Octahydroindolizine alkaloid Homocrepidine A from Dendrobium crepidatum attenuate P. acnes-induced inflammatory in vitro and in vivo.

Ethnopharmacological Relevance: Dendrobium crepidatum Lindl. ex Paxton is a perennial epiphyte of Dendrobium genus, distributed in southern China, and utilized as the traditional Chinese medicine "Shihu" in Yunnan Province. Due to its heat-clearing and detoxicating properties, it is formulated as the "XiaoCuoWan" as recorded in the China Pharmacopoeia, and specially used to treat chronic skin inflammatory diseases, such as acne.

Adsorption Characteristics and Enrichment of Emodin from Marine-Derived HN4-13 Extract by Macroporous Resin XAD-16.

Emodin, a hydroxyanthraquinone derivative, has been used as medicine for more than 2000 years due to its extensive pharmacological activities. Large-scale production of emodin has been achieved by optimizing the fermentation conditions of marine-derived HN4-13 in a previous study. However, the fermentation broth contained complex unknown components, which adversely affected the study of emodin.

Enhancement of Emodin Production by Medium Optimization and KHPO Supplementation in Submerged Fermentation of Marine-Derived HN4-13.

Emodin is a widely distributed anthraquinone derivative with a variety of biological activities, one that can be efficiently produced by marine-derived fungus HN4-13. However, its relatively low fermentation yield limits further development and pharmaceutical research work. In this study, Plaekett-Burman design and central composite design were adopted to optimize the fermentation conditions of .

Bioactive Indole Diketopiperazine Alkaloids from the Marine Endophytic Fungus sp. YJ191021.

Six new prenylated indole diketopiperazine alkaloids, asperthrins A-F (-), along with eight known analogues (-), were isolated from the marine-derived endophytic fungus sp. YJ191021. Their planar structures and absolute configurations were elucidated by HR-ESI-MS, 1D/2D NMR data, and time-dependent density functional theory (TDDFT)/ECD calculation.

Epistatically interacting substitutions are enriched during adaptive protein evolution.

Most experimental studies of epistasis in evolution have focused on adaptive changes-but adaptation accounts for only a portion of total evolutionary change. Are the patterns of epistasis during adaptation representative of evolution more broadly? We address this question by examining a pair of protein homologs, of which only one is subject to a well-defined pressure for adaptive change. Specifically, we compare the nucleoproteins from human and swine influenza.

Stability-mediated epistasis constrains the evolution of an influenza protein.

John Maynard Smith compared protein evolution to the game where one word is converted into another a single letter at a time, with the constraint that all intermediates are words: WORD→WORE→GORE→GONE→GENE. In this analogy, epistasis constrains evolution, with some mutations tolerated only after the occurrence of others. To test whether epistasis similarly constrains actual protein evolution, we created all intermediates along a 39-mutation evolutionary trajectory of influenza nucleoprotein, and also introduced each mutation individually into the parent.

Permissive secondary mutations enable the evolution of influenza oseltamivir resistance.

The His274-->Tyr274 (H274Y) mutation confers oseltamivir resistance on N1 influenza neuraminidase but had long been thought to compromise viral fitness. However, beginning in 2007-2008, viruses containing H274Y rapidly became predominant among human seasonal H1N1 isolates. We show that H274Y decreases the amount of neuraminidase that reaches the cell surface and that this defect can be counteracted by secondary mutations that also restore viral fitness.