Synthesis of platinum (II) N-heterocyclic carbenes based on adenosine

Funding Information: This research was funded by national funds through FCT?Funda??o para a Ci?ncia e a Tecnologia, I.P., Project MOSTMICRO-ITQB (refs. UIDB/04612/2020 and UIDP/04612/2020), and IF/00109/2014/CP1244/CT0007. This work was also supported by FCT fellowships number PD/BD/135483/2018 (M.I.P.S.L.) and SFRH/BD/1444412019 (G.F.). Clara S. B. Gomes acknowledges the Associate Laboratory for Green Chemistry?LAQV and the Applied Molecular Biosciences Unit?UCIBIO, which are financed by national funds from Funda??o para a Ci?ncia e a Tecnologia (UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, UIDP/04378/2020, respectively).The NMR spectra were acquired at CERMAX?ITQB, integrated in the National NMR Network and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC). Mass spectroscopy measurements were obtained by the UniMass Laboratory at ITQB-NOVA, Portugal. Clara S. B. Gomes acknowledges the XTAL?Macromolecular Crystallography group for granting access to the X-ray diffractometer. X-ray infrastructure financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Funding Information: Funding: This research was funded by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., Project MOSTMICRO-ITQB (refs. UIDB/04612/2020 and UIDP/04612/2020), and IF/00109/2014/CP1244/CT0007. This work was also supported by FCT fellowships number PD/BD/135483/2018 (M.I.P.S.L.) and SFRH/BD/1444412019 (G.F.). Clara S. B. Gomes acknowledges the Associate Laboratory for Green Chemistry—LAQV and the Applied Molecular Biosciences Unit—UCIBIO, which are financed by national funds from Fundação para a Ciência e a Tecnologia (UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, UIDP/04378/2020, respectively). Funding Information: Acknowledgments: The NMR spectra were acquired at CERMAX—ITQB, integrated in the National NMR Network and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC). Mass spectroscopy measurements were obtained by the UniMass Laboratory at ITQB-NOVA, Portugal. Clara S. B. Gomes acknowledges the XTAL—Macromolecular Crystallography group for granting access to the X-ray diffractometer. X-ray infrastructure financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Organometallic derivatization of nucleosides is a highly promising strategy for the im-provement of the therapeutic profile of nucleosides. Herein, a methodology for the synthesis of metalated adenosine with a deprotected ribose moiety is described. Platinum (II) N-heterocyclic carbene complexes based on adenosine were synthesized, namely N-heterocyclic carbenes bearing a protected and unprotected ribose ring. Reaction of the 8-bromo-2′,3′,5′-tri-O-acetyladenosine with Pt (PPh3)4 by C8−Br oxidative addition yielded complex 1, with a PtII centre bonded to C-8 and an unprotonated N7. Complex 1 reacted at N7 with HBF4 or methyl iodide, yielding protic carbene 2 or methyl carbene 3, respectively. Deprotection of 1 to yield 4 was achieved with NH4OH. Deprotected compound 4 reacted at N7 with HCl solutions to yield protic NHC 5 or with methyl iodide yielding methyl carbene 6. Protic N-heterocyclic carbene 5 is not stable in DMSO solutions leading to the formation of compound 7, in which a bromide was replaced by chloride. The cis-influence of complexes 1–7 was examined by31P{1H} and195Pt NMR. Complexes 2, 3, 5, 6 and 7 induce a decrease of1 JPt,P of more than 300 Hz, as result of the higher cis-influence of the N-heterocyclic carbene when compared to the azolato ligand in 1 and 4.publishersversionpublishe

Gold Mono and Bis N-Heterocyclic Carbenes based on mRNA cap0

Eukaryotic mRNA contains a cap structure which consists of a methylated guanosine (mRNA cap0) connected to the first transcribed nucleotide by an unusual 5′-5′-triphosphate bridge. Herein we describe the synthesis gold mono and bis-N-Heterocyclic carbenes derived from 7-methylguanosine at room temperature. The compounds can be synthesized directly from 7-methylguanosine and the synthesis does not require the protection of the hydroxyl groups pf the ribose to be effective

Synthesis and Medicinal Applications of N-Heterocyclic Carbene Complexes Based on Caffeine and Other Xanthines

Xanthines are purine derivatives predominantly found in plants. Xanthines include compounds such as caffeine, theophylline, and theobromine and exhibit a variety of pharmacological properties, demonstrating efficacy in treating neurodegenerative disorders, respiratory dysfunctions, and also in cancer. The versatile attributes of these materials render them privileged scaffolds for the development of compounds for various biological applications. Xanthines are N-heterocyclic carbene precursors that combine a pyrimidine and an imidazole ring. Owing to their biological relevance, xanthines have been employed as N-heterocyclic carbenes in the development of metallodrugs for anticancer and antimicrobial purposes. In this conceptual review, we examine key examples of N-heterocyclic carbene complexes derived from caffeine and other xanthines, elucidating their synthetic methods and describing their pertinent medicinal applications

Polyphenol-Rich Larix decidua Bark Extract with Antimicrobial Activity against Respiratory-Tract Pathogens: A Novel Bioactive Ingredient with Potential Pharmaceutical and Nutraceutical Applications

none8noLarch (Larix decidua) bark is a sawmill waste, traditionally used for antiseptic, expectorant and dermatological (wound healing, eczema, psoriasis) purposes. In this work, we developed a food-grade dry larch bark extract (LBE) from sawmill by-products using hydro-alcoholic extraction. The antibacterial activity of LBE was evaluated against respiratory-tract pathogens, i.e., Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa and Haemophilus influenza, and it was compared to that of grapefruit seed extract (GSE), a commercially available raw material commonly proposed as antibacterial ingredient for over-the-counter products. Procyanidins (PACs) and other polyphenols contents in LBE were determined by HPLC-FLD-MS and HPLC-DAD-MSn, respectively. The antimicrobial activity of LBE and GSE was assessed using the micro-plate dilution technique in concentration range of 2-200 µg/mL, and the safety of these dosages was assessed in cellular and animal models. LBE showed considerable contents of PACs (15% w/w; especially B-type) and other polyphenols (3.8% w/w), among which the characteristic spiropolyphenols larixinol and epilarixinol were identified, together with the flavonoids isoquercitrin and rutin, already reported as growth inhibitors of different respiratory-tract pathogens. LBE showed higher antimicrobial activity compared to GSE, demonstrated by a growth inhibition range of 10-40% towards five of six strains tested, compared to 10-15% of GSE. These results suggest that LBE may represent a natural and sustainable source of active compounds with antibacterial activity for pharmaceutical and nutraceutical applications.openFaggian, Marta; Bernabè, Giulia; Ferrari, Sara; Francescato, Stefano; Baratto, Gianni; Castagliuolo, Ignazio; Dall'Acqua, Stefano; Peron, GregorioFaggian, Marta; Bernabè, Giulia; Ferrari, Sara; Francescato, Stefano; Baratto, Gianni; Castagliuolo, Ignazio; Dall'Acqua, Stefano; Peron, Gregori

Novel Compounds Synergize With Venetoclax to Target KMT2A-Rearranged Pediatric Acute Myeloid Leukemia

In pediatric acute myeloid leukemia (AML), fusions involving lysine methyltransferase 2A (KMT2A) are considered hallmarks of aggressive AML, for whom the development of targeted specific therapeutic agents to ameliorate classic chemotherapy and obtain a complete eradication of disease is urgent. In this study, we investigated the antiapoptotic proteins in a cohort of 66 pediatric AML patients, finding that 75% of the KMT2A-r are distributed in Q3 + Q4 quartiles of BCL-2 expression, and KMT2A-r have statistically significant high levels of BCL-2, phospho-BCL-2 S70, and MCL-1, indicating a high anti-apoptotic pathway activation. In an attempt to target it, we tested novel drug combinations of venetoclax, a B-cell lymphoma-2 (BCL-2) inhibitor, in KMT2A-MLLT3, for being the most recurrent, and KMT2A-AFDN, for mediating the worst prognosis, rearranged AML cell lines. Our screening revealed that both the bromodomain and extra-terminal domain (BET) inhibitor, I-BET151, and kinase inhibitor, sunitinib, decreased the BCL-2 family protein expression and significantly synergized with venetoclax, enhancing KMT2A-r AML cell line death. Blasts t (6; 11) KMT2A-AFDN rearranged, both from cell lines and primary samples, were shown to be significantly highly responsive to the combination of venetoclax and thioridazine, with the synergy being induced by a dramatic increase of mitochondrial depolarization that triggered blast apoptosis. Finally, the efficacy of novel combined drug treatments was confirmed in KMT2A-r AML cell lines or ex vivo primary KMT2A-r AML samples cultured in a three-dimensional system which mimics the bone marrow niche. Overall, this study identified that, by high-throughput screening, the most KMT2A-selective drugs converged in different but all mitochondrial apoptotic network activation, supporting the use of venetoclax in this AML setting. The novel drug combinations here unveiled provide a rationale for evaluating these combinations in preclinical studies to accelerate the introduction of targeted therapies for the life-threatening KMT2A-AML subgroup of pediatric AML

Surgical Repair of Aortic Coarctation in Pediatric Age. A Single Center Two Decades Experience

Background: To evaluate early and long-term results of surgical treatment of aortic coarctation (CoAo) in infants and children. METHODS: A retrospective clinical review of patients less than 18 years with CoAo, undergoing surgery between 1995 and 2015. Data were retrieved from our institutional database, to identify preoperative and postoperative characteristics. Statistical analysis was performed by bivariate, Cox's, and logistic regression analysis. RESULTS: Three hundred forty-one consecutive patients (male/female: 192/149; the median age at surgery of 25 days; interquartile range [IQR], 10-143\u2009days) were included; 187 patients were less than 1 month (54.9%); 276 underwent extended end-to-end anastomosis (EEEA) (80.9%). Hypoplastic aortic arch (HAA) occurred in 34.6% and bicuspid aortic valve in 21.1%. The isolated type was present in 249 (73.0%). Significant postoperative complications occurred in 5.6%. Thirty-day mortality was 1.4%. At a median follow-up of 10.2 years (IQR, 6-15\u2009years; FU completeness, 91.2%), there were eight late deaths (2.6%), most in the complex type. Among 298 survivors, 284 (95.3%) were in NYHA class I; 10 (3.0%) were on antihypertensive treatment. Reinterventions on aortic arch occurred only in 4.5%, being HAA a significant risk factor for reoperation ( P\u2009=\u20090.00173). Freedom from mortality and reintervention on aorta at 21 years were 93.5% and 93.6%, respectively. CONCLUSIONS: Surgical repair of CoAo by EEEA without CPBP is a safe and low-risk procedure, concerning either early or late outcomes, despite the presence of HAA and neonatal age can influence recoarctation. Most patients are clinically well in the long-term, and only a few require antihypertensive therapy

The 8q24 region hosts miRNAs altered in biospecimens of colorectal and bladder cancer patients

Abstract Background The 8q24 locus is enriched in cancer‐associated polymorphisms and, despite containing relatively few protein‐coding genes, it hosts the MYC oncogene and other genetic elements connected to tumorigenesis, including microRNAs (miRNAs). Research on miRNAs may provide insights into the transcriptomic regulation of this multiple cancer‐associated region. Material and methods We profiled all miRNAs located in the 8q24 region in 120 colorectal cancer (CRC) patients and 80 controls. miRNA profiling was performed on cancer/non‐malignant adjacent mucosa, stool, and plasma extracellular vesicles (EVs), and the results validated with The Cancer Genome Atlas (TCGA) data. To verify if the 8q24‐annotated miRNAs altered in CRC were dysregulated in other cancers and biofluids, we evaluated their levels in bladder cancer (BC) cases from the TCGA dataset and in urine and plasma EVs from a set of BC cases and healthy controls. Results Among the detected mature miRNAs in the region, 12 were altered between CRC and adjacent mucosa (adj. p < 0.05). Five and four miRNAs were confirmed as dysregulated in the CRC and BC TCGA dataset, respectively. A co‐expression analysis of tumor/adjacent tissue data from the CRC group revealed a correlation between the dysregulated miRNAs and CRC‐related genes (PVT1 and MYC) annotated in 8q24 region. miR‐30d‐5p and miR‐151a‐3p, altered in CRC tissue, were also dysregulated in stool of CRC patients and urine of BC cases, respectively. Functional enrichment of dysregulated miRNA target genes highlighted terms related to TP53‐mediated cell cycle control. Conclusions Altered expression of 8q24‐annotated miRNAs may be relevant for the initiation and/or progression of cancer