RESUMEN
Highly selective and catalyst-free tandem multi-functionalization of terminal alkynes was developed with 2-oxindoles and benzo-furan-2(3H)-one using TEMPO both as a radical promoter and a trapping reagent. This work expands the scope of the radical-cascade addition/trapping process of alkynes for the effective construction of various ß-oxyl carbonyls in moderate to good yields.
RESUMEN
We report the first catalyst-free and trans-selective iodoalkylation reaction of alkynes with a series of α-carbonyl compounds. This unprecedented three-component iodoalkylation reaction is enabled by using (iodoethynyl)trimethylsilane as a radical initiator and iodide source. The 1,2-difunctionalization affords alkenyl iodides, which are versatile building blocks for the construction of tri-substituted alkene derivatives.
RESUMEN
Correction for 'Unprecedented formation of 3-(tetrahydrofuran-2-yl)-4H-chromen-4-one in a reaction between 3,3a-dihydro-9H-furo[3,4-b]chromen-9-one and malononitrile' by Jie-Jie Liu, et al., Org. Biomol. Chem., 2017, DOI: 10.1039/c7ob00904f.
RESUMEN
Chromone skeletons are widespread among natural products as well as bioactive molecules. Here, we describe an unprecedented reaction of furo[3,4-b]chromen-9-one with malononitrile to afford 3-(tetrahydrofuran-2-yl)-4H-chromen-4-ones. Experimental data suggest that a sequence of Michael/retro-Michael/nucleophilic addition is involved in this unprecedented transformation.
RESUMEN
An effective transition-metal-free approach for the synthesis of 3-alkynyl-2-oxindoles through a radical-radical coupling process was developed. The reaction was general with respect to 2-oxindoles and iodoalkynes and provided the desired products bearing a quaternary center at C3 in good to excellent yields, making this method synthetically viable and attractive for the synthesis of spiro and fused 2-oxindole derivatives.
RESUMEN
Wound healing is a troublesome problem in diabetic patients. Besides, there is also an increased risk of postsurgical wound complications for diabetic patient. It has been revealed that traditional Chinese medicine may promote healing and inhibit scar formation, while the changes of morphology and physiology of wounds on such medicine treatment still remain elusive. In this study, we first used the ultralow temperature preparation method to produce mixed superfine powder from Agrimonia pilosa (A), Nelumbo nucifera (N), Boswellia carteri (B), and Pollen typhae (P), named as ANBP. Applying ANBP on 40 streptozotocin (STZ)-induced diabetic C57BL/6 mice (4-6 weeks, 20 ± 2 g), we observed that the wound healing process was accelerated and the wound healing time was shortened (14 days, P < .05). Pathological observation using hematoxylin-eosin staining indicated that inflammatory cells were reduced (P < .05) while the thickness of granulation tissue and length of epithelial tongue were increased (P < .05). The vascular density was increased on 7 and 14 days after ANBP treatment. Masson and Sirius red staining showed that, at the early stage of trauma, the expressions of Col I and Col III, especially Col III, were increased in the ANBP group (P < .05). Studies in vitro demonstrated that tubular formation was significantly increased after ANBP treatment on human vascular endothelial cells in a dose-dependent way. Taken together, our studies revealed that ANBP treatment could accelerate wound healing, promote vascularization, and inhibit inflammation, suggesting the potential clinic application of ANBP for diabetes mellitus and refractory wounds.
Asunto(s)
Diabetes Mellitus Experimental , Medicamentos Herbarios Chinos/uso terapéutico , Fitoterapia , Cicatrización de Heridas/efectos de los fármacos , Animales , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
The four-herb Chinese medicine ANBP is a pulverized mixture of four herbs including Agrimonia Eupatoria (A), Nelumbo Nucifera Gaertn (N), Boswellia Carteri (B) and Pollen Typhae Angustifoliae (P). The combination of the four herbs was first described in Chinese canonical medicine about 2000 years ago for treatment of various trauma disorders, such as hemostasis, antiinflammatory, analgesia, and wound healing, etc. However, the precise mechanisms of ANBP are still unclear. In our study, using rabbit ear hypertrophic scar models of full-thickness skin defect, we showed that local ANBP treatment not only significantly enhanced wound healing by relieving inflammation, increasing formation of granulation tissue and accelerating re-epithelialization, but also reduced scar formation by decreasing collagen production, protuberant height and volume of scars, and increasing collagen maturity. We demonstrated that these effects of ANBP are associated with transforming growth factor (TGF)-ß1-mediated signalling pathways through Smad-dependent pathways. ANBP treatment significantly increased expression of TGF-ß1 and Smad2/3 mRNA at the early stage of wound healing, and led to markedly decrease expression of TGF-ß1 and Smad2/3 compared with the control group after 14 days post-wounding. Taken together, our results defined a bidirectional regulation role of ANBP for TGF-ß1/Smad pathway in promoting wound healing and alleviating scar formation, which may be an effective therapy for human wounds at the earliest stage.