Biosynthesis of gold nanoparticles by fungi and its potential in SERS.

Surface enhanced Raman spectroscopy (SERS) by using gold nanoparticles (AuNPs) has gained relevance for the identification of biomolecules and some cancer cells. Searching for greener NPs synthesis alternatives, we evaluated the SERS properties of AuNPs produced by using different filamentous fungi. The AuNPs were synthesized utilizing the supernatant of Botrytis cinerea, Trichoderma atroviride, Trichoderma asperellum, Alternaria sp. and Ganoderma sessile. The AuNPs were characterized by ultraviolet-visible spectroscopy (UV-Vis) to identify its characteristic surface plasmon resonance, which was located at 545 nm (B. cinerea), 550 nm (T. atroviride), 540 nm (T. asperellum), 530 nm (Alternaria sp.), and 525 nm (G. sessile). Morphology, size and crystal structure were characterized through transmission electron microscopy (TEM); colloidal stability was assessed by Z-potential measurements. We found that, under specific incubation conditions, it was possible to obtain AuNPs with spherical and quasi-spherical shapes, which mean size range depends on the fungal species supernatant with 92.9 nm (B. cinerea), 24.7 nm (T. atroviride), 16.4 nm (T. asperellum), 9.5 nm (Alternaria sp.), and 13.6 nm (G. sessile). This, as it can be expected, has an effect on Raman amplification. A micro-Raman spectroscopy system operated at a wavelength of 532 nm was used for the evaluation of the SERS features of the AuNPs. We chose methylene blue as our target molecule since it has been widely used for such a purpose in the literature. Our results show that AuNPs synthesized with the supernatant of T. atroviride, T. asperellum and Alternaria sp. produce the stronger SERS effect, with enhancement factor (EF) of 20.9, 28.8 and 35.46, respectively. These results are promising and could serve as the base line for the development of biosensors through a facile, simple, and low-cost green alternative.

Collateral grading systems in retrograde percutaneous coronary intervention of chronic total occlusions.

BACKGROUND: The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade. AIMS: To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success. METHODS: A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%. RESULTS: Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589). CONCLUSIONS: The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success.

Wire-based antegrade dissection re-entry technique for coronary chronic total occlusions percutaneous revascularization: Experience from the ERCTO Registry.

BACKGROUND: The recent development and widespread adoption of antegrade dissection re-entry (ADR) techniques have been underlined as one of the antegrade strategies in all worldwide CTO consensus documents. However, historical wire-based ADR experience has suffered from disappointing long-term outcomes. AIMS: Compare technical success, procedural success, and long-term outcome of patients who underwent wire-based ADR technique versus antegrade wiring (AW). METHODS: One thousand seven hundred and ten patients, from the prospective European Registry of Chronic Total Occlusions (ERCTO), underwent 1806 CTO procedures between January 2018 and December 2021, at 13 high-volume ADR centers. Among all 1806 lesions attempted by the antegrade approach, 72% were approached with AW techniques and 28% with wire-based ADR techniques. RESULTS: Technical and procedural success rates were lower in wire-based ADR than in AW (90.3% vs. 96.4%, p < 0.001; 87.7% vs. 95.4%, p < 0.001, respectively); however, wire-based ADR was used successfully more often in complex lesions as compared to AW (p = 0.017). Wire-based ADR was used in most cases (85%) after failure of AW or retrograde procedures. At a mean clinical follow-up of 21 ± 15 months, major adverse cardiac and cerebrovascular events (MACCEs) did not differ between AW and wire-based ADR (12% vs. 15.1%, p = 0.106); both AW and wire-based ADR procedures were associated with significant symptom improvements. CONCLUSIONS: As compared to AW, wire-based ADR is a reliable and effective strategy successfully used in more complex lesions and often after the failure of other techniques. At long-term follow-up, patient's MACCEs and symptoms improvement were similar in both antegrade techniques.

Gender differences in percutaneous coronary intervention for chronic total occlusions from the ERCTO study.

BACKGROUND: Gender-specific data addressing percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) in female patients are scarce and based on small sample size studies. AIMS: We aimed to analyze gender-differences regarding in-hospital clinical outcomes after CTO-PCI. METHODS: Data from 35,449 patients enrolled in the prospective European Registry of CTOs were analyzed. The primary outcome was the comparison of procedural success rate in the two cohorts (women vs. men), defined as a final residual stenosis less than 20%, with Thrombolysis In Myocardial Infarction grade flow = 3. In-hospital major adverse cardiac and cerebrovascular events (MACCEs) and procedural complications were deemed secondary outcomes. RESULTS: Women represented 15.2% of the entire study population. They were older and more likely to have hypertension, diabetes, and renal failure, with an overall lower J-CTO score. Women showed a higher procedural success rate (adjusted OR [aOR] = 1.115, confidence interval [CI]: 1.011-1.230, p = 0.030). Apart from previous myocardial infarction and surgical revascularization, no other significant gender differences were found among predictors of procedural success. Antegrade approach with true-to-true lumen techniques was more commonly used than retrograde approach in females. No gender differences were found regarding in-hospital MACCEs (0.9% vs. 0.9%, p = 0.766), although a higher rate of procedural complications was observed in women, such as coronary perforation (3.7% vs. 2.9%, p < 0.001) and vascular complications (1.0% vs. 0.6%, p < 0.001). CONCLUSIONS: Women are understudied in contemporary CTO-PCI practice. Female sex is associated with higher procedural success after CTO-PCI, yet no sex differences were found in terms of in-hospital MACCEs. Female sex was associated with a higher rate of procedural complications.

Definitions and Clinical Trial Design Principles for Coronary Artery Chronic Total Occlusion Therapies: CTO-ARC Consensus Recommendations.

Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence.

Dual guidewire balloon antegrade fenestration and re-entry technique for coronary chronic total occlusions percutaneous coronary interventions.

OBJECTIVES: To describe the experience of coronary chronic total occlusions (CTOs) percutaneous coronary interventions (PCI) using antegrade fenestration and re-entry (AFR) technique with a dedicated dual guidewire balloon (DGB). BACKGROUND: Antegrade dissection and re-entry (ADR) techniques has been emphasized in recent worldwide CTO consensus documents. We investigated the feasibility and safety of DGB as a dedicated device to perform guidewire-based AFR. METHODS AND RESULTS: Fourteen consecutive patients with complex CTO (J-CTO score: 3.1 ± 0.9) underwent DGB-AFR in the years 2020-2021. DGB-AFR consists in advancing the DGB over a guidewire that reached the vessel distal to the CTO in an extra plaque fashion, inflating/deflating the DGB to create fenestration between subintimal space and the true lumen and advancing a proximal re-entry guidewire through fenestration in the true lumen. DGB-AFR alone was successful in 10 of 14 (71%) cases, a rescue wire-based ADR was needed in two cases for re-entry into the true lumen with a total success rate in 12 of 14 (86%) cases. Among all DGB-AFR cases, four (28%) were performed as a first-line strategy while the remaining 10 (71%) cases were performed as a bail-out strategy after failure of other antegrade crossings for 30 min of procedural time. No DGB-related complications were observed. CONCLUSIONS: DGB-AFR is a user-friendly reliable strategy for the treatment of many CTO lesions. It can be used as bail-out after failure of conventional antegrade wiring techniques, achieving high procedural success rate and low occurrence of procedural adverse events.

Outcomes of chronic total occlusion percutaneous coronary intervention in patients with reduced left ventricular ejection fraction.

BACKGROUND: The relationship between left ventricular ejection fraction (LVEF) and the success and safety of coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We examined the clinical characteristics and outcomes of CTO PCI in the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO) after stratifying patients by LVEF (≤35%, 36%-49%, and ≥50%). RESULTS: A total of 7827 CTO PCI procedures with LVEF data were included. Mean age was 64 ± 10 years, 81% were men, 43% had diabetes mellitus, 61% had prior PCI, 45% had prior myocardial infarction, and 29% had prior coronary artery bypass graft surgery. Technical success was similar in the three LVEF strata: 85%, 86%, and 87%, p = 0.391 for LVEF ≤35%, 36%-49%, and ≥50%, respectively. In-hospital mortality was higher in lower LVEF patients (1.1%, 0.4%, and 0.3%, respectively, p = 0.001). In-hospital major adverse cardiovascular events (MACE) were numerically higher in lower EF patients (2.7%, 2.1%, and 1.9%, p = 0.271). At a median follow-up of 2 months (interquartile range: 19-350 days), patients with lower LVEF continued to have higher mortality (4.9%, 3.2%, and 1.4%, p < 0.001) while the MACE rates were similar (9.3%, 9.6%, and 7.4%, p = 0.172). CONCLUSION: CTO PCI can be performed with high technical success in patients with reduced LVEF but is associated with higher in-hospital and post-discharge mortality.

Sequential sampling plan for Ceratitis capitata (Diptera: Tephritidae) in guava orchards.

This study aimed to elaborate a sequential sampling plan for C. capitata in commercial orchards of guava. 90 McPhail traps were randomly installed in three guava orchards in a transverse direction for 23 weeks. The data were submitted to sequential probability ratio test. Adopted the average of 0.3 C. capitata for the level of security and 0.7 for the control action. In this sequential sampling plan was defined the average number of 0.40 adults of C. capitata for each trap McPhail (sample). The sequential plan generated is unprecedented and will contribute to the rapid and safe decision making in the control of C. capitata population in guava farming.

Management of refractory angina: an update.

Despite the use of anti-anginal drugs and/or percutaneous coronary interventions (PCI) or coronary artery bypass grafting, the proportion of patients with coronary artery disease who have daily or weekly angina ranges from 2% to 24%. Refractory angina refers to long-lasting symptoms (for >3 months) due to established reversible ischaemia, which cannot be controlled by escalating medical therapy with the use of 2nd- and 3rd-line pharmacological agents, bypass grafting, or stenting. While there is uncertain prognostic benefit, the treatment of refractory angina is important to improve the quality of life of the patients affected. This review focuses on conventional pharmacological approaches to treating refractory angina, including guideline directed drug combination and dosages. The symptomatic and prognostic impact of advanced and novel revascularization strategies such as chronic total occlusion PCI, transmyocardial laser revascularization, coronary sinus occlusion, radiation therapy for recurrent restenosis, and spinal cord stimulation are also covered and recommendations of the 2019 ESC Guidelines on the Diagnosis and Management of Chronic Coronary Syndromes discussed. Finally, the potential clinical use of current angiogenetic and stem cell therapies in reducing ischaemia and/or pain is evaluated.

Synthesis, Mechanism Elucidation and Biological Insights of Tellurium(IV)-Containing Heterocycles.

Inspired by the synthetic and biological potential of organotellurium substances, a series of five- and six-membered ring organotelluranes containing a Te-O bond were synthesized and characterized. Theoretical calculations elucidated the mechanism for the oxidation-cyclization processes involved in the formation of the heterocycles, consistent with chlorine transfer to hydroxy telluride, followed by a cyclization step with simultaneous formation of the new Te-O bond and deprotonation of the OH group. Moreover, theoretical calculations also indicated anti-diastereoisomers to be major products for two chirality center-containing compounds. Antileishmanial assays against Leishmania amazonensis promastigotes disclosed 1,2λ4 -oxatellurane LQ50 (IC50 =4.1±1.0; SI=12), 1,2λ4 -oxatellurolane LQ04 (IC50 =7.0±1.3; SI=7) and 1,2λ4 -benzoxatellurole LQ56 (IC50 =5.7±0.3; SI=6) as more powerful and more selective compounds than the reference, being up to four times more active. A stability study supported by 125 Te NMR analyses showed that these heterocycles do not suffer structural modifications in aqueous-organic media or at temperatures up to 65 °C.

Multicenter experience with the antegrade fenestration and reentry technique for chronic total occlusion recanalization.

OBJECTIVES: We aimed to evaluate the efficacy and safety of antegrade fenestration and reentry (AFR) for chronic total occlusion (CTO) recanalization in a multicenter registry. BACKGROUND: Adoption of antegrade dissection/reentry (ADR) for CTO recanalization has been limited, and novel ADR techniques are needed. METHODS: AFR involves the balloon-induced creation of multiple fenestrations between the false and true lumen. A targeted true lumen reentry is subsequently achieved with a low tip-load polymer-jacketed guidewire. Following the initial description and dissemination of AFR, patients undergoing AFR-based CTO recanalization at nine centers were included in the present registry. Study endpoints were AFR success, procedural success, and target-lesion failure (TLF) on follow-up. RESULTS: We included 41 patients. Mean J-CTO score was 2.5 ± 1.4. In 80.5% of cases, AFR was performed after failed antegrade wire escalation. Another ADR technique was used before AFR in one-third of cases. AFR achieved distal true lumen reentry in n = 27/41 (65.9%) cases. In n = 14/41 (34.1%) cases with AFR failure, use of alternative techniques led to successful CTO recanalization in eight additional patients. The overall technical and procedural success rates were 85.4% and 82.9%, respectively. No AFR-related complications were observed. One-year TLF rate was 8.3% overall, with no differences between successful and failed AFR. CONCLUSIONS: We report on AFR feasibility in a multicenter registry of patients undergoing CTO recanalization. We observed a moderate success rate, coupled with the absence of complications. Moreover, even a failed AFR attempt did not preclude the use of alternative techniques to achieve recanalization. Further studies should confirm and extend our findings.

Evaluation of remnant cholesterol levels and Monocyte-to-HDL-cholesterol ratio in South Asian patients with acute coronary syndrome.

BACKGROUND AND AIMS: In the present study, we aimed to compare the clinical and coronary angiography features between South Asian and Caucasian patients with Acute Coronary Syndrome (ACS). In particular, we focused our analysis on the evaluation of recent cardiovascular risk markers, such as remnant cholesterol, corresponding to all plasma cholesterol minus HDL-C (high-density lipoprotein cholesterol) and LDL-C (low-density lipoprotein cholesterol), and the Monocyte-to-HDL-cholesterol ratio. We also compared values of several lipoprotein ratios and the Platelet-to-lymphocyte ratio, accurate predictors of coronary events and coronary artery disease. METHODS AND RESULTS: We recruited 40 South Asian and 40 Caucasian patients admitted for ACS. Data were collected by consulting patients' medical records. We used Chi-square test and Student's t-test to analyse qualitative and quantitative variables, respectively. South Asian patients, compared to Caucasians, showed higher mean values of the parameters analysed: remnant cholesterol (32.6 ± 17 vs 26.5 ± 9.6), Monocyte-to-HDL-cholesterol ratio (26.4 ± 48.7 vs 16.5 ± 8.3), Platelet-to-lymphocyte ratio (124.7 ± 130.7 vs 120.5 ± 58.8). Moreover, higher mean values of several lipoprotein ratios were also found in South Asian patients compared to the control group. However, statistical significance was not reached for any of these differences observed. CONCLUSIONS: The evaluation of the parameters analysed in this study might provide accurate information regarding the cardio-metabolic risk in South Asian patients. However, further studies with larger samples are needed to obtain more significant results.

Randomized Controlled Comparison of Optimal Medical Therapy with Percutaneous Recanalization of Chronic Total Occlusion (COMET-CTO).

The aim of this randomized prospective study was to evaluate the quality of life (QoL) using the "Seattle Angina Questionnaire" (SAQ) in patients with chronic total occlusion (CTO) in coronary arteries treated with either percutaneous coronary intervention (PCI) or optimal medical therapy (OMT), or only with OMT.The potential benefits of recanalization of CTO by PCI have been controversial because of the scarcity of randomized controlled trials.A total of 100 patients with CTO were randomized (1:1) prospectively into the PCI CTO or the OMT group (50 patients in each group). There were no baseline differences in the SAQ scores between the groups, except for physical limitation scores (P = 0.03). During the mean follow-up (FUP) of 275 ± 88 days, patients in the PCI group reported less physical activity limitations (72.7 ± 21.3 versus 60.5 ± 27, P = 0.014), less frequent angina episodes (89.8 ± 17.6 versus 76.8 ± 27.1, P = 0.006), better QoL (79.9 ± 22.7 versus 62.5 ± 25.5, P = 0.001), greater treatment satisfaction (91.2 ± 13.6 versus 81.4 ± 18.4, P = 0.003), and borderline differences in angina stability (61.2 ± 26.5 versus 51.0 ± 23.7, P = 0.046) compared to patients in the OMT group. There were no significant differences in SAQ scores in the OMT group at baseline and during the FUP. There was a statistically significant increase in all five domains in the PCI group.Symptoms and QoL measured by the SAQ were significantly improved after CTO PCI compared to OMT alone.

Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention.

Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI. 1. Ischemic symptom improvement is the primary indication for CTO-PCI. 2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI. 3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges. 4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs. 5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use. 6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation. 7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training.

Competitive Reactivity of Tautomers in the Degradation of Organophosphates by Imidazole Derivatives.

The harmful impact caused by pesticides on human health and the environment necessitates the development of efficient degradation processes and control of prohibited stocks of such substances. Organophosphates (OPs) are among the most used agrochemicals in the world and their degradation can proceed through several possible pathways. Investigating the reactivity of OPs with nucleophilic species allows one to propose new and efficient catalyst scaffolds for use in detoxification. In light of the remarkable catalytic activity of imidazole (IMZ) at promoting dephosphorylation processes of OPs, the reactivity of 4(5)-hydroxymethylimidazole (HMZ) with diethyl-2,4-dinitrophenylphosphate (DEDNPP) and Paraoxon are evaluated by combining experimental and theoretical approaches. It is observed that HMZ is an efficient and regiospecific catalyst with reactivity modulated by competing tautomers. To propose an optimal IMZ-based catalyst, quantum chemical calculations were performed for monosubstituted 4(5)IMZ derivatives that might cleave DEDNPP. Both inductive effects and hydrogen bonding by the substituents are shown to influence barriers and mechanisms.

Outcomes with retrograde versus antegrade chronic total occlusion revascularization.

OBJECTIVES: The aim of the study was to evaluate the outcomes of retrograde versus antegrade approach in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: The retrograde approach has increased the success rate of CTO PCI but has been associated with a higher risk for complications. METHODS: We conducted a meta-analysis of studies published between 2000 and August 2019 comparing the in-hospital and long-term outcomes with retrograde versus antegrade CTO PCI. RESULTS: Twelve observational studies (10,240 patients) met our inclusion criteria (retrograde approach 2,789 patients, antegrade approach 7,451 patients). Lesions treated with the retrograde approach had higher J-CTO score (2.8 vs. 1.9, p < .001). Retrograde CTO PCI was associated with a lower success rate (80.9% vs. 87.4%, p < .001). Both approaches had similar in-hospital mortality, urgent revascularization, and cerebrovascular events. Retrograde CTO PCI was associated with higher risk of in-hospital myocardial infarction (MI; odds ratio [OR] 2.37, 95% confidence intervals [CI] 1.7, 3.32, p < .001), urgent pericardiocentesis (OR 2.53, 95% CI 1.41-4.51, p = .002), and contrast-induced nephropathy (OR 2.12, 95% CI 1.47-3.08; p < .001). During a mean follow-up of 48 ± 31 months retrograde crossing had similar mortality (OR 1.79, 95% CI 0.84-3.81, p = .13), but a higher incidence of MI (OR 2.07, 95% CI 1.1-3.88, p = .02), target vessel revascularization (OR 1.92, 95% CI 1.49-2.46, p < .001), and target lesion revascularization (OR 2.08, 95% CI 1.33-3.28, p = .001). CONCLUSIONS: Compared with antegrade CTO PCI, retrograde CTO PCI is performed in more complex lesions and is associated with a higher risk for acute and long-term adverse events.

Integrated control of target spot and yield of cotton in the Brazilian cerrado biome.

Target spot is a disease that has caused serious damage to cotton crops. This study was carried out to examine if different cotton genotypes, plant heights and fungicide treatments can be used as tools of an integrated control methods of target spot. The experiment was carried out in the 2014/15 crop season, in cerrado biome of Chapadão do Sul - MS, Brazil. It was used a randomized block design in a 2 × 3 × 3 factorial arrangement with four replicates. The factors were two plant heights (1 and 1.5 m), three cultivars (FMT 701, FM 975, and FM 944), and three fungicide treatments (control, FT1, and FT2). Fungicide treatments consisted of sequential applications of different fungicides of the triazole, strobilurin, and carboxamide groups. Cultivar FM 944 showed lower susceptibility to target spot. The shorter plants exhibited lower disease severity. The fungicides pyraclostrobin + fluxapyroxad and trifloxystrobin + prothioconazole reduced the severity of target spot. Cultivar FM 975 had the highest yield. A higher yield was obtained in the upper stratum than in the lower stratum of the plant.

Puzzling Reaction of Imidazole with Methyl Parathion: P=S versus P=O Mechanistic Shift Dilemma in Organophosphates.

Organophosphates (OPs) constitute many toxic agrochemicals and warfare and can undergo a wide spectrum of mechanisms, some which are fairly unexplored. In this sense, concise mechanistic elucidation stands out as a strategic tool for achieving efficient detoxification and for monitoring processes. Particularly intriguing is the effect of substituting the oxygen atom of the phosphoryl moiety (P=O) in OPs with a sulfur atom to give the thio-derived OPs (i.e., OTPs, P=S). In general, imidazole (IMZ) reacts very efficiently with OPs by targeting the phosphorus atom, although herein we evidence a thio-driven shift with OTPs: IMZ undergoes unusual nucleophilic attack at the aliphatic carbon atom of methyl parathion. Alkylation of IMZ under mild conditions (aqueous weakly basic medium) is also novel and should be applicable to other novel IMZ-based architectures, and thereby, it can be a great ally for organic synthesis. Overall, a broader understanding of the mechanistic trend involved in such highly toxic agents is provided.

Synthesis, Antioxidant Activity and Cytotoxicity of N-Functionalized Organotellurides.

The use of antioxidants is the most effective means to protect the organism against cellular damage caused by oxidative stress. In this context, organotellurides have been described as promising antioxidant agents for decades. Herein, a series of N-functionalized organotellurium compounds has been tested as antioxidant and presented remarkable activities by three different in vitro chemical assays. They were able to reduce DPPH radical with IC50 values ranging from 5.08 to 19.20 µg mL-1, and some of them also reduced ABTS+ radical and TPTZ-Fe3+ complex in ABTS+ and FRAP assays, respectively. Initial structure-activity relationship discloses that the nature of N-substituent strongly influenced both activity and cytotoxicity of the studied compounds. Furthermore, radical scavenging activities of N-functionalized organotellurides have been compared with those of their selenilated congeners, demonstrating that the presence of tellurium atom has an essential role in antioxidant activity.