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1.
Org Lett ; 26(23): 4958-4962, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38833318

RESUMEN

Inspired by previous selection outcomes, we investigated and developed a rhodium-promoted C-H activation/annulation reaction of DNA-linked terminal alkynes and aromatic acids. This reaction exhibits excellent efficiency with high conversions and a broad substrate scope. Most importantly, the unique DEL-compatible conditions provide a better scenario for yielding an isocoumarin scaffold compared to conventional organic reaction conditions, and this newly developed on-DNA method has confirmed its feasibility in preparing DNA-encoded libraries.


Asunto(s)
Alquinos , ADN , Rodio , Rodio/química , Alquinos/química , Estructura Molecular , ADN/química , Catálisis , Isocumarinas/química , Isocumarinas/síntesis química
2.
Int J Biol Macromol ; 270(Pt 2): 132541, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38777012

RESUMEN

Bio-based polymers are materials of high interest given the harmful environmental impact that involves the use of non-biodegradable fossil products for industrial applications. These materials are also particularly interesting as bio-based ligands for the preparation of metal nanoparticles (MNPs), employed as catalysts for the synthesis of high value chemicals. In the present study, Ru (0) and Rh(0) Metal Nanoparticles supported on Sodium Carboxymethyl cellulose (MNP(0)s-CMCNa) were prepared by simply mixing RhCl3x3H2O or RuCl3 with an aqueous solution of CMCNa, followed by NaBH4 reduction. The formation of MNP(0)s-CMCNa was confirmed by FT-IR and XRD, and their size estimated to be around 1.5 and 2.2 nm by TEM analysis. MNP(0)s-CMCNa were employed for the hydrogenation of (E)-cinnamic aldehyde, furfural and levulinic acid. Hydrogenation experiments revealed that CMCNa is an excellent ligand for the stabilization of Rh(0) and Ru(0) nanoparticles allowing to obtain high conversions (>90 %) and selectivities (>98 %) with all substrates tested. Easy recovery by liquid/liquid extraction allowed to separate the catalyst from the reaction products, and recycling experiments demonstrated that MNPs-CS were highly efficiency up to three times in best hydrogenation conditions.


Asunto(s)
Carboximetilcelulosa de Sodio , Nanopartículas del Metal , Solubilidad , Agua , Carboximetilcelulosa de Sodio/química , Catálisis , Agua/química , Nanopartículas del Metal/química , Hidrogenación , Rutenio/química , Rodio/química
3.
Eur J Med Chem ; 272: 116478, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38718624

RESUMEN

Metallodrugs exhibiting distinct mechanisms of action compared with cisplatin hold promise for overcoming cisplatin resistance and improving the efficacy of anticancer drugs. In this study, a new series of rhodium (Rh)(III) complexes containing tris(triphenylphosphine)rhodium(I) chloride [(TPP)3RhCl] (TPP = triphenylphosphine, TPP=O = triphenylphosphine oxide) and 8-hydroxyquinoline derivatives (H-XR1-H-XR4), namely [Rh(XR1)2(TPP)Cl]·(TPP=O) (Yulin Normal University-1a [YNU-1a]), [Rh(XR2)2(TPP)Cl] (YNU-1b), [Rh(XR3)2(TPP)Cl] (YNU-1c), and [Rh(XR4)2(TPP)Cl] (YNU-1d), was synthesized and characterized via X-ray diffraction, mass spectrometry and IR. The cytotoxicity of the compounds YNU-1a-YNU-1d in Hep-G2 and HCC1806 human cancer cell lines and normal HL-7702 cell line was evaluated. YNU-1c exhibited cytotoxicity and selectivity in HCC1806 cells (IC50 = 0.13 ± 0.06 µM, selectivity factor (SF) = 384.6). The compounds YNU-1b and YNU-1c, which were selected for mechanistic studies, induced the activation of apoptotic pathways and mitophagy. In addition, these compounds released cytochrome c, cleaved caspase-3/pro-caspase-3 and downregulated the levels of mitochondrial respiratory chain complexes I/IV (M1 and M4) and ATP. The compound YNU-1c, which was selected for in vivo experiments, exhibited tumor growth inhibition (58.9 %). Importantly, hematoxylin and eosin staining and TUNEL revealed that HCC1806 tumor tissues exhibited significant apoptotic characteristics. YNU-1a-YNU-1d compounds are promising drug candidates that can be used to overcome cisplatin resistance.


Asunto(s)
Antineoplásicos , Proliferación Celular , Complejos de Coordinación , Ensayos de Selección de Medicamentos Antitumorales , Mitofagia , Oxiquinolina , Rodio , Humanos , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Rodio/química , Rodio/farmacología , Oxiquinolina/química , Oxiquinolina/farmacología , Oxiquinolina/síntesis química , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Animales , Relación Estructura-Actividad , Proliferación Celular/efectos de los fármacos , Mitofagia/efectos de los fármacos , Estructura Molecular , Compuestos Organofosforados/farmacología , Compuestos Organofosforados/química , Compuestos Organofosforados/síntesis química , Relación Dosis-Respuesta a Droga , Apoptosis/efectos de los fármacos , Ratones , Línea Celular Tumoral
4.
Org Lett ; 26(20): 4212-4217, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38743309

RESUMEN

An unusual rhodium-catalyzed C-H activation/Lossen rearrangement/oxa-Michael addition tandem cyclization has been achieved along with a tunable well-known C-H activation/[4 + 2] annulation, leading to regio-, chemo-, and diastereoselective access to diverse pentacyclic α-carbolines and ß-carboline-1-one derivatives in moderate to good yields with significant anticancer activity.


Asunto(s)
Antineoplásicos , Carbolinas , Rodio , Rodio/química , Carbolinas/química , Carbolinas/síntesis química , Carbolinas/farmacología , Catálisis , Ciclización , Estructura Molecular , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Estereoisomerismo , Humanos , Ensayos de Selección de Medicamentos Antitumorales
5.
Dalton Trans ; 53(22): 9330-9349, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38747564

RESUMEN

Four neutral Rh1-Rh4 complexes of the general formula [Rh2(CH3COO)4L2], where L is an N-alkylimidazole ligand, were synthesized and characterized using various spectroscopic techniques, and in the case of Rh4 the crystal structure was confirmed. Investigation of the interactions of these complexes with HSA by fluorescence spectroscopy revealed that the binding constants Kb are moderately strong (∼104 M-1), and site-marker competition experiments showed that the complexes bind to Heme site III (subdomain IB). Competitive binding studies for CT DNA using EB and HOE showed that the complexes bind to the minor groove, which was also confirmed by viscosity experiments. Molecular docking confirmed the experimental data for HSA and CT DNA. Antimicrobial tests showed that the Rh2-Rh4 complexes exerted a strong inhibitory effect on G+ bacteria B. cereus and G- bacteria V. parahaemolyticus as well as on the yeast C. tropicalis, which showed a higher sensitivity compared to fluconazole. The cytotoxic activity of Rh1-Rh4 complexes tested on three cancer cell lines (HeLa, HCT116 and MDA-MB-231) and on healthy MRC-5 cells showed that all investigated complexes elicited more efficient cytotoxicity on all tested tumor cells than on control cells. Investigation of the mechanism of action revealed that the Rh1-Rh4 complexes inhibit cell proliferation via different mechanisms of action, namely apoptosis (increase in expression of the pro-apoptotic Bax protein and caspase-3 protein in HeLa and HCT116 cells; changes in mitochondrial potential and mitochondrial damage; release of cytochrome c from the mitochondria; cell cycle arrest in G2/M phase in both HeLa and HCT116 cells together with a decrease in the expression of cyclin A and cyclin B) and autophagy (reduction in the expression of the protein p62 in HeLa and HCT116 cells).


Asunto(s)
Antineoplásicos , Apoptosis , Complejos de Coordinación , Rodio , Humanos , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Apoptosis/efectos de los fármacos , Rodio/química , Rodio/farmacología , Simulación del Acoplamiento Molecular , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antiinfecciosos/síntesis química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Candida tropicalis/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Células HeLa
6.
Org Lett ; 26(16): 3338-3342, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38608176

RESUMEN

Isoquinolone is one of the most common heterocyclic core structures in countless natural products and many bioactive compounds. Here, a highly efficient approach to synthesize isoquinolone scaffolds on DNA via rhodium(III)-catalyzed C-H activation has been described. This chemistry transformation is robust and has shown good compatibility with DNA, which is suitable for DNA-encoded library synthesis.


Asunto(s)
ADN , Rodio , Rodio/química , Catálisis , Estructura Molecular , ADN/química , Isoquinolinas/química , Isoquinolinas/síntesis química
7.
ACS Appl Mater Interfaces ; 16(17): 21653-21664, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38644787

RESUMEN

Analogous to thermal ablation techniques in clinical settings, cell necrosis induced during tumor photothermal therapy (PTT) can provoke an inflammatory response that is detrimental to the treatment of tumors. In this study, we employed a straightforward one-step liquid-phase reduction process to synthesize uniform RhRe nanozymes with an average hydrodynamic size of 41.7 nm for non-inflammatory photothermal therapy. The obtained RhRe nanozymes showed efficient near-infrared (NIR) light absorption for effective PTT, coupled with a remarkable capability to scavenge reactive oxygen species (ROS) for anti-inflammatory treatment. After laser irradiation, the 4T1 tumors were effectively ablated without obvious tumor recurrence within 14 days, along with no obvious increase in pro-inflammatory cytokine levels. Notably, these RhRe nanozymes demonstrated high biocompatibility with normal cells and tissues, both in vitro and in vivo, as evidenced by the lack of significant toxicity in female BALB/c mice treated with 10 mg/kg of RhRe nanozymes over a 14 day period. This research highlights RhRe alloy nanoparticles as bioactive nanozymes for non-inflammatory PTT in tumor therapy.


Asunto(s)
Aleaciones , Ratones Endogámicos BALB C , Terapia Fototérmica , Renio , Rodio , Animales , Rodio/química , Rodio/farmacología , Ratones , Aleaciones/química , Aleaciones/farmacología , Femenino , Renio/química , Renio/farmacología , Línea Celular Tumoral , Humanos , Especies Reactivas de Oxígeno/metabolismo
8.
ACS Sens ; 9(5): 2325-2333, 2024 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-38666660

RESUMEN

Organophosphorus nerve agents (OPNAs) pose a great threat to humanity. Possessing extreme toxicity, rapid lethality, and an unassuming appearance, these chemical warfare agents must be quickly and selectively identified so that treatment can be administered to those affected. Chromogenic detection is the most convenient form of OPNA detection, but current methods suffer from false positives. Here, nitrogenous base adducts of dirhodium(II,II) acetate were synthesized and used as chromogenic detectors of diethyl chlorophosphate (DCP), an OPNA simulant. UV-vis spectrophotometry was used to evaluate the sensitivity and selectivity of the complexes in the detection of DCP. Visual limits of detection (LOD) for DCP were as low as 1.5 mM DCP, while UV-vis-based LODs were as low as 0.113 µM. The dirhodium(II,II) complexes were also tested with several potential interferents, none of which produced a visual color change that could be mistaken for OPNA response. Ultimately, the Rh2(OAc)4(1,8-diazabicyclo[5.4.0]undec-7-ene)2 complex showed the best combination of detection capability and interferent resistance. These results, when taken together, show that dirhodium(II,II) paddlewheel complexes with nitrogenous base adducts can produce instant, selective, and sensitive detection of DCP. It is our aim to further explore and apply this new motif to produce even more capable OPNA sensors.


Asunto(s)
Agentes Nerviosos , Rodio , Rodio/química , Agentes Nerviosos/análisis , Agentes Nerviosos/química , Complejos de Coordinación/química , Compuestos Organofosforados/análisis , Compuestos Organofosforados/química , Límite de Detección , Compuestos Cromogénicos/química , Sustancias para la Guerra Química/análisis , Sustancias para la Guerra Química/química
9.
J Am Chem Soc ; 146(17): 11866-11875, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38621677

RESUMEN

The available methods of chemical synthesis have arguably contributed to the prevalence of aromatic rings, such as benzene, toluene, xylene, or pyridine, in modern pharmaceuticals. Many such sp2-carbon-rich fragments are now easy to synthesize using high-quality cross-coupling reactions that click together an ever-expanding menu of commercially available building blocks, but the products are flat and lipophilic, decreasing their odds of becoming marketed drugs. Converting flat aromatic molecules into saturated analogues with a higher fraction of sp3 carbons could improve their medicinal properties and facilitate the invention of safe, efficacious, metabolically stable, and soluble medicines. In this study, we show that aromatic and heteroaromatic drugs can be readily saturated under exceptionally mild rhodium-catalyzed hydrogenation, acid-mediated reduction, or photocatalyzed-hydrogenation conditions, converting sp2 carbon atoms into sp3 carbon atoms and leading to saturated molecules with improved medicinal properties. These methods are productive in diverse pockets of chemical space, producing complex saturated pharmaceuticals bearing a variety of functional groups and three-dimensional architectures. The rhodium-catalyzed method tolerates traces of dimethyl sulfoxide (DMSO) or water, meaning that pharmaceutical compound collections, which are typically stored in wet DMSO, can finally be reformatted for use as substrates for chemical synthesis. This latter application is demonstrated through the late-stage saturation (LSS) of 768 complex and densely functionalized small-molecule drugs.


Asunto(s)
Rodio , Catálisis , Rodio/química , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/síntesis química , Hidrogenación , Estructura Molecular
10.
Chem Pharm Bull (Tokyo) ; 72(3): 313-318, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38494725

RESUMEN

Generating reliable data on functional group compatibility and chemoselectivity is essential for evaluating the practicality of chemical reactions and predicting retrosynthetic routes. In this context, we performed systematic studies using a functional group evaluation kit including 26 kinds of additives to assess the functional group tolerance of carbene-mediated reactions. Our findings revealed that some intermolecular heteroatom-hydrogen insertion reactions proceed faster than intramolecular cyclopropanation reactions. Lewis basic functionalities inhibited rhodium-catalyzed C-H functionalization of indoles. While performing these studies, we observed an unexpected C-H functionalization of a 1-naphthol variant used as an additive.


Asunto(s)
Metano/análogos & derivados , Rodio , Catálisis , Rodio/química , Metano/química , Hidrógeno/química
11.
J Colloid Interface Sci ; 662: 413-425, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38359505

RESUMEN

Acute kidney injury (AKI) results from the rapid deterioration of renal function, which is mainly treated by transplantation and dialysis, and has a high mortality rate. Inflammation induced by excess reactive oxygen/nitrogen species (RONS) plays a crucial role in AKI. Although small molecule antioxidants have been utilized to alleviate AKI, low bioavailability and side-effect of these drugs tremendously limit their clinical use. Hence, we successfully construct ultra-small (2-4 nm) rhodium nanoparticles modified with l-serine (denoted as Rh-Ser). Our results show that Rh-Ser with multiple enzyme-mimicking activities, allows remove various RONS to protect damaged kidney cells. Additionally, the ultrasmall size of Rh-Ser is conducive to enrichment in the renal tubules, and the modification of l-serine enables Rh-Ser to bind to kidney injury molecule-1, which is highly expressed on the surface of damaged renal cells, thereby targeting the damaged kidney and increasing the retention time. Moreover, Rh-Ser allows the production of oxygen at the inflammatory site, thus further improving hypoxia and inhibiting pro-inflammatory macrophages to relieve inflammation, and increasing the survival rate of AKI mice from 0 to 80%, which exhibits a better therapeutic effect than that of small molecule drug. Photoacoustic and fluorescence imaging can effectively monitor and evaluate the enrichment and therapeutic effect of Rh-Ser. Our study provides a promising strategy for the targeted treatment of AKI via RONS scavenging and inflammatory regulation.


Asunto(s)
Lesión Renal Aguda , Rodio , Ratones , Animales , Especies Reactivas de Oxígeno/metabolismo , Oxígeno , Rodio/farmacología , Especies de Nitrógeno Reactivo/efectos adversos , Medicina de Precisión , Riñón , Lesión Renal Aguda/tratamiento farmacológico , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/metabolismo , Inflamación/tratamiento farmacológico , Serina
12.
Chem Biodivers ; 21(4): e202301431, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38363027

RESUMEN

Terpene-derived alkaloids show a variety of biological activities, including antioxidant, anti-inflammatory, antimicrobial and cytotoxicity effects. In this work, homologated monoterpene amines have been prepared via a rhodium-catalyzed hydroaminomethylation of biomass-based alkenes, such as (R)-limonene, linalool, myrcene and camphene, in combination with secondary amines of aliphatic and aromatic nature, namely morpholine and N-methylaniline, leading to highly chemo- and regioselective processes. The as-prepared amines were obtained in 50-99 % overall yields, and in vitro tested on a human colon cancer cell line (HCT-116) to evaluate their cytotoxic potential. The lead compound of the series (3 a) showed cytotoxicity in the micromolar range (IC50 52.46 µM) via the induction of cell death by apoptosis, paving the way towards further structure-activity relationship studies.


Asunto(s)
Aminas , Rodio , Humanos , Aminas/farmacología , Terpenos/farmacología , Estructura Molecular , Catálisis
13.
Angew Chem Int Ed Engl ; 63(18): e202401626, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38416546

RESUMEN

Coenzyme B12 (AdoCbl; 5'-deoxy-5'-adenosylcobalamin), the quintessential biological organometallic radical catalyst, has a formerly unanticipated, yet extensive, role in photoregulation in bacteria. The light-responsive cobalt-corrin AdoCbl performs this nonenzymatic role by facilitating the assembly of CarH photoreceptors into DNA-binding tetramers in the dark, suppressing gene expression. Conversely, exposure to light triggers the decomposition of this AdoCbl-bound complex by a still elusive photochemical mechanism, activating gene expression. Here, we have examined AdoRhbl, the non-natural rhodium analogue of AdoCbl, as a photostable isostructural surrogate for AdoCbl. We show that AdoRhbl closely emulates AdoCbl in its uptake by bacterial cells and structural functionality as a regulatory ligand for CarH tetramerization, DNA binding, and repressor activity. Remarkably, we find AdoRhbl is photostable even when bound "base-off/His-on" to CarH in vitro and in vivo. Thus, AdoRhbl, an antivitamin B12, also represents an unprecedented anti-photoregulatory ligand, opening a pathway to precisely target biomimetic inhibition of AdoCbl-based photoregulation, with new possibilities for selective antibacterial applications. Computational biomolecular analysis of AdoRhbl binding to CarH yields detailed structural insights into this complex, which suggest that the adenosyl group of photoexcited AdoCbl bound to CarH may specifically undergo a concerted non-radical syn-1,2-elimination mechanism, an aspect not previously considered for this photoreceptor.


Asunto(s)
Fosfotreonina/análogos & derivados , Rodio , Ligandos , Cobamidas/química , Bacterias/metabolismo , ADN
14.
Small ; 20(25): e2309487, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38197548

RESUMEN

Cellular senescence, a vulnerable state of growth arrest, has been regarded as a potential strategy to weaken the resistance of tumor cells, leading to dramatic improvements in treatment efficacy. However, a selective and efficient strategy for inducing local tumor cellular senescence has not yet been reported. Herein, piezoelectric catalysis is utilized to reduce intracellular NAD+ to NADH for local tumor cell senescence for the first time. In detail, a biocompatible nanomedicine (BTO/Rh-D@M) is constructed by wrapping the piezoelectric BaTiO3/(Cp*RhCl2)2 (BTO/Rh) and doxorubicin (DOX) in the homologous cytomembrane with tumor target. After tumors are stimulated by ultrasound, negative and positive charges are generated on the BTO/Rh by piezoelectric catalysis, which reduce the intracellular NAD+ to NADH for cellular senescence and oxidize H2O to reactive oxygen species (ROS) for mitochondrial damage. Thus, the therapeutic efficacy of tumor immunogenic cell death-induced chemo-immunotherapy is boosted by combining cellular senescence, DOX, and ROS. The results indicate that 23.9% of the piezoelectric catalysis-treated tumor cells senesced, and solid tumors in mice disappeared completely after therapy. Collectively, this study highlights a novel strategy to realize cellular senescence utilizing piezoelectric catalysis and the significance of inducing tumor cellular senescence to improve therapeutic efficacy.


Asunto(s)
Senescencia Celular , Doxorrubicina , Inmunoterapia , Especies Reactivas de Oxígeno , Senescencia Celular/efectos de los fármacos , Animales , Doxorrubicina/farmacología , Doxorrubicina/uso terapéutico , Catálisis , Especies Reactivas de Oxígeno/metabolismo , Ratones , Inmunoterapia/métodos , NAD/metabolismo , NAD/química , Línea Celular Tumoral , Humanos , Titanio/química , Titanio/farmacología , Neoplasias/terapia , Neoplasias/patología , Neoplasias/tratamiento farmacológico , Rodio/química , Rodio/farmacología , Compuestos de Bario
15.
Steroids ; 204: 109362, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38278283

RESUMEN

Research published between 2001 and 2022 on the functionalization of remote positions of steroids, as well as the use of this technique in the generation of biologically active compounds has been reviewed. In the first section of the analysis established and novel methods for activation of sites deemed to be remote were reported. A series of manganese- (mainly), rhodium-, ruthenium- and osmium-centered porphyrins as catalysts in the presence of PIDA as oxidant have effected hydroxylation at C-1, -5, -6, -7, -11, -14, -15, -16, -17, -20, -24 and -25. Dioxiranes have been utilized in inserting hydroxyl groups at the 5, 12, 14, 15, 16, 17, 20, 24 and 25 positions (tertiary centers for the most part). Alcohols at C-12 and -16 were oxidized further to ketones. The Schönecker oxidation, discovered and developed during the period, has revolutionized the selective functionalization at C-12 of steroids possessing a 17-keto group. In the presence of iron-centered PDP- and MCP-based catalysts, hydrogen peroxide and acetic acid, substrates tended to be hydroxylated at C-6 and -12, with further oxidation to ketones often accompanying this reaction. The hypohalite reaction, utilizing the more modern Suarez conditions (irradiation in the presence of iodine and PIDA), was reported to facilitate the insertion of a hydroxyl moiety five atoms away from an existing alcohol oxygen. Steroidal-3ß-diazoacetates tend to decompose on heating with di-rhodium-centered catalysts while activating carbons four or five atoms away. Chromium- and iron-based acetates were observed to functionalize C-5 and -25. Other reactions involving ring cleavage and halogenation, ketone irradiation and α-hydroxylation of ethers were also covered. The syntheses of compounds with marked biological activity from readily available steroids is described in the second section of the study. Cyclopamine, cephalostatin-1, ritterazine B and three polyhydroxypregnanaes (pergularin, utendin and tomentogenin) were generated in sequences in which a key step required hydroxylation at C-12 using the Schönecker reaction. A crucial stage in the preparation of cortistatin A, the saundersioside core, eurysterol A, 5,6-dihydroglaucogenin C, as well as clinostatins A and B involved the functionalization of C-18 or -19 utilizing hypohalite chemistry. The synthetic route to xestobergsterol A, pavonin-4-aglycone and ouagabagenin included a transformation where ketone irradiation played a part in either producing a Δ14 or a C-19 activated steroid. The radical relay reaction, where a 17α-chloro-steroid was formed, was central in the generation of pythocholic acid. The lead tetraacetate reaction was pivotal in the functionalization of C-19 during the synthesis of cyclocitrinol.


Asunto(s)
Rodio , Rodio/química , Esteroides/química , Hidroxilación , Alcoholes , Cetonas , Hierro , Catálisis
16.
Inorg Chem ; 63(2): 1296-1316, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38174357

RESUMEN

Organometallic half-sandwich complexes [(η5-Cp)IrCl(L)]PF6 (1) and [(η5-Cp)RhCl(L)]PF6 (2) were prepared using pentamethylcyclopentadienyl chloride dimers of iridium(III) or rhodium(III) with the 4-amino-N-(2,2'-bipyridin-5-yl)benzenesulfonamide ligand (L) and ammonium hexafluorophosphate. The crystal structures of L, 1, and 2 were analyzed in detail. The coordination reactions of the ligand with the central ions were confirmed using various spectroscopic techniques. Additionally, the interactions between sulfaligand, Ir(III), and Rh(III) complexes with carbonic anhydrase (CA), human serum albumin (HSA), and CT-DNA were investigated. The iridium(III) complex (1) did not show any antiproliferative properties against four different cancer cell lines, i.e., nonsmall cell lung cancer A549, colon cancer HCT-116, breast cancer MCF7, lymphoblastic leukemia Nalm-6, and a nonmalignant human embryonic kidney cell line HEK293, due to high binding affinity to GSH. The sulfonamide ligand (L) and rhodium(III) complex (2) were further studied. L showed competitive inhibition toward CA, while complexes 1 and 2, uncompetitive. All compounds interacted with HSA, causing a conformational change in the protein's α-helical structure, suggesting the induction of a more open conformation in HSA, reducing its biological activity. Both L and 2 were found to induce cell death through a caspase-dependent pathway. These findings position L and 2 as potential starting compounds for pharmaceutical, therapeutic, or medicinal research.


Asunto(s)
Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Complejos de Coordinación , Neoplasias Pulmonares , Rodio , Humanos , Complejos de Coordinación/química , Ligandos , Iridio/farmacología , Iridio/química , Rodio/farmacología , Rodio/química , Células HEK293 , Antineoplásicos/química , Línea Celular Tumoral
17.
J Inorg Biochem ; 251: 112435, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38016327

RESUMEN

Anionic cyclopentadienyl (Cp) and its pentamethyl-substituted derivative (Cp*) serve as crucial ligands for creating stable π-coordinated materials, including catalysts. From a structural perspective, the π-extended analog of Cp, known as an N-fused porphyrin (NFP), is recognized as an intriguing 18π aromatic chromophore, offering near-infrared (NIR) optical properties that can be fine-tuned through metal complexation. When coordinated with rhodium at the central NFP core, it forms a sandwich binuclear rhodium(III) complex along with terminal and bridging chloride ligands, denoted as Rh-1, and its bromo derivative, Rh-1-Br. In contrast to the bis-NFP complex of iron(II) reported previously by our team, both Rh-1 and Rh-1-Br complexes exhibit strong NIR optical properties and narrow HOMO-LUMO energy gaps, attributed to minimal orbital interactions between the two co-facial NFP ligands. Leveraging these NIR absorption properties, we assessed the photothermal conversion properties of Rh-1 and ligand 1, revealing high conversion efficiency. This suggests their potential application as photothermal agents for use in photothermal therapy.


Asunto(s)
Porfirinas , Rodio , Rodio/química , Porfirinas/química , Cloruros , Catálisis , Ligandos
18.
J Mater Chem B ; 12(1): 233-239, 2023 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-38084014

RESUMEN

The exogenous administration of nitric oxide (NO) is considered a potential therapeutic treatment against a great variety of diseases due to its significant role in multiple physiological functions. Due to the gaseous nature, short lifetime and dose- and tissue-dependent activity of this molecule, the development of new administration procedures is required to control the NO delivery in terms of dosage, timing, and location. In this work, we propose a new molecular material based on robust metal-organic polyhedra (MOPs) for controlled NO release. We select dirhodium paddlewheel complex-based cuboctahedral MOPs (RhMOP), in which NO can chemically coordinate to the open-metal sites at the axial sites of dirhodium paddlewheel moieties. We further prepare amorphous coordination polymer particles (CPPs) by connecting RhMOP with bis(imidazole) linkers at the external axial sites. Both molecular MOPs and polymeric CPPs show relevant NO payloads and the release of NO can be triggered by two different stimuli: light and humidity. We show that imidazole ligands coordinating to the external axial sites of the paddlewheel moieties tune the light-triggered NO release property. We further demonstrate that the size and the extrinsic pores of CPPs are important for enhanced NO release.


Asunto(s)
Óxido Nítrico , Rodio , Imidazoles , Polímeros/química
19.
ACS Nano ; 17(22): 22418-22429, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-37931219

RESUMEN

Plasmonic optical nanoantennas offer compelling solutions for enhancing light-matter interactions at the nanoscale. However, until now, their focus has been mainly limited to the visible and near-infrared regions, overlooking the immense potential of the ultraviolet (UV) range, where molecules exhibit their strongest absorption. Here, we present the realization of UV resonant nanogap antennas constructed from paired rhodium nanocubes. Rhodium emerges as a robust alternative to aluminum, offering enhanced stability in wet environments and ensuring reliable performance in the UV range. Our results showcase the nanoantenna's ability to enhance the UV autofluorescence of label-free streptavidin and hemoglobin proteins. We achieve significant enhancements of the autofluorescence brightness per protein by up to 120-fold and reach zeptoliter detection volumes, enabling UV autofluorescence correlation spectroscopy (UV-FCS) at high concentrations of several tens of micromolar. We investigate the modulation of fluorescence photokinetic rates and report excellent agreement between the experimental results and numerical simulations. This work expands the applicability of plasmonic nanoantennas to the deep UV range, unlocking the investigation of label-free proteins at physiological concentrations.


Asunto(s)
Rodio , Proteínas/química , Polímeros , Espectrometría de Fluorescencia/métodos
20.
Comput Biol Med ; 167: 107657, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37931525

RESUMEN

Apoptosis is regulated by the BCL-2 family, which includes the anti-apoptotic and pro-apoptotic proteins (Bax, Bok, Bak, etc.). These proteins often interact in dimers and act as apoptotic switches. Anti-apoptotic proteins, such as BCL-2, block the functions of these pro-apoptotic proteins. The pro-apoptotic and anti-apoptotic protein-protein interactions must be inhibited to prevent tumor cells from escaping apoptosis. This method has been used to develop anticancer drugs by inhibiting BCL-2 with both natural and synthetic compounds. Metal-containing compounds were used as pharmaceuticals for human cancer patients for a long time, and cisplatin was the first candidate of this class. Drug design, however, needs to pay more attention to metal complexes. We have studied the X-ray crystal structure of the BCL-2 protein in detail and identified the hydrophobic nature of the site with two less solvent-accessible sites. Based on the hydrophobic nature of the compounds, 74 organometallic compounds with X-ray crystallographically characterized bioactivity (including anticancer activity) were selected from the Cambridge crystallographic database. For testing, molecular docking was used to determine which compound was most effective against the BCL-2 protein. Organometallic compounds (benzene)-chloro-(1-{[(9H-fluoren-2-yl)imino]methyl}naphthalen-2-olato)-ruthenium (2), (1-((1,1'-biphenyl)-4-yl)-2,3,4,5-tetramethylcyclopentadienyl)-chloro-(4,4'-dimethyl-2,2'-bipyridine)-rhodium hexafluorophosphate (37), (µ-1,1'-(butane-1,4-diyl)bis(3-oxy-2-methylpyridin-4(1H)-one))-dichloro-bis(pentamethyl-cyclopentadienyl)-di-rhodium tetrahydrate (46), (µ-1,1'-(butane-1,4-diyl)bis(3-oxy-2-methylpyridin-4(1H)-one))-dichloro-bis(pentamethyl-cyclopentadienyl)-di-iridium (47) etc are found to be important compounds in this study. The capability of different types of complex interactions was identified using Hirshfeld surface analysis of the complexes. A NCI plot was conducted to understand the nature of the interaction between complex amino acids and active-site amino acids. A DFT study was conducted to examine the stability and chemical reactivity of the selected complexes. Using this study, one suitable hydrophobic lead anti-cancer organometallic pharmaceutical was found that binds at the less solvent-accessible hydrophobic site of BCL-2.


Asunto(s)
Compuestos Organometálicos , Rodio , Humanos , Proteína X Asociada a bcl-2/metabolismo , Simulación del Acoplamiento Molecular , Proteínas Proto-Oncogénicas c-bcl-2/química , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Reguladoras de la Apoptosis/química , Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/fisiología , Compuestos Organometálicos/farmacología , Aminoácidos , Solventes , Butanos
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