Base-Mediated Annulation of Electrophilic Benzothiophene with Naphthols and Phenols: Accessing Benzothiophene-Fused Heteroacenes.

A base-mediated annulation of 2-nitrobenzothiophenes with naphthols was realized for the synthesis of hitherto unknown class of heteroacenes, namely benzothieno[2,3-b]naphthofurans. By using naphthols with a hydroxyl group positioned at 1st or 2nd position, we could synthesize two positional isomers, benzothieno[2,3-b]naphtho[2,1-d]furans or benzothieno[2,3-b]naphtho[2,3-d]furans. The annulation was found to be general with a range of substituted 2-nitrobenzothiophenes and naphthols. This heteroannulation of benzothiophene was extended using a range of phenols affording the corresponding benzothieno[2,3-b]benzofurans in moderate yields. The basic photophysical properties of these heteroacenes were evaluated, and we also demonstrated the applicability of this annulation on the gram scale.

One-Pot MCR-Oxidation Approach toward Indole-Fused Heteroacenes.

A straightforward synthetic route toward indole-fused heteroacenes was developed. The strategy is composed of a one-pot process starting with a multicomponent reaction of cyclohexanone, primary amine and N-tosyl-3-nitroindole followed by an oxidation step. The one-pot approach was found to be general, affording both symmetric and nonsymmetric indolo[3,2-b]indoles in good yields. The strategy was also utilized for accessing 5-ring fused benzo[g]indolo[3,2-b]indole. We could extend the methodology for the synthesis of benzothieno[3,2-b]indoles starting from 3-nitrobenzothiophene. The importance of the developed method was exemplified by performing the reaction sequence on gram scale and also by the synthetic transformations of indolo[3,2-b]indoles. In addition, the change in photophysical properties with extension of conjugation of the synthesized heteroacenes was studied.

A Cross-Sectional Study on Sedentary Lifestyle Among Budding Doctors: Silent Killer?

Background Internship is the time period when young doctors learn to balance between professional and personal lives. If they have good awareness and practice of any kind of physical activity during this period, it will help them to continue it forward. This enables them to educate and inspire people and patients around them. The main objectives of this study were to assess patterns of physical activity among medical interns and to understand the factors preventing physical activity among them. Methodology This cross-sectional survey was carried out among interns of a tertiary care hospital in western Maharashtra from July 2022 to September 2022. Ethical clearance was obtained before starting data collection. The survey was administered to those who fulfilled the inclusion criteria. The questionnaire was adopted from the Global Physical Activity Questionnaire. The data collected were entered into Microsoft Excel (Microsoft Corporation, Redmond, WA) and analysis was done using MedCalc v.18.2.1 (MedCalc Software Ltd, Ostend, Belgium). Results A total of 220 interns were enrolled in the survey, of which 13 were removed due to incomplete data and 28 interns did not participate in the study. Finally, 179 interns were included for analysis in the study. The response rate was 87.27%. The mean age of participants was 23.12 years. The study population consisted of 72 (40.22%) males and 107 (59.78%) females. Among participants, 33 interns (18.44%) were involved in vigorous activity during work, and 108 interns (60.34%) were involved in moderate physical activity during work. The median time of a sedentary lifestyle was 300 minutes per day and was more common among males. Cumulatively busy working schedules and exam preparation were the important reasons for reduced physical activity. Conclusion There is a gap in the practice of physical activity among interns. A sedentary lifestyle was more prevalent among male interns than in female interns. The main constraints were demanding working hours and the pressure of competitive exams. Medical students will become doctors in the future who can advise their patients on healthy lifestyle habits. We recommend that it is necessary to promote physical activity in medical schools and to reinforce the importance of physical exercise in the medical curriculum.

Synthesis of Benzothienobenzofurans via Annulation of Electrophilic Benzothiophenes with Phenols.

We have developed a metal-free, mild, and green synthetic route toward benzothieno[3,2-b]benzofurans by the annulation of 3-nitrobenzothiophene with phenols. The reaction was found to be general with a range of substituted phenols. In addition, we could extend the methodology for the synthesis of pentacenes and could demonstrate the synthesis in gram-scale. Moreover, we extended the strategy for the synthesis of benzothieno[2,3-b]benzofurans by starting from 2-nitrobenzothiophenes.

Protective nature of low molecular weight chitosan in a chitosan-Amphotericin B nanocomplex - A physicochemical study.

Chitosan, a biopolymer of immense potential, has been well-explored over the past decade in the biomedical field. Despite its numerous biological properties like anti-microbial, anti-inflammatory, anti-diabetic etc., limited studies have been conducted on its ability to protect therapeutic molecules in nano-formulations. Amphotericin B (AMP) is one such therapeutic molecule which requires protection as it possesses inherent limitations of poor water-solubility, susceptibility to oxidation- and/or light-induced degradation etc. Although AMP formulations have been quite successful in treating chronic fungal infections, their high cost, prolonged nature of therapy and instability over longer durations has necessitated the development of alternative carriers. In the present study, a stable nanoparticulate formulation was successfully prepared using low molecular weight chitosan and the anti-fungal agent AMP and this was found to offer protection to the labile AMP. The developed nanocomplexes could prevent degradation of AMP up to six months, in solution form, unlike the native drug which degraded in <24 h. Antifungal studies of the developed nanocomplexes revealed a surface charge-dependent antifungal activity. Furthermore, the nanocomplexes did not affect the viability of mammalian cells and showed excellent intracellular uptake and retention, and hence suggested potential of the nanocomplexes in alleviating systemic fungal infections.

Heteroannulation of 3-Nitroindoles and 3-Nitrobenzo[b]thiophenes: A Multicomponent Approach toward Pyrrole-Fused Heterocycles.

A simple, efficient, and general multicomponent reaction involving an enolizable ketone, a primary amine, and an N-protected 3-nitroindole was developed for the synthesis of a range of functionalized pyrrolo[3,2-b]indoles. The methodology was efficaciously utilized for the "pyrroloindoliztion" of natural products, the pyrrolization of 3-nitrobenzo[b]thiophene, and the gram-scale synthesis of pyrroloindole. Furthermore, a "one-pot" approach for accessing indolo[3,2-b]indoles was realized.

Proton play in the formation of low molecular weight chitosan (LWCS) by hydrolyzing chitosan with a carbon based solid acid.

Low molecular weight chitosan (LWCS) constitute a special class of value added chemicals that are primarily obtained from crustacean shells, which are the main water pollutants from crabs and shrimp processing centers. Unlike chitin and chitosan, LWCS possess improved solubility in water and aqueous solutions, making them widely applicable in numerous fields ranging from drug delivery to waste water treatment. Among the methods employed for their production, chemical breakdown by strong liquid acids has yielded good success. However, this method is met with severe concerns arising from the harsh nature of liquid acids, which may corrode the reactors for commercial synthesis, and their limited reusability. The physical methods like ultrasound and microwave are energy intensive in nature, while the enzymatic methods are expensive and offers limited scope for reuse. We have attempted to overcome these problems by employing carbon based solid acid (CSA) for hydrolyzing chitosan to LWCS. CSA can be easily produced using activated carbon, a cost-effective and easily available raw material. Reactions were carried out between chitosan and CSA in a hydrothermal glass reactor and the products, separated by cold centrifugation, were purified and dried. The dried products were characterized for their molecular weight and solubility. Results indicated more than ten-fold decrease in the molecular weight of chitosan and the product exhibited water solubility. The CSA could be used upto four times, without regeneration, to give a consistent quality product. The aqueous solution of resulting LWCS exhibited a pH of 6.03±0.11, as against the acidic pH range of solutions of commercially available LWCS, indicating its suitability for biomedical applications. Our investigation facilitates a 'green approach' that may be employed for commercial production of value added chemicals from waste products of marine industry.

SiRNA-based therapies for pulmonary diseases.

Various delivery strategies, involving siRNA as a therapeutic tool for gene silencing, have been highlighted through several investigations all over the world. One such medical target, where the siRNA-based therapies have been immensely explored and have met with considerable success, is the area of pulmonary disorders. Lung diseases have presented themselves as attractive targets for studying siRNA-mediated cures due to their widespread persistence and lethality. Another interesting feature in this case is that the lung is accessible to therapeutic agents via multiple administration routes including the nasal, oral and intravenous routes. Recent advances in pulmonary delivery highlight the exploitation of all these routes for administration of siRNA-based therapies, particularly by employing non-viral carriers like nanoparticles. Through this manuscript we aim to provide a comprehensive overview of the most important and the latest developments in non-viral siRNA delivery for lung diseases. We have focused our discussion on the diverse systems, which have been investigated for a plethora of pulmonary disorders, ranging from inflammatory conditions like asthma and COPD, to infectious diseases like tuberculosis, and to lung cancer. An overview of the preclinical and clinical investigations conducted in this area has also been presented to the readers. While a variety of these systems have been found to be promising in pre-clinical studies, their successful transition as therapeutics will ultimately depend upon their clinical safety and efficacy, as well as the specificity of the carriers and methods employed for their administration.