The Influence of Wind-Induced Waves on ENSO Simulations

We evaluated the influence of wind-induced waves on El Niño-Southern Oscillation (ENSO) simulations based on the First Institute of Oceanography-Earth System Model version 2 (FIO-ESM 2.0), a global coupled general circulation model (GCM) with a wave component. Two sets of experiments, the GCM, with and without a wave model, respectively, were conducted in parallel. The simulated sea surface temperature (SST) was cooled by introducing the wave model via the enhancement of the vertical mixing in the ocean upper layer. The strength of ENSO was intensified and better simulated with the inclusion of wave-induced mixing, particularly the La Niña amplitude. Furthermore, the simulated amplitude and spatial pattern of El Niño events were slightly altered with the wave model. Heat budget analyses revealed the intensification of La Niña events to be generally attributed to wave-induced vertical advection, followed by the zonal and meridional advection terms

Discovery of Prenyltransferase-Guided Hydroxyphenylacetic Acid Derivatives from Marine Fungus <i>Penicillium</i> sp. W21C371

Traditional isolation methods often lead to the rediscovery of known natural products. In contrast, genome mining strategies are considered effective for the continual discovery of new natural products. In this study, we discovered a unique prenyltransferase (PT) through genome mining, capable of catalyzing the transfer of a prenyl group to an aromatic nucleus to form C-C or C-O bonds. A pair of new hydroxyphenylacetic acid derivative enantiomers with prenyl units, (±)-peniprenydiol A (1), along with 16 known compounds (2–17), were isolated from a marine fungus, Penicillium sp. W21C371. The separation of 1 using chiral HPLC led to the isolation of the enantiomers 1a and 1b. Their structures were established on the basis of extensive spectroscopic analysis, including 1D, 2D NMR and HRESIMS. The absolute configurations of the new compounds were determined by a modified Mosher method. A plausible biosynthetic pathway for 1 was deduced, facilitated by PT catalysis. In the in vitro assay, 2 and 3 showed promising inhibitory activity against Escherichia coli β-glucuronidase (EcGUS), with IC50 values of 44.60 ± 0.84 μM and 21.60 ± 0.76 μM, respectively, compared to the positive control, D-saccharic acid 1,4-lactone hydrate (DSL). This study demonstrates the advantages of genome mining in the rational acquisition of new natural products

Genome Sequence Analysis of Auricularia heimuer Combined with Genetic Linkage Map

Auricularia heimuer is one of the most popular edible fungi in China. In this study, the whole genome of A. heimuer was sequenced on the Illumina HiSeq X system and compared with other mushrooms genomes. As a wood-rotting fungus, a total of 509 carbohydrate-active enzymes (CAZymes) were annotated in order to explore its potential capabilities on wood degradation. The glycoside hydrolases (GH) family genes in the A. heimuer genome were more abundant than the genes in the other 11 mushrooms genomes. The A. heimuer genome contained 102 genes encoding class III, IV, and V ethanol dehydrogenases. Evolutionary analysis based on 562 orthologous single-copy genes from 15 mushrooms showed that Auricularia formed an early independent branch of Agaricomycetes. The mating-type locus of A. heimuer was located on linkage group 8 by genetic linkage analysis. By combining the genome sequence analysis with the genetic linkage map, the mating-type locus of A. heimuer was located on scaffold45 and consisted of two subunits, &alpha; and &beta;. Each subunit consisted of a pair of homeodomain mating-type protein genes HD1 and HD2. The mapping revealed conserved synteny at the whole mating-type loci and mirror symmetry relations near the &beta; subunit between A. heimuer and Exidia glandulosa. This study proposed the potential for the bioethanol production by consolidated bioprocessing of A. heimuer. It will promote understanding of the lignocellulose degradation system and facilitate more efficient conversion of the agricultural wastes used for mushroom cultivation. It also will advance the research on the fruiting body development and evolution of A. heimuer

Soil organic carbon and nutrient losses resulted from spring dust emissions in Northern China

Dust emissions due to wind erosion have significant impacts on air quality, climate, and biogeochemical processes. Arid and semi-arid regions in Northern China are a major contributor to global dust emissions. However, how dust emissions affect soil organic carbon (SOC) and nutrient losses in this region are poorly understood. In this study, we estimated the spatial patterns and temporal dynamics of SOC and nutrient (total nitrogen (TN) and total phosphorus (TP)) losses in spring using a process-based dust emission model in Northern China during 1982-2011. Spatial patterns of SOC and nutrient losses are consistent with dust emission rates across the research region. Annual losses of SOC, TN, and TP resulted from wind erosion in spring were 0.985 +/- 0.149 Tg yr(-1), 0.094 +/- 0.014 Tg yr(-1), and 0.089 +/- 0.013 Tg yr(-1), respectively. Two distinct periods with opposite trends were identified in dust emissions and SOC and nutrient losses, declining from 1982 to 1997 and then increasing. The opposite patterns in Northern China are largely attributed to the changes in vegetation growth due to climate change and shifts of green-up date of vegetation. The findings could help to reduce the uncertainties in simulating regional biogeochemical cycling in Northern China

&alpha;-Glucosidase and Bacterial &beta;-Glucuronidase Inhibitors from the Stems of Schisandra sphaerandra Staph

&alpha;-Glucosidase (AGS) is a therapeutic target for Type 2 diabetes mellitus (T2DM) that tends to complicate with other diseases. Some medications for the treatment of T2DM complications have the risk of inducing severe adverse reactions such as diarrhea via the metabolism of intestinal bacterial &beta;-glucuronidase (BGUS). The development of new AGS and/or BGUS inhibitors may improve the therapeutic effects of T2DM and its complications. The present work focused on the isolation and characterization of AGS and/or BGUS inhibitors from the medicinal plant Schisandra sphaerandra. A total of eight compounds were isolated and identified. Sphaerandralide A (1) was obtained as a previously undescribed triterpenoid, which may have chemotaxonomy significance in the authentication of the genus Schisandra and Kadsura. 2&prime;-acetyl-4&prime;,4-dimethoxybiphenyl-2-carbaldehyde (8) was obtained from a plant source for the first time, while compounds 2&ndash;7 were isolated from S. sphaerandra for the first time. In the in vitro assay, compounds 1&ndash;5 showed potent to moderate activity against AGS. Interestingly, compound 3 also exhibited significant BGUS inhibitory activity, demonstrating the potential of being developed as a bifunctional inhibitor that may find application in the therapy of T2DM and/or the diarrhea induced by medications for the treatment of T2DM complications

α-Glucosidase Inhibitors from Two Mangrove-Derived Actinomycetes

α-Glucosidase (AGS) inhibitors have been regarded as an ideal target for the management of type 2 diabetes mellitus (T2DM) since they can maintain an acceptable blood glucose level by delaying the digestion of carbohydrates and diminishing the absorption of monosaccharides. In the process of our endeavor in mining AGS inhibitors from natural sources, the culture broth of two mangrove-derived actinomycetes Streptomyces sp. WHUA03267 and Streptomyces sp. WHUA03072 exhibited an apparent inhibitory activity against AGS. A subsequent chemical investigation into the two extracts furnished 28 secondary metabolites that were identified by spectroscopic methods as two previously undescribed linear polyketides 1–2, four benzenoid ansamycins 3–6, fourteen cyclodipeptides 7–18, one prenylated indole derivative 19, two fusicoccane-type diterpenoids 20–21, two hydroxamate siderophore 22–23, and five others 24–28. Among all of the isolates, 11 and 24 were obtained from actinomycetes for the first time, while 20–21 had never been reported to occur in a marine-derived microorganism previously. In the in vitro AGS inhibitory assay, compounds 3, 8, 9, 11, 14, 16, and 17 exhibited potent to moderate activity with IC50 values ranging from 35.76 ± 0.40 to 164.5 ± 15.5 μM, as compared with acarbose (IC50 = 422.3 ± 8.4 μM). The AGS inhibitory activity of 3, 9, 14, 16, and 17 was reported for the first time. In particular, autolytimycin (3) represented the first ansamycin derivative reported to possess the AGS inhibitory activity. Kinetics analysis and molecular docking were performed to determine the inhibition types and binding modes of these inhibitors, respectively. In the MTT assay, 3, 8, 9, 11, 14, 16, and 17 exhibited no apparent cytotoxicity to the human normal hepatocyte (LO2) cells, suggesting satisfactory safety of these AGS inhibitors

Silver nanoparticles inhibit beige fat function and promote adiposity

Objective: Obesity is a complex chronic disease of high prevalence worldwide. Multiple factors play integral roles in obesity development, with rising interest focusing on the contribution of environmental pollutants frequent in modern society. Silver nanoparticles (AgNPs) are widely used for bactericidal purpose in various applications in daily life. However, their potential toxicity and contribution to the obesity epidemic are not clear. Methods: Beige adipocytes are newly discovered adipocytes characterized by high thermogenic and energy dissipating capacity upon activation and the “browning” process. In the present study, we assess the impact of AgNPs exposure on beige adipocytes differentiation and functionality both in vitro and in vivo. We also systematically investigate the influence of AgNPs on adiposity and metabolic performance in mice, as well as the possible underlying molecular mechanism. Results: The results showed that, independent of particle size, AgNPs inhibit the adipogenic, mitochondrial, and thermogenic gene programs of beige adipocytes, thus suppressing their differentiation ability, mitochondrial activity, and thermogenic response. Importantly, exposure to AgNPs in mice suppresses browning gene programs in subcutaneous fat, leading to decreased energy expenditure and increased adiposity in mice. Mechanistically, we found that AgNPs increase reactive oxidative species (ROS) levels and specifically activate MAPK-ERK signaling in beige adipocytes. The negative impacts of AgNPs on beige adipocytes can be ameliorated by antioxidant or ERK inhibitor FR180204 treatment. Conclusions: Taken together, these results revealed an unexpected role of AgNPs in promoting adiposity through the inhibition of beige adipocyte differentiation and functionality, possibly by disrupting ROS homeostasis and ERK phosphorylation. Future assessments on the health risk of AgNPs applications and their safe dosages are warranted. Keywords: Adiposity, Beige fat, Silver nanoparticles, Browning, Energy expenditure, Reactive oxidative specie