Strategies for the Construction of Benzobicyclo[3.2.1]octane in Natural Product Synthesis.

Benzobicyclo[3.2.1]octane is a cage-like unique motif containing a bicyclo[3.2.1]octane structure fused with at least one benzene ring. It is found in various natural products that exhibit structural complexities and important biological activities. The total synthesis of natural products possessing this challenging structure has received considerable attention, and great advances have been made in this field during the past 15 years. This review summarizes thus far achieved chemical syntheses and synthetic studies of natural compounds featuring the benzobicyclo[3.2.1]octane core. It focuses on strategic approaches constructing the bridged structure, aiming to provide a useful reference for inspiring further advancements in strategies and total syntheses of natural products with such a framework.

Metal- and light-free decarboxylative direct C-H alkylation of heteroarenes at room temperature.

This study reports a metal- and light-free decarboxylative C-H alkylation of heteroarenes at room temperature. The reaction generates various primary, secondary, and tertiary alkyl radicals and functionalizes seven different privileged scaffolds widely present in bioactive molecules. During this process, one equivalent of hypervalent iodine(III) carboxylates (HICs) plays dual roles as an alkyl radical precursor and an oxidant.

A CuSO4/Bicinchoninic acid/Reducing sugar based stable and non-ROS catalyst system for the CuAAC reaction in bioanalysis.

The limitations of commonly used sodium ascorbate-based catalyst system for copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction include excess production of reactive oxygen species and rapid catalyst deactivation. In this study instead of using a highly active reducing agent, such as, sodium ascorbate, we chose reducing sugar as a mild reducing agent to build up the catalyst system for CuAAC reaction. Interestingly, the bicinchoninic acid (BCA) assay system containing reducing sugar satisfies the essential elements of the catalyst system for CuAAC reaction. We found that CuSO4/BCA/Reducing sugar system can catalyze the CuAAC reaction but with low yield. Rational analyses of various parameters in CuSO4/BCA/Glucose catalyst system suggested storage at room temperature might enhance the catalytic activity, which was proven to be the case. Importantly, the system remains stable at room temperature and minimal H2O2 was detected. Notably, our study showed that the coordination between the slow reduction of Cu(I) by reducing sugar and the selective chelation of Cu(I) by BCA is key to developing this system. The CuSO4/BCA/Reducing sugar catalyst system was successfully applied to various CuAAC reaction based bioanalyses, and it is suitable for the CuAAC reaction based bioanalyses that are sensitive to ROS or request long reaction time.

Three-Step Synthesis of the Antiepileptic Drug Candidate Pynegabine.

Pynegabine, an antiepileptic drug candidate in phase I clinical trials, is a structural analog of the marketed drug retigabine with improved chemical stability, strong efficacy, and a better safety margin. The reported shortest synthetic route for pynegabine contains six steps and involves the manipulation of highly toxic methyl chloroformate and dangerous hydrogen gas. To improve the feasibility of drug production, we developed a concise, three-step process using unconventional methoxycarbonylation and highly efficient Buchwald-Hartwig cross coupling. The new synthetic route generated pynegabine at the decagram scale without column chromatographic purification and avoided the dangerous manipulation of hazardous reagents.

Asymmetric Total Synthesis of Naphthospironone A.

Naphthospironone A, a polyhydroxy cagelike bioactive natural product, was synthesised for the first time in this study. The spiro[bicyclo[3.2.1]octane-pyran] core was constructed by an acid-promoted epoxide-opening lactonisation and a base-induced intramolecular aldol-type cyclisation.

Long-pulsed neodymium-doped yttrium-aluminum-garnet laser versus cryotherapy for the treatment of cutaneous warts: A randomized controlled trial.

BACKGROUND: Observational studies have shown promising therapeutic effects of long-pulsed neodymium-doped yttrium-aluminum-garnet (LP-Nd:YAG) laser on warts. OBJECTIVE: To evaluate whether LP-Nd:YAG laser was superior to cryotherapy for cutaneous warts. METHODS: In this study, 150 adult patients with warts were randomized equally to receive laser or cryotherapy every 3 to 4 weeks, for a maximum of 4 sessions. The primary outcomes were the cure rates at 16 weeks and 6 months; secondary outcomes included time to clearance of warts and treatment-related adverse effects. RESULTS: There was no difference in the cure rate for laser versus cryotherapy at 16 weeks (54.1% vs 46.7%, respectively) and 6 months (59.5% vs 57.3%, respectively). However, time to clearance of warts, up to 16 weeks and 6 months, tended to be shorter for laser versus cryotherapy (P = .04 and .08, respectively). Post hoc analyses showed a significantly higher cure rate for laser versus cryotherapy in 3 subgroups of human papillomavirus 2/27/57-induced recalcitrant warts but not in their counterpart subgroups. Laser had more mild adverse effects. LIMITATIONS: Single center. CONCLUSIONS: The overall therapeutic effects of LP-Nd:YAG laser were similar to cryotherapy, but laser may be more effective to relatively recalcitrant warts and may be associated with shorter time to clearance of warts.

Toward the total synthesis of grayanane diterpene mollanol A by a Prins [3 + 2] strategy.

Toward the total synthesis of a novel grayanoid, mollanol A, we developed a concise convergent strategy based on a formal [3 + 2] cyclization initiated by the Prins reaction. In this key intermolecular reaction between an unprotected hydroxyaldehyde and activating-group-free olefins, two chiral carbons and one densely substituted tetrahydrofuran ring were constructed stereoselectively.

Strategies and Efforts towards the Total Synthesis of Palhinine Alkaloids.

The palhinine family of Lycopodium alkaloids were first reported in 2010, which feature an intriguing isotwistane carbon cage and a nine-membered azonane ring. It is noteworthy that the tetracyclic 5/6/6/9 skeleton was unprecedented in Lycopodium alkaloids before their seminal discovery. Over the past decade, extensive synthetic efforts stemming from seven research groups have resulted in two racemic total syntheses to date. This review article takes the opportunity to survey these efforts and achievements so as to promote further research towards the asymmetric total synthesis of palhinine alkaloids.

Combination of PhI(OAc)2 and 2-Nitropropane as the Source of Methyl Radical in Room-Temperature Metal-Free Oxidative Decarboxylation/Cyclization: Construction of 6-Methyl Phenanthridines and 1-Methyl Isoquinolines.

A room-temperature metal-free method for generating highly unstable methyl radical was realized from the combination of PhI(OAc)2 and 2-nitropropane, which provides an efficient approach to methylated phenanthridines and isoquinolines. The strategy was also extended to the generation of other alkyl radicals and a concise synthesis of Roxadustat.

Silver-catalyzed C2-selective direct alkylation of heteroarenes with tertiary cycloalkanols.

A silver-catalyzed regioselective C2-alkylation of heteroarenes with tertiary cycloalkanols under radical conditions was developed. This tandem process, which includes selective C-H activation, C(sp3)-C(sp3) bond cleavage, and C(sp3)-C(sp2) bond formation, affords a novel and environmentally friendly approach for the production of carbonyl-containing alkyl-substituted heteroarenes with moderate to good yields.

[Research on Prevention and Treatment of Cardiovascular Disease by Translational Medicine Based Chinese Medicine].

Translational medicine is inevitable in the development of modern medicine, and the uprising concept of translational medicine provides an opportunity for the development of Chinese medicine (CM). Their ideas are well communicated. There are two patterns of researching on CM based on translational medicine: 'literature to bench to bedside' and 'bench to bedside to bench'. CM has her advantages in preventing and treating cardiovascular disease. Effective methods for preventing and treating cardiovascular disease by CM should be further studied based on translational medicine concepts.

Chinese Herbal Medicine for the Treatment of Adult Viral Myocarditis: An Overview of Systematic Reviews and Meta-analyses of Randomized Controlled Trials.

PURPOSE: Viral myocarditis (VMC) is a life-threatening disease that can affect all ages and genders, with middle-aged adults being particularly susceptible. Numerous systematic reviews have been conducted to investigate the efficacy and safety of Chinese herbal medicine (CHM) in treating adult viral myocarditis (AVM). The objective of this study was to conduct a comprehensive overview of systematic reviews and meta-analyses of randomized controlled trials (RCTs) regarding the efficacy and safety of CHM for AVM. METHODS: A comprehensive systematic search was conducted across 8 electronic databases from their inception to June 23, 2022, augmented by manual searches of the gray literature. Systematic reviews were independently selected and data extracted in accordance with predetermined criteria by 2 reviewers. Included systematic reviews were assessed for methodologic and reporting quality using Assessing the Methodological Quality of Systematic Reviews 2 and Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The quality of evidence relating to outcome measures was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation tool. Recalculation of effect sizes and subsequent determination of 95% CIs were conducted with either a fixed-effects or random-effects model. FINDINGS: The current overview of systematic reviews included a total of 6 systematic reviews, which reported on 67 RCTs with a participant pool of 5611 individuals. The findings of our study indicate that the combination of CHM and Western medications had positive effects on the effective rate, cure rate, ECG recovery, atrial premature contraction/premature ventricular contraction, left ventricular ejection fraction, myocardial enzymes, and improvement of clinical symptoms for AVM. The adverse drug reactions in the combination therapy group were generally less than or lighter than that in the Western medication group (relative risk = 0.79; 95% CI, 0.44-1.40; P > 0.05, I2 = 0). IMPLICATIONS: Our research results provide evidence that combining CHM with Western medicine could offer potential benefits for patients with AVM. However, the number of studies included in our review is limited and the methodologic quality of these studies is modest. Therefore, there are potential uncertainties regarding the conclusion that CHM with Western medication may benefit patients with AVM. We call for more large-scale, high-quality studies with standardized designs to further verify and support our findings. This would promote a better understanding of the efficacy and safety profile of CHM and provide reliable reference evidence for clinical practice and policy making. Moreover, future research should explore optimal drug combinations, examine therapeutic doses and durations of CHM combination therapy, and evaluate its long-term efficacy and safety.

Iodine(III)-mediated tandem oxidative cyclization for construction of 2-nitrobenzo[b]furans.

Various 3-alkyl-2-nitrobenzo[b]furans were synthesized from common intermediate 2-(2-nitroethyl)phenols via a hypervalent iodine-induced oxidative cyclization, with good to excellent yields. This facile route is able to efficiently functionalize 2-nitrobenzo[b]furans, which are difficult to obtain by classical methods.

[Current research situation of atherosclerotic vulnerable plaque and discussion of the efficacy of simiao yongan decoction].

The vulnerable plaque is the basis for atherosclerosis (AS) plaque rupture and thrombosis, thus further leading to the occurrence of acute cardiovascular events (ACEs). By analyzing the current research situation of atherosclerotic vulnerable plaque, identifying that inflammation and thrombosis are key links in plaque vulnerability, and the roles of white blood cell and platelet aggregation, endothelial cell adhesion and their common connection mechanisms: PS/PSGL-1 in inflammation and the formation of thrombosis. From the viewpoints of inhibiting cell adhesion, fighting against inflammation reaction and thrombosis, the research ideas of Simiao Yongan Decoction in stabilizing atherosclerotic vulnerable plaque were explored.

[Analysis on the Chinese medicine syndrome and therapy in patients with coronary heart disease after intervention].

Along with the extensive application of intervention in treating coronary heart disease (CHD), problems such as post-interventional restenosis, no reflowing, and slow flowing, and so on increasingly emerge. Chinese medicine and pharmacy occupy advantages covering preventing post-intervention risk factors, improving and relieving patients' symptoms, and so on. It is a good support and supplement for routine therapies in modern medicine. Taking the pathological stages of CHD and clinical problems of coronary intervention as the breakthrough points, the Chinese medical syndromes and correspondent Chinese medicine recipes and herbs were preliminarily studied by combining Chinese medicine's recognition and clinical observation on coronary intervention.

K2S2O8-mediated radical cyclisation of 2-alkynylthioanisoles or -selenoanisoles: a green and regioselective route to 3-nitrobenzothiophenes and benzoselenophenes.

An acid, transition-metal, and chromatography-free radical nitration/cyclisation of 2-alkynylthioanisoles or -selenoanisoles has been developed. This is the first example of the use of highly unstable 2-nitrovinyl radicals for C-S bond formation. This facile route efficiently produces 3-nitrobenzothiophenes and benzoselenophenes, which are difficult to access via classical methods. Density functional theory (DFT) calculations were carried out to probe the reaction mechanism. The resulting products were tested for their in vitro anti-tuberculosis activity, and compounds 2d and 2l showed significant activities against sensitive and drug-resistant strains.

Rhodium-Catalyzed Ring-Opening Hydroacylation of Alkylidenecyclopropanes with Chelating Aldehydes for the Synthesis of γ,δ-Unsaturated Ketones.

The first intermolecular ring-opening hydroacylation of alkylidenecyclopropanes with chelating aldehydes through a rhodium-catalyzed acrylamide-promoted protocol is reported. This highly efficient catalytic system enables the direct synthesis of a diverse range of linear γ,δ-unsaturated ketones. Good functional group compatibility is demonstrated for the completely atom-economical and remarkably selective proximal C-C bond cleavage process. Mechanistic studies reveal that the bidentate coordination of N,N-dimethylmethacrylamide (L1) to the acylrhodium intermediates might facilitate the cyclopropane ring fragmentation and isomerization.

Synthesis of the Tricyclic Caged Core of Palhinine Alkaloids Based on a Non-Diels-Alder-Type Strategy.

A concise synthesis of the tricyclo[4.3.1.03,7]decane caged core of palhinine alkaloids was developed with SmI2-mediated cyclization and light-initiated radical addition-fragmentation as key steps. Compared with the reported racemic routes which are all based on Diels-Alder-type key reactions, our strategy would be more readily accessible to the asymmetric total syntheses of the palhinine alkaloids.

A randomized clinical study on optimum proposal of integration of disease and syndrome to treat viral myocarditis.

OBJECTIVE: To determine the optimum treatment for viral myocarditis (VMC). METHODS: A total of 126 VMC patients were randomly divided into the control group (42 cases) that was treated with conventional Western medicine, and the intervention group (84 cases) that was treated with a combination of Chinese medicine (CM) and Western medicine intervention termed optimum proposal of integration of disease and syndrome (OPIDS). Before and after 4 weeks of treatment, the integral of CM syndrome, self-rating depression and anxiety scales (SDS and SAS, respectively), echocardiograms (ECGs), heart rate variability and left ventricular systolic function were observed. RESULTS: Compared with the control group, the intervention group showed significant reductions on the SDS and SAS (P <0.05); improvement of premature ventricular beats, atrioventricular blocks, ST-segment abnormalities, and significant T wave changes (P <0.05); greater reductions in standard deviation of NN intervals (SDNN), standard deviation for per 5 min averages NN intervals (SDANN), and root-mean-square of successive difference of NN intervals (rMSSD) (P <0.05); and increases in cardiac output, stroke volume, and ejection fraction, the last of which was statistically significant (P <0.05). Overall, the treatment efficacy rate was significantly better P<0.05) in the intervention group (75.61%) compared with the control group (69.70%). CONCLUSION: OPIDS is quite effective in treating VMC and improves symptoms such as anxiety and depression, left ventricular systolic dysfunction, premature ventricular contraction, and cardiac autonomic nervous system dysfunction. [ REGISTRATION: Chinese clinical trial center (No. ChiCTR-TRC-00000298)].