Eu(OTf)3 -Catalyzed Formal Dipolar [4π+2σ] Cycloaddition of Bicyclo-[1.1.0]butanes with Nitrones: Access to Polysubstituted 2-Oxa-3-azabicyclo[3.1.1]heptanes.

Herein, we have synthesized multifunctionalized 2-oxa-3-azabicyclo[3.1.1]heptanes, which are considered potential bioisosteres for meta-substituted arenes, through Eu(OTf)3 -catalyzed formal dipolar [4π+2σ] cycloaddition of bicyclo[1.1.0]butanes with nitrones. This methodology represents the initial instance of fabricating bicyclo[3.1.1]heptanes adorned with multiple heteroatoms. The protocol exhibits both mild reaction conditions and a good tolerance for various functional groups. Computational density functional theory calculations support that the reaction mechanism likely involves a nucleophilic addition of nitrones to bicyclo[1.1.0]butanes, succeeded by an intramolecular cyclization. The synthetic utility of this novel protocol has been demonstrated in the concise synthesis of the analogue of Rupatadine.

Association between new plasma inflammatory markers and risk of colorectal neoplasms in individuals over 50 years old.

OBJECTIVE(S): The prognostic value of systemic cytokine profiles and inflammatory markers in colorectal cancer were explored by several studies. We want to know more about inflammatory biomarkers in colorectal adenoma and early cancer. METHOD: The level of 38 inflammatory markers in the plasma of 112 adenoma patients, 72 Tis-T1 staging of colorectal carcinoma patients, 34 T2-T4 staging of colorectal carcinoma patients and 53 normal subjects were detected and compared. RESULT(S): Eight inflammatory biomarkers (Eotaxin, GCSF, IL-4, IL-5, IL-17E, MCP-1, TNF-α and VEGF-A) have higher plasma concentrations in colorectal adenoma and cancer patients compared with normal participants over 50 years old. CONCLUSION(S): Inflammatory markers may have the prognostic value for colorectal adenoma and early-stage carcinoma.

Molecular regulation of immunity in tea plants.

Tea, which is mainly produced using the young leaves and buds of tea plants (Camellia sinensis (L.) O. Kuntze), is one of the most common non-alcoholic beverages consumed in the world. The standard of tea mostly depends on the variety and quality of tea plants, which generally grow in subtropical areas, where the warm and humid conditions are also conducive to the occurrence of diseases. In fighting against pathogens, plants rely on their sophisticated innate immune systems which has been extensively studied in model plants. Many components involved in pathogen associated molecular patterns (PAMPs) triggered immunity (PTI) and effector triggered immunity (ETI) have been found. Nevertheless, the molecular regulating network against pathogens (e.g., Pseudopestalotiopsis sp., Colletotrichum sp. and Exobasidium vexans) causing widespread disease (such as grey blight disease, anthracnose, and blister blight) in tea plants is still unclear. With the recent release of the genome data of tea plants, numerous genes involved in tea plant immunity have been identified, and the molecular mechanisms behind tea plant immunity is being studied. Therefore, the recent achievements in identifying and cloning functional genes/gene families, in finding crucial components of tea immunity signaling pathways, and in understanding the role of secondary metabolites have been summarized and the opportunities and challenges in the future studies of tea immunity are highlighted in this review.

First report of Botryosphaeria dothidea as the causal agent of a new fruit rot disease of pepper in China.

Pepper is an important and widely cultivated economic vegetable in the world (Yin et al., 2021). In June 2021, approximately 25% to 33.3% of the pepper plants had rot disease symptoms in Zhuanghang Comprehensive Experimental Base (30.894829 °N, 121.391374 °E), Fengxian district, Shanghai city, China. Water-soaked spots appeared on fruits that increased in size and leading to smelly fruit decay. To isolate the pathogen, three pepper samples with severe symptoms were collected. The samples were surface disinfected with 70% ethanol for 30 sec, 10% chlorine bleach for 10 min, rinsing with sterile water for three times and the rot tissues were cut and dried on sterile filter paper. The dried paper was later placed on potato dextrose agar (PDA) medium and incubated at 28°C (Tang et al., 2021). After 2-3 days, four types of colonies with different colony appearances were observed, in which only one can induce fruit rot phenotype (data not shown). Four isolates were cultured for molecular identification in each type. ITS1/ITS4, T1/ßt-2b and EF1-526F/EF1-1567R primers were used to amplify the internal transcribed spacer region (ITS), the beta-tubulin (TUB2) and the translation elongation factor I alpha (EF1-α) genes, respectively (Chen et al., 2018) and corresponding sequences from the isolates were analyzed with BLAST. Sequences of the isolate which can induce pepper decay were submitted to GenBank under the accession numbers of OM663701 (ITS), OM720127 (TUB2) and OM720128 (EF1-α). The results showed that the pathogen had 99% sequence homology to most strains of Botryosphaeria dothidea (B. dothidea) and displayed the highest sequence similarity to strain LBSX-1 (ITS: KF55123), strain JGT01 (TUB2: MW202404) and isolate CZA (EF1-α: MN025271). Based on molecular characterization, the isolate was identified as B. dothidea isolate SH01. A phylogenetic tree was constructed using Maximum Parsimony (MP) methods by MEGA7, and showed that SH01 was closely related to isolate CMW9075. To confirm the pathogenicity, five healthy pepper fruits were surface sterilized, 500µl of conidial suspension (1×103 conidia/ml) were injected into pepper (sterilized distilled water as control). Six days post inoculation (dpi), fruit rot symptoms appeared and the pepper decayed at 12 dpi. Four days post inoculation with mycelium plugs (from a 4-day-old culture on PDA, PDA plugs as control), hyphae were observed in the inoculation site and B. dothidea was re-isolated from the symptomatic areas, thus fulfilling Koch's postulates (Back et al., 2021, Chen et al., 2020). The pepper rotted severely at 7 dpi. The colonies of SH01 were pale to white and gradually turned into gray in 4-6 days. Conidia of the pathogen were unicellular, aseptate, hyaline and fusiform to fusoid, with dimensions of 19.7-23.5 µm × 3.8-5.2 µm (average = 21.9 µm × 4.8 µm, n = 50). Hyphae were transparent, branched and composed of multiple cells. The characteristic was consistent with the descriptions of B. dothidea (Vasic et al., 2013). B. dothidea belongs to Botryosphaeriaceae, causing widespread diseases in many plant species, commonly associated with cankers and dieback of woody plants and economic crops, such as plumcot trees (Back et al., 2021), eucalyptus (Yu et al., 2009) and soybeans (Chen et al., 2020) in China and Korea. Our findings reported for the first time that B. dothidea (SH01) can induce the pepper rot disease and future work on its pathogenesis may provide strategies for disease control against this fungus.

Indolo[2,3-b]carbazole synthesized from a double-intramolecular Buchwald-Hartwig reaction: its application for a dianchor DSSC organic dye.

A new synthetic strategy for indolo[2,3-b]carbazole via a double-intramolecular Buchwald-Hartwig reaction has been established. The N-alkylated indolo[2,3-b]carbazole then was adopted as the geometry-fixed core for the synthesis of a new molecule (ICZDTA) bearing two bithiophene π-bridged 2-cyanoacrylic acid groups as the bidentate anchor. The bidentate anchoring together with efficient HOMO (indolo[2,3-b]carbazole) → LUMO (TiO2 nanocluster) electron transfer leads to the successful development of ICZDTA-based DSSC with a power conversion efficiency of 6.02%.