Leaf wax composition and distribution of Tillandsia landbeckii reflects moisture gradient across the hyperarid Atacama Desert

In the hyperarid Atacama Desert, water availability plays a crucial role in allowing plant survival. Along with scant rainfall, marine advective fog frequently occurs along the coastal escarpment fueling isolated mono-specific patches of Tillandsia vegetation. In this study, we investigate the lipid biomarker composition of the bromeliad Tillandsia landbeckii (CAM plant) to assess structural adaptations at the molecular level as a response to extremely arid conditions. We analyzed long-chain n-alkanes and fatty acids in living specimens (n = 59) collected from the main Tillandsia dune ecosystems across a 350 km coastal transect. We found that the leaf wax composition was dominated by n-alkanes with concentrations (total average 160.8 ± 91.4 µg/g) up to three times higher than fatty acids (66.7 ± 40.7 µg/g), likely as an adaptation to the hyperarid environment. Significant differences were found in leaf wax distribution (Average Chain Length [ACL] and Carbon Preference Index [CPI]) in the northern zone relative to the central and southern zones. We found strong negative correlations between fatty acid CPI and n-alkane ACL with precipitation and surface evaporation pointing at fine-scale adaptations to low moisture availability along the coastal transect. Moreover, our data indicate that the predominance of n-alkanes is reflecting the function of the wax in preventing water loss from the leaves. The hyperarid conditions and good preservation potential of both n-alkanes and fatty acids make them ideal tracers to study late Holocene climate change in the Atacama Desert.

Organic matter characteristics of a rapidly eroding permafrost cliff in NE Siberia (Lena Delta, Laptev Sea region)

Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff. The characterisation of OM from eroding permafrost leads to a better assessment of the greenhouse gas potential of the OC released into river and nearshore waters in future, which is important to understand the consequences of a warming climate in Arctic environments on the global carbon cycle.

Isolation and Structural Elucidation of Secondary Metabolites from New Zealand Marine Sponge Aaptos confertus

<p>This study reports on the spectroscopy-guided isolation and structural elucidation of secondary metabolites from the New Zealand marine sponge Aaptos confertus. An extraction of the sponge material, followed by several purification steps, led to the isolation of potential new compounds CJP02 20A, CJP02 20C and CJP02 04CB, a known 2,5-diketopiperzine cyclo(L-Phe-L-Pro), and a previously reported 3-((13-methylhexadecyl)oxy)propane-1,2-diol. Corrections to the ¹H NMR data reported for 3-((13-methylhexadecyl)oxy)propane-1,2-diol were also recorded. The relationship between the oceanic climate where a marine organism habituates and its production of secondary metabolites is discussed. The isolation of a diverse range of compounds, either novel or new to the genus, suggests that organisms originating in temperate climates are similar in value to those from tropical climates, where higher rates of predation (and therefore, selective pressure) are thought to produce superior diversity in their secondary metabolic distribution. In addition to the new compounds isolated, the diketopiperazine described is the first reported molecule of that class from the genus Aaptos. The significance of the isolated compounds is discussed, in the context of drug discovery and development. The potential of the branched-chain mono-glycerol ether 3-((13-methylhexadecyl)oxy)propane-1,2-diol as a lipid biomarker for the genus Aaptos was examined, as this compound has only been reported from species of that genera. In addition, it’s potential as an immunomodulatory drug is discussed, including the significance of the ether linkage in contrast to the more common ester linkage. The isolation of the 2,5-diketopiperazine cyclo(L-Phe-L-Pro) new to the genus was shown to support the potential in diversity of climate and geographical distribution. This class of molecule is generated through the shikimate biosynthetic pathway; a metabolic route used by bacteria, fungi and algae. A proposed symbiotic relationship between the sponge Aaptos confertus and a proximal bacteria, fungi or algae exemplifies the value of New Zealand’s diverse and unique marine organisms.</p>

Isolation and Structural Elucidation of Secondary Metabolites from New Zealand Marine Sponge Aaptos confertus

<p>This study reports on the spectroscopy-guided isolation and structural elucidation of secondary metabolites from the New Zealand marine sponge Aaptos confertus. An extraction of the sponge material, followed by several purification steps, led to the isolation of potential new compounds CJP02 20A, CJP02 20C and CJP02 04CB, a known 2,5-diketopiperzine cyclo(L-Phe-L-Pro), and a previously reported 3-((13-methylhexadecyl)oxy)propane-1,2-diol. Corrections to the ¹H NMR data reported for 3-((13-methylhexadecyl)oxy)propane-1,2-diol were also recorded. The relationship between the oceanic climate where a marine organism habituates and its production of secondary metabolites is discussed. The isolation of a diverse range of compounds, either novel or new to the genus, suggests that organisms originating in temperate climates are similar in value to those from tropical climates, where higher rates of predation (and therefore, selective pressure) are thought to produce superior diversity in their secondary metabolic distribution. In addition to the new compounds isolated, the diketopiperazine described is the first reported molecule of that class from the genus Aaptos. The significance of the isolated compounds is discussed, in the context of drug discovery and development. The potential of the branched-chain mono-glycerol ether 3-((13-methylhexadecyl)oxy)propane-1,2-diol as a lipid biomarker for the genus Aaptos was examined, as this compound has only been reported from species of that genera. In addition, it’s potential as an immunomodulatory drug is discussed, including the significance of the ether linkage in contrast to the more common ester linkage. The isolation of the 2,5-diketopiperazine cyclo(L-Phe-L-Pro) new to the genus was shown to support the potential in diversity of climate and geographical distribution. This class of molecule is generated through the shikimate biosynthetic pathway; a metabolic route used by bacteria, fungi and algae. A proposed symbiotic relationship between the sponge Aaptos confertus and a proximal bacteria, fungi or algae exemplifies the value of New Zealand’s diverse and unique marine organisms.</p>

HR-MS Based Untargeted Lipidomics Reveals Characteristic Lipid Signatures of Wilson’s Disease

Background and Aims: The diagnosis of Wilson’s disease (WD) is challenging by clinical or genetic criteria. A typical early pathological change of WD is the increased liver lipid deposition and lowered serum triglyceride (TG). Therefore, the contents of serum lipids may provide evidence for screening of biomarkers for WD.Methods: 34 WD patients, 31 WD relatives, and 65 normal controls were enrolled in this study. Serum lipidomics data was acquired by an ultra-high-performance liquid chromatography high-resolution mass spectrometry system, and the data were analyzed by multivariate statistical methods.Results: Of all 510 identified lipids, there are 297 differential lipids between the WD and controls, 378 differential lipids between the relatives and controls, and 119 differential lipids between the patients and relatives. In WD, the abundances of most saturated TG were increased, whereas other unsaturated lipids decreased, including phosphatidylcholine (PC), sphingomyelin (SM), lysophosphatidylcholine (LPC), ceramide (Cer), and phosphatidylserine (PS). We also found many serum lipid species may be used as biomarkers for WD. The areas under the receiver operating characteristic curve (AUC) of PS (35:0), PS (38:5), and PS (34:0) were 0.919, 0.843, and 0.907. The AUCs of TG (38:0) and CerG1 (d42:2) were 0.948 and 0.915 and the AUCs of LPC (17:0) and LPC (15:0) were 0.980 and 0.960, respectively. The lipid biomarker panel exhibits good diagnostic performance for WD. The correlation networks were built among the different groups and the potential mechanisms of differential lipids were discussed. Interestingly, similar lipid profile of WD is also found in their relatives, which indicated the changes may also related to the mutation of the ATP7B gene.Conclusions: Lipid deregulation is another important hallmark of WD besides the deposition of copper. Our lipidomic results provide new insights into the diagnostic and therapeutic targets of WD.

Supplemental Material: Putative fossils of chemotrophic microbes preserved in seep carbonates from Vestnesa Ridge, off northwest Svalbard, Norway

Detailed methods, supplemental figures showing microfacies context of microstructures and nanoSIMS data correlation plots, as well as supplemental data file including nanoSIMS data, lipid biomarker data, mineralogy, and carbonate stable carbon and oxygen isotope compositions.<br>

Supplemental Material: Putative fossils of chemotrophic microbes preserved in seep carbonates from Vestnesa Ridge, off northwest Svalbard, Norway

Detailed methods, supplemental figures showing microfacies context of microstructures and nanoSIMS data correlation plots, as well as supplemental data file including nanoSIMS data, lipid biomarker data, mineralogy, and carbonate stable carbon and oxygen isotope compositions.<br>