrict E. pisi growth, providing new insights into the metabolic and signalling pathways required for PM resistance in legumes.

Pyranones are six-membered unsaturated cyclic esters, which possess both alkene and aromatic characteristics. They are useful key synthons for the development of various pi-conjugated systems that have shown remarkable potential in biomedical and material sciences applications. A small library of donor–acceptor-based pyranones and their derived π-conjugated systems were screened by Goel and co-workers, and they observed that few pyranone derivatives in the library showed bright fluorescence in the solution and/or in the solid state. They systematically tuned the scaffold by modulating donor–acceptor and chromophoric moieties and discovered highly emissive compounds 6-(anthracen-9-yl)-4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile ( 1 ) and 6-(4-methoxyphenyl)-4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile ( 2 ). Organic light-emitting devices prepared using these compounds displayed pure white emission external quantum efficiencies of 1.9% and 1.2% at 100 cd/m 2 , having CIE coordinates of (0.29, 0.31) and (0.32, 0.32), respectively.

Host materials having high triplet energies offer great commercial potential for the development of solution-processable high-performance phosphorescent organic light-emitting diodes (PhOLEDs). While plenty of vacuum-deposited host materials are available, the literature reveals a dearth of solution-processable host materials. Therefore, a series of biarylcarbazoles (BACs) were designed as host materials by incorporating donor-acceptor functionalities and doped with blue, green, yellow, and orange phosphorescent emitters to develop energy-saving high-performance PhOLEDs with low turn-on voltages. All of the synthesized host materials exhibited good thermal stability in the range of 294-355 degrees C and exhibited remarkably high triplet energies of 2.50-2.81 eV. Surprisingly, PhOLEDs prepared by incorporating a host material 6a doped with a green phosphorescent emitter, i.e., Ir(ppy)3, displayed admirable efficiencies with a maximum power efficiency (PE) of 55.6 lm/W, a current efficiency (CE) of 53.2 cd/A, and an external quantum efficiency of 17.1% with a maximum brightness (L max) of 27 000 cd/m2. BAC host material 6a exhibited better performance compared to that of commercial host 4,4 '-bis(N-carbazolyl)-1,1 '-biphenyl (CBP) and 4,4 ',4 ''-tris(carbazol-9-yl)triphenylamine. The BAC 6a host was also found to be compatible with orange, yellow, and blue phosphorescent emitters, which displayed PEs of 31.9, 21.4, and 14.1 lm/W, respectively, at a brightness of 100 cd/m2. Notably, the green PhOLED with donor-acceptor-based host 6a exhibited 23% roll-up in CE while moving from 100 to 1000 cd/m2. The enhancement of the performance of the green PhOLED is attributed to higher singlet and triplet energies of host 6a compared to that of the utilized green emitter tris(2-phenylpyridine)iridium(III), leading to effective host-guest energy transfer and the ability to form efficient excitons in the host-guest matrix, thus enhancing the OLED performance. Thus, BAC 6a has commercial potential as a suitable host material for the fabrication of efficient multicolor PhOLEDs.