Search For Biological Activities Research Articles

The Search for Domestic Pharmaceutical Substances among Metal Complexes Based on (Hetero)arylamides of 4-Aryl-2-hydroxy-4-oxo-2-butenoic Acids

The data obtained on the synthesis and search for biological activity among metal complexes based on 4-aryl-2-hydroxy-4-oxo-2-butenoic acid (hetero)arylamides were integrated. The data on the antimicrobial, anti-inflammatory, analgesic, hypoglycemic, antihypoxic, and immunotropic activities of the synthesized compounds were analyzed. The relationship between the chemical structure and biological activity of chelate complexes was discussed and some regular features were identified. Promising compounds for further research and development of new domestic pharmaceutical substances were found.

Carbonaceous microstructures from sedimentary laminated chert within the 3.46 Ga Apex Basalt, Chinaman Creek locality, Pilbara, Western Australia

Hydrothermal black chert veins intruding the 3.46Ga Apex Basalt contain some of Earth’s oldest microfossil-like objects, whose biogenicity has been questioned. Whilst these black chert veins have been studied in great detail, relatively little is known about the stratiform, seafloor, sedimentary cherts that are conformably interbedded with volcanic rocks of the Apex Basalt.Herein, we document and assess the biogenicity of carbonaceous microstructures present in the lowermost of the stratiform chert units (informally known as the ‘Apex chert’), at the Chinaman Creek locality in the Marble Bar greenstone belt, Pilbara Craton, Western Australia. Carbonaceous material mostly occurs within clotted grey-black cherts and microgranular ‘grainstone-like’ cherts within the stratiform unit, the latter being the major focus of this study. In the clotted cherts, carbon occurs as lobate, fluffy grains, rare compressed flakes, and as a grain boundary phase around spherulitic silica. There is no morphological evidence to support the biogenicity of these microstructures. In contrast, the microgranular chert contains fluffy and flaky carbonaceous grains, plus laminated grains comprising multiple non-isopachous wrinkled carbonaceous laminae, with noted thickening towards some ridge crests, as determined by confocal laser scanning microscopy. Roll-up structures provide evidence of an initial plasticity, interpreted to have formed via the tearing-up and current-induced plastic deformation of microbial mat fragments. Geochemical mapping, using laser Raman micro-spectroscopy and NanoSIMS, respectively demonstrates the antiquity of the carbon, and reveals a close correlation between carbon, nitrogen and sometimes sulphur, concentrated within dark brown to black laminae. Adjacent to microgranular zones are zones of more persistent carbonaceous, undulose, filament-like laminae that entrain relict sediment grains. These microstructures are directly comparable to a sub-type of microbially induced sedimentary structure (MISS), widely reported from younger siliciclastic sediments colonised by microbial biofilms.The morphology and chemical composition of both the non-isopachous laminated grains and the filament-like laminae are consistent with a biological interpretation, suggesting microscopic MISS were present in the microgranular stratiform ‘Apex chert’. However, the fact that neither macroscopic MISS nor bona fide microfossils have yet been reported from this unit, coupled with the proximity of these structures to active hydrothermal vents, potentially discharging hot carbon-rich fluids, urges caution in such an interpretation. The Chinaman Creek ‘Apex chert’ investigated here is one of at least five sedimentary, laminated cherts within the Apex Basalt. These horizons are promising targets in the search for biological activity within a dominantly volcanic Archaean environment.

Biological activity and the Earth's surface evolution: Insights from carbon, sulfur, nitrogen and iron stable isotopes in the rock record

The search for early Earth biological activity is hindered by the scarcity of the rock record. The very few exposed sedimentary rocks have all been affected by secondary processes such as metamorphism and weathering, which might have distorted morphological microfossils and biogenic minerals beyond recognition and have altered organic matter to kerogen. The search for biological activity in such rocks therefore relies entirely on chemical, molecular or isotopic indicators. A powerful tool used for this purpose is the stable isotope signature of elements related to life (C, N, S, Fe). It provides key informations not only on the metabolic pathways operating at the time of the sediment deposition, but more globally on the biogeochemical cycling of these elements and thus on the Earth's surface evolution. Here, we review the basis of stable isotope biogeochemistry for these isotopic systems. Rather than an exhaustive approach, we address some examples to illustrate how they can be used as biosignatures of early life and as proxies for its environment, while keeping in mind what their limitations are. We then focus on the covariations among these isotopic systems during the Archean time period to show that they convey important information both on the evolution of the redox state of the terrestrial surface reservoirs and on co-occurring ecosystems in the Archean.

Life Detection Using Glucose and Tetrasaccharide Enantiomer Pairs

A life-detection system based on the expectation that any viable organism will utilize stereoisomers of a given compound asymmetrically is examined. Aqueous extracts of common soil, Mars regolith simulant JSC Mars-1, and suspensions of E. coli and S. cerevisiae were incubated with stereoisomer pairs. The enantiomeric pairs were either D- and L-glucose or a pair of chiral tetrasaccharides. Following an incubation period of 10 days, stereoisomeric selectivity is detectable with the glucose pair by mass spectrometry in extracts made from soil at 0.5 g/ml, in extracts made from JSC Mars-1 at 2.5 g/ml, and in cell suspensions down to 1.0 x 10(7) cells/ml. For the tetrasaccharide pair, stereoisomeric selectivity was detected in extracts made from 0.5 g/ml or more of common soil but not in JSC Mars-1 simulant. The effective sensitivity in extracts was 2.5 x 10(7) cells/ml or better for the glucose pair and 5.0 x 10(8) cells/ml or better for the tetrasaccharide pair. The sensitivity of the glucose pair was such that it could detect life in samples that would be found to be devoid of organic matter by the GCMS system carried by the Viking landers. The results demonstrate the utility of the approach in the search for biological activity on Mars. However, sensitivity is a function of the enantiomer pair used, and this might also be different for hypothetical martian organisms. Therefore, it will be necessary to characterize additional stereoisomeric pairs and, ultimately, to include several in a single test environment.

Search for biological activities from an invasive shrub species rosemyrtle (Rhodomyrtus tomentosa)

Abstract. Kusuma IW, Ainiyati N, Suwinarti W. 2016. Search for biological activities from an invasive shrub species rose myrtle (Rhodomyrtus tomentosa). Nusantara Bioscience 8: 55-59. Research into the potential of diversity, ethnobotany and ethnopharmacology and bioactivity of Indonesia plants is essential. In continuation of our search into biologically-active substances from plant sources, the ethanol extract of fruit, leaves, twig, and stem of masisin or rose myrtle (Rhodomyrtus tomentosa) were evaluated for their antioxidant and antimicrobial properties and toxicity. Antioxidant property was evaluated by DPPH free radical scavenging activity. Antimicrobial activity was examined by agar well diffusion against Salmonella typhi, Bacillus cereus, Propionibacterium acnes, and Candida albicans. Toxicity of the plant was determined by brine shrimp lethality test. The plant ethanolic extracts showed the occurrences of flavonoid, triterpenoid, and carbohydrate in the phytochemical analysis. In the antioxidant assay, the plant extracts exhibited 90-93% of DPPH radical scavenging activity at 50 ppm. Ascorbic acid, a standard compound showed 96-98% activity at the same concentration tested. In the antimicrobial assay, the activities against B. cereus and C. albicans were displayed by the fruit and leaves of R. tomentosa with activity index (AI) of 0.42 and 0.35, respectively. Leaves, stem, twig, and fruit of the plant showed activity against S. typhi and P. acnes with AI of 0.19-0.50 in comparison to that of reference compound, chloramphenicol. In the brine shrimp lethality test, leaves and fruit showed cytotoxicity with LD50 of 43.4 and 8.5 μg/mL. The stem and twig ethanolic extracts were shown to be cytotoxic inactive. The present results showed potential of R. tomentosa extracts as natural antioxidant, antimicrobial and cytotoxic agents.