Correction: Professor (Dr) Sukh Dev: an iconic scientist with an innate sixth sense who radicalized natural product synthesis & organic chemistry.

Correction for 'Professor (Dr) Sukh Dev: an iconic scientist with an innate sixth sense who radicalized natural product synthesis & organic chemistry' by Harry Kochat et al., Org. Biomol. Chem., 2024, 22, 5466-5469, https://doi.org/10.1039/D4OB90071E.

Architectural analysis of root system and phytohormone biosynthetic genes expression in wheat (Triticum aestivum L.) inoculated with Penicillium oxalicum.

In this study, a fungal plant growth promoter Penicillium oxalicum T4 isolated from non-rhizosphere soil of Arunachal Pradesh, India, was screened for different plant growth promoting traits in a gnotobiotic study. Though inoculation improved the overall growth of the plants, critical differences were observed in root architecture. Confocal Laser Scanning Microscope, Scanning electron microscope and the stereo microscopic study showed that inoculated wheat plants could develop profuse root hairs as compared to control. Root scanning indicated improvement in cumulative root length, root area, root volume, number of forks, links, crossings, and other parameters. A confocal scanning laser microscope indicated signs of endophytic colonization in wheat roots. Gene expression studies revealed that inoculation of T4 modulated the genes affecting root hair development. Significant differences were marked in the expression levels of TaRSL4, TaEXPB1, TaEXPB23, PIN-FORMED protein, kaurene oxidase, lipoxygenase, ACC synthase, ACC oxidase, 9-cis-epoxycarotenoid dioxygenase, and ABA 8'-hydroxylase genes. These genes contribute to early plant development and ultimately to biomass accumulation and yield. The results suggested that P. oxalicum T4 has potential for growth promotion in wheat and perhaps also in other cereals.

Prevalence of Hepatitis B and C among HIV Infected Patients in Nepal over 1990-2020.

Background Hepatitis B and C (HBV and HCV) are viral infections caused by corresponding viruses. Here in this study we planned to conduct this meta-analysis to pool data on the prevalence and risk factors of HBV and/or HCV among HIV patients in Nepal. Method We used MOOSE guideline for the systemic review of available literature. We searched online databases using appropriate keywords. We used CMA-3 for data synthesis. Odds ratio, and proportion were used to estimate the outcome with a 95% confidence interval where appropriate. We assessed the heterogeneity using the I-squared (I2 ) test. Result We included nine studies for our synthesis. Pooling of data showed HBV in 4.6% (CI: 3.7-5.6), HCV in 19.7% (CI: 10.8-33.0), both HBV and HCV in 1.3% (CI: 0.5-3.7) in HIV affected individuals. Among HBV co-infected HIV positive patients, 59.5% (CI: 25.5-86.3) were male; 76.1% (CI: 30.1-96.0) were married and 43.6% (CI: 3.8-93.8) had a history of intravenous drug use (IVDU). Among HCV co-infected HIV positive individuals 88.3% (CI: 73.6-95.4) were male; 63.6% (CI: 55.4-71.1) were married; 91.5% (CI: 68.6-98.1) were literate; 59.2% (CI: 49.9-67.9) were on ART; and 92.2% (95%CI: 84.9-96.1) had a history of IVDU. Conclusion The pooled prevalence of co-infection with HBV, HCV, and combined HBV and HCV were 4.6%, 19.7% and 1.3% respectively among HIV positive patients. Thus, it is necessary to appropriately screen for HBV and HCV in individuals diagnosed with HIV and high-risk populations. IVDU remains the most common risk factor found in co-infected individuals.

MEALTIME BOLUS INSULIN DOSE TIMING IN CHILDREN WITH TYPE 1 DIABETES: REAL-LIFE DATA FROM A TERTIARY CARE CENTRE IN NORTHERN INDIA.

Context: Mealtime insulin bolus is traditionally administered before meals in children with type 1 diabetes (T1D). Controlled studies on the use of pre-and postprandial insulin bolus have shown variable results. There are no real-world studies on postprandial bolusing of insulin in young children with T1D. Methods: Children with T1D aged <7 years were grouped into preprandial (Group 1) or postprandial (Group 2) groups according to the practice of prandial insulin use. Their retrospective data on mean glycosylated hemoglobin (HbA1c), hypoglycemic events, and diabetic ketoacidosis (DKA) episodes were compared. Results: Forty-four children (mean age 4.1±1.3 years, range 2-7 years) with mean diabetes duration of 2.0±0.7 years (range, 1-4 years) were identified; 23 (52.3%) belonged to Group 1 and 21 (47.7%) to Group 2. There were no differences in the mean HbA1c levels, mean hypoglycemic events, and DKA episodes between the two groups during a mean follow-up duration of two years. Conclusion: Young children with T1D administered insulin bolus during or immediately after meals showed similar long-term glycemic control and diabetes-related adverse event profile compared to the premeal timing of insulin bolus. Larger real-world studies are needed on flexible insulin bolus timing in young children with T1D.

Synthesis and biological evaluation of 1-amino isochromans from 2-bromoethyl benzaldehyde and amines in acid medium.

We have developed a facile and efficient synthetic route to substituted isochromans for the first time by reacting 2-(2-bromoethyl)benzaldehyde with a variety of aryl, heteroaryl amines in AcOH. The reaction is catalyst/additive free and takes place at reflux conditions with short reaction time to furnish products in good to excellent yields. All the compounds have been characterized by spectral techniques such as IR, 1H NMR and Mass etc. Synthesized compounds were evaluated for antimicrobial activity against specific bacterial like 1) Staphylococcus strains aureus 2) Bacillus subtilis 3) Escherichia coli 4) Pseudomonas aeruginosa. Compounds 3e, 3n, 3 m, 3 l, 3 k, 3j and 3b showed most potent in vitro activity against bacterial strains.

Silver(i)-catalyzed sequential hydroamination and Prins type cyclization for the synthesis of fused benzo-δ-sultams.

An intramolecular annulation strategy has been developed for the synthesis of tetrahydrobenzo[e]pyrano[4,3-c][1,2]thiazine derivatives by means of coupling of aldehydes with 2-(4-hydroxybut-1-yn-1-yl)-N-arylsulfonamides using a catalytic amount of silver hexafluoroantimonate in toluene at 80 °C. This is the first report on the synthesis of fused benzo-δ-sultam derivatives through C-N, C-O, and C-C bond formations. The reaction proceeds through a cascade of hydroamination and Prins type cyclization.

Substitution dependent stereoselective construction of bicyclic lactones and its application to the total synthesis of pyranopyran, tetraketide and polyrhacitide A.

A novel bicyclization strategy has been developed for the stereoselective synthesis of bicyclic lactones, i.e. 7-aryl or alkyl-2,6-dioxabicyclo[3.3.1]nonan-3-ones through a domino cyclization of (R)-3-hydroxyhex-5-enoic acid with an aldehyde in the presence of 10 mol% trimethylsilyltriflate under mild conditions. The salient features of this methodology are high yields, excellent selectivity, low catalyst loading and faster reaction times. This method has been successfully applied to the total synthesis of pyranopyran, tetraketide and polyrhacitide A.

Cooperative Multicatalytic System for the One-Pot Synthesis of Octahydrospiro-ß-carbolines.

A domino cyclization of 3-((3-(2-aminophenyl)prop-2-ynylamino)methyl)but-3-en-1-ol with aldehydes has been accomplished employing 5 mol % of the Ph3PAuCl/AgSbF6/In(OTf)3 system to afford the corresponding octahydrospiro[pyran-4,4'-pyrido[3,4-b]indole] derivatives in good yields with high selectivity. This is the first report on the synthesis of spiro-ß-carbolines through a multicatalytic cascade process.

Tandem Prins/Wagner/Ritter process for the stereoselective synthesis of (3-oxabicyclo[4.2.0]octanyl)amide and (1-(5-aryltetrahydrofuran-3-yl)cyclobutyl)amide derivatives.

Three-component coupling of aldehydes, vinylcyclopropyl carbinols, and nitriles in the presence of 10 mol% TMSOTf at -40 to 0 °C in dichloromethane affords a novel class of (3-oxabicyclo[4.2.0]octanyl)amides in high yields with excellent selectivity, whereas (1-vinylcyclobutyl)methanol provides the corresponding (1-(5-aryltetrahydrofuran-3-yl)cyclobutyl)amides under similar conditions. This is the first report on the synthesis of oxabicycles through a sequential Prins/Wagner/Ritter process.

Synthesis and determination of absolute configuration of α-pyrones isolated from Penicillium corylophilum.

The first total synthesis of (S)-6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one, 4-hydroxy-3-methyl-6-((2S,4R)-2,4,11-trihydroxyundecyl)-2H-pyran-2-one, and its unnatural 2R,4R-isomer starting from commercially available 1,8-octanediol is described. The synthesis led to the revision of the proposed structural assignment of the natural product as (R)-6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one. The key steps include chiral auxiliary mediated asymmetric acetate aldol reaction, dianion addition, and base mediated cyclization to form an α-pyrone ring.

Tuning the reactivity of oxygen/sulfur by acidity of the catalyst in Prins cyclization: oxa- versus thia-selectivity.

An unprecedented oxa- versus thia-selectivity has been observed in Prins cyclization of 6-mercaptohex-3-en-1-ol with aldehydes. In the presence of a stoichiometric amount of strong Lewis or Brønsted acids, the reaction provides the hexahydro-2H-thieno[3,2-c]pyran skeleton predominantly via oxonium-Prins cyclization. In contrast, a catalytic amount of weak Lewis or Brønsted acids provides the hexahydro-2H-thiopyrano[4,3-b]furan preferentially through thionium-Prins cyclization.

Thee-component, one-pot synthesis of hexahydroazepino[3,4-b]indole and tetrahydro-1H-pyrido[3,4-b]indole derivatives and evaluation of their cytotoxicity.

A three-component, four-center Ugi reaction has been developed to produce a novel class of 2-aryl-3-oxo-hexahydroazepino[3,4-b]indole and 2-aryl-3-oxo-tetrahydro-1H-pyrido[3,4-b]indole derivatives in good to high yields. A few of them exhibit moderate cytotoxicity against various cancer cell lines such as HeLa (human epithelial cervical cancer), A549 (human lung carcinoma epithelial), DU145 (human prostate carcinoma epithelial) and MCF-7 (human breast adenocarcinoma).

The protecting-group directed diastereoselective Nozaki-Hiyama-Kishi (NHK) reaction: total synthesis and biological evaluation of zeaenol, 7-epi-zeaenol and its analogues.

The stereoselective total synthesis of zeaenol and 7-epi-zeaenol is achieved in a convergent manner using Julia-Kocienski olefination, protecting group-directed intermolecular diastereoselective Nozaki-Hiyama-Kishi (NHK) reaction, De Brabander's lactonization reaction and CBS reduction as the key steps. In this article, we have observed the most suitable protecting groups with respect to selectivity during the protecting group directed intermolecular asymmetric Nozaki-Hiyama-Kishi reaction. The zeaenol, 7-epi-zeaenol and its derivatives were analyzed for their biological activity and screened in four cancer cell lines.

Simultaneous single-cell protein production and COD removal with characterization of residual protein and intermediate metabolites during whey fermentation by K. marxianus.

Cheese whey fermentation with Kluyveromyces marxianus was carried out at 40 °C and pH 3.5 to examine simultaneous single-cell protein production and chemical oxygen demand (COD) removal, determine the fate of soluble whey protein and characterize intermediate metabolites. After 36 h of batch fermentation, the biomass concentration increased from 2.0 to 6.0 g/L with 55 % COD reduction (including protein), whereas soluble whey protein concentration decreased from 5.6 to 4.1 g/L. It was confirmed through electrophoresis (SDS-PAGE) that the fermented whey protein was different from native whey protein. HPLC and GC-MS analysis revealed a change in composition of organic compounds post-fermentation. High inoculum concentration in batch fermentation resulted in an increase in biomass concentration from 10.3 to 15.9 g/L with 80 % COD reduction (including protein) within 36 h with residual protein concentration of 4.5 g/L. In third batch fermentation, the biomass concentration increased from 7.3 to 12.4 g/L with 71 % of COD removal and residual protein concentration of 4.3 g/L after 22 h. After 22 h, the batch process was shifted to a continuous process with cell recycle, and the steady state was achieved after another 60 h with biomass yield of 0.19 g biomass/g lactose and productivity of 0.26 g/L h. COD removal efficiency was 78-79 % with residual protein concentration of 3.8-4.2 g/L. The aerobic continuous fermentation process with cell recycle could be applied to single-cell protein production with substantial COD removal at low pH and high temperature from cheese whey.

Recovery of residual soluble protein by two-step precipitation process with concomitant COD reduction from the yeast-cultivated cheese whey.

The present study was conducted to recover the residual soluble protein after cultivation of yeast (K. marxianus) in cheese whey. Cheese whey continuous fermentation with cell recycle system was carried out at 40 °C and pH 3.5. The yeast biomass was separated from the fermented broth by centrifugation and residual soluble protein from fermented whey supernatant was precipitated by heat treatment (at 100 °C, pH 4.5 and 10 min incubation). The maximum soluble protein recovery up to 53 % was achieved at pH 4.5 with 54 % residual COD removal. However, gravity sedimentable precipitates were obtained at pH 3.5 with 47 % protein recovery. Therefore, the reactor (scale up) study was conducted at pH 3.5 with agitation, which resulted in 68 % of residual soluble protein recovery and simultaneously residual COD removal of 62 %. Further precipitation/coagulation of soluble protein was also evaluated using carboxymethylcellulose (CMC) and then two precipitation (thermal followed by CMC precipitation) processes were combined to increase the protein precipitation, which finally reached up to 81 % of total soluble protein recovery from the supernatant. This optimized process could be applied to recover the residual protein left after fermentation of cheese whey without centrifugation.

Extracellular polymeric substances of bacteria and their potential environmental applications.

Biopolymers are considered a potential alternative to conventional chemical polymers because of their ease of biodegradability, high efficiency, non-toxicity and non-secondary pollution. Recently, extracellular polymeric substances (EPS, biopolymers produced by the microorganisms) have been recognised by many researchers as a potential flocculent for their applications in various water, wastewater and sludge treatment processes. In this context, literature information on EPS is widely dispersed and is very scarce. Thus, this review marginalizes various studies conducted so far about EPS nature-production-recovery, properties, environmental applications and moreover, critically examines future research needs and advanced application prospective of the EPS. One of the most important aspect of chemical composition and structural details of different moieties of EPS in terms of carbohydrates, proteins, extracellular DNA, lipid and surfactants and humic substances are described. These chemical characteristics of EPS in relation to formation and properties of microbial aggregates as well as degradation of EPS in the matrix (biomass, flocs etc) are analyzed. The important engineering properties (based on structural characteristics) such as adsorption, biodegradability, hydrophilicity/hydrophobicity of EPS matrix are also discussed in details. Different aspects of EPS production process such as bacterial strain maintenance; inoculum and factors affecting EPS production were presented. The important factors affecting EPS production include growth phase, carbon and nitrogen sources and their ratio, role of other nutrients (phosphorus, micronutrients/trace elements, and vitamins), impact of pH, temperature, metals, aerobic versus anaerobic conditions and pure and mixed culture. The production of EPS in high concentration with high productivity is essential due to economic reasons. Therefore, the knowledge about all the aspects of EPS production (listed above) is highly essential to formulate a logical and scientific basis for the research and industrial activities. One of the very important issues in the production/application/biodegradation of EPS is how the EPS is extracted from the matrix or a culture broth. Moreover, EPS matrix available in different forms (crude, loosely bound, tightly bound, slime, capsular and purified) can be used as a bioflocculant material. Several chemical and physical methods for the extraction of EPS (crude form or purified form) from different sources have been analyzed and reported. There is ample information available in the literature about various EPS extraction methods. Flocculability, dewaterability and biosorption ability are the very attractive engineering properties of the EPS matrix. Recent information on important aspects of these properties qualitatively as well as quantitatively has been described. Recent information on the mechanism of flocculation mediated by EPS is presented. Potential role of EPS in sludge dewatering and biosorption phenomenon has been discussed in details. Different factors influencing the EPS ability to flocculate and dewaterability of different suspensions have been included. The factors considered for the discussion are cations, different forms of EPS, concentration of EPS, protein and carbohydrate content of EPS, molecular weight of EPS, pH of the suspension, temperature etc. These factors were selected for the study based upon their role in the flocculation and dewatering mechanism as well the most recent available literature findings on these factors. For example, only recently it has been demonstrated that there is an optimum EPS concentration for sludge flocculation/dewatering. High or low concentration of EPS can lead to destabilization of flocs. Role of EPS in environmental applications such as water treatment, wastewater flocculation and settling, colour removal from wastewater, sludge dewatering, metal removal and recovery, removal of toxic organic compounds, landfill leachate treatment, soil remediation and reclamation has been presented based on the most recent available information. However, data available on environmental application of EPS are very limited. Investigations are required for exploring the potential of field applications of EPS. Finally, the limitations in the knowledge gap are outlined and the research needs as well as future perspectives are highlighted.

Thia-prins bicyclization approach for the stereoselective synthesis of dithia- and azathia-bicycles.

A novel thia-Prins bicyclization approach has been developed for the first time for the synthesis of hexahydro-2H-thieno[3,2-c]thiopyran derivatives from the coupling of homoallylic mercaptans such as hex-3-ene-1,6-dithiol with various aldehydes using 10 mol % InBr3 in dichloromethane with high selectivity. In addition, the coupling of (E)-N-(6-mercaptohex-3-enyl)-4-methylbenzenesulfonamide with aldedydes affords the corresponding N-tosyloctahydrothiopyrano[4,3-b]pyrrole derivatives in good yields. This reaction is a stereoselective affording trans-fused product from E-homoallyllic mercaptan and cis-fused product from Z-homoallyllic mercaptan.

Synthesis of the C1-C25 southern domain of spirastrellolides B and F.

Synthesis of the C1-C25 ABC spiroketal ring system of spirastrellolides B and F has been executed. The synthetic strategy relied on radical cyclization, HWE olefination, (BDP)CuH conjugate reduction and spiro acetalization reactions.

Bismuth(III) salts as synthetic tools in organic transformations.

Bismuth is the heaviest stable element of the periodic table and even though it carries the status of heavy metal, it is rated as relatively nontoxic and noncarcinogenic unlike its neighboring elements. Additionally, the fact that it tolerates air and moisture makes the chemistry of bismuth attractive to synthetic chemists. The catalytic nature of this metal is attributed to the capability of its salts to acts as Lewis acids in reactions. The nontoxicity together with the ability to endure moisture makes bismuth compounds favorites of chemists and scientists who are concerned about environmental hazards, and such properties are highly desirable for scale-up of a method. The Lewis acidic nature of salts of this element have been thoroughly investigated in various types of reactions such as cycloaddition reactions, reactions of sugars, protection and deprotection reactions, synthesis of heterocyclic systems etc. Since the 1990s, various research groups have successfully utilized this catalytic nature for many organic transformations. Our group's contribution towards the development of methodologies that are useful in accomplishing various functional group manipulations by making use of the catalytic properties of bismuth salts is portrayed here. The mechanistic aspects and the catalytic efficiency of the bismuth(III) salts are accented together with the synthetic utility and the biological and pharmacological applications of the methodologies developed.