Iron-Catalyzed Photoredox Alcohol α-C-H Alkylation and Tandem Intramolecular Cyclization: Facile Access to Multisubstituted 2,3-Dihydrofurans and γ-Butyrolactones.

Multisubstituted furans occupy a pivotal position within the realms of synthetic chemistry and pharmacological science due to their distinctive chemical configurations and inherent properties. We herein introduce a tandem difunctionalization protocol of alcohols for the efficient synthesis of multisubstituted 2,3-dihydrofurans and γ-butyrolactones through the combination of photocatalysis and iron catalysis under mild conditions. Photoredox alcohol α-C(sp3)-H activation and Pinner-type intramolecular cyclization are two key processes. This method features significant convenience, economic benefits, and environmental friendliness.

Highly selective and sensitive benzopyran-based fluorescent probes for imaging exogenous and endogenous peroxynitrite.

Peroxynitrite is widely present in organisms and closely related to many pathophysiological functions. Therefore, it is of great physiological significance to develop capable probes for detecting ONOO-. In this work, a novel fluorescent probe B-Ch was designed based on the intramolecular charge transfer (ICT) effect. By means of molecular engineering, the replacement from diethylamine group to hydroxyl group has improved the detection sensitivity of the probe. After the addition of ONOO-, the solution color and fluorescence showed noticeable changes, which were visible to the naked eye. The probe showed excellent advantages: visualization, good selectivity, low sensitivity (22.4 nM), good stability and biocompatibility, exogenous and endogenous imaging of ONOO- in HeLa cells.

Spectral features of the ferrous-CO complex in cytochrome P450: a revisit using TDDFT calculations.

There are different views in the literature regarding how to interpret the observed spectral features of the ferrous-CO complexes in cytochrome P450 enzymes (P450s). In this work, we applied density functional theory (DFT) and time-dependent DFT (TDDFT) calculations at the B3LYP-D3BJ/def2-TZVP level with a CPCM correction to the ferrous-CO models of P450s as well as of proteins that contain a histidine-ligated heme. Our results support the notion derived from a previously reported iterative extended Hückel calculation that the involvement of the sulfur lone-pair orbital (S(nz)) of the axial cysteine ligand in the electronic excitations gives rise to a spectral anomaly. The Q and the shorter-wavelength Soret (B') peaks are primarily due to the electronic transitions from the a2u- and S(nz)-type molecular orbitals (MOs), generated via an orbital interaction of fragment orbitals, to the near-degenerate eg-type π* MOs, respectively. The transitions from the a1u-type MO to the eg-type MOs contribute most to the longer wavelength Soret (B) peaks. Both a2u- and S(nz)-type MOs contribute to the B peaks, but the contribution of the latter is greater. When the axial ligand is histidine, the Q and Soret peaks originate essentially from the excitations from the a2u- and a1u-type MOs to the eg-type MOs. The transitions from the b2u-type MOs to the eg-type MOs play the most significant role in the N peaks of such ferrous-CO complexes. Here, the b2u-type MOs have a large contribution from the imidazole π orbital.

Energy Decomposition Analysis of the Nature of Coordination Bonding at the Heme Iron Center in Cytochrome P450 Inhibition.

Drug compounds or their metabolic intermediates (MIs) sometimes inhibit the function of cytochrome P450 enzymes (P450s) by forming a coordination bond with the Fe(III) heme or Fe(II) heme of P450s. Such inhibition is one of the major causes of drug-drug interactions (DDIs), a subject of longstanding academic and practical interest. However, such coordination bonding is not fully understood at the quantum mechanical level, thus hampering rational improvement of the accuracy of DDI-related predictions. In this work, we employed density functional theory (DFT) and the generalized Kohn-Sham energy decomposition analysis (GKS-EDA) scheme to investigate the nature of the coordination bonding formed in the reversible and quasi-irreversible inhibition of P450s. The GKS-EDA results highlighted a previously unrecognized role of the electron correlation effect in P450 inhibition. The correlation effect tends to be larger in Fe(II) complexes of MI-type inhibitors and is particularly prominent for the nitrosoalkane ligand. An additional natural bond orbital (NBO) analysis provided insight into the relative significance of the σ donation and π backdonation effects in various heme-inhibitor complexes.

Iron-Catalyzed Photoredox Functionalization of Methane and Heavier Gaseous Alkanes: Scope, Kinetics, and Computational Studies.

Herein, we report the development of the photocatalytic C-H functionalization of methane, ethane, and heavier gaseous alkanes with good yields and selectivity, broad scope (57 examples), mild conditions, and low cost. Kinetics and density functional theory calculations were investigated for the key photoinduced ligand-to-metal charge transfer and hydrogen atom transfer processes to reveal the detailed mechanism of iron photocatalysis. This work may bring novel ideas for feedstock upgrading and catalyst design.

Similar infection rates in a new wound closure method following knee arthroplasty.

Surgical site infections, defined as acute wound infections requiring surgical intervention within 90 days post-surgery, were retrospectively compared between a novel, zipper-like closure method (ZM) and staples in 682 patients (904 knees) and 772 patients (971 knees), respectively. The incidence of deep infections was 0.6% for staples and 0.2% for ZM (p = 0.169) and superficial infections was 0.1% for staples and 0.0% for ZM (p = 0.518). With no difference in wound complications, the ZM may be preferred since the two-week post-operative clinic visit required for wound check and staple removal was eliminated, thereby, decreasing clinic volume.

[Efficacy of Decitabine Combined with Pre-Excitation Chemotherapy in the Treatment of Middle-Aged and Elderly MDS Transformed Acute Myeloid Leukemia].

OBJECTIVE: To investigate the efficacy of domestic decitabine (D) combined with pre-excitation chemotherapy consisted of Ara-c, THP and G-CSF(CTG) in treatment of middle-aged and elderly patients with MDS-transformed AML and prognosis-related factors. METHODS: Seventy-six patients with MDS-transformed AML treated in our hospital from June 2013 to June 2015 were selected according to treatment regimens, 76 patients were divided into 2 groups: CTG group(36 cases) and D+CTG group(40 cases). The patients in CTG group received treatment with Ara-C, THP and G-CSF; the patients received the treatment with decitabine plus CTG. The patients in 2 groups all received 4 course treatment, then received maintaining treatment. The therapeutic efficacy and incidence of adverse reactions in 2 group were compared, at the same time, the risk factors affecting the prognos of patients treated with D+CTG were analyzed. RESULTS: There were no siginificant differences in age, sex, initial blood cell count, bone marrow blast ratio, disease types, chromosome karyotypes and FLT3-ITD gene mutation between 2 groups. The efficacy analysis showed that the efficacy of D+CTG was superior to CTG, ORR in D+CTG group was significantly higher than that in CTG group (72、52 vs 50%) (P<0.05), moreover, no significant differences in bone marrow inhibition digree infeetion, gastroinfestinal response and liver damage were found between 2 groups (P>0.05). The follow-np for 2 years showed that the median survival time in D+CTG group was significantly longer than that in CTG group (19.9 vs 11.0 months) (P<0.05). The multivariate analysis showed that the 1 course efficacy (RR=3.926, P=0.015) and FLT3-ITD gene mutation (RR=4.347, P=0.004) were independent risk factors affecting the efficacy of D+CTG treatment. CONCLUSION: The short-and long-term efficacy of domestic decitasine combined with preexcitation chenotherapy in treatment of middec-aged and eldery patients with MDS transformed AML is superior to single pre-excitation chenothrapy, moreover the incidence of adverse reactions did not increase. The 1 course efficacy and FLT-3 ITD gene mutation are the independent risk factors affecting the prognosis of patients. .