Experimental and Computational NMR Studies of Large Alkaloids Exemplified With Vindoline Trimer: Advantages and Limitations.

The complete H and C NMR assignments of a trimeric vindoline together with its individual components, dimeric vindolicine and monomeric vindoline, are performed based on a thorough analysis of the ROESY, COSY, HSQC, and HMBC spectra in combination with the state-of-the-art quantum-chemical calculations. A spatial structure of vindoline trimer is determined by means of computational conformational analysis in combination with the probability distribution map of its basic conformers. On the example of monoterpene indole alkaloid, the trimer vindoline, the present study reveals the power of modern computational NMR to perform identification and stereochemical studies of large natural compounds with some limitations, which may arise in the quantum chemical computing workflow.

Photo- and X-ray Induced Cytotoxicity of CeF-YF-TbF Nanoparticle-Polyvinylpyrrolidone-"Radachlorin" Composites for Combined Photodynamic Therapy.

The CeYTbF nanoparticles with a CeF hexagonal structure were synthesized using the co-precipitation technique. The average nanoparticle diameter was 14 ± 1 nm. The luminescence decay curves of the CeYTbF nanoparticles (λ = 541 nm, D-F transition of Tb) conjugated with Radachlorin using polyvinylpyrrolidone coating as well as without Radachlorin were detected.

Evaluation of the effectiveness and safety of photodynamic therapy in the treatment of precancerous diseases of the cervix (neoplasia) associated with the human papillomavirus: A systematic review.

This study provides an overview of the effectiveness and safety of PDT for the treatment of HPV-associated precancerous cervical conditions and contains recent findings from relevant research studies. A comprehensive literature search of MEDLINE/PubMed, Cochrane Central Library, and Google Scholar was conducted, including analytic epidemiological studies, and 11 papers were included. The narrative synthesis approach was used to summarize the results of the included studies.

Star algorithm for neural network ensembling.

Neural network ensembling is a common and robust way to increase model efficiency. In this paper, we propose a new neural network ensemble algorithm based on Audibert's empirical star algorithm. We provide optimal theoretical minimax bound on the excess squared risk.

6aH-Benzo[α]fluorene: NMR evidence of the unexpected product of the reaction of butyryl chloride with 1,2-diphenylacetylene.

The reaction of butyryl chloride with ethynylbenzene in the presence of AlCl afforded a mixture of the Z/E-isomers of 1-chloro-2-phenylhex-1-en-3-one. 1,2-Diphenylethyne under these conditions gave a novel polycarbocycle core, 6aH-benzo[a]fluorene. The chemical structure of 11-chloro-5,6-diphenyl-6a-propyl-6aH-benzo[a]fluorene was established by means of IE-MS, H, C NMR, COSY, HSQC, HMBC, and 2D INADEQUATE technique.