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265,766 result(s) for "Organic chemicals"
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Enhanced Water Stability and Photoresponsivity in Metal-Organic Framework (MOF): A Potential Tool to Combat Drug-resistant Bacteria
In this work, we have successfully synthesized a bimetallic (Zinc and Cobalt) Zeolitic Imidazolate Framework (Zn 50 Co 50 -ZIF), a class in a wider microporous Metal-Organic Framework (MOF) family. The synthesized nanostructures maintain both water stability like ZIF-8 (solely Zn containing) and charge transfer electronic band in the visible optical spectrum as ZIF-67 (solely Co containing). Crystal structure from XRD, high resolution transmission electron microscopy (HRTEM) followed by elemental mapping (EDAX) confirm structural stability and omnipresence of the metal atoms (Zn and Co) across the nanomaterial with equal proportion. Existence of charge transfer state consistent with ZIF67 and intact ultrafast excited state dynamics of the imidazolate moiety in both ZIF-8 and ZIF-67, is evidenced from steady state and time resolved optical spectroscopy. The thermal and aqueous stabilities of Zn 50 Co 50 -ZIF are found to be better than ZIF-67 but comparable to ZIF-8 as evidenced by solubility, scanning electron microscopy (SEM) and XRD studies of the material in water. We have evaluated the photoinduced ROS generation by the mixed ZIF employing dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. We have also explored the potentiality of the synthesized material for the alternate remediation of methicillin resistant Staphylococcus aureus (MRSA) infection through the photoinduced reactive oxygen species (ROS) generation and methylene blue (MB) degradation kinetics.
A dose-escalation study of HP501, a highly selective URAT1 inhibitor, in male Chinese patients with hyperuricemia
HP501 is a highly selective renal urate transporter 1 (URAT1) inhibitor used for treating hyperuricemia. This study aimed to evaluate the tolerability, pharmacokinetics, and pharmacodynamics of HP501 in male Chinese patients. Patients with hyperuricemia were sequentially assigned to receive oral doses of HP501 (30, 50, 60, 90, and 120 mg) as a single dose on Day 1 and as once-daily doses from Days 4 to 13. Safety, pharmacokinetic, and pharmacodynamic data were collected. Multiple oral doses of HP501 were well-tolerated in all the cohorts. The most common adverse events (≥ 10% of patients) of any grade regardless of drug relationship were gout flare (14 patients, 25.93%), diarrhea (12 patients, 22.22%), elevated ALT (8 patients, 14.81%), hypertriglyceridemia (7 patients, 12.96%), dry mouth (7 patients, 12.96%) and oral ulcer (7 patients, 12.96%). All adverse events were mild or moderate. The C max and exposure (AUC) of HP501 was approximately dose-proportional between 30 and 120 mg. A dose-dependent serum uric acid (UA)-lowering effect was observed in the dose range of 30 to 60 mg and the serum UA lowering effect was similar between 90 and 120 mg on day 13, indicating that the maximal serum UA lowering effect of HP501 was achieved at 90 mg in the patients with hyperuricemia. In conclusion, the tolerability, pharmacokinetics, and pharmacodynamics supported 90 mg HP501 for subsequent clinical studies of this highly selective URAT1 inhibitor. Clinical Trial registration: No. CTR20212259 ( http://www.chinadrugtrials.org.cn/ ) was registered in September 2021, and No. CTR20222257 was registered in September 2022.
Synthesis of many different types of organic small molecules using one automated process
Small-molecule synthesis usually relies on procedures that are highly customized for each target. A broadly applicable automated process could greatly increase the accessibility of this class of compounds to enable investigations of their practical potential. Here we report the synthesis of 14 distinct classes of small molecules using the same fully automated process. This was achieved by strategically expanding the scope of a building block–based synthesis platform to include even Csp3-rich polycyclic natural product frameworks and discovering a catch-and-release chromatographic purification protocol applicable to all of the corresponding intermediates. With thousands of compatible building blocks already commercially available, many small molecules are now accessible with this platform. More broadly, these findings illuminate an actionable roadmap to a more general and automated approach for small-molecule synthesis.
Safety and efficacy of the HIV-1 integrase inhibitor raltegravir (MK-0518) in treatment-experienced patients with multidrug-resistant virus: a phase II randomised controlled trial
Raltegravir (MK-0518) is an HIV-1 integrase inhibitor with potent in-vitro activity against HIV-1 strains including those resistant to currently available antiretroviral drugs. The aim of this study was to assess the safety and efficacy of raltegravir when added to optimised background regimens in HIV-infected patients. HIV-infected patients with HIV-1 RNA viral load over 5000 copies per mL, CD4 cell counts over 50 cells per μL, and documented genotypic and phenotypic resistance to at least one nucleoside reverse transcriptase inhibitor, one non-nucleoside reverse transcriptase inhibitor, and one protease inhibitor were randomly assigned to receive raltegravir (200 mg, 400 mg, or 600 mg) or placebo orally twice daily in this multicentre, triple-blind, dose-ranging, randomised study. The primary endpoints were change in viral load from baseline at week 24 and safety. Analyses were done on a modified intention-to-treat basis. This trial is registered with ClinicalTrials.gov, with the number NCT00105157. 179 patients were eligible for randomisation. 44 patients were randomly assigned to receive 200 mg raltegravir, 45 to receive 400 mg raltegravir, and 45 to receive 600 mg raltegravir; 45 patients were randomly assigned to receive placebo. One patient in the 200 mg group did not receive treatment and was therefore excluded from the analyses. For all groups, the median duration of previous antiretroviral therapy was 9·9 years (range 0·4–17·3 years) and the mean baseline viral load was 4·7 (SD 0·5) log10 copies per mL. Four patients discontinued due to adverse experiences, three (2%) of the 133 patients across all raltegravir groups and one (2%) of the 45 patients on placebo. 41 patients discontinued due to lack of efficacy: 14 (11%) of the 133 patients across all raltegravir groups and 27 (60%) of the 45 patients on placebo. At week 24, mean change in viral load from baseline was −1·80 (95% CI −2·10 to −1·50) log10 copies per mL in the 200 mg group, −1·87 (−2·16 to −1·58) log10 copies per mL in the 400 mg group, −1·84 (−2·10 to −1·58) log10 copies per mL in the 600 mg group, and −0·35 (−0·61 to −0·09) log10 copies per mL for the placebo group. Raltegravir at all doses showed a safety profile much the same as placebo; there were no dose-related toxicities. In patients with few remaining treatment options, raltegravir at all doses studied provided better viral suppression than placebo when added to an optimised background regimen. The safety profile of raltegravir is comparable with that of placebo at all doses studied.
Pharmacodynamic Activity of the Novel Neurokinin-3 Receptor Antagonist SJX-653 in Healthy Men
Abstract Context SJX-653 is a novel neurokinin 3 receptor (NK3R) antagonist. The NK3 pathway is a central regulator of gonadotropin releasing hormone (GnRH) secretion and has also been implicated in the generation of hot flashes. Therefore, decreases of luteinizing hormone (LH) and testosterone in men serve as sensitive pharmacodynamic (PD) markers of central NK3 antagonism. Objective To characterize the safety, tolerability, pharmacokinetics, and pharmacodynamic activity of SJX-653 in healthy men. Design A randomized, placebo-controlled, double-blind, single ascending dose study. Setting Phase 1 unit. Patients or Other Participants Seven cohorts of 6 healthy men 18–45 years of age (4:2 randomization to SJX-653/placebo per cohort). Intervention(s) Single oral doses of 0.5–90 mg SJX-653. Main Outcome Measure(s) Safety assessments and serial pharmacokinetic (PK)/PD measurements. Results SJX-653 was well tolerated at all dose levels. Cmax and AUC0-24 increased in a dose-proportional manner. The terminal elimination half-life ranged between 9.8 and 12.5 hours independent of dose. A statistically significant, dose-dependent, reversible reduction of LH and testosterone was observed with near maximal effect after 15 mg and little to no effect at 4.5 mg. Maximal LH reduction was 70 ± 7% (mean ± sd) at 6 hours after 30 mg SJX-653 versus 10 ± 43% for placebo (P = 0.0006); maximal T reduction was of 68 ± 5% at 8 hours after 60 mg SJX-653 versus 18 ± 11% for placebo (P < 0.0001). The plasma IC50 for LH reduction was 33 ng/mL. Conclusions These data demonstrate clinical proof-of-mechanism for SJX-653 as a potent centrally-acting NK3R antagonist.
Flux synthesis of two-dimensional covalent organic frameworks
Covalent organic frameworks (COFs) are crystalline porous polymers constructed from organic building blocks into ordered two- or three-dimensional networks through dynamic covalent bonds. Attributed to their high porosity, well-defined structure, tailored functionality and excellent chemical stability, COFs have been considered ideal sorbents for various separation applications. The synthesis of COFs mainly employs the solvothermal method, which usually requires organic solvents in sealed Pyrex tubes, resulting in unscalable powdery products and environmental pollution that seriously limits their practical applications. Herein, our protocol focuses on an emerging synthesis method for COFs based on organic flux synthesis without adding solvents. The generality of this synthesis protocol has been applied in preparing various types of COFs, including olefin-linked, imide-linked, Schiff-based COFs on both gram and kilogram scales. Furthermore, organic flux synthesis avoids the disadvantages of solvothermal synthesis and enhances the crystallization and porosity of COFs. Typically, COF synthesis takes 3–5 d to complete, and subsequent washing procedures leading to pure COFs need 1 d. The procedure for kilogram-scale production of COFs with commercially available monomers is also provided. The resulting COFs are suitable for separation applications, particularly as adsorbent materials for industrial gas separation and water treatment applications. The protocol is suited for users with prior expertise in the synthesis of inorganic materials and porous organic materials. Key points This protocol describes a flux synthesis approach for two-dimensional covalent organic frameworks (COFs). Compared with other approaches, the method described here does not use solvents, making it environmentally friendly, and is scalable up to the kilogram scale. In addition, high-quality COF monoliths can be generated rather than powdery products, and COFs prepared by this protocol usually possess higher crystallinity and BET surface area than those prepared by traditional solvothermal methods. This protocol describes a flux synthesis approach for two-dimensional covalent organic frameworks. Compared with other approaches, this method does not use solvents, making it environmentally friendly, and is scalable up to the kilogram scale.
Raltegravir with Optimized Background Therapy for Resistant HIV-1 Infection
For patients infected with multidrug-resistant human immunodeficiency virus type 1 (HIV-1), therapeutic options are limited. Raltegravir is a new molecule that inhibits HIV integrase. In two phase 3 studies, raltegravir was found to be superior to placebo, in the context of optimized background antiviral therapy, in suppressing HIV viral load at 48 weeks (62.1% vs. 32.9%). In two phase 3 studies, raltegravir was found to be superior to placebo, in the context of optimized background antiviral therapy, in suppressing HIV viral load at 48 weeks (62.1% vs. 32.9%). Highly active antiretroviral therapy is the standard of care for patients with advanced human immunodeficiency virus (HIV) infection. 1 Combination regimens have resulted in improved survival, decreased morbidity, and cost-effective care for patients with a CD4 count of less than 350 per cubic millimeter. 2 – 8 However, viral suppression cannot always be achieved or sustained with standard treatments because of the development of viral resistance, toxic effects of drugs, or lack of adherence. 9 – 18 The majority of HIV-infected patients in whom highly active antiretroviral therapy fails have resistant viral quasispecies. 12 – 15 , 19 , 20 Cross-resistance to agents within a drug class may exhaust . . .
Subgroup and Resistance Analyses of Raltegravir for Resistant HIV-1 Infection
In subgroups of two phase 3 studies, patients with high-risk features for failure of antiretroviral therapy, such as a low CD4 count, high base-line level of human immunodeficiency virus (HIV) type 1 RNA, or unfavorable genotypic or phenotypic sensitivity score, raltegravir was superior to placebo in terms of a virologic response at 48 weeks. However, among these patients, in whom antiretroviral therapy had been used previously, 23% of raltegravir recipients had virologic failure by 48 weeks. In patients with high-risk features for failure of antiretroviral therapy, raltegravir was superior to placebo in terms of a virologic response at 48 weeks. However, among these patients, in whom antiretroviral therapy had been used previously, 23% of raltegravir recipients had virologic failure by 48 weeks. Despite the substantial decrease in mortality and morbidity rates associated with highly active antiretroviral therapy over the past decade, there is still a substantial need for effective antiretroviral drugs for patients infected with resistant human immunodeficiency virus type 1 (HIV-1). 1 , 2 The majority of licensed antiretroviral drugs belong to three classes targeting either the HIV-1 protease or reverse transcriptase, and considerable cross-resistance exists among drugs within each class. 3 , 4 In patients with resistant virus, use of antiretroviral agents from new classes offers considerable potential benefit because of the absence of cross-resistance. 5 – 7 HIV-1 integrase represents a new therapeutic target. 8 , . . .
Organic chemicals jeopardize the health of freshwater ecosystems on the continental scale
Organic chemicals can contribute to local and regional losses of freshwater biodiversity and ecosystem services. However, their overall relevance regarding larger spatial scales remains unknown. Here, we present, to our knowledge, the first risk assessment of organic chemicals on the continental scale comprising 4,000 European monitoring sites. Organic chemicals were likely to exert acute lethal and chronic long-term effects on sensitive fish, invertebrate, or algae species in 14% and 42% of the sites, respectively. Of the 223 chemicals monitored, pesticides, tributyltin, polycyclic aromatic hydrocarbons, and brominated flame retardants were the major contributors to the chemical risk. Their presence was related to agricultural and urban areas in the upstream catchment. The risk of potential acute lethal and chronic long-term effects increased with the number of ecotoxicologically relevant chemicals analyzed at each site. As most monitoring programs considered in this study only included a subset of these chemicals, our assessment likely underestimates the actual risk. Increasing chemical risk was associated with deterioration in the quality status of fish and invertebrate communities. Our results clearly indicate that chemical pollution is a large-scale environmental problem and requires far-reaching, holistic mitigation measures to preserve and restore ecosystem health.
Safety, Pharmacokinetics, and Pharmacodynamics of ME-401, an Oral, Potent, and Selective Inhibitor of Phosphatidylinositol 3-Kinase P110δ, Following Single Ascending Dose Administration to Healthy Volunteers
ME-401 is a novel selective inhibitor of phosphatidylinositol 3 kinase p110δ, an enzyme often found overexpressed and overactive in B-cell malignancies. The current study was performed to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending oral doses of ME-401 in healthy volunteers. This analysis was an open-label, nonrandomized study in healthy male volunteers. Three sequential groups were dosed. Each group received single doses of ME-401 on two occasions; the doses tested ranged from 10 to 150 mg. Blood was drawn at various time points to analyze plasma concentrations of ME-401 and inhibition of basophil activation, a marker of phosphatidylinositol 3 kinase p110δ inhibition. Fifteen subjects received a single dose of ME-401 on two occasions. Three adverse events that were considered possibly related to the study drug were reported: one event of pain, one event of headache, and one event of upper abdominal pain. ME-401 exhibited dose proportionality up to 60 mg, and supra-proportional increases in exposure were observed above doses of 60 mg. In addition, there was a dose-proportional increase in the inhibition of basophil activation up to 60 mg. Mean t1/2 ranged from 9.36 to 29.23 hours across the dose range. A 60 mg dose of ME-401 approached 90% inhibition of basophil activation, and thereafter no further increase to the percent inhibition of basophil activation was observed for higher doses. Once-daily dosing of 60 mg ME-401 was forecasted to result in trough plasma levels exceeding the concentration needed for 90% inhibition of basophil activation. This first-in-human study showed that ME-401 was well tolerated after single doses up to 150 mg. Pharmacologic activity was confirmed after administration of single ascending oral doses of 10 to 150 mg. ME-401 60 mg, administered once daily, was selected as the starting dose for patient studies. ClinicalTrials.gov identifier: NCT02521389.