Extending the Grading of Recommendations Assessment, Development and Evaluation (GRADE) in Traditional Chinese Medicine (TCM): The GRADE-TCM.

AIM: To extend and form the "Grading of Recommendations Assessment, Development and Evaluation in Traditional Chinese Medicine" (GRADE-TCM). METHODS: Methodologies were systematically reviewed and analyzed concerning evidence-based TCM guidelines worldwide. A survey questionnaire was developed based on the literature review and open-end expert interviews. Then, we performed expert consensus, discussion meeting, opinion collection, external examination, and the GRADE-TCM was formed eventually. RESULTS: 265 Chinese and English TCM guidelines were included and analyzed. Five experts completed the open-end interviews. Ten methodological entries were summarized, screened and selected. One round of consensus was conducted, including a total of 22 experts and 220 valid questionnaire entries, concerning 1) selection of the GRADE, 2) GRADE-TCM upgrading criteria, 3) GRADE-TCM evaluation standard, 4) principles of consensus and recommendation, and 5) presentation of the GRADE-TCM and recommendation. Finally, consensus was reached on the above 10 entries, and the results were of high importance (with voting percentages ranging from 50 % to 81.82 % for "very important" rating) and strong reliability (with the Cr ranging from 0.93 to 0.99). Expert discussion meeting (with 40 experts), opinion collection (in two online platforms) and external examination (with 14 third-party experts) were conducted, and the GRADE-TCM was established eventually. CONCLUSION: GRADE-TCM provides a new extended evidence-based evaluation standard for TCM guidelines. In GRADE-TCM, international evidence-based norms, characteristics of TCM intervention, and inheritance of TCM culture were combined organically and followed. This is helpful for localization of the GRADE in TCM and internationalization of TCM guidelines.

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.

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.

Comparative phosphoproteomic analysis reveals that phosphorylation of sucrose synthase GhSUS2 by Ca2+-dependent protein kinases GhCPK84/93 affects cotton fiber development.

Cotton fiber elongation is a critical growth phase that affects final fiber length. Morphological analysis indicated an asynchronous fiber elongation pattern between two cotton varieties, J7-1 and J14-1. Through phosphoproteomic analysis, a total of 89 differentially-phosphorylated proteins (DPPs) were identified in elongating fibers between J7-1 and J14-1. Gene ontology (GO) analysis showed that these DPPs were mainly enriched in sucrose synthase activity, transferase activity, and UDP-glycosyltransferase activity. In J14-1, the phosphorylation level of GhSUS2, a key sucrose synthase in the sucrose metabolism pathway, was significantly higher than that in J7-1. We further revealed that GhSUS2 positively regulates fiber elongation, and GhSUS2-silenced transgenic cotton displayed the phenotype of 'short fibers' compared with the controls. During fiber development, the residue Ser11 in the GhSUS2 protein is phosphorylated by the Ca2+-dependent protein kinases GhCPK84 and GhCPK93. Phosphorylated GhSUS2 is localized in the cytoplasm, whereas unphosphorylated GhSUS2 is localized in the plasma membrane. Moreover, abscisic acid (ABA) could promote the transcription and translation of GhCPK84 and GhCPK93, thereby enhancing the phosphorylation of GhSUS2 to impede fiber elongation. Thus, our data demonstrates that GhSUS2 plays a positive role in fiber development, but its phosphorylation by GhCPK84 and GhCPK93 hinders fiber elongation of cotton.

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.

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.

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.

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.