Chemical constitutes from Tuber indicum with immunosuppressive activity uncovered by transcriptome analysis.

Three previously undescribed compounds including a polyketide (1) and two lactams (2 and 3) were obtained from Tuber indicum. The structures of new findings were elucidated by HRESIMS, NMR as well as NMR and ECD calculations. Transcriptome analysis through RNA-seq revealed that compound 2 exhibits immunosuppressive activity. Lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages were employed as a model to explore the effect of these compounds in immunosuppressive activity. The results showed that 2 could reduce the generation of inflammatory mediators including nitric oxide (NO), reactive oxygen species (ROS), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). Western blotting analysis demonstrated that 2 could suppressed the PI3K pathway by decreasing the levels of p-PI3K and p-Akt, while increasing the levels of p-PTEN. The anti-inflammatory activity of 2 was further confirmed using a zebrafish in vivo model.

Detection of the tetrahedral reaction intermediate of the reaction of acetyl chloride with ethanol in microdroplets via laser desorption/ionization tandem mass spectrometry.

Understanding the fundamental mechanisms of chemical reactions is of great interest to scientists working in many fields as it enables the rationalization, prediction, and design of reactions. Many chemical processes involve the formation of short-lived reaction intermediates, most of which cannot be isolated and are challenging to detect. One such intermediate is the tetrahedral intermediate often proposed to be generated upon the reactions of acetyl chlorides with simple alcohols via an addition/elimination mechanism. However, the formation of this tetrahedral intermediate is a subject of controversy as it has not been detected. Furthermore, some kinetic evidence suggests the SN2 mechanism for this reaction. In the present investigation, a 266 nm pulsed Nd:YAG laser was used to evaporate and ionize reactants, reaction intermediates, and products in microdroplets of acetyl chloride and ethanol. A linear quadrupole ion trap mass spectrometer was used to detect the ions and collision-activated dissociation (CAD) experiments were employed for their structural characterization. The results demonstrate the formation of the protonated tetrahedral intermediate of the addition/elimination reaction. The protonated reaction intermediate was isolated and subjected to CAD, which resulted in the loss of water and ethylene, thus confirming its structure. These results demonstrate that the ethanolysis of acetyl chloride proceeds via an addition/elimination mechanism involving a tetrahedral reaction intermediate. However, the parallel occurrence of the SN2 mechanism cannot be ruled out.

Pretreatment elevated fibrinogen level predicts worse oncologic outcomes in upper tract urothelial carcinoma.

This study aimed to further validate the prognostic role of fibrinogen in upper tract urothelial carcinoma (UTUC) in a large Chinese cohort. A total of 703 patients who underwent radical nephroureterectomy were retrospectively identified. Fibrinogen levels of ≥4.025 g l-1 were defined as elevated. Logistic regression analysis was performed to determine the association between fibrinogen and adverse pathological features. Kaplan-Meier analysis and Cox regression models were used to assess the associations of fibrinogen with cancer-specific survival (CSS), disease recurrence-free survival (RFS), and overall survival (OS). Harrell c-index and decision curve analysis were used to assess the clinical utility of multivariate models. The median follow-up duration was 42 (range: 1-168) months. Logistic regression analysis revealed that elevated fibrinogen was associated with higher tumor stage and grade, lymph node involvement, lymphovascular invasion, sessile carcinoma, concomitant variant histology, and positive surgical margins (all P < 0.05). Multivariate Cox regression analysis demonstrated that elevated fibrinogen was independently associated with decreased CSS (hazard ratio [HR]: 2.33; P < 0.001), RFS (HR: 2.09; P < 0.001), and OS (HR: 2.09; P < 0.001). The predictive accuracies of the multivariate models were improved by 3.2%, 2.0%, and 2.8% for CSS, RFS, and OS, respectively, when fibrinogen was added. Decision curve analysis showed an added benefit for CSS prediction when fibrinogen was added to the model. Preoperative fibrinogen may be a strong independent predictor of worse oncologic outcomes in UTUC; therefore, it may be valuable to apply this marker to the current risk stratification in UTUC.

Polar Effects Control the Gas-Phase Reactivity of para-Benzyne Analogs.

We report herein a gas-phase reactivity study on a para-benzyne cation and its three cyano-substituted, isomeric derivatives performed using a dual-linear quadrupole ion trap mass spectrometer. All four biradicals were found to undergo primary and secondary radical reactions analogous to those observed for the related monoradicals, indicating the presence of two reactive radical sites. The reactivity of all biradicals is substantially lower than that of the related monoradicals, as expected based on the singlet ground states of the biradicals. The cyano-substituted biradicals show substantially greater reactivity than the analogous unsubstituted biradical. The greater reactivity is rationalized by the substantially greater (calculated) electron affinity of the radical sites of the cyano-substituted biradicals, which results in stabilization of their transition states through polar effects. This finding is in contrast to the long-standing thinking that the magnitude of the singlet-triplet splitting controls the reactivity of para-benzynes.