Aspewentins A-C, Norditerpenes from a Cryptic Pathway in an Algicolous Strain of Aspergillus wentii

Through addition of suberoylanilide hydroxamic acid, two new aromatic norditerpenes, aspewentins A (1) and B (2), along with an oxygenated derivative, aspewentin C (3), were obtained from the culture of an Aspergillus wentii strain (na-3) isolated from the tissue of the brown alga Sargassum fusiforme. The structures and absolute configurations were unambiguously elucidated by spectroscopic analyses and quantum chemical calculations. Aspewentins A-C were produced before sporulation and exhibited potent bioactivities against some marine-derived organisms.Through addition of suberoylanilide hydroxamic acid, two new aromatic norditerpenes, aspewentins A (1) and B (2), along with an oxygenated derivative, aspewentin C (3), were obtained from the culture of an Aspergillus wentii strain (na-3) isolated from the tissue of the brown alga Sargassum fusiforme. The structures and absolute configurations were unambiguously elucidated by spectroscopic analyses and quantum chemical calculations. Aspewentins A-C were produced before sporulation and exhibited potent bioactivities against some marine-derived organisms

Nutrient Cycling and Plant Nutrition in Forest Ecosystems

Nutrient cycling is essential for maintaining nutrient supply to forest plants and for enhancing forest productivity. Nutrient cycling is also strongly linked to greenhouse gas emissions and thus to global climate change. Nutrient cycling and plant nutrition can be severely affected by anthropogenic and natural disturbance regimes. This Special Issue will provide an avenue to publish recent progress on research on nutrient cycling and plant nutrition in forest ecosystems and how nutrient cycling and plant nutrition are affected by disturbance regimes such as harvesting, atmospheric deposition and climate change

Ergosteroid derivatives from an algicolous strain of Aspergillus ustus

One new ergosteroid derivative, isocyathisterol (1), and eight known compounds (2-9) were isolated from the culture of an algicolous strain (cf-42) of Aspergillus ustus obtained from the fresh tissue of marine green alga Codium fragile. The structure and absolute configuration of 1 were unequivocally identified by using NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 1 exhibited weak antibacterial activity.One new ergosteroid derivative, isocyathisterol (1), and eight known compounds (2-9) were isolated from the culture of an algicolous strain (cf-42) of Aspergillus ustus obtained from the fresh tissue of marine green alga Codium fragile. The structure and absolute configuration of 1 were unequivocally identified by using NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 1 exhibited weak antibacterial activity

A rule to distinguish diastereomeric bianthrones by H-1 NMR

Bianthrones have occurred widely in drug and material developments, but the stereochemistry remains in chaos so far due to the meso, racemic, and axis-rotating phenomena. Based on the computational and experimental results, an effective rule to distinguish between cis and trans bianthrones by H-1 NMR is concluded, which applies to both homo- and heterobianthrones.Bianthrones have occurred widely in drug and material developments, but the stereochemistry remains in chaos so far due to the meso, racemic, and axis-rotating phenomena. Based on the computational and experimental results, an effective rule to distinguish between cis and trans bianthrones by H-1 NMR is concluded, which applies to both homo- and heterobianthrones

Actinobacteria and Myxobacteria

Bacterial infections cause millions of deaths globally, particularly in children and the elderly, and four of the 10 leading causes of death are infectious diseases in low- and middle-income countries. The continuous use of antibiotics has resulted in multi-resistant bacterial strains all over the world, such as Community-associated Methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum β-lactamases (ESBLs), and, as expected, hospitals have become breeding grounds for human-associated microorganisms, especially in critical care units

Tracer and Timescale Methods for Passive and Reactive Transport in Fluid Flows

Geophysical, environmental, and urban fluid flows (i.e., flows developing in oceans, seas, estuaries, rivers, aquifers, reservoirs, etc.) exhibit a wide range of reactive and transport processes. Therefore, identifying key phenomena, understanding their relative importance, and establishing causal relationships between them is no trivial task. Analysis of primitive variables (e.g., velocity components, pressure, temperature, concentration) is not always conducive to the most fruitful interpretations. Examining auxiliary variables introduced for diagnostic purposes is an option worth considering. In this respect, tracer and timescale methods are proving to be very effective. Such methods can help address questions such as, "where does a fluid-born dissolved or particulate substance come from and where will it go?" or, "how fast are the transport and reaction phenomena controlling the appearance and disappearance such substances?" These issues have been dealt with since the 19th century, essentially by means of ad hoc approaches. However, over the past three decades, methods resting on solid theoretical foundations have been developed, which permit the evaluation of tracer concentrations and diagnostic timescales (age, residence/exposure time, etc.) across space and time and using numerical models and field data. This book comprises research and review articles, introducing state-of-the-art diagnostic theories and their applications to domains ranging from shallow human-made reservoirs to lakes, river networks, marine domains, and subsurface flow

Alkaloids from an algicolous strain of Talaromyces sp.

Compounds isolated and identified in a culture of the alga-endophytic fungus Talaromyces sp. cf-16 included two naturally occurring alkaloids, 2-[(S)-hydroxy(phenyl)methyl]-3-methylquinazolin-4(3H)-one (1a) and 2-[(R)-hydroxy(phenyl)methyl]-3-methylquinazolin-4(3H)-one (1b), that were identified for the first time. In addition, seven known compounds (2-8) were obtained from the culture. Following chiral column chromatography, compounds 1a and 1b were identified as enantiomers by spectroscopic analyses and quantum chemical calculations. Bioassay results showed that 5 was more toxic to brine shrimp than the other compounds, and that 3-6 could inhibit Staphylococcus aureus

Mycochemistry of marine algicolous fungi

Marine algicolous fungi refer to the fungi inhabiting or associated with marine algae, which have attracted a great attention for natural product researchers due to their chemical diversity and biological activity during the past two decades. Up to the end of 2014, a total of 366 new natural products, including polyketides, terpenoids, polyketide-terpenoids, peptides, alkaloids, and shikimate derivatives, have been characterized from them. Among these metabolites, 240 compounds feature cytotoxic, antibacterial, antifungal, antimicroalgal, zooplankton-toxic, antiprotozoal, antioxidative, enzyme-modulatory, and/or some other activities. This review gives a comprehensive coverage of both chemical and biological aspects of the secondary metabolites from marine algicolous fungi

Sustainability of Rural Tourism and Promotion of Local Development

This Special Issue contains articles include, but not limited to, empirical, analytical, or design-oriented approaches to the following topics: Monitoring of carrying capacity and mechanisms for managing tourist flows in rural areas; Systems and tools to measure the social, economic, and environmental sustainability of rural tourism; Integration between public tourism policies and private strategies in the promotion and implementation of sustainable practices; Policies for promoting public participation in the planning and development of sustainable rural tourism; The impacts of tourism on traditional agricultural activities; Identity enhancement of the territory and its productions; "Good practices" in the implementation of rural tourism sustainability

Marine Carbohydrate-Based Compounds with Medicinal Properties

The marine environment is considered one of the most important sources of natural bioactive compounds with extremely rich biodiversity. Marine glycans are remarkable molecules, playing a determinant role in biological processes. Marine сarbohydrate-containing substances have drawn increasing attention in the field of biomedicine for their various biological activities, such as antitumor, antivirus, hypoglycemic, immunomodulatory, and anticoagulant. These compounds obtained from marine sources, such as algae, microbes, and animals, are usually biodegradable and biocompatible, and exhibit biological properties that contribute to the discovery of a wide range of new bioactive substances with special pharmacological properties of interest to medicine. Carbohydrate-based compounds include glycans, glycoproteins, proteoglycans, glycolipids, and low-molecular and complex glycosides of differential origin. Many of the polysaccharides allow for loading lower drug dosages, which may lead to a drastic reduction of the side effects caused by the drugs. In addition, the structure of polysaccharides can be relatively easily modified in order to synthesize derivatives with desirable characteristics for drug delivery. Complexes on the basis of carbohydrates are often prepared to improve their functional properties. In this Special Issue, we seek to contribute to the discussion of various aspects of marine carbohydrate-containing compounds and provide a unique platform for a new concept for their use in medicine in order to continue to facilitate further research in this area