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Frontiers in Genetics 2024
PubMed: 38919954
DOI: 10.3389/fgene.2024.1429024 -
Ecology and Evolution Jun 2024The Arctic archipelago of Svalbard is a hotspot of global warming and many fjords experience a continuous increase in seawater temperature and glacial melt while sea-ice...
The Arctic archipelago of Svalbard is a hotspot of global warming and many fjords experience a continuous increase in seawater temperature and glacial melt while sea-ice cover declines. In 1996/1998, 2012-2014, and 2021 macroalgal biomass and species diversity were quantified at the study site Hansneset, Kongsfjorden (W-Spitsbergen) in order to identify potential changes over time. In 2021, we repeated the earlier studies by stratified random sampling (1 × 1 m, = 3) along a sublittoral depth transect (0, 2.5, 5, 10, and 15 m) and investigated the lower depth limits of dominant brown algae between 3 and 19 m. The maximum fresh weight (FW) of all seaweeds was 11.5 kg m at 2.5 m and to 99.9% constituted of kelp. Although biomass distribution along the depth transect in 2021 was not significantly different compared to 2012/2013, the digitate kelp community (/) had transformed into an -dominated kelp forest. Consequently, a pronounced shift in kelp forest structure occurred over time as we demonstrate that biomass allocation to thallus parts is kelp species-specific. Over the past decade, kelp demography changed and in 2021 a balanced age structure of kelps (juveniles plus many older kelp individuals) was only apparent at 2.5 m. In addition, the abundances and lower depth limits of all dominant brown algae declined noticeably over the last 25 years while the red algal flora abundance remained unchanged at depth. We propose that the major factor driving the observed changes in the macroalgal community are alterations in underwater light climate, as in situ data showed increasing turbidity and decreasing irradiance since 2012 and 2017, respectively. As a consequence, the interplay between kelp forest retreat to lower depth levels caused by coastal darkening and potential macroalgal biomass gain with increasing temperatures will possibly intensify in the future with unforeseen consequences for melting Arctic coasts and fjord ecosystem services.
PubMed: 38919650
DOI: 10.1002/ece3.11606 -
Frontiers in Chemistry 2024Fungal diseases cause substantial loss to agricultural crops, affecting both quantities and quality. Although several methods are used for preventing disease incidence,...
Fungal diseases cause substantial loss to agricultural crops, affecting both quantities and quality. Although several methods are used for preventing disease incidence, fungicides remain crucial for higher yields and better quality. But in the past, the efficacy of several fungicides has decreased due to increased cases of fungicide resistant. In our pursuit of new effective fungicides, we synthesised a series of twenty 2-Indazol-1-yl-chromen-4-one derivatives (6a- 6t). The characterization of synthesized compounds was performed by several spectroscopic methods including Infrared, Nuclear Magnetic Resonance (H and C) and HRMS. Out of 20 synthesised compounds, 19 (6b- 6t) were found to be novel. All synthesised indazolylchromones showed very good antifungal activity against and . Among the tested compounds, and exhibited very good fungicidal activity against with an ED of 10.10 mg L and 16.18 mg L, respectively. In case of compound displayed good' activity with an ED value of 27.82 mg L. Molecular docking study was done to predict the binding sites of most active compounds, and with Cytochrome P450 14alpha -sterol demethylase (CYP51) enzyme using molsoft software. The acute toxicity predictions the of synthesized compounds for fish (LC,96 Hr), daphnid (LC, 48 Hr) and green algae (EC, 96Hr) and the chronic toxicity predictions (ChV) were assessed using Ecological Structure Activity Relationship (ECOSAR) model. As per ECOSAR prediction, all the chemicals are inside AD and not missing predictions.
PubMed: 38919273
DOI: 10.3389/fchem.2024.1411187 -
Current Pharmaceutical Biotechnology Jun 2024Cancer is one of the most complicated and prevalent diseases in the world, and its incidence is growing worldwide. Natural products containing pharmacological activity...
Cancer is one of the most complicated and prevalent diseases in the world, and its incidence is growing worldwide. Natural products containing pharmacological activity are widely used in the pharmaceutical industry, especially in anticancer drugs, due to their diverse structures and distinctive functional groups that inspire new drug results by means of synthetic chemistry. Terrestrial medicinal plants have traditionally been the primary source for developing natural products (NPs). However, over the past thirty years, marine organisms such as invertebrates, plants, algae, and bacteria have revealed many new pharmaceutical compounds known as marine NPs. This field constantly evolves as a discipline in molecular targeted drug discovery, incorporating advanced screening tools that have revolutionised and become integral to modern antitumor research. This review discusses recent studies on new natural anticancer alkaloids obtained from marine organisms. The paper illustrates the structure and origin of marine alkaloids and demonstrates the cytotoxic action of new alkaloids from several structural families and their synthetic analogs. The most recent findings about the potential or development of some of them as novel medications, together with the status of our understanding of their current mechanisms of action, are also compiled.
PubMed: 38918975
DOI: 10.2174/0113892010316791240611093022 -
Environmental Research Jun 2024The nutraceutical value, and physicochemical profile as well as anti-inflammatory activity potential of Odonthalia floccose and Odonthalia dentata (red macroalgae) dry...
The nutraceutical value, and physicochemical profile as well as anti-inflammatory activity potential of Odonthalia floccose and Odonthalia dentata (red macroalgae) dry biomass were investigated in this study. Proximate composition study results revealed that the dry biomass of O. floccose and O. dentae were found to be as ash: 9.11 & 8.7 g 100 g, moisture: 8.24 & 8.1 g 100 g, total fat: 6.9 & 7.2 g 100 g, protein: 24.52 & 25.6 g 100 g, and total carbohydrate/polysaccharides: 53.84 & 48.85 g 100 g of dry weight biomass respectively. Both algae biomass contain considerable quantity of minerals (Fe, Cu, Mg, and Zn). Furthermore, the major saturated fatty acids (6.24 & 5.82 g FAME 100 g of total fat of O. floccose and O. dentate) (ΣFAs) present in the test algae were stearic acid, palmitic acid, and margaric acids. O. floccose and O. dentata also contain remarkable protein composition profile that compiled with considerable quantity of essential and non-essential amino acids. The vitamins such as vitamin A, B1, B2, B3, B6, B9, C, and E of O. floccose and O. dentate biomass were also identified at sufficient quantity level. The swelling capacity (SWC), water holding capacity (WHC), and oil holding capacity (OHC) properties of O. floccose and O. dentate at various temperature conditions (25 and 37 ᵒC) were found to be 8.11 & 7.02 mL g and 8.95 & 7.55 mL g, 5.1 & 4.87 and 4.8 & 4.1 mL g, as well as 2.11 & 1.81 and 1.96 & 1.89 mL g respectively. Among these two marine red macroalgae samples, the O. dentate showed better anti-inflammatory activity than O. floccose at 150 μg mL dosage. Thus, this O. floccose and O. dentate biomass can be considerable as nutritional supplement and pharmaceutical product development related research.
PubMed: 38917932
DOI: 10.1016/j.envres.2024.119487 -
Marine Environmental Research Jun 2024Photosymbiosis indicates a long-term association between animals and photosynthetic organisms. It has been mainly investigated in photosymbiotic cnidarians, while other...
Photosymbiosis indicates a long-term association between animals and photosynthetic organisms. It has been mainly investigated in photosymbiotic cnidarians, while other photosymbiotic associations have been largely neglected. The acoel Symsagittifera roscoffensis lives in obligatory symbiosis with the microalgal Tetraselmis convolutae and has recently emerged as alternative model to study photosymbiosis. Here, we investigated the effects of Bisphenol A, a common plastic additive, on two pivotal stages of its lifecycle: aposymbiotic juvenile development and photosymbiogenesis. Based on our results, this pollutant altered the development of the worms and their capacity to engulf algae from the environment at concentrations higher than the levels detected in seawater, yet aligning with those documented in sediments of populated areas. Data provide novel information about the effects of pollutants on photosymbiotic associations and prompt the necessity to monitor their concentrations in marine environmental matrices.
PubMed: 38917659
DOI: 10.1016/j.marenvres.2024.106617 -
The ISME Journal Jun 2024As unicellular predators, ciliates engage in close associations with diverse microbes, laying the foundation for the establishment of endosymbiosis. Originally...
As unicellular predators, ciliates engage in close associations with diverse microbes, laying the foundation for the establishment of endosymbiosis. Originally heterotrophic, ciliates demonstrate the ability to acquire phototrophy by phagocytizing unicellular algae or by sequestering algal plastids. This adaptation enables them to gain photosynthate and develop resistance to unfavorable environmental conditions. The integration of acquired phototrophy with intrinsic phagotrophy results in a trophic mode known as mixotrophy. Additionally, ciliates can harbor thousands of bacteria in various intracellular regions, including the cytoplasm and nucleus, exhibiting species specificity. Under prolonged and specific selective pressure within hosts, bacterial endosymbionts evolve unique lifestyles and undergo particular reductions in metabolic activities. Investigating the research advancements in various endosymbiotic cases within ciliates will contribute to elucidate patterns in cellular interaction and unravel the evolutionary origins of complex traits.
PubMed: 38916437
DOI: 10.1093/ismejo/wrae117 -
Journal of the American Chemical Society Jun 2024Fucoidan, a sulfated polysaccharide found in algae, plays a central role in marine carbon sequestration and exhibits a wide array of bioactivities. However, the...
Fucoidan, a sulfated polysaccharide found in algae, plays a central role in marine carbon sequestration and exhibits a wide array of bioactivities. However, the molecular diversity and structural complexity of fucoidan hinder precise structure-function studies. To address this, we present an automated method for generating well-defined linear and branched α-fucan oligosaccharides. Our syntheses include oligosaccharides with up to 20 -glycosidic linkages, diverse branching patterns, and 11 sulfate monoesters. In this study, we demonstrate the utility of these oligosaccharides by (i) characterizing two -acting fucoidan glycoside hydrolases (GH107), (ii) utilizing them as standards for NMR studies to confirm suggested structures of algal fucoidans, and (iii) developing a fucoidan microarray. This microarray enabled the screening of the molecular specificity of four monoclonal antibodies (mAb) targeting fucoidan. It was found that mAb BAM4 has cross-reactivity to β-glucans, while mAb BAM2 has reactivity to fucoidans with 4--sulfate esters. Knowledge of the mAb BAM2 epitope specificity provided evidence that a globally abundant marine diatom, , synthesizes a fucoidan with structural homology to those found in brown algae. Automated glycan assembly provides access to fucoidan oligosaccharides. These oligosaccharides provide the basis for molecular level investigations into fucoidan's roles in medicine and carbon sequestration.
PubMed: 38916244
DOI: 10.1021/jacs.4c02348 -
Frontiers in Plant Science 2024, an aerial green alga, exhibits remarkable adaptability to the extreme conditions of Antarctica by forming layered colonies capable of utilizing far-red light for...
, an aerial green alga, exhibits remarkable adaptability to the extreme conditions of Antarctica by forming layered colonies capable of utilizing far-red light for photosynthesis. Despite a recent report on the structure of 's unique light-harvesting chlorophyll (Chl)-binding protein complex (Pc-frLHC), which facilitates far-red light absorption and uphill excitation energy transfer to photosystem II, the specific genes encoding the subunits of Pc-frLHC have not yet been identified. Here, we report a draft genome sequence of strain 4113, originally isolated from soil samples on Ongul Island, Antarctica. We obtained a 92 Mbp sequence distributed in 1,045 scaffolds comprising 10,244 genes, reflecting 87.1% of the core eukaryotic gene set. Notably, 26 genes associated with the light-harvesting Chl / binding complex (LHC) were identified, including four Pc-frLHC genes, with similarity to a noncanonical Lhca gene with four transmembrane helices, such as Ot_Lhca6 in and Cr_LHCA2 in . A comparative analysis revealed that Pc-frLHC shares homology with certain Lhca genes found in and species. This similarity indicates that Pc-frLHC has evolved from an ancestral Lhca gene with four transmembrane helices and branched out within the Trebouxiaceae family. Furthermore, RNA-seq analysis conducted during the initiation of Pc-frLHC gene induction under red light illumination indicated that Pc-frLHC genes were induced independently from other genes associated with photosystems or LHCs. Instead, the genes of transcription factors, helicases, chaperones, heat shock proteins, and components of blue light receptors were identified to coexpress with Pc-frLHC. Those kinds of information could provide insights into the expression mechanisms of Pc-frLHC and its evolutional development.
PubMed: 38916036
DOI: 10.3389/fpls.2024.1409116 -
National Science Review Jun 2024This perspective reviews how atmospheric compositions, animals and marine algae evolved together to determine global ocean habitability during the past 500 million years.
This perspective reviews how atmospheric compositions, animals and marine algae evolved together to determine global ocean habitability during the past 500 million years.
PubMed: 38915915
DOI: 10.1093/nsr/nwae099