(+)-Epogymnolactam, a novel autophagy inducer from mycelial culture of Gymnopus sp

CuII-Catalyzed cis-Selective Synthesis of Ketoepoxides from Phenacyl Bromides and Water

A verity of α,β-ketoepoxides was synthesized using a Cu^II-catalyzed oxidative C-C/O-C coupled cyclization strategy with high yield and cis-selectivity. Water is used as the source of oxygen and phenacyl bromide as the carbon in the valuable epoxides. The self-coupling method was extended to cross-coupling between phenacyl bromides with benzyl bromides. A high cis-diastereoselectivity was observed in all the synthesized ketoepoxides. Control experiments and density functional theory (DFT) study were performed to understand the Cu^II-Cu^I transition mechanism.

Morpho-Molecular Evidence Reveals Four Novel Species of Gymnopus (Agaricales, Omphalotaceae) from China

Nine collections of gymnopoid fungi were studied based on morpho-molecular characteristics. The macromorphology was made according to the photograph of fresh basidiomata and field notes, while the micromorphology was examined via an optical microscope. Simultaneously, the phylogenetic analyses were performed by maximum likelihood and Bayesian inference methods based on a combined dataset of nrITS1-nr5.8S-nrITS2-nrLSU sequences. Integrated analysis of these results was therefore, G. efibulatus belonging to sect. Androsacei, G. iodes and G. sinopolyphyllus belonging to sect. Impudicae and G. strigosipes belonging to sect. Levipedes are proposed as new to science. The detailed descriptions, colour photos of basidiomata and line-drawings of microscopic structures are provided. The comparisons with closely related species and a key to known species of Gymnopus s. str. reported with morpho-molecular evidence in China is also given.

Application of The Dess-Martin Oxidation in Total Synthesis of Natural Products

Dess-Martin periodinane (DMP), a commercially available chemical, is frequently utilized as a mild oxidative agent for the selective oxidation of primary and secondary alcohols to their corresponding aldehydes and ketones, respectively. DMP shows several merits over other common oxidative agents such as chromiumand DMSO-based oxidants; thus, it is habitually employed in the total synthesis of natural products. In this review, we try to underscore the applications of DMP as an effective oxidant in an appropriate step (steps) in the multi-step total synthesis of natural products.

A new lignan from Schefflera arboricola

A new lignan, arborlignan A, along with five known substances, neoechinulin A, 4-hydroxy-3,5-dimethoxybenzaldehyde, 3,3′-dimethoxy-4,4′-dihydroxystilbene, β-hydroxypropiovanillone, and coniferyl aldehyde, are isolated from Schefflera arboricola. Their structures are elucidated by mass spectrometry and nuclear magnetic resonance spectroscopy experiments and by comparison with literature data. These compounds are isolated from the genus Schefflera for the first time.

An Overview of Saturated Cyclic Ethers: Biological Profiles and Synthetic Strategies

Saturated oxygen heterocycles are widely found in a broad array of natural products and other biologically active molecules. In medicinal chemistry, small and medium rings are also important synthetic intermediates since they can undergo ring-opening and -expansion reactions. These applications have driven numerous studies on the synthesis of oxygen-containing heterocycles and considerable effort has been devoted toward the development of methods for the construction of saturated oxygen heterocycles. This paper provides an overview of the biological roles and synthetic strategies of saturated cyclic ethers, covering some of the most studied and newly discovered related natural products in recent years. This paper also reports several promising and newly developed synthetic methods, emphasizing 3-7 membered rings.

The logic of biologically active small molecules: amazing ability of microorganisms*

In this review article, I will outline my way of thinking about biologically active small molecules. The structure of liposidomycin B from Streptomyces species resulted in my initial sense that a structure tells its function. A biologically active small molecule may save directly or indirectly a number of people. Even if the molecule has not been used as a therapeutic agent, it can be used as a useful chemical probe for dissecting a living cell into different biochemical pieces. Such biologically active small molecules derived from microorganisms have been primarily found in cultivable microorganisms that make up only 1% of total microbes in nature. Discovery of novel growth factors, zincmethylphyrin, zinc coproporphyrin, and coproporphyrin enabled laboratory cultivation of previously uncultured Leucobacter sp. These findings might expand the possibility for further discovery of novel therapeutic agents or chemical probes.

Total Synthesis of (-)-L-755,807: Establishment of Relative and Absolute Configurations

The first total synthesis of (-)-L-755,807 and its three stereoisomers was achieved by our Horner-Wadsworth-Emmons reaction for stereoselective formation of trisubstituted olefins, highly diastereoselective Darzens condensation to construct the epoxy-γ-lactam ring, and late-stage coupling of the ring and side-chain segments for efficient convergent synthesis. This synthesis shows that the originally proposed structure of natural (-)-L-755,807 was incorrect and establishes its relative and absolute configurations.