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2.
Org Biomol Chem ; 21(33): 6772-6777, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37563967

RESUMEN

A novel photocatalytic protocol for effective and efficient synthesis of cyclic 1,5-diketones containing chroman-4-one skeletons in moderate to good yields via radical cascade acylmethylation/cyclization of 2-(allyloxy)arylaldehydes with α-bromo ketones has been described. This reaction features a broad substrate scope, good functional group tolerance, and metal- and oxidant-free conditions. An acylmethyl radical-triggered cascade cyclization was involved.

3.
Microb Pathog ; 181: 106201, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37321424

RESUMEN

Foxtail millet (Setaria italica [L.] P. Beauv.) is an important cereal worldwide. From 2021 to 2022, stalk rot disease of foxtail millet was identified in Shanxi province, northern China, with an 8% and 2% field incidence rate in Xinzhou (2 different locations), respectively. It caused necrosis, decay, stem lodging, and sometimes death. This study aimed to identify the causal agent of the disease through morphophysiological and molecular identification of the isolates. Stalk rot specimens were collected in Xinzhou, from foxtail millet plants exhibiting typical symptoms, and the pathogen was isolated with dilution plating. It was cultured at 28 °C for 48 h on nutrient agar, revealing circular, convex, and pale-yellow colonies, with a smooth surface and an entire edge. Scanning electron microscopy showed that the pathogen is rod shaped, round ended and has an uneven surface ranging from 0.5 to 0.7 µm in diameter and 1.2-2.7 µm in length. It is a motile gram-negative facultative anaerobic bacterium that can reduce nitrate and synthesize catalase but cannot hydrolyze starch. It also shows a negative reaction in the methyl red test and optimum growth at 37 °C. The pathogenicity test was performed on foxtail millet variety 'Jingu 21' stem to confirm Koch's postulates. The biochemical tests were done in the Biolog Gen III MicroPlate, revealing 21 positive chemical sensitivity tests, except those for minocycline and sodium bromate. Furthermore, among 71 carbon sources, the pathogen utilized 50 as the sole carbon source, including sucrose, d-maltose, α-d-lactose, d-galactose, D-sorbitol, D-mannitol, glycerol, and inositol. Finally, molecular characterization of the pathogen using 16S rRNA and rpoB gene sequencing and subsequent phylogenetic analysis identified the strain as Kosakonia cowanii. This study is the first to report K. cowanii as a stalk rot-causing pathogen in foxtail millet.


Asunto(s)
Setaria (Planta) , Filogenia , Setaria (Planta)/genética , Composición de Base , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
4.
Front Neurosci ; 17: 1203104, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37383107

RESUMEN

Recent years have witnessed a significant advancement in brain imaging techniques that offer a non-invasive approach to mapping the structure and function of the brain. Concurrently, generative artificial intelligence (AI) has experienced substantial growth, involving using existing data to create new content with a similar underlying pattern to real-world data. The integration of these two domains, generative AI in neuroimaging, presents a promising avenue for exploring various fields of brain imaging and brain network computing, particularly in the areas of extracting spatiotemporal brain features and reconstructing the topological connectivity of brain networks. Therefore, this study reviewed the advanced models, tasks, challenges, and prospects of brain imaging and brain network computing techniques and intends to provide a comprehensive picture of current generative AI techniques in brain imaging. This review is focused on novel methodological approaches and applications of related new methods. It discussed fundamental theories and algorithms of four classic generative models and provided a systematic survey and categorization of tasks, including co-registration, super-resolution, enhancement, classification, segmentation, cross-modality, brain network analysis, and brain decoding. This paper also highlighted the challenges and future directions of the latest work with the expectation that future research can be beneficial.

5.
J Org Chem ; 88(13): 8329-8344, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37265419

RESUMEN

A novel three-component Pd/norbornene cooperative catalysis cascade decarboxylative [2+2+2]/[2+2+3]cyclization of 4-iodoisoquinolin-1(2H)-ones and o-bromobenzoic acids or 8-bromo-1-naphthoic acid has been developed. The method affords a range of fused phenanthridinones and hepta[1,2-c]isoquinolinones and displays unique regioselectivity and broad substrate scope. Palladium/norbornene (Pd/NBE)-catalyzed C-H activation and subsequent decarboxylative coupling reactions were involved, and NBE acts as a building block for the construction of rigid nonplanar molecular architectures.


Asunto(s)
Norbornanos , Paladio , Paladio/química , Ciclización , Norbornanos/química , Catálisis
6.
J Asian Nat Prod Res ; 22(4): 353-358, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30835549

RESUMEN

Twelve dihydrostilbenes (including five new analogues) were prepared by the Witting-Hornor reaction from appropriate aromatic aldehydes and phosphonate esters, followed by hydrogenation in five steps. The in vitro inhibition activity against human neutrophil elastase (HNE) of these dihydrostilbenes was evaluated, and three 1,2-dihydroxylated dihydrostilbenes (6b, 6j, and 6l) exhibited stronger inhibitory activity against HNE than other analogues.


Asunto(s)
Dihidrostilbenoides , Elastasa de Leucocito , Humanos , Estructura Molecular
7.
Nat Prod Res ; 31(2): 239-244, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27580458

RESUMEN

A new cyclopeptide, neriitide A (1) and a new lignan, neriilignan (2), along with six known compounds including two diterpenoids, three sesquiterpenoids and one sterol were isolated from the leaves of Podocarpus neriifolius. Their structures were elucidated by means of extensive spectroscopic analysis including HREIMS, 1D and 2D NMR techniques. This is the first report of cyclopeptide and lignan separated from this plant.


Asunto(s)
Lignanos/química , Péptidos Cíclicos/química , Pinaceae/química , Diterpenos/química , Diterpenos/aislamiento & purificación , Lignanos/aislamiento & purificación , Estructura Molecular , Péptidos Cíclicos/aislamiento & purificación , Hojas de la Planta/química , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Análisis Espectral , Esteroles/química , Esteroles/aislamiento & purificación
8.
Nat Prod Res ; 31(7): 844-848, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27784178

RESUMEN

A new abietane mono-norditerpenoid, nagiol A (1), along with three known diterpenoids were isolated from the leaves of Podocarpus nagi. Their structures were elucidated by means of extensive spectroscopic analysis. This is the first report of abietane mono-norditerpenoid separated from plant of the genus Podocarpus. Compound 1 was assessed for its cytotoxicity against five human tumour lines (HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and the result showed that it had no activity.


Asunto(s)
Abietanos/química , Abietanos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Plantas/química , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Humanos , Espectroscopía de Resonancia Magnética , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Espectrometría de Masa por Ionización de Electrospray
9.
Nat Prod Res ; 29(17): 1650-6, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25560928

RESUMEN

Human neutrophil elastase (HNE) has been implicated as a major contributor in the pathogenesis of diseases, such as lung disorders and other inflammatory diseases. A series of 12 new nigranoic acid esters were regioselectively synthesised in good yields and evaluated for HNE inhibitory activity. Nigranoic acid exhibited significant inhibitory activity against HNE with the IC50 value of 3.77 µM, and six esters displayed considerable inhibitory effects on HNE with IC50 values in the range of 2.61-8.95 µM. The nigranoic acid esters having phenyls substituted with bromine and trimethoxyls (3h and 3b) showed stronger inhibitory activity on HNE than nigranoic acid.


Asunto(s)
Elastasa de Leucocito/antagonistas & inhibidores , Triterpenos/química , Ésteres/síntesis química , Ésteres/química , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Triterpenos/síntesis química
10.
Nat Prod Res ; 28(19): 1539-43, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24897412

RESUMEN

A new naphthol, 7-hydroxy-6-methyl-1-naphthoic acid methyl ester (1), together with eight known compounds, 6-hydroxy-7-(hydroxymethyl)-1-isopropyl-4-methyl-naphthalene (2), α-hydroxyacetosyringone (3), hexadecyl ferulate (4), scoparone (5), (+)-syringaresinol (6), stigmast-1,5-dien-3ß-ol (7), ß-sitosterol (8) and daucosterol (9), were isolated from the twigs and leaves of Pterospermum yunnanense Hsue. Their structures were elucidated by using spectroscopic analysis. All the compounds were isolated for the first time from P. yunnanense Hsue. Compound 1 was assessed for its cytotoxicity against five human tumour lines (HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and the result showed that it has no activity.


Asunto(s)
Malvaceae/química , Naftoles/aislamiento & purificación , Ácidos Carboxílicos , Humanos , Estructura Molecular , Naftalenos , Naftoles/química , Extractos Vegetales/química , Hojas de la Planta/química , Sitoesteroles , Triterpenos/química
11.
Org Lett ; 13(19): 5224-7, 2011 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-21913681

RESUMEN

An effective, regioselective C-2 arylation of imidazo[2,1-b]thiazoles catalyzed by Cu(I) has been developed. This arylation proceeded smoothly without promotion of the ligands, and various functional (22 samples) groups were well tolerated. Preliminary mechanistic studies of this arylation are also reported.


Asunto(s)
Cobre/química , Imidazoles/química , Tiazoles/química , Catálisis , Ligandos , Estructura Molecular
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