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Azooxanthellate scleractinian corals, a group of species that lack a symbiotic relationship with dinoflagellates, are influenced by environmental variables at various scales. As the global commitment to sustainably manage ocean ecosystems and resources rises, there is a growing need to describe biodiversity trends in previously unsampled areas. Benthic invertebrate research in South Africa is a developing field, and many taxa in deep water environments remain inadequately characterized. Recently, the South African azooxanthellate scleractinian fauna was taxonomically reviewed, but their distributional correlations with physical parameters have not been studied. Here we aim to understand the biodiversity gradients of the South African azooxanthellate coral fauna by analysing the environmental correlates of museum samples. The associated coordinate data were georeferenced and depth obtained from a national bathymetric dataset, prior to undertaking a multivariate analysis. This analysis encompassed several steps, including the grouping of the longitude and depth data (environmental data), identifying families characteristic of the group variability, and examining the correlation of the associated data with the biological data. Additionally, the analysis involved quantifying diversity patterns along the environmental gradients. Overall, our results confirmed two longitudinal groups (eastern margin [Group A] vs southern and western margin [Group B]) and 11 depth categories represented within two bathymetric zones (shallow [50–200 m] and deep [300–1000 m]). Caryophylliids, flabellids, and dendrophylliids contributed the most towards distinguishing longitudinal and depth gradients. Both abiotic variable (longitudinal and depth) partially explained coral distribution patterns, with depth being highly correlated to the species variation observed. Data limitations within our data set resulted to unexplained variance, however, despite these limitations, the study demonstrates that historical museum samples provide a valuable data source that can fill research sampling gaps and help improve the understanding of biodiversity patterns of the coral fauna in under sampled marine ecosystems. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's Disease (AD), the most common cause of dementia, is characterized by the amyloid plaques accumulation, generated after the APP cleavage by enzymes, being the most important the beta‐secretase‐1 (BACE1) (Hardy and Selkoe, 2002). Small‐molecule BACE1 inhibitors reduced the production of amyloid‐β peptide, but clinical trials have demonstrated some adverse effects, although non‐progressive and reversible, which indicates that BACE1 inhibition should be better investigated (McDade et al., 2021). Peptides are molecules few explored in the drug development field, but have several advantages, such as specificity, bioavailability and ability to cross the brain‐blood barrier (BBB) (Craik et al., 2013). Marine animals are a rich source of peptides, some of them already used in the clinics (Malve, 2016). Thus, the objective of this work was to find new BACE1 inhibitor peptides from Macrorhynchia philippina venom, a Brazilian marine animal. Method: M. philippina venom was obtained by methanol/acetic acid extraction and tested in SH‐SY5Y neurons for toxicity evaluation. The extract was analyzed by mass spectrometry for peptides identification and sequencing, and had their secondary structure determined and prepared for molecular docking with BACE1 (PDB code 2VKM), conducted by MDockPep serve (Xu and Zou, 2020). Results were analyzed by UCSFChimera, and molecules were selected according to their positioning in the enzyme active site, with distance lower than 3 Å between atoms. Selected molecules were also analyzed by ProtParam tool (Gasteiger et al., 2005) for determining physico‐chemical properties, BBB permeability and stability. Result: Nineteen peptides were obtained, and none of them have already been described, according to similarity analysis by BLAST algorithm. None of them caused significant cytotoxicity for neurons. From that, 10 were positioned in the BACE1 active site after a global docking analysis, in the same place than a known inhibitor (Ki 1.8 nM). One of them was stable, according to algorithms created from known peptides and high aliphatic index. Moreover, the peptide had high hydrophobicity, according to GRAVY index, indicating high BBB permeation. Conclusion: One new peptide was obtained with potential activity on BACE1 inhibition, with suitable characteristics for a drug. The bioactive peptide represents a good alternative for AD treatment. [ABSTRACT FROM AUTHOR]