Preparative Scale Research Articles

Access to 1,2,3-triphospholide ligands by reduction of di-tert-butyldiphosphatetrahedrane.

Di-tert-butyldiphosphatetrahedrane (tBuCP)2 (A) is a reactive tetrahedral molecule which may serve as a source of new phosphaorganic molecules and ligands. However, the redox chemistry of this compound has not yet been investigated. Here, we show that the reduction of A with alkali metals (AM = Li, Na, K, Rb and Cs) affords 1,2,3-triphospholides [AM(crown ether)][1,2,3-P3C2tBu2] (1-5, [AM(crown ether)] = [Li([12]crown-4)2]+, [Na([15]crown-5)2]+, [K([18]crown-6)]+, [Rb([18]crown-6)]+, and Cs+) with 1,3-diphospholides [AM(crown ether)][1,3-P2C3tBu3] (6-10) formed as by-products. The potassium salt 3 was isolated on a preparative scale, allowing for reactivity studies. Transmetalation with iron(II) and ruthenium(II) chlorides yielded the sandwich complexes [Cp*M(η5-1,2,3-P3C2tBu2)] (11, M = Fe; 12, M = Ru, Cp* = C5Me5) featuring η5-coordinated triphospholide ligands. Treatment of 3 with [Cp2Fe][BAr4F] or [H(Et2O)2BAr4F] (BAr4F = B{C6H3(CF3)2}4) afforded the polyphosphorus compound tBu4C4P6 (13), which presumably results from the dimerisation of a 1,2,3-triphospholyl radical intermediate (1,2,3-P3C2tBu2)˙ (3˙). Tetracyclic 13 is closely structurally related to an isomer of the hydrocarbon hypostrophene (C10H10).

Preparative scale Achmatowicz and aza-Achmatowicz rearrangements catalyzed by Agrocybe aegerita unspecific peroxygenase.

The unspecific peroxygenase (UPO) from Agrocybe aegerita (rAaeUPO-PaDa-I-H) is an effective and practical biocatalyst for the oxidative expansion of furfuryl alcohols/amines on a preparative scale, using the Achmatowicz and aza-Achmatowicz reaction. The high activity and stability of the enzyme, which can be produced on a large scale as an air-stable lyophilised powder, renders it a versatile and scalable biocatalyst for the preparation of synthetically valuable 6-hydroxypyranones and dihydropiperidinones. In several cases, the biotransformation out-performed the analogous chemo-catalysed process, and operates under milder and greener reaction conditions.

In silico modeling enables greener analytical and preparative chromatographic methods

Environmental impact of chromatographic separation at both analytical and preparative scale can be significantly reduced using In Silico Modeling.

Glycerol-derived organic carbonates: environmentally friendly plasticizers for PLA.

Polylactic acid (PLA) stands as a promising material, sourced from renewables and exhibiting biodegradability-albeit under stringent industrial composting settings. A primary challenge impeding PLA's broad applications is its inherent brittleness, as it fractures with minimal elongation despite its commendable tensile strength. A well-established remedy involves blending PLA with plasticizers. In this study, a range of organic carbonates-namely, 4-ethoxycarbonyloximethyl-[1,3]dioxolan-2-one (1), 4-methoxycarbonyloximethyl-[1,3]dioxolan-2-one (2), glycerol carbonate (3), and glycerol 1-acetate 2,3-carbonate (4)-were synthesized on a preparative scale (∼100 g), using renewable glycerol and CO2-derived diethyl carbonate (DEC) or dimethyl carbonate (DMC). Significantly, 1-4 exhibited biodegradability under ambient conditions within a week, ascertained through soil exposure at 25 °C-outpacing the degradation of comparative cellulose. Further investigations revealed 1's efficacy as a PLA plasticizer. Compatibility with PLA, up to 30 phr (parts per hundred resin), was verified using an array of techniques, including DSC, DMA, SEM, and rotational rheometry. The resulting blends showcased enhanced ductility, evident from tensile property measurements. Notably, the novel plasticizer 1 displayed an advantage over conventional acetyltributylcitrate (ATBC) in terms of morphological stability. Slow crystallization, observed in PLA/ATBC blends over time at room temperature, was absent in PLA/1 blends, preserving amorphous domain dimensions and mitigating plasticizer migration-confirmed through DMA assessments of aged and unaged specimens. Nevertheless, biodegradation assessments of the blends revealed that the biodegradable organic carbonate plasticizers did not augment PLA's biodegradation. The PLA in the blends remained mostly unchanged under ambient soil conditions of 25 °C over a 6 month period. This work underscores the potential of organic carbonates as both eco-friendly plasticizers for PLA and as biodegradable compounds, contributing to the development of environmentally conscious polymer systems.

Retirement Preparation (RP) scale index in Thailand: Development and validation

Retirement Preparation (RP) scale index in Thailand: Development and validation

Efikasnost superkritične fluidne hromatografije u kreiranju ekološki prihvatljivih rešenja u farmaceutskoj analizi

Initially employed primarily at a preparative scale for enantiomer separation of chiral drug candidates, Supercritical Fluid Chromatography (SFC) is nowadays extensively used in the analytical mode. Recent advances in SFC separation science have emphasized its potential for modern and environmentally friendly pharmaceutical analysis. The aim of this review is to provide a deeper insight into the main fundamental and practical aspects of the SFC technique in order to familiarize readers with its versatile nature and efficiency in creating sustainable chromatographic solutions. All considerations are made primarily in the context of the most widely used mode of operation - achiral SFC. In addition, recent applications of this promising technique are presented at the end of the article to further promote its use in pharmaceutical analytical practice.

Excellent Bowel Preparation Quality Is Not Superior to Good Bowel Preparation Quality for Improving Adenoma/Polyp Detection Rate

Background: Adequate bowel preparation quality is essential for high-quality colonoscopy according to the current guidelines. However, the effect of excellent bowel preparation on adenoma/polyp detection rate (ADR/PDR) remained controversial. Methods: During the period from December 2020 to August 2022, a total of 1566 consecutive patients underwent colonoscopy by an endoscopist. Their medical records were reviewed. According to the Boston bowel preparation scale, patients were divided into excellent, good, and poor bowel preparation quality groups. ADR/PDR, diminutive ADR/PDR, small ADR/PDR, intermediate ADR/PDR, large ADR/PDR, and number of adenomas/polyps were compared among them. Logistic regression analyses were performed to identify the factors that were significantly associated with ADR/PDR. Results: Overall, 1232 patients were included, of whom 463, 636, and 133 were assigned to the excellent, good, and poor groups, respectively. The good group had a significantly higher ADR/PDR (66% vs 55%, P = .015) and a larger number of adenomas/polyps (2.5 ± 3.2 vs 2.0 ± 2.8, P = .030) than the poor group. Both ADR/PDR (63% vs 55%, P = .097) and number of adenomas/polyps (2.2 ± 2.8 vs 2.0 ± 2.8, P = .219) were not significantly different between excellent and poor groups. The excellent (9% vs 4%, P = .045) and good (9% vs 4%, P = .040) groups had a significantly higher intermediate ADR/PDR than the poor group. Logistic regression analyses showed that either good (odds ratio [OR] = 1.786, 95% CI = 1.046-3.047, P = .034) or excellent (OR = 2.179, 95% CI = 1.241-3.826, P = .007) bowel preparation quality was independently associated with a higher ADR/PDR compared with poor bowel preparation quality. Excellent (OR = 1.202, 95% CI = 0.848-1.704, P = .302) bowel preparation quality was not independently associated with a higher ADR/PDR compared with good bowel preparation quality. Conclusions: The pursuit of excellence in bowel preparation does not show an association with increased ADR/PDR and number of adenomas/polyps compared with a good level. In addition, our study further contributes to the existing evidence that poor bowel preparation compromises ADR/PDR and number of adenomas/polyps.

Effectiveness and safety of a 1L polyethylene glycol and ascorbic acid preparation for colonoscopy in routine clinical practice in Spain.

Large clinical trials and small real-world studies show that a 1L polyethylene glycol and ascorbic acid solution (1L PEG-ASC) is an effective and safe bowel preparation for colonoscopy. Here, the effectiveness and safety of 1L PEG-ASC was evaluated in a large cohort of patients in routine clinical practice in Spain. A sub-analysis was performed in an observational, multicenter, retrospective study assessing the effectiveness and safety of 1L PEG-ASC in adult patients undergoing a colonoscopy at 10 centers in Spain. Cleansing quality was assessed with the Boston Bowel Preparation Scale, scores ≥6 with all segmental scores ≥2 was considered adequate colon cleansing, high-quality was considered as cleansing ≥8 or =3 in the right colon. Polyp and adenoma detection rates, and adverse events were also assessed. Data was collected from 7160 patients: 48.3% males; mean age 58.0, 33.6% ≥65 years old. Adequate overall bowel cleansing was achieved in 95.6% of patients (95% CI 95.1%-96.0%), high quality cleansing in 74.4% (95% CI 73.4%-75.4%) and high-quality right colon cleansing in 66.0% (95% CI 64.9-67.1). The adequate overall cleansing rate was 97.0% with a split-dose and 94.0% with same-day regimen (P<0.0001), and high-quality right colon cleansing was 69.0% and 62.5% (P<0.0001), respectively. Colonoscopy was completed in 97.2% of cases. A multivariate regression analysis revealed that an overnight split-dose regimen and age <65 years were independent predictors of adequate bowel cleansing of the overall colon, age <65 years and female gender were independent predictors of HQ cleansing of the overall colon, and the three covariates were independent predictors of HQ cleansing of the right colon. At least one adverse event was experienced by 3.3% of participants, with nausea (1.5%) and vomiting (1.2%) being the most frequent. This sub-analysis confirmed 1L PEG-ASC to be an effective and safe bowel cleansing preparation in a real world setting in Spain.

Chromatographic separation of itaconic anhydride recycling products with 5-amino-1-phenylpyrazoles

An important role in the creation of the entire variety of modern physiologically active compounds is played by the synthesis of complexly constructed poly–substituted molecules – analogues of natural substances. Effective design methods involve a significant increase in molecular complexity with a minimum number of stages. However, such an approach often involves complex processes involving multifunctional reagents, which, ultimately, can lead to difficult-to-separate mixtures of the target compound and a number of by-products, both undesirable and promising. This problem remains very significant in the design of various polyazaheterosystems, including those with a pyrazolopyridine skeleton, which is one of the most common fragments in the structures of natural and synthetic biologically active compounds. Therefore, an urgent task is to develop effective methods for the separation of such mixtures and purification of target compounds. Currently, column chromatography is used to solve it, which is one of the most important methods for separating liquid or solid mixtures of organic substances on a preparative scale. In this paper, the reactions of itacone anhydride with substituted 5-amino-1-phenylpyrazoles are investigated, a chromatographic method for separating alternative interaction products and their identification is proposed.

Design and validation of an artificial intelligence system to detect the quality of colon cleansing before colonoscopy

Background and aimsPatients’ perception of their bowel cleansing quality may guide rescue cleansing strategies before colonoscopy. The main aim of this study was to train and validate a convolutional neural network (CNN) for classifying rectal effluent during bowel preparation intake as “adequate” or “inadequate” cleansing before colonoscopy. Patients and methodsPatients referred for outpatient colonoscopy were asked to provide images of their rectal effluent during the bowel preparation process. The images were categorized as adequate or inadequate cleansing based on a predefined 4-picture quality scale. A total of 1203 images were collected from 660 patients. The initial dataset (799 images), was split into a training set (80%) and a validation set (20%). The second dataset (404 images) was used to develop a second test of the CNN accuracy. Afterward, CNN prediction was prospectively compared with the Boston Bowel Preparation Scale (BBPS) in 200 additional patients who provided a picture of their last rectal effluent. ResultsOn the initial dataset, a global accuracy of 97.49%, a sensitivity of 98.17% and a specificity of 96.66% were obtained using the CNN model. On the second dataset, an accuracy of 95%, a sensitivity of 99.60% and a specificity of 87.41% were obtained. The results from the CNN model were significantly associated with those from the BBPS (P<0.001), and 77.78% of the patients with poor bowel preparation were correctly classified. ConclusionThe designed CNN is capable of classifying “adequate cleansing” and “inadequate cleansing” images with high accuracy.

Enzymatische Peptid‐ und Proteinbromierung: Der BromoTrp Tag

AbstractBioorthogonale Reaktionen von Proteinen und ungeschützten Peptiden sind von hohem Wert für die chemische Biologie. Die Kombination aus enzymatischer Halogenierung und übergangsmetallkatalysierter Kreuzkupplung bietet einen praktikablen Ansatz zur Modifizierung von Proteinen und ungeschützten Peptiden. Durch semirationales Protein Engineering, wurden Varianten der Tryptophan 6‐Halogenase Thal identifiziert, welche die Bromierung von Peptiden mit einem C‐terminalen Tryptophanrest ermöglichen. Das Substratspektrum wurde anhand von Di‐, Tri‐ und Tetrapeptid‐Bibliotheken charakterisiert, und ein optimierter Peptid‐Tag identifiziert, dem wir den Namen BromoTrp‐Tag gegeben haben. Dieser Tag wurde in drei Modellproteine eingeführt. Deren präparative, posttranslationale Bromierung mit nur einem Kultivierungs‐ und Aufreinigungsschritt wurde durch das bromierende E. coli Koexpressionssystem Brocoli ermöglicht. Pd‐katalysierte Suzuki–Miyaura Kreuzkupplung war mittels Pd‐Nanopartikeln als Katalysator bei 37 °C möglich, was das vielversprechende Potential dieser Strategie zum Zweck bioorthogonaler Funktionalisierung und Konjugation demonstriert.

Access to carbonyl compounds via the electroreduction of N-benzyloxyphthalimides: Mechanism confirmation and preparative applications

A method to access carbonyl compounds using reductive conditions was evaluated via electrochemical reduction of their corresponding N-benzyloxyphthalimide derivatives (NBOPIs). The mechanism of this originally reported electrochemical reaction was proposed based on DFT calculation and is experimentally confirmed herein, contrasting simulated and experimental cyclic voltammetry data. The reaction scope studied in a preparative scale and using redox sensitive functional groups showed good selectivity and tolerance toward oxidation under the reaction conditions with a moderate to good yield (50–71%). Nevertheless, some restrictions with reducible functional groups, like benzyl-brominated and nitro-aromatic derivatives, were observed. The present approach can be considered a self-sustainable electrochemical catalysis for the synthesis of aromatic carbonylic compounds passing through anion radical intermediates produced by a cathodic reaction.

Enzymatic Peptide and Protein Bromination: The BromoTrp Tag.

Bio-orthogonal reactions for modification of proteins and unprotected peptides are of high value in chemical biology. The combination of enzymatic halogenation with transition metal-catalyzed cross-coupling provides a feasible approach for the modification of proteins and unprotected peptides. By a semirational protein engineering approach, variants of the tryptophan 6-halogenase Thal were identified that enable efficient bromination of peptides with a C-terminal tryptophan residue. The substrate scope was explored using di-, tri-, and tetrapeptide arrays, leading to the identification of an optimized peptide tag we named BromoTrp tag. This tag was introduced into three model proteins. Preparative scale post-translational bromination was possible with only a single cultivation and purification step using the brominating E. coli coexpression system Brocoli. Palladium-catalyzed Suzuki-Miyaura cross-coupling of the bromoarene was achieved with Pd nanoparticle catalysts at 37 °C, highlighting the rich potential of this strategy for bio-orthogonal functionalization and conjugation.

Effectiveness and safety of Shankhaprakshalana-a yogic technique-in bowel preparation for colonoscopy: A retrospective study.

Shankhaprakshalana (SP) is a yogic method aiming to cleanse the bowel. It involves the use of warm saline water and a combination of five asanas. This study was designed to assess the effectiveness and safety of bowel preparation by SP. This is a retrospective observational study of prospectively collected data. Patients planned for colonoscopy were screened and enrolled to undergo bowel preparation by SP on the day of the colonoscopy. Patients having comorbid conditions, poor performance status, suspected or previously diagnosed intestinal stricture and past history of major abdominal surgery and those unable to perform asanas of SP were excluded. A low-fiber diet was advised for one day before the colonoscopy. Patients were advised to drink 400mL of lukewarm saline water followed by five asanas (exercises) of SP, each done eight times dynamically and sequentially. After completing six such cycles, patients underwent colonoscopy. Boston Bowel Preparation Scale (BBPS) score was used to assess the quality of bowel preparation. Total 238 patients were included. The major indications for colonoscopy were abdominal pain (35.3%), hematochezia (23.9%), diarrhea (20.2%), constipation (10.9%) and anemia (9.7%). The mean age was 37.7 (± 12) years. The mean BBPS was 8 (± 1.2). Bowel preparation was inadequate (BBPS < 6) in only two patients. Mean segmental BBPS for the three segments of the colon (right, transverse and left) was 2.6 (± 0.5), 2.7 (± 0.4) and 2.6 (± 0.7), respectively. Minor adverse events (nausea, abdominal pain, vomiting, giddiness and bloating) were noted in 10 participants (4.2%), which did not require hospitalization. Bowel preparation was completed in 133 (± 35) minutes. Shankhaprakshalana is an effective and safe method to achieve adequate bowel preparation before colonoscopy. Since this is a single-center and retrospective study, future multi-centric, prospective studies comparing it with the standard bowel preparation regimens are warranted.

Development and validation of a three-dimensional deep learning-based system for assessing bowel preparation on colonoscopy video.

The performance of existing image-based training models in evaluating bowel preparation on colonoscopy videos was relatively low, and only a few models used external data to prove their generalization. Therefore, this study attempted to develop a more precise and stable AI system for assessing bowel preparation of colonoscopy video. We proposed a system named ViENDO to assess the bowel preparation quality, including two CNNs. First, Information-Net was used to identify and filter out colonoscopy video frames unsuitable for Boston bowel preparation scale (BBPS) scoring. Second, BBPS-Net was trained and tested with 5,566 suitable short video clips through three-dimensional (3D) convolutional neural network (CNN) technology to detect BBPS-based insufficient bowel preparation. Then, ViENDO was applied to complete withdrawal colonoscopy videos from multiple centers to predict BBPS segment scores in clinical settings. We also conducted a human-machine contest to compare its performance with endoscopists. In video clips, BBPS-Net for determining inadequate bowel preparation generated an area under the curve of up to 0.98 and accuracy of 95.2%. When applied to full-length withdrawal colonoscopy videos, ViENDO assessed bowel cleanliness with an accuracy of 93.8% in the internal test set and 91.7% in the external dataset. The human-machine contest demonstrated that the accuracy of ViENDO was slightly superior compared to most endoscopists, though no statistical significance was found. The 3D-CNN-based AI model showed good performance in evaluating full-length bowel preparation on colonoscopy video. It has the potential as a substitute for endoscopists to provide BBPS-based assessments during daily clinical practice.

Application of the C3-Methyltransferase StspM1 for the Synthesis of the Natural Pyrroloindole Motif.

Even though pyrroloindoles are widely present in natural products with different kinds of biological activities, their selective synthesis remains challenging with existing tools in organic chemistry, and there is furthermore a demand for stereoselective and mild methods to access this structural motif. Nature uses C3-methyltransferases to form the pyrroloindole framework, starting from the amino acid tryptophan. In the present study, the SAM-dependent methyltransferase StspM1 from Streptomyces sp. HPH0547 is used to build the pyrroloindole structural motif in tryptophan-based diketopiperazines (DKP). The substrate scope of the enzyme regarding different Trp-Trp-DKP isomers was investigated on an experimental and computational level. After further characterization and optimization of the methylation reaction with a design of experiment approach, a preparative scale reaction with the immobilized enzyme including a SAM regeneration system was performed to show the synthetic use of this biocatalytic tool to access the pyrroloindole structural motif.

Electroreductive Synthesis of Nickel(0) Complexes**

AbstractOver the last fifty years, the use of nickel catalysts for facilitating organic transformations has skyrocketed. Nickel(0) sources act as useful precatalysts because they can enter a catalytic cycle through ligand exchange, without needing to undergo additional elementary steps. However, most Ni(0) precatalysts are synthesized with stoichiometric aluminum–hydride reductants, pyrophoric reagents that are not atom‐economical and must be used at cryogenic temperatures. Here, we demonstrate that Ni(II) salts can be reduced on preparative scale using electrolysis to yield a variety of Ni(0) and Ni(II) complexes that are widely used as precatalysts in organic synthesis, including bis(1,5‐cyclooctadiene)nickel(0) [Ni(COD)2]. This method overcomes the reproducibility issues of previously reported methods by standardizing the procedure, such that it can be performed anywhere in a robust manner. It can be transitioned to large scale through an electrochemical recirculating flow process and extended to an in situ reduction protocol to generate catalytic amounts of Ni(0) for organic transformations. We anticipate that this work will accelerate adoption of preparative electrochemistry for the synthesis of low‐valent organometallic complexes in academia and industry.

Electroreductive Synthesis of Nickel(0) Complexes.

Over the last fifty years, the use of nickel catalysts for facilitating organic transformations has skyrocketed. Nickel(0) sources act as useful precatalysts because they can enter a catalytic cycle through ligand exchange, without needing to undergo additional elementary steps. However, most Ni(0) precatalysts are synthesized with stoichiometric aluminum-hydride reductants, pyrophoric reagents that are not atom-economical and must be used at cryogenic temperatures. Here, we demonstrate that Ni(II) salts can be reduced on preparative scale using electrolysis to yield a variety of Ni(0) and Ni(II) complexes that are widely used as precatalysts in organic synthesis, including bis(1,5-cyclooctadiene)nickel(0) [Ni(COD)2 ]. This method overcomes the reproducibility issues of previously reported methods by standardizing the procedure, such that it can be performed anywhere in a robust manner. It can be transitioned to large scale through an electrochemical recirculating flow process and extended to an in situ reduction protocol to generate catalytic amounts of Ni(0) for organic transformations. We anticipate that this work will accelerate adoption of preparative electrochemistry for the synthesis of low-valent organometallic complexes in academia and industry.

Stereoselective Construction of β-, γ-, and δ-Lactam Rings via Enzymatic C-H Amidation.

Lactam rings are found in many biologically active natural products and pharmaceuticals, including important classes of antibiotics. Methods for the asymmetric synthesis of these molecules are therefore highly desirable, particularly through the selective functionalization of unreactive aliphatic C-H bonds. Here we show the development of a strategy for the asymmetric synthesis of β-, γ-, and δ-lactams via hemoprotein-catalysed intramolecular C-H amidation reaction with readily available dioxazolone reagents. Engineered myoglobin variants serve as excellent biocatalysts for this transformation yielding the desired lactam products in high yields, high enantioselectivity, and on preparative scale. Mechanistic and computational studies elucidate the nature of the C-H amination and enantiodetermining steps and provide insights into protein-mediated control of regioselectivity and stereoselectivity. Additionally, an alkaloid natural product and a drug molecule were synthesized chemoenzymatically in much fewer steps (7-8 vs. 11-12) than previously reported, further demonstrating the power of biosynthetic strategy for the preparation of complex bioactive molecules.

3 L split-dose polyethylene glycol is superior to 2 L polyethylene glycol in colonoscopic bowel preparation in relatively high-BMI (≥ 24 kg/m2) individuals: a multicenter randomized controlled trial

BackgroundWhether body mass index (BMI) is a risk factor for poor bowel preparation is controversial, and the optimal bowel preparation regimen for people with a high BMI is unclear.MethodsWe prospectively included 710 individuals with high BMIs (≥ 24 kg/m2) who were scheduled to undergo colonoscopy from January to November 2021 at 7 hospitals. Participants were randomly allocated into 3 L split-dose polyethylene glycol (PEG) group (n=353) and 2 L PEG group (n=357). The primary outcome was the rate of adequate bowel preparation, and the secondary outcomes included Boston Bowel Preparation Scale (BBPS) score, polyp detection rate, cecal intubation rate, and adverse reactions during bowel preparation. Furthermore, we did exploratory subgroup analyses for adequate bowel preparation.ResultsAfter enrollment, 15 individuals didn’t undergo colonoscopy, finally 345 participants took 3 L split-dose PEG regimen, and 350 participants took 2 L PEG regimen for colonoscopic bowel preparation. 3 L split-dose PEG regimen was superior to 2 L PEG regimen in the rate of adequate bowel preparation (81.2% vs. 74.9%, P = 0.045), BBPS score (6.71±1.15 vs. 6.37±1.31, P < 0.001), and the rate of polyp detection (62.0% vs. 52.9%, P = 0.015). The cecal intubation rate was similar in both groups (99.7%). Regarding adverse reactions, individuals were more likely to feel nausea in the 3 L PEG group (30.9% vs. 19.3%; P = 0.001); however, the degree was mild. In the subgroup analysis for adequate bowel preparation, 3 L split-dose PEG regimen performed better than 2 L PEG regimen in the overweight (BMI 25-29.9 kg/m2 ) (P = 0.006) and individuals with constipation (P = 0.044), while no significant differences were observed in relatively normal (BMI 24-24.9 kg/m2) (P = 0.593) and obese individuals (BMI ≥ 30 kg/m2) (P = 0.715).Conclusions3 L split-dose PEG regimen is superior to 2 L PEG regimen for colonoscopic Bowel Preparation in relatively high-BMI individuals, especially overweight individuals (BMI 25-29.9 kg/m2 ).Trial RegistrationThis trial was registered in the Chinese Clinical Trials Registry (ChiCTR2000039068). The date of first registration, 15/10/2020, http://www.chictr.org.cn