Hydrogen peroxide-mediated synthesis of 2,4-substituted quinazolines via one-pot three-component reactions under metal-free conditions.

An efficient metal-free synthesis of 2,4-substituted quinazolines via a hydrogen peroxide-mediated one-pot three-component reaction of 2-aminoaryl ketones, aldehydes, and ammonium acetate has been developed. The transformation proceeded readily under mild conditions in the presence of commercially available hydrogen peroxide. The significant advantages of this approach are (1) the readily available atom-efficient and green hydrogen peroxide as oxidant; (2) no transition metal catalyst is required; (3) mild reaction conditions; and (4) wide substrate scope. To the best of our knowledge, utilizing hydrogen peroxide as an atom-efficient and green oxidant for the synthesis of 2,4-substituted quinazolines has not previously been reported in the literature. This method is complementary to previous protocols for the synthesis of 2,4-substituted quinazolines.

Plant Metabolite Databases: From Herbal Medicines to Modern Drug Discovery.

Traditional herbal medicine has been an inseparable part of the traditional medical science in many countries throughout history. Nowadays, the popularity of using herbal medicines in daily life, as well as clinical practices, has gradually expanded to numerous Western countries with positive impacts and acceptance. The continuous growth of the herbal consumption market has promoted standardization and modernization of herbal-derived products with present pharmacological criteria. To store and extensively share this knowledge with the community and serve scientific research, various herbal metabolite databases have been developed with diverse focuses under the support of modern advances. The advent of these databases has contributed to accelerating research on pharmaceuticals of natural origins. In the scope of this study, we critically review 30 herbal metabolite databases, discuss different related perspectives, and provide a comparative analysis of 18 accessible noncommercial ones. We hope to provide you with fundamental information and multidimensional perspectives from herbal medicines to modern drug discovery.

Alternative pathways to α,ß-unsaturated ketones via direct oxidative coupling transformation using Sr-doped LaCoO3 perovskite catalyst.

A strontium-doped lanthanum cobaltite perovskite material was prepared, and used as a recyclable and effective heterogeneous catalyst for the direct oxidative coupling of alkenes with aromatic aldehydes to produce α,ß-unsaturated ketones. The reaction afforded high yields in the presence of di-tert-butylperoxide as oxidant. Single oxides or salts of strontium, lanthanum and cobalt, and the undoped perovskite offered a lower catalytic activity than the strontium-doped perovskite. Benzaldehyde could be replaced by benzyl alcohol, dibenzyl ether, 2-oxo-2-phenylacetaldehyde, 2-bromoacetophenone or (dimethoxymethyl) benzene in the oxidative coupling reaction with alkenes. To our best knowledge, reactions between these starting materials with alkenes are new and unknown in the literature.

Synthesis of triphenylpyridines via an oxidative cyclization reaction using Sr-doped LaCoO3 perovskite as a recyclable heterogeneous catalyst.

An La0.6Sr0.4CoO3 strontium-doped lanthanum cobaltite perovskite was prepared via a gelation and calcination approach and used as a heterogeneous catalyst for the synthesis of triphenylpyridines via the cyclization reaction between ketoximes and phenylacetic acids. The transformation proceeded via the oxidative functionalization of the sp3 C-H bond in phenylacetic acid. The La0.6Sr0.4CoO3 catalyst demonstrated a superior performance to that of the pristine LaCoCO3 as well as a series of homogeneous and heterogeneous catalysts. Furthermore, the La0.6Sr0.4CoO3 catalyst was facilely recovered and reused without considerable decline in its catalytic efficiency. To the best of our knowledge, the combination of ketoximes with easily available phenylacetic acids is novel.

VIETHERB: A Database for Vietnamese Herbal Species.

Vietnam carries a highly diverse practice of traditional medicine in which various combinations of herbs have been widely used as remedies for many types of diseases. Poor hand-written records and current text-based databases, however, perplex the process of conventionalizing and evaluating canonical therapeutic effects. In efforts to reorganize the valuable information, we provide the VIETHERB database ( http://vietherb.com.vn/ ) for herbs documented in Vietnamese traditional medicines. This database is constructed with confidence to provide users with information on herbs and other side information including metabolites, diseases, morphologies, and geographical locations for each individual species. Our data in this release consist of 2,881 species, 10,887 metabolites, 458 geographical locations, and 8,046 therapeutic effects. The numbers of species-metabolite, species-therapeutic effect, species-morphology, and species-distribution binary relationships are 17,602, 2,718, 11,943, and 16,089, respectively. The information on Vietnamese herbal species can be easily accessed or queried using their scientific names. Searching for species sharing side information can be simply done by clicking on the data. The database primarily serves as an open source facilitating users in studies of modernizing traditional medicine, computer-aided drug design, conservation of endangered plants, and other relevant experimental sciences.