Therapeutic Potential of Ramalin Derivatives with Enhanced Stability in the Treatment of Alzheimer's Disease.

Alzheimer's disease (AD) remains a significant public health challenge with limited effective treatment options. Ramalin, a compound derived from Antarctic lichens, has shown potential in the treatment of AD because of its strong antioxidant and anti-inflammatory properties. However, its instability and toxicity have hindered the development of Ramalin as a viable therapeutic agent.

The neuroprotective and anti-neuroinflammatory effects of ramalin synthetic derivatives in BV2 and HT22 cells.

Ramalin, a strong antioxidant isolated from Antarctic lichens, has been shown to have potential therapeutic effects in the treatment of Alzheimer's disease. However, this compound is readily degraded in aqueous solutions, which restricts its development as a therapeutic agent. With a view toward addressing this problem, in this study, we modified the structure of ramalin to obtain more stable compounds and attempted to identify a derivative with the strongest neuroprotective properties.

A novel exopolysaccharide (p-CY01) from the Antarctic bacterium sp. strain CY01 cryopreserves human red blood cells.

Cryopreservation of human red blood cells (RBCs) is vital for regenerative medicine and organ transplantation, but current cryoprotectants (CPAs) like glycerol and hydroxyethyl starch (HES) have limitations. Glycerol requires post-thaw washing due to cell membrane penetration, while HES causes high viscosity. To address these issues, we explored exopolysaccharides (EPS) from Antarctic sp.

Microbial metabolic responses and CO emissions differentiated by soil water content variation in subarctic tundra soils.

Recent rapid air temperature increases across the northern-latitude tundra have prolonged permafrost thawing and snow melting periods, resulting in increased soil temperature (T) and volumetric soil water content (SWC). Under prolonged soil warming at 8°C, Alaskan tundra soils were incubated in a microcosm system and examined for the SWC differential influence on the microbial decomposition activity of large molecular weight (MW) humic substances (HS). When one microcosm soil (AKC1-1) was incubated at a constant SWC of 41% for 90 days (T = 90) and then SWC was gradually decreased from 41% to 29% for another T = 90, the initial HS was partly depolymerized.

PTP1B Inhibitory Secondary Metabolites from an Antarctic Fungal Strain sp. SF-7394.

Chemical investigation of the Antarctic lichen-derived fungal strain sp. SF-7394 yielded a new amphilectane-type diterpene, acrepseudoterin (), and a new acorane-type sesquiterpene glycoside, isocordycepoloside A (). In addition, three known fungal metabolites, (-)-ternatin (), [D-Leu]-ternatin (), and pseurotin A (), were isolated from the EtOAc extract of the fungal strain.

Anti-Inflammatory Effects of Metabolites from Antarctic Fungal Strain sp. SF-7343 in HaCaT Human Keratinocytes.

Chemical investigation of the Antarctic fungi sp. SF-7343 revealed four known secondary fungal metabolites: alternate C (), altenusin (), alternariol (), and altenuene (). The compound structures were identified primarily by NMR and MS analyses.

Genome-wide identification and structural analysis of heat shock protein gene families in the marine rotifer Brachionus spp.: Potential application in molecular ecotoxicology.

Heat shock proteins (Hsp) are class of conserved and ubiquitous stress proteins present in all living organisms from primitive to higher level. Various studies have demonstrated multiple cellular functions of Hsp in living organisms as an important biomarker in response to abiotic and biotic stressors including temperature, salinity, pH, hypoxia, environmental pollutants, and pathogens. However, full understanding on the mechanism and pathway involved in the induction of Hsp still remains challenging, especially in aquatic invertebrates.

White matter and neurological disorders.

The central nervous system is simply divided into two distinct anatomical regions based on the color of tissues, i.e. the gray and white matter.

Total Syntheses of Lobaric Acid and Its Derivatives from the Antarctic Lichen Stereocaulon alpinum.

The first total syntheses of the natural products lobaric acid (1) and its derivatives isolated from the Antarctic lichen Stereocaulon alpinum are reported in this study. Lobarin (3), with a pseudodepsidone structure, was synthesized first in 11 steps by utilizing an Ullmann aryl ether coupling reaction, and lobaric acid was synthesized in an additional three steps by a seven-membered lactonization reaction. Various derivatives were also obtained from the prepared lobaric acid, and the synthetic compounds exhibited significant PTP1B inhibitory activities.

Anti-Cancer Activity of Lobaric Acid and Lobarstin Extracted from the Antarctic Lichen Stereocaulon alpnum.

Lobaric acid and lobarstin, secondary metabolites derived from the antarctic lichen , exert various biological activities, including antitumor, anti-proliferation, anti-inflammation, and antioxidant activities. However, the underlying mechanisms of these effects have not yet been elucidated in human cervix adenocarcinoma and human colon carcinoma. In the present study, we evaluated the anticancer effects of lobaric acid and lobarstin on human cervix adenocarcinoma HeLa cells and colon carcinoma HCT116 cells.

Anticancer Activity of Ramalin, a Secondary Metabolite from the Antarctic Lichen Ramalina terebrata, against Colorectal Cancer Cells.

Colorectal cancer is a leading cause of death worldwide and occurs through the highly complex coordination of multiple cellular pathways, resulting in carcinogenesis. Recent studies have increasingly revealed that constituents of lichen extracts exhibit potent pharmaceutical activities, including anticancer activity against various cancer cells, making them promising candidates for new anticancer therapeutic drugs. The main objective of this study was to evaluate the anticancer capacities of ramalin, a secondary metabolite from the Antarctic lichen , in the human colorectal cancer cell line HCT116.