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1.
Org Lett ; 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33792337

RESUMO

The vicinal diamine motif plays a significant role in natural products, drug design, and organic synthesis, and development of synthetic methods for the synthesis of diamines is a long-standing interest. Herein, we report a regioselective intermolecular three-component vicinal diamination of styrenes with acetonitrile and azodicarboxylates. The diamination products can be produced in moderate to excellent yields via the Ritter reaction. Synthetic applications and theoretical studies of this reaction have been conducted.

2.
Nat Prod Res ; : 1-5, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33759661

RESUMO

Amomum maximum Roxb. rhizome is a fork medicine mainly used in South and Southeast Asia. In present study, the hypoglycaemic effects of the ethanolic extract of A. maximum rhizome were demonstrated both on α-glucosidase assay in vitro and streptozotocin (STZ)-induced postprandial hyperglycaemia in mice. Furthermore, six labdane diterpenes, amoxanthin A (1), ottensinin (2), coronarin D (3), coronarin D methyl ether (4), isocoronarin D (5), and zerumin (6), were isolated from its ethyl acetate sub-fraction with the guidance of α-glucosidase inhibitory activity. Among these compounds, 2 and 6 exhibited significant inhibitory effect on α-glucosidase, as well as on STZ-induced high postprandial blood glucose levels in mice. Additionally, molecular docking analysis revealed that 2 and 6 could firmly bind to the active sites of α-glucosidase. These results suggest that compounds 2 and 6 are the main anti-hyperglycaemic agents present in A. maximum, which may demonstrate potential beneficial effects in diabetes management.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33749966

RESUMO

Asymmetric aminoazidation and diazidation of alkenes are straightforward strategies to build value-added chiral nitrogen-containing compounds from feedstock chemicals. They provide direct access to chiral organoazides and complement enantioselective diamination. Notwithstanding the advances in non-asymmetric reactions, asymmetric aminoazidation or diazidation based on acyclic systems have not been previously reported. Here we describe the iron-catalyzed intermolecular asymmetric aminoazidation and diazidation of styrenes. The method is practically useful and requires relatively low loading of catalyst and chiral ligand. With mild reaction conditions, the reaction can be completed on a 20 mmol scale. Studies of the mechanism suggest that the reaction proceeds via a radical pathway and involves stereocontrol of an acyclic free radical which probably takes place through a group transfer mechanism.

4.
Cancer Med ; 10(6): 2063-2074, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33624385

RESUMO

AIMS: To investigate novel biomarker for diagnosis of cervical cancer, we analyzed the datasets in Gene Expression Omnibus (GEO) and confirmed the candidate biomarker in patient sample. MATERIALS AND METHODS: We collected major datasets of cervical cancer in GEO, and analyzed the differential expression of normal and cancer samples online with GEO2R and tested the differences, then focus on the GSE63514 to screen the target genes in different histological grades by using the R-Bioconductor package and R-heatmap. Then human specimens from the cervix in different histological grades were used to confirm the top 8 genes expression by immunohistochemical staining using Ki67 as a standard control. RESULTS: We identified genes differentially expressed in normal and cervical cancer, 274 upregulated genes and 206 downregulated genes. After intersection with GSE63514, we found the obvious tendency in different histological grades. Then we screened the top 24 genes, and confirmed the top 8 genes in human cervix tissues. Immunohistochemical (IHC) results confirmed that keratin 17 (KRT17) was not expressed in normal cervical tissues and was over-expressed in cervical cancer. Cysteine-rich secretory protein-2 (CRISP2) was less expressed in high-grade squamous intraepithelial lesions (HSILs) than in other histological grades. CONCLUSION: For the good repeatability and consistency of KRT17 and CRISP2, they may be good candidate biomarkers. Combined analysis of KRT17, CRISP2 expression at both genetic and protein levels can determine different histological grades of cervical squamous cell carcinoma. Such combined analysis is capable of improving diagnostic accuracy of cervical cancer.

5.
Cell Death Differ ; 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568778

RESUMO

The ubiquitin-proteasome system regulates many distinct biological processes. Its dysregulation causes various diseases, including but not limited to cancer. In this study, based on the analysis of gene expression in several colorectal cancer (CRC) datasets, we show that FBXL6, a poorly-characterized F-box protein, is amplified, over-expressed, and highly correlated with poor prognosis in human CRC patients. Mechanistically, FBXL6 targets phospho-p53 (S315) to mediate its polyubiquitination and proteasomal degradation, thereby inhibiting p53 signaling. FBXL6 depletion inhibits proliferation of p53 wild-type (WT) CRC cells by inducing cell cycle arrest and apoptosis. Furthermore, p53 transcriptionally suppresses FBXL6 expression by binding its core promoter region. Taken together, these results identify the feed-forward loop of FBXL6-p53 as a potential therapeutic target for CRC treatments.

6.
Plant Sci ; 303: 110770, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33487354

RESUMO

Dodder is a holoparasitic flowering plant that re-establishes parasitism with the host when broken off from the host. However, how in vitro dodder shoots recycle stored nutrients to maintain growth for reparasitizing hosts is not well characterized. Here, the spatial and temporal distribution characteristics of carbohydrates and reactive oxygen species (ROS) were analysed to explore the mechanism of recycling stored nutrients in dodder shoots in vitro. Our results showed that in vitro dodder shoots grew actively for more than 10 d, while dry mass decreased continuously. During this process, the transcript levels and activities of amylases gradually increased until 2 d and then declined in basal stems, which induced starch degradation at the tissue, cellular and subcellular levels. Additionally, the distribution characteristics of H2O2 and the activities and transcript levels of antioxidant enzymes indicated that shoot tips exhibited more robust ROS-scavenging capacity, and basal stems maintained higher ROS accumulation. Comparative proteomics analysis revealed that starch in basal stems acted as an energy source, and the glycolysis, TCA cycle and pentose phosphate pathway represented the energy supply for shoot tip elongation with time. These results indicated that efficient nutrient recycling and ROS modulation facilitated the parasitism of dodder grown in vitro by promoting shoot elongation growth to reach the host.

7.
Ther Clin Risk Manag ; 16: 1151-1163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33299317

RESUMO

Purpose: This retrospective study compared effectiveness between ≤4 cycles and ≥5 cycles of L-asparaginase/pegaspargase-based chemoradiation in newly diagnosed low-risk extranodal natural killer/T-cell lymphoma (ENKTL), nasal type classified according to the Prognostic Index of Natural Killer (PINK) lymphoma model. Patients and Methods: Patients were categorized into ≤4-cycle (2-4 chemotherapy cycles, n = 166) and ≥5-cycle groups (5-6 cycles, n = 86). Propensity score matching analysis was used to reduce potential confounding bias between the two groups. Treatment responses, adverse events, and survival outcomes between the two groups were analyzed. Results: No matter before or after matching (65 in the ≤4-cycle group, 65 in the ≥5-cycle group), response rates and survival outcomes were similar between the ≤4-cycle and ≥5-cycle groups. Incidences of grade 1-2 anemia and transaminase elevation were higher in the ≥5-cycle group. After matching, for stage IE disease, there were no differences in response rates and survival outcomes between the two groups. For stage IIE disease, the complete response rate was higher in the ≥5-cycle group (72.4% vs 92.6%, p = 0.049), and the 3-year overall survival (65.5% vs 85.2%, p = 0.024) and 3-year progression-free survival (58.6% vs 81.5%, p = 0.027) rates were significantly extended in the ≥5-cycle group. Conclusion: When chemoradiotherapy strategies with L-asparaginase/pegaspargase-based regimens are applied to modern low-risk ENKTL patients classified according to the PINK model, it may be better to moderately extend chemotherapy courses in patients with stage IIE disease.

8.
Signal Transduct Target Ther ; 5(1): 289, 2020 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-33376237

RESUMO

Advanced natural killer/T cell lymphoma (NKTL) has demonstrated poor prognosis with currently available therapies. Here, we report the efficacy of anti-programmed death 1 (PD-1) antibody with the P-GEMOX (pegaspargase, gemcitabine, and oxaliplatin) regimen in advanced NKTL. Nine patients underwent six 21-day cycles of anti-PD-1 antibody (day 1), pegaspargase 2000 U/m2 (day 1), gemcitabine 1 g/m2 (days 1 and 8) and oxaliplatin 130 mg/m2 (day 1), followed by anti-PD-1 antibody maintenance every 3 weeks. Programmed death-ligand 1 (PD-L1) expression and genetic alterations were determined in paraffin-embedded pretreatment tissue samples using immunohistochemistry and next-generation sequencing (NGS) analysis. Responses were assessed using 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) and computed tomography or magnetic resonance imaging. Eight patients exhibited significant responses, comprising of seven complete remissions and one partial remission (overall response rate: 88.9%). After a median follow-up of 10.6 months, 6/9 patients (66.7%) remained in complete remission. The most common grade 3/4 adverse events were anemia (33.3%), neutropenia (33.3%), and thrombocytopenia (33.3%); all of which were manageable and resolved. Immunochemotherapy produced a high response rate in patients with positive PD-L1 expression (5/6, 83.3%). NGS analysis suggested that STAT3/JAK3/PD-L1 alterations and ARID1A mutation were associated with immunochemotherapy efficacy. Mutation in DDX3X and alteration in epigenetic modifiers of KMT2D, TET2, and BCORL1 might indicate a poor response to immunochemotherapy. In conclusion, the anti-PD-1 antibody plus P-GEMOX regimen demonstrated promising efficacy in advanced NKTL. PD-L1 expression combined with specific genetic alterations could be used as potential biomarkers to predict therapeutic responses to immunochemotherapy.

9.
Front Oncol ; 10: 561330, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194627

RESUMO

Background: Little is known about the clinical significance of laryngeal cancer as a subsequent tumor. We aimed to determine the impact of a prior cancer history on the prevalence and prognosis of patients with laryngeal cancer. Methods: We retrospectively reviewed patients diagnosed with laryngeal cancer between 2004 and 2011 in the Surveillance, Epidemiology, and End Results (SEER) database. The t-test and chi-squared test were used to compare variables as appropriate. Matched 1:1 case control-adjusted Kaplan-Meier analyses and Cox regression models were performed to investigate the impact of prior cancer on overall survival (OS). Results: Among 20,987 patients with laryngeal cancer, nearly one-fifth (n = 3,915, 18.65%) had a prior cancer. The top three common prior cancers were prostate (588, 28.1%), lung and bronchus (354, 16.9%), and head and neck (306, 14.6%). A total of 73.4% of the prior cancers were diagnosed within 5 years of the laryngeal cancer diagnosis. Compared to patients without prior cancer, a worse survival was significantly associated with a prior cancer among laryngeal cancer patients, regardless of the interval time of the prior cancer (log-rank tests P < 0.001). Furthermore, prior cancer was an independent predictor of worse OS based on the Cox regression model [hazard ratio (HR) = 1.396, 95% confidence interval, 1.336-1.458]. In addition, patients with prior lung and bronchus cancer tended to have the worst survival (log-rank tests P < 0.001). Conclusions: Prior cancer has an adverse effect on clinical outcomes among patients with laryngeal cancer. These results suggest that individualized treatment should be seriously considered in patients with laryngeal cancer and a history of prior cancer, regardless of the interval time of prior cancer.

10.
ACS Omega ; 5(43): 27953-27961, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33163778

RESUMO

Fulvic acid (FA) is a complex organic mixture composed of small molecules. The structure and composition of FA vary greatly because of the different raw materials used for preparing FA. In this work, FA was extracted from shallow low-rank lignite by hydrogen peroxide (H2O2) in a microwave field, and the functional groups of FA were characterized. The optimal extraction process was determined, with the H2O2 concentration being the key factor affecting the yield of FA. Thermogravimetric analysis showed that FA was mainly composed of low molecular weight and readily pyrolyzed compounds. As shown by Fourier transform infrared spectroscopy, in the process of FA extraction by H2O2 oxidation of lignite, the content of -COOH increased, long-chain aliphatic compounds decreased, stretching vibrations of aromatic ring skeletons disappeared, and aromatic ring substitution became mainly tri- or disubstitution. Fluorescence spectroscopy indicated that FA had a low degree of aromaticity. X-ray photoelectron spectroscopy qualitatively and quantitatively revealed that the main modes of carbon-oxygen bonding in FA were C-O-, COO-, and C=O. Thus, this study not only lays a foundation for studying the composition and structure of coal-based FA but also opens a new avenue for a clean and efficient utilization of lignite.

11.
J Ethnopharmacol ; : 113551, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33152434

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Psoriasis is a complex recurrent inflammatory skin disease with different pathological changes in different stages. Psoriasis in its active stage, which is comparable to the blood-heat type in traditional Chinese medicine (TCM), has been treated by Liangxue Jiedu Decoction (LJD) in TCM for decades, with proven efficacy. According to TCM theories, LJD has the function of removing heat and pathogenic factors from the blood. AIM OF THE STUDY: We aimed to investigate the molecular features associated with the active stage psoriasis and identify genes responding to LJD treatment accompanied by lesion remission. MATERIALS AND METHODS: Healthy volunteers and psoriasis patients who met specific diagnostic criteria were recruited. Twenty-six transcriptomes were profiled from the peripheral blood mononuclear cells (PBMCs) of 10 psoriasis patients (pre- and post-treatment) and 6 healthy volunteers. RNA sequencing data were analyzed using an integrated approach combining differential gene expression analysis (DGEA) and weighted gene co-expression network analysis (WGCNA), by which gene expression was linked to multiple clinical traits, including psoriasis area and severity index (PASI), as well as the improvement rate of skin lesions (ΔPASI). The actions of LJD were then verified using an in vitro cell assay coupled to flow cytometric analysis and RT-PCR. RESULTS: We identified four network modules with statistical significance (P < 0.05), two of which connected to the PASI score, while the other two connected to 8-week treatment and ΔPASI, respectively. In psoriasis patients, activated inflammatory pathways and inhibited G-protein signaling genes (GTPase IMAP family member and G protein-coupled receptor) co-occurred, with high expression of CD83 and CD69, and low expression of CD160 and CD180, compared with the health. Accompanying LJD treatment and lesion remission, the expression of CD69 and cell cycle-related genes, including CCNA2, CCNB2, CDK1, and TOP2A, was down-regulated. The inhibitory role of LJD on CD69 expression was confirmed by the decline of activating naïve CD4+ T lymphocytes. CONCLUSION: Our study suggests that active psoriasis is characterized by unbalanced immune status with dendrite cell and lymphocyte-associated inflammatory activation as well as NK cell- and B cell-associated defense response aberrance. LJD played an inhibitory role in T cell activation, a process located downstream pathological cascade of psoriasis.

12.
J Am Chem Soc ; 142(42): 18014-18021, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33035049

RESUMO

Chiral allenes are important structural motifs frequently found in natural products, pharmaceuticals, and other organic compounds. Asymmetric 1,4-difunctionalization of 1,3-enynes is a promising strategy to construct axial chirality and produce substituted chiral allenes from achiral substrates. However, the previous state of the art in 1,4-difunctionalization of 1,3-enynes focused on the allenyl anion pathway. Because of this, only electrophiles can be introduced into the allene backbones in the second functionalization step, consequently limiting the reaction and allene product types. The development of asymmetric 1,4-difunctionalization of 1,3-enynes via a radical pathway would complement previous methods and support expansion of the toolbox for the synthesis of asymmetric allenes. Herein, we report the first radical enantioselective allene formation via a group transfer pathway in the context of copper-catalyzed radical 1,4-difunctionalization of 1,3-enynes. This method addresses a longstanding unsolved problem in asymmetric radical chemistry, provides an important strategy for stereocontrol with free allenyl radicals, and offers a novel approach to the valuable, but previously inaccessible, chiral allenes. This work should shed light on asymmetric radical reactions and may lead to other enantioselective group transfer reactions.

13.
PLoS One ; 15(10): e0240223, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052930

RESUMO

The Aedes aegypti mosquito plays an important role in the spread of diseases, including epidemic ones, such as dengue fever, Zika virus disease, yellow fever, and chikungunya disease. To control the population of Ae.aegypti, we transferred an HR3 RNAi fragment into the microalgae Chlamydomonas, which serves as food for Ae.aegypti larvae. Results showed that the HR3 RNAi transgenic algal strains were lethal to Ae.aegypti. The integumentary system of larvae fed with HR3 RNAi transgenic algal strains was severely damaged. Muscles of the larvae were unevenly distributed and disordered, and their midgut showed disintegration of the intestinal cavity. RNA-Seq results demonstrated that on the 4th day of inoculation with the transgenic algae, the abundance of early expressed genes in the 20E signal transduction pathway of larvae fed with the HR3 RNAi transgenic algal strain significantly reduced. These genes include E74, E75, E93, and 20E receptor complex EcR/USP and FTZ-F1 gene regulated by HR3. In later experiments, a scale test of 300 Ae.aegypti eggs per group was carried out for 30 days, and the survival rate of Ae.aegypti fed with the HR3 RNAi transgenic strain was only 1.3%. These results indicate that the HR3 RNAi transgenic strain exerts obvious insecticidal effect.

14.
Otol Neurotol ; 41(10): 1379-1386, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32947491

RESUMO

OBJECTIVE: The aim of this study was to evaluate the feasibility and safety of transcanal underwater endoscopic bone resection (TUEBR) of the external auditory canal (EAC) for the management of cholesteatoma involving the antrum and mastoid. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Pediatric and adult patients with primary cholesteatoma extending to the antrum and mastoid who underwent transcanal endoscopic ear surgery (TEES) with TUEBR between March 2016 and June 2017. INTERVENTION: A rigid 2.7 mm diameter, 18 cm length Hopkins-rod telescope with an endoscopic sheath was inserted in the EAC and continuously perfused with saline during the dissection. TUEBR was performed to expose extensive cholesteatoma by using a high speed drill with curved burrs and a protected shaft. Next, removal of visible disease, reconstruction of the resected EAC, ossiculoplasty, and tympanoplasty were accomplished with TEES. RESULTS: There were no intra- or postoperative severe complications such as facial palsy and inner ear injury except one patient suffering from secondary labyrinthitis. There was a negative linear relationship (r = -0.909) between the procedure time and procedure number of TUEBR. There was a weak relationship (r = 0.224) between the procedure time of TUEBR and the degree of the extension of cholesteatoma into the antrum and mastoid. There were two cases with residual cholesteatoma at 12 and 22 months follow-up postoperatively. CONCLUSION: TUEBR is a safe and efficient technique for the resection of EAC bone and transcanal exposure of extensive cholesteatoma that would otherwise require mastoid dissection.

15.
Carbohydr Polym ; 247: 116740, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829859

RESUMO

Pulmonary fibrosis (PF) is a lung disease with highly heterogeneous and mortality rate, but its therapeutic options are now still limited. Corona virus disease 2019 (COVID-19) has been characterized by WHO as a pandemic, and the global number of confirmed COVID-19 cases has been more than 8.0 million. It is strongly supported for that PF should be one of the major complications in COVID-19 patients by the evidences of epidemiology, viral immunology and current clinical researches. The anti-PF properties of naturally occurring polysaccharides have attracted increasing attention in last two decades, but is still lack of a comprehensively understanding. In present review, the resources, structural features, anti-PF activities, and underlying mechanisms of these polysaccharides are summarized and analyzed, which was expected to provide a scientific evidence supporting the application of polysaccharides for preventing or treating PF in COVID-19 patients.


Assuntos
Betacoronavirus , Produtos Biológicos/uso terapêutico , Infecções por Coronavirus/complicações , Pandemias , Pneumonia Viral/complicações , Polissacarídeos/uso terapêutico , Fibrose Pulmonar/tratamento farmacológico , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Bleomicina/toxicidade , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Proteína Forkhead Box O3/fisiologia , Fungos/química , Ribonucleoproteína Nuclear Heterogênea D0/fisiologia , Humanos , Macrófagos/efeitos dos fármacos , Medicina Tradicional Chinesa , Camundongos , Neutrófilos/efeitos dos fármacos , Fitoterapia , Plantas Medicinais/química , Polissacarídeos/farmacologia , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/prevenção & controle , RNA Longo não Codificante/antagonistas & inibidores , Ratos , Alga Marinha/química , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/fisiologia , Proteína Smad3/fisiologia , Fator de Crescimento Transformador beta1/antagonistas & inibidores
16.
Org Lett ; 22(13): 5261-5265, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32610936

RESUMO

The regioselective synthesis of fluorinated allenes via a metal-free 1,4-fluoroamination of 1,3-enynes is presented. This method employs commercially available N-fluorobenzenesulfonimide serving as both the nitrogen source and the fluorine source, affording access to various tetrasubstituted allenes in a straightforward and atom-economic pathway. Preliminary mechanistic studies and theoretical studies revealed that this reaction might undergo an intimate ion-pair mechanism.

17.
Cancer Manag Res ; 12: 4999-5008, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612387

RESUMO

Introduction: Primary gastric diffuse large B-cell lymphoma (GDLBCL) is a heterogeneous disease in clinicopathological features and prognosis. Programmed death ligand-1 (PD-L1) and microRNA-34a (miR-34a) play crucial roles in GDLBCL progress. The purpose of this research is to explore the clinical significance of PD-L1 and miR-34a expression in GDLBCL. Patients and Methods: The expressions of PD-L1 and miR-34a were examined by IHC and qRT-PCR in 109 patients who were diagnosed with GDLBCL and were treated with rituximab plus cyclophosphamide, doxorubicin, prednisone vincristine and prednisone chemotherapy (R-CHOP) from January 2010 to December 2018. Results: PD-L1 level was significantly higher in tumor tissues than adjacent non-tumor tissues (60.5%, P<0.001), while the miR-34a level was just reversed (50.5%, P<0.001), which was negatively correlated (r=-0.524, P<0.001). Notably, PD-L1-positive and miR-34a-negative expressions were significantly correlated with the advanced Lugano stage of IIE-IV stage (P<0.001 and P<0.01), elevated serumal LDH levels (P<0.001 and P<0.05), B symptoms present (P<0.001 and P<0.001), non-GCB subtype (P<0.001 and P<0.001) and negative Bcl-2 expression (P<0.05 and P<0.001). PD-L1 high and miR-34a low expression groups had more patients with IPI scores of 2 or greater (P<0.001 and P<0.05) and poor R-IPI (P<0.01 and P<0.01). The complete response rate was upregulated in patients with negative PD-L1 and positive miR-34a expression after R-CHOP treatment. Discussion: PD-L1 expression and miR-34a expression were significantly associated with clinicopathological characteristics and survival prognosis; they may serve as novel prognostic markers in GDLBCL patients who were treated with R-CHOP. Immunotherapies targeting PD-L1 and miR-34a pathway may have therapeutic potential in GDLBCL.

19.
Chem Commun (Camb) ; 56(47): 6400-6403, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32390034

RESUMO

The first example of main group metal Bi(iii)-catalyzed aminooxygenation of fluorinated propargyl amidines was developed to produce 2-fluoroalkyl imidazole-5-carbaldehydes in moderate to excellent yields, in which phenol played a critical role and could be recovered and recycled. In the presence of KOt-Bu, an unconventional decarbonylation occurred on the 2-fluoroalkyl imidazole-5-carbaldehydes.

20.
Plant Biotechnol J ; 18(12): 2436-2443, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32438486

RESUMO

The CRISPR/Cas9 and Cas12a (Cpf1) tools have been used on a large scale for genome editing. A new effector with a single nuclease domain, a relatively small size, low-frequency off-target effects and cleavage capability under high temperature has been recently established and designated CRISPR/Cas12b (C2c1). Cas12b has also shown temperature inducibility in mammalian systems. Therefore, this system is potentially valuable for editing the genomes of plant species, such as cotton, that are resistant to high temperatures. Using this new system, mutants of upland cotton were successfully generated following Agrobacterium-mediated genetic transformation under a range of temperatures. Transformants (explants infected by Agrobacterium) exposed to 45 °C for 4 days showed the highest editing efficiency. No off-target mutation was detected by whole-genome sequencing. Genome edits by AacCas12b in T0 generation were faithfully passed to the T1 generation. Taken together, CRISPR/Cas12b is therefore an efficient and precise tool for genome editing in cotton plants.

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