Search

Plastic pollution has emerged as a growing environmental concern, affecting even the most remote regions of the planet as the Antarctic continent, endangering its ecosystem and contributing to climate change. In this context, a continuous atmospheric microplastics monitoring study was conducted at Carlini Argentine Antarctic Station located in the southwest of 25 de Mayo (King George) Island (South Shetlands). Passive samplers were installed at three locations throughout the station, chosen based on the intensity of human activity and proved to be effective in collecting atmospheric particles over a one-year study period. Micro-FTIR and micro-Raman spectroscopies were used to characterize the suspected microplastic particles. These techniques revealed a wide variety of plastic polymers compositions and industrial dyes associated with textile and plastic materials. Microfibers were found to be the predominant particle form, constituting approximately 80% of the particles detected at each sampling point. Semi-synthetic cotton, polyester, and polyamide were widely detected, along with other plastic compositions. Micro-Raman spectroscopy confirmed the presence of indigo blue, reactive blue 238, and copper phthalocyanine on both synthetic and semi-synthetic fibers, representing the first report of these types of anthropogenic pigments in the Antarctic atmosphere. The results suggest a significant role of short-range transport from local human activities; however, the potential influence of large-scale atmospheric patterns should also be evaluated. Our findings highlight the need to expand the monitoring network to additional scientific stations and remote regions with minimal human activity. Increasing the number of observational sites and conducting complementary studies on airborne dispersion will strengthen assessments of potential long-range pollution sources., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Two nor-diterpenes, 9,11-dihydrogracilin A (1) and the previously unreported 9,11-dihydrogracillinone A (2), were isolated from the sponge Dendrilla antarctica. The sponge was collected by trawling at a depth of 49 m, from the research vessel Puerto Deseado, near the coast of Tierra del Fuego, farther north than the reported habitat for this species. Since these compounds were particularly abundant and the sponge was free from epibionts, both 1 and 2 were included in soluble-matrix paints and tested for antifouling activity in the ocean. The results obtained from these experiments clearly indicated a potent antifouling activity for both compounds against a variety of colonizing organisms, and established a probable role as natural antifoulants for these abundant secondary metabolites and other structurally related compounds previously isolated from Dendrilla spp., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

Seven new steroids, compounds 1-7, were isolated from the Antarctic octocoral Anthomastus bathyproctus. The structures of the new metabolites have been established by analysis of their spectroscopic data. The in vitro cytotoxicity has been tested against three human tumor cell lines.

The main objective of this study was to identify some micro fungi isolated from soil of Potter peninsula (Antarctica), which were involved in food spoiling at Jubany base. Different solid culture media were used to isolate 66 fungal strains from spoiled food and soil. Twelve saprophytic, spoiling and/or toxicogenic taxa belonging to the genera Doratomyces, Geomyces, Oidiodendron y Penicillium were identified; eight of them with full descriptions and drawings. This is the first record of Geomyces pannorum var. vinaceus and Oidiodendron griseum recovered from the Argentine Antarctica.

The chemical study of the Antarctic octocoral Dasystenella acanthina has led to the isolation of the new polyoxygenated steroids (24R,22E)-24-hydroxycholest-4,22-dien-3-one (1), 23-acetoxy-24,25-epoxycholest-4-en-3-one (2), 12beta-acetoxycholest-4-en-3,24-dione (3), 12beta-acetoxy-24,25-epoxycholest-4-en-3-one (4), (22E)-25-hydroxy-24-norcholest-4,22-dien-3-one (5), 3alpha-acetoxy-25-hydroxycholest-4-en-6-one (6), and 3alpha,11alpha-diacetoxy-25-hydroxycholest-4-en-6-one (7), whose structures have been established by spectroscopic analysis. The absolute stereochemistry at C-24 in compound 1 has been determined through the 1H NMR study of the corresponding (R)- and (S)-MPA esters. All the new compounds showed significant activities as growth inhibitors of several human tumor cell lines. In addition, cytostatic and cytotoxic effects were also observed on selected tumor cell lines.

Fifteen illudalane sesquiterpenoids, alcyopterosins A-O (1-15) have been isolated from the subAntarctic soft coral Alcyonium paessleri which was collected at a depth of 200 m near the South Georgia Islands, and their structures were elucidated by spectroscopic techniques. Eight of these compounds (2, 3, 5-8, 10, and 13) are the first natural nitrate esters, while the other four (1, 4, 11, and 12) are chlorinated. These compounds are as well the first illudalane sesquiterpenoids to be isolated from the marine environment. Compounds 1, 3, 5, and 8 showed mild cytotoxicity toward human tumor cell lines.