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Abstract With the popularity of breast screening, more and more intraductal papillary lesions (IDPL)were detected by ultrasound or mammography, which is a spectrum of diseases ranging from benign to malignant lesions. Patients with pathological nipple discharge (PND) may indicate IDPL, but it is difficult to clarify their biological characteristics before the operation. As to patients with IDPL without PND, it is even an enormous challenge to differentiate their benign or malignant characteristics. Therefore, to avoid inadequate treatment, it is necessary to analyze the clinicopathological and imaging characteristics of patients with papillary lesions before surgery for the preliminary diagnosis of benign or malignant papillary lesions. 267 cases of IDPL with or without PND, namely PND group and non-PND group, were studied using continuous clinical data from October 2020 to September 2023. We analyzed the clinicopathological and imaging characteristics in the two groups of patients with malignancy compared with benign patients. Meanwhile, these characteristics were analyzed in malignant papillary patients with PND or not. 267 patients were pathologically diagnosed with IDPL during three years, accounting for 15.4% of surgical cases of the same period. There were 55 patients with malignant lesions (20.6%), including 28 cases in the PND group (16.5%) and 27 cases in the non-PND group (27.8%), and the incidence of malignant lesions was higher in the non-PND group than that of the PND group. There was a close correlation between age and malignant lesions in the two groups; the number of patients older than 50 years in malignant patients (74.5%) exceeded that of benign patients (42.5%). There were nearly one-third of malignancies in patients with nipple bloody discharge, and the rate increased to 50% when the patient was older than 50 years, but the malignant rate was meager in patients without bloody discharge. There were some factors relating to malignancy in non-PND patients, including age, lesion size, the distance from the nipple to the lesson (DFNL), and abnormal mammogram; there was a significant difference in this positive manifestation between benign and malignant patients. In malignant intraductal papillary lesions, 40.8% of the cases were invasive carcinoma in the non-PND group, higher than in the PND group (10.7%). Meanwhile, immunohistochemistry was more likely to be hormone receptor-positive (92.6%) and Her-2 negative in the non-PND group, compared with the PND group. Breast IDPL is a common disease, among which malignant lesions are higher than reports in previous literature. There are some clinical and imaging manifestations indicating malignancy; patients more than 50 years old with bloody nipple discharge are at high risk of malignancy. When old non-PND patients have more significant lesions, remote DFNL, and abnormal mammograms, there is a high probability of malignancy in them. Although there are different biological characteristics in malignant IDPL with or without PND, they are all low-grade malignancies compared with traditional breast cancer.

【Objective】The use of artificial inoculation to ferment cigar tobacco leaves is an inevitable trend in the industrial production of cigar tobacco leaves, and the neutral aroma components are the important quality components of cigar tobacco leaves. The study aims to investigate the effect of Bacillus safensis GL2 on the neutral aroma components of cigar tobacco leaves.【Method】GL2 was screened from Cuban cigar Cohiba Robert and used to ferment cigar leaves. The neutral aroma components in tobacco leaves were determined by distillation extraction-gas chromatography-mass spectrometry, and multivariate statistical methods were used for analysis and statistics.【Result】The total aroma and the contents of most neutral aroma components in cigar tobacco leaves were significantly increased after GL2 fermentation (P < 0.05), and the increased aroma substances mainly included olefins, ketones and alcohols. A total of 13 differentially neutral aroma components were selected by VIP > 1 and P < 0.05, and 9 of them were significantly up-regulated and positively correlated with tobacco leaf aroma. There were 7 species with significant positive correlation (P < 0.05), which were the key differential aroma components of 2, 6, 6-trimethyl-2-cyclohexene-1, 4-dione, 2, 6, 6-trimethyl-1, 4-cyclohexanedione, geraniyl acetone, acanthyl acetone, neophydiene, solanone and phytoalcohol. In addition, 4 different aroma components were significantly decreased and negatively correlated with tobacco leaf aroma, among which 2, 4-di-tert-butyl-6-nitrophenol was significantly negatively correlated with cigar tobacco aroma (P < 0.05). 2, 6, 6-trimethyl-2-cyclohexene-1, 4-dione, geranyl acetone, solanone and phytol contributed significantly to the aroma of fermented cigar tobacco leaves, resulting in a stronger overall dry and floral fragrances. As a result, they enriched the aroma and improved the sensory quality of cigar tobacco leaves.【Conclusion】Inoculation of B. safensis during cigar tobacco fermentation is beneficial for improving the quality of cigar tobacco leaves, which provide theoretical support for improving the fermentation quality of cigar tobacco leaves with biotechnology.

Abstract Background Breast cancer is the most common malignant tumor among women worldwide. GREB1L is a protein-coding gene. Previous studies have shown that GREB1L plays a vital role in lung and gastric adenocarcinoma. Currently, there is no relevant report about its role in breast cancer. Methods The Cancer Genome Atlas database was used to compare the expression level of GREB1L between tumor and normal tissues. The TISIDB website was used for prognosis analysis. The LinkedOmics database was used to predict the potential biological mechanism of GREB1L in breast cancer. Immunohistochemistry was used to detect the GREB1L expression level in breast tissue. Western blotting was used to detect the GREB1L expression level in cell lines. Transwell assays, CCK-8 cell proliferation assays, and colony formation assays were used to detect the migration, invasion, proliferation, and colony formation abilities of cells. Subcutaneous xenograft models were used to detect the in vivo tumor formation abilities of cells. Results GREB1L is highly expressed in breast cancer tissues and breast cancer cells. KEGG enrichment analysis suggested that GREB1L participates in the regulation of the Hedgehog signaling pathway; changes in GREB1L expression affected the migration and invasion abilities of MCF7 and MDA-MB-231 cells. Although changes in GREB1L expression did not affect their proliferation and colony formation abilities in vitro and in vivo, they affected the expression of tumor metastasis-related genes in vivo. The overexpression of GREB1L in breast cancer predicted a favorable prognosis. Conclusion These results showed that GREB1L is involved in the development of breast cancer, and it may be a potential molecular marker for predicting the prognosis of breast cancer.

The reaction centre light-harvesting 1 (RC-LH1) complex is the core functional component of bacterial photosynthesis. We determined the cryo-electron microscopy (cryo-EM) structure of the RC-LH1 complex from Rhodospirillum rubrum at 2.5 Å resolution, which reveals a unique monomeric bacteriochlorophyll with a phospholipid ligand in the gap between the RC and LH1 complexes. The LH1 complex comprises a circular array of 16 αβ-polypeptide subunits that completely surrounds the RC, with a preferential binding site for a quinone, designated QP, on the inner face of the encircling LH1 complex. Quinols, initially generated at the RC QB site, are proposed to transiently occupy the QP site prior to traversing the LH1 barrier and diffusing to the cytochrome bc1 complex. Thus, the QP site, which is analogous to other such sites in recent cryo-EM structures of RC-LH1 complexes, likely reflects a general mechanism for exporting quinols from the RC-LH1 complex.

Abstract Background Pathogenic viruses can be transmitted by female Aedes aegypti (Ae. aegypti) mosquitoes during blood-meal acquisition from vertebrates. Silencing of mosquito- and midgut-specific microRNA (miRNA) 1174 (miR-1174) impairs blood intake and increases mortality. Determining the identity of the proteins and metabolites that respond to miR-1174 depletion will increase our understanding of the molecular mechanisms of this miRNA in controlling blood-feeding and nutrient metabolism of mosquitoes. Methods Antisense oligonucleotides (antagomirs [Ant]) Ant-1174 and Ant-Ct were injected into female Ae. aegypti mosquitoes at 12–20 h posteclosion, and depletion of miR-1174 was confirmed by reverse transcription quantitative real-time PCR (RT-qPCR). Ant-1174-injected and control mosquitoes were collected before the blood meal at 72 h post-injection for tandem mass tag-based proteomic analysis and liquid chromatography-tandom mass spectrometry non-target metabolomic analysis to identify differentially expressed proteins and metabolites, respectively. RNA interference (RNAi) using double-stranded RNA (dsRNA) injection was applied to investigate the biological roles of these differentially expressed genes. The RNAi effect was verified by RT-qPCR and western blotting assays. Triglyceride content and ATP levels were measured using the appropriate assay kits, following the manufacturers’ instructions. Statistical analyses were conducted with GraphPad7 software using the Student’s t-test. Results Upon depletion of mosquito- and midgut-specific miR-1174, a total of 383 differentially expressed proteins (DEPs) were identified, among which 258 were upregulated and 125 were downregulated. Functional analysis of these DEPs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment suggested that miR-1174 plays important regulatory roles in amino acid metabolism, nucleotide metabolism, fatty acid metabolism and sugar metabolism pathways. A total of 292 differential metabolites were identified, of which 141 were upregulated and 151 were downregulated. Integrative analysis showed that the associated differential proteins and metabolites were mainly enriched in a variety of metabolic pathways, including glycolysis, citrate cycle, oxidative phosphorylation and amino acid metabolism. Specifically, the gene of one upregulated protein in miR-1174-depleted mosquitoes, purine nucleoside phosphorylase (PNP; AAEL002269), was associated with the purine, pyrimidine and niacin-nicotinamide metabolism pathways. PNP knockdown seriously inhibited blood digestion and ovary development and increased adult mortality. Mechanically, PNP depletion led to a significant downregulation of the vitellogenin gene (Vg); in addition, some important genes in the ecdysone signaling and insulin-like peptide signaling pathways related to ovary development were affected. Conclusions This study demonstrates differential accumulation of proteins and metabolites in miR-1174-depleted Ae. aegypti mosquitoes using proteomic and metabolomic techniques. The results provide functional evidence for the role of the upregulated gene PNP in gut physiological activities. Our findings highlight key molecular changes in miR-1174-depleted Ae. aegypti mosquitoes and thus provide a basis and novel insights for increased understanding of the molecular mechanism involved in a lineage-specific miRNA in mosquito vectors. Graphical Abstract

Signaling pathways are responsible for transmitting information between cells and regulating cell growth, differentiation, and death. Proteins in cells form complexes by interacting with each other through specific structural domains, playing a crucial role in various biological functions and cell signaling pathways. Protein–protein interactions (PPIs) within cell signaling pathways are essential for signal transmission and regulation. The spatiotemporal features of PPIs in signaling pathways are crucial for comprehending the regulatory mechanisms of signal transduction. Bimolecular fluorescence complementation (BiFC) is one kind of imaging tool for the direct visualization of PPIs in living cells and has been widely utilized to uncover novel PPIs in various organisms. BiFC demonstrates significant potential for application in various areas of biological research, drug development, disease diagnosis and treatment, and other related fields. This review systematically summarizes and analyzes the technical advancement of BiFC and its utilization in elucidating PPIs within established cell signaling pathways, including TOR, PI3K/Akt, Wnt/β-catenin, NF-κB, and MAPK. Additionally, it explores the application of this technology in revealing PPIs within the plant hormone signaling pathways of ethylene, auxin, Gibberellin, and abscisic acid. Using BiFC in conjunction with CRISPR-Cas9, live-cell imaging, and ultra-high-resolution microscopy will enhance our comprehension of PPIs in cell signaling pathways.

Abstract Objective To provide a rare case of local recurrent Paget’s disease after nipple-sparing mastectomy (NSM) with immediate breast reconstruction with 10 years of disease-free survival and to analyze the clinical and pathological characteristics. Background Mammary Paget’s disease can be considered a rare type of local recurrence after breast cancer treatment, both in cases of conservative surgery and NSM with immediate breast reconstruction (Lohsiriwat et al, Ann Surg Oncol 19:1850-1855, 2012). Recurrent patients who present with nipple-areolar Paget’s disease usually have unfavorable primary pathological characteristics and different latency periods. However, the recurrent status in patients with favorable primary pathological characteristics and the latency periods after NSM with immediate breast reconstruction are unclear. Methods First, we present a case of local recurrent Paget’s disease in a young patient diagnosed with invasive breast carcinoma at age 30 who underwent NSM with primary silicone reconstruction. Then, the keywords “Paget’s disease” and “nipple-sparing mastectomy” were selected. Articles including the local recurrence of Paget’s disease after NSM were collected from the PubMed, Springer, and OVID databases, and the acquired relevant data were analyzed. We did not restrict our search by study design or publication date. Results Five studies describing 31 cases of local recurrent Paget’s disease after NSM with implant breast reconstruction were included. The mean patient age reported was 45 years, and the average latency period from NSM to the local recurrence of Paget’s disease was 40.2 months. Recurrent tumor histological features were Paget’s disease with ductal carcinoma in situ (DCIS) in 16 patients (50%), Paget’s disease without DCIS in 13 patients (40.6%), and Paget’s disease with ductal intraepithelial neoplasia (DIN) in 3 patients (9.4%). The primary tumor histological feature was estrogen receptor (ER)(−)/progesterone receptor (PR)(−)/human epidermal growth factor receptor (HER-2)(+) in 21 patients (77.8%). Neither locoregional relapse nor metastatic events were found in these recurrent patients who accepted NAC excision after 4–5 years of follow-up. Our reported case showed that the patient experienced pregnancy and lactation after primary adjuvant chemotherapy and endocrine therapy. However, she developed an eczematoid lesion in the NAC 120 months after breast surgery. The histopathological examination was consistent with Paget’s disease of the breast. Complete NAC and breast silicone prosthesis removal were performed. The patient accepted no systematic or local therapy and is currently alive. It is noteworthy that the biological features of the primary tumor were ER(+), PR(+), and HER-2(−); however, the recurrent tumor changed to ER(−), PR(−), and HER-2(+). Conclusions The local recurrence of Paget’s disease after NSM is uncommon; it may develop at a very early age and have a very long time to recurrence, as in our patient, who presented with recurrence 10 years after primary surgery. Surgeons should be wary of local recurrence of the nipple-areola complex after NSM in patients with ER-negative and HER-2-positive primary tumors. However, patients with ER/PR-positive and HER-2-negative tumors should not be neglected; we reported a case of an ER/PR-positive and HER-2-negative primary tumor, and ER-positive recurrent cases have the longest latency period. The local recurrence rate of Paget’s disease after NSM is low, and the prognosis is good in recurrent patients who accept further extensive NAC excision. Further systematic treatment was not considered for this patient.

Inherently chiral calixarenes have garnered significant attention due to their distinctive properties, yet the development of efficient catalytic asymmetric synthesis methods remains a critical challenge. Herein, we report the asymmetric synthesis of calix[4]arenes featuring inherent or both inherent and axial chirality via a cobalt‐catalyzed C−H activation/annulation strategy in high yield with excellent enantio‐ and diastereoselectivity (up to >99 % ee and >20 : 1 dr). Electrooxidation was also suitable for this transformation to obviate the sacrificial metal oxidants, underscoring the environmentally friendly potential of this approach. A key octahedral cobaltacycle intermediate was synthesized and characterized, providing valuable insights into the mode of enantio‐ and diastereocontrol of this protocol. Noteworthy photoluminescence quantum yields of up to 0.94 were measured, underscoring the potential of these compounds in the domain of organic fluorescent materials. [ABSTRACT FROM AUTHOR]

Abstract Background P53 pathway inactivation plays an important role in the process of breast cancer tumorigenesis. Post-translational protein modification abnormalities have been confirmed to be an important mechanism underlying inactivation of p53. Numerous deubiquitinating enzymes are aberrantly expressed in breast cancer, and a few deubiquitination enzymes can deubiquitinate and stabilize p53. Here, we report that ovarian tumor (OTU) deubiquitinase 3 (OTUD3) is a deubiquitylase of p53 in breast carcinoma (BC). Methods Correlations between the mRNA expression levels of OTUD3, TP53 and PTEN and the prognosis of BC were assessed with the Kaplan-Meier Plotter tool. OTUD3 protein expression in 80 pairs of specimens in our cohort was examined by immunohistochemistry and western blotting. The relationship among OTUD3, p53, and p21 proteins was analyzed. Half-life analysis and ubiquitylation assay were performed to elucidate the molecular mechanism by which OTUD3 stabilizes p53. The interaction between OTUD3 and p53 in BC cells was verified by a co-immunoprecipitation assay and GST pulldown experiments. MTS assay for proliferation detection, detection of apoptosis induced by cisplatin and colony formation assay were employed to investigate the functional effects of OTUD3 on breast cancer cells. Results OTUD3 downregulation is correlated with a poor prognosis in BC patients. OTUD3 expression is decreased in breast cancer tissues and not associated with the histological grade. OTUD3 also inhibits cell proliferation and clone formation and increases the sensitivity of BC cells to apoptosis induced by chemotherapy drugs. Reduced OTUD3 expression accompanied by decreased p53 abundance is correlated with human breast cancer progression. Ectopic expression of wild-type OTUD3, but not its catalytically inactive mutant, stabilizes and activates p53. Mechanistically, OTUD3 interacts directly with p53 through the amino-terminal OTU region. Finally, OTUD3 protects p53 from murine double minute 2 (Mdm2)-mediated ubiquitination and degradation, enabling the deubiquitination of p53 in BC cells. Conclusions In summary, we found that OTUD3 may be a potential therapeutic target for restoring p53 function in breast cancer cells and suggest that the OTUD3-p53 signaling axis may play a critical role in tumor suppression.

Background The architecture of inflorescence and the development of floral organs can influence the yield of seeds and have a significant impact on plant propagation. E-class floral homeotic MADS-box genes exhibit important roles in regulation of floral transition and differentiation of floral organs. Woad (Isatis indigotica) possesses unique inflorescence, floral organs and fruit. However, very little research has been carried out to determine the function of MADS-box genes in this medicinal cruciferous plant species. Results SEPALLATA orthologs in I. indigotica were cloned by degenerate PCR. The sequence possessing the highest identity with SEP2 and SEP4 of Arabidopsis were named as IiSEP2 and IiSEP4, respectively. Constitutive expression of IiSEP2 in Columbia (Col-0) ecotype of Arabidopsis led to early flowering, and the number of the flowers and the lateral branches was reduced, indicating an alteration in architecture of the inflorescences. Moreover, the number of the floral organs was declined, the sepals were turned into carpelloid tissues bearing stigmatic papillae and ovules, and secondary flower could be produced in apetalous terminal flowers. In 35S::IiSEP4-GFP transgenic Arabidopsis plants in Landsberg erecta (Ler) genetic background, the number of the floral organs was decreased, sepals were converted into curly carpelloid structures, accompanied by generation of ovules. Simultaneously, the size of petals, stamens and siliques was diminished. In 35S::IiSEP4-GFP transgenic plants of apetalous ap1 cal double mutant in Ler genetic background, the cauliflower phenotype was attenuated significantly, and the petal formation could be rescued. Occasionally, chimeric organs composed of petaloid and sepaloid tissues, or petaloid and stamineous tissues, were produced in IiSEP4 transgenic plants of apl cal double mutant. It suggested that overexpression of IiSEP4 could restore the capacity in petal differentiation. Silencing of IiSEP4 by Virus-Induced Gene Silencing (VIGS) can delay the flowering time, and reduce the number and size of the floral organs in woad flowers. Conclusion All the results showed that SEPALLATA-like genes could influence the architecture of the inflorescence and the determinacy of the floral meristems, and was also related to development of the floral organs.

The N6-methyladenosine (m6A) has been considered as a new layer of epitranscriptomic regulation on mRNA processing, stability, and translation. However, potential roles of m6A RNA methylation modification in tumor immune microenvironment (TIME) of breast cancer are yet fully understood. In this study, we comprehensively evaluated the genetic variations and transcript expressions of 15 m6A regulators in 1,079 breast cancer samples from the Cancer Genome Atlas (TCGA) database. We validated major regulators had significantly differential mRNA and protein expression in tumor tissue compared to normal tissues from 39 pairs of clinical breast cancer samples with different molecular subtypes, and especially high expression of m6A readers YTHDF1 and YTHDF3 predicted poor survival. Two clusters of breast cancer patients identified by the 15 m6A regulators’ pattern showed distinct overall survival, immune activation status, and immune cell infiltration, and clinical samples confirmed the diversity of lymphocytic infiltration. The profiles of these two clusters accorded with that of two classical cancer-immune phenotypes, immune-excluded and immune-inflamed phenotypes, it suggested that m6A regulators-based patterns might serve as crucial mediators of TIME in breast cancer. Moreover, the m6A phenotype-related gene signatures could also be survival predictor in breast cancer. Therefore, comprehensive evaluation of tumor m6A modification pattern will contribute to enhance our understanding of the characterization of immune cell infiltration in the tumor microenvironment and promote the responsiveness of breast cancer to immunotherapy.

Abstract Background Female Aedes aegypti mosquitoes are vectors of arboviruses that cause diverse diseases of public health significance. Blood protein digestion by midgut proteases provides anautogenous mosquitoes with the nutrients essential for oocyte maturation and egg production. Midgut-specific miR-1174 affects the functions of the midgut through its target gene serine hydroxymethyltransferase (SHMT). However, less is known about SHMT-regulated processes in blood digestion by mosquitoes. Methods RNAi of SHMT was realized by injection of the double-stranded RNA at 16 h post-eclosion. The expression of SHMT at mRNA level and protein level was assayed by real-time PCR and Western blotting, respectively. Statistical analyses were performed with GraphPad7 using Student’s t-test. Results Here, we confirmed that digestion of blood was inhibited in SHMT RNAi-silenced female A. aegypti mosquitoes. Evidence is also presented that all SHMT-depleted female mosquitoes lost their flight ability and died within 48 h of a blood meal. Furthermore, most examined digestive enzymes responded differently in their transcriptional expression to RNAi depletion of SHMT, with some downregulated, some upregulated and some remaining stable. Phylogenetic analysis showed that transcriptional expression responses to SHMT silence were largely unrelated to the sequence similarity between these enzymes. Conclusions Overall, this research shows that SHMT was expressed at a low level in the midgut of Aedes aegypti mosquitoes, but blood-meal digestion was inhibited when SHMT was silenced. Transcriptional expressions of different digestive enzymes were affected in response to SHMT depletion, suggesting that SHMT is required for the blood-meal digestion in the midgut and targeting SHMT could provide an effective strategy for vector mosquito population control.

Author(s): Lorna A. Malone [sup.1] , Pu Qian [sup.1] , Guy E. Mayneord [sup.1] , Andrew Hitchcock [sup.1] , David A. Farmer [sup.1] , Rebecca F. Thompson [sup.2] , David [...], The cytochrome b.sub.6 f (cytb.sub.6 f ) complex has a central role in oxygenic photosynthesis, linking electron transfer between photosystems I and II and converting solar energy into a transmembrane proton gradient for ATP synthesis.sup.1-3. Electron transfer within cytb.sub.6 f occurs via the quinol (Q) cycle, which catalyses the oxidation of plastoquinol (PQH.sub.2) and the reduction of both plastocyanin (PC) and plastoquinone (PQ) at two separate sites via electron bifurcation.sup.2. In higher plants, cytb.sub.6 f also acts as a redox-sensing hub, pivotal to the regulation of light harvesting and cyclic electron transfer that protect against metabolic and environmental stresses.sup.3. Here we present a 3.6 A[combining ring above] resolution cryo-electron microscopy (cryo-EM) structure of the dimeric cytb.sub.6 f complex from spinach, which reveals the structural basis for operation of the Q cycle and its redox-sensing function. The complex contains up to three natively bound PQ molecules. The first, PQ1, is located in one cytb.sub.6 f monomer near the PQ oxidation site (Q.sub.p) adjacent to haem b.sub.p and chlorophyll a. Two conformations of the chlorophyll a phytyl tail were resolved, one that prevents access to the Q.sub.p site and another that permits it, supporting a gating function for the chlorophyll a involved in redox sensing. PQ2 straddles the intermonomer cavity, partially obstructing the PQ reduction site (Q.sub.n) on the PQ1 side and committing the electron transfer network to turnover at the occupied Q.sub.n site in the neighbouring monomer. A conformational switch involving the haem c.sub.n propionate promotes two-electron, two-proton reduction at the Q.sub.n site and avoids formation of the reactive intermediate semiquinone. The location of a tentatively assigned third PQ molecule is consistent with a transition between the Q.sub.p and Q.sub.n sites in opposite monomers during the Q cycle. The spinach cytb.sub.6 f structure therefore provides new insights into how the complex fulfils its catalytic and regulatory roles in photosynthesis. A 3.6 A[combining ring above] resolution cryo-electron microscopy structure of the dimeric cytochrome b.sub.6f complex from spinach reveals the structural basis for operation of the quinol cycle and its redox-sensing function.

The combination of achiral Cp*Rh(III) with chiral carboxylic acids (CCAs) represents an efficient catalytic system in transition metal‐catalyzed enantioselective C−H activation. However, this hybrid catalysis is limited to redox‐neutral C−H activation reactions and the adopt to oxidative enantioselective C−H activation remains elusive and pose a significant challenge. Herein, we describe the development of an electrochemical Cp*Rh(III)‐catalyzed enantioselective C−H annulation of sulfoximines with alkynes enabled by chiral carboxylic acid (CCA) in an operationally friendly undivided cell at room temperature. A broad range of enantioenriched 1,2‐benzothiazines are obtained in high yields with excellent enantioselectivities (up to 99 % yield and 98 : 2 er). The practicality of this method is demonstrated by scale‐up reaction in a batch reactor with external circulation. A crucial chiral Cp*Rh(III) intermediate is isolated, characterized, and transformed, providing rational support for a Rh(III)/Rh(I) electrocatalytic cycle. [ABSTRACT FROM AUTHOR]

Author(s): Pu Qian [sup.1] , C. Alistair Siebert [sup.2] , Peiyi Wang [sup.3] , Daniel P. Canniffe [sup.1] , C. Neil Hunter [sup.1] Author Affiliations: (1) Department of Molecular Biology [...], The light-harvesting 1-reaction centre (LH1-RC) complex is a key functional component of bacterial photosynthesis. Here we present a 2.9 Å resolution cryo-electron microscopy structure of the bacteriochlorophyll b-based LH1-RC complex from Blastochloris viridis that reveals the structural basis for absorption of infrared light and the molecular mechanism of quinone migration across the LH1 complex. The triple-ring LH1 complex comprises a circular array of 17 [beta]-polypeptides sandwiched between 17 [alpha]- and 16 [gamma]-polypeptides. Tight packing of the [gamma]-apoproteins between [beta]-polypeptides collectively interlocks and stabilizes the LH1 structure; this, together with the short Mg-Mg distances of bacteriochlorophyll b pairs, contributes to the large redshift of bacteriochlorophyll b absorption. The &apos;missing&apos; 17th [gamma]-polypeptide creates a pore in the LH1 ring, and an adjacent binding pocket provides a folding template for a quinone, Q .sub.P, which adopts a compact, export-ready conformation before passage through the pore and eventual diffusion to the cytochrome bc.sub.1 complex. A cryo-electron microscopy structure of the light-harvesting-reaction centre (LH1-RC) complex of the photosynthetic bacterium Blastochloris viridis suggests factors that underlie the large redshift in the absorption spectrum of bacteriochlorophyll in the complex and that promote quinone-quinol translocation across the LH1 ring.