Publications by authors named "Jayasinghe L"

Five new metabolites, including three cyclic dipeptide derivatives (-) and two new polyketides (-), together with nine known ones (- and -), were isolated from the mangrove-sediments-derived fungus sp. SCSIO 41431. Their structures were determined using detailed NMR, MS spectroscopic analyses, and quantum chemical calculations.

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Fourier-transform infrared spectroscopy (FTIR) serves as a rapid analytical technique to characterize food specimens chemically. The purpose of this study was to investigate the potential of FTIR combined with multivariate statistics to detect Alpha-glucosidase (Alpha-glu) inhibitory activities of a non-cereal flour-like coconut testa flour (CTF). CTF of five distinct local cultivars was sequentially extracted with hexane, ethyl acetate (EtOAc), and methanol (MeOH) to assay the Alpha-glu inhibitory activity.

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Article Synopsis
  • - The study explores the use of CdS nanorods modified with a catalyst to efficiently generate the nicotinamide cofactor 1,4-NADH, which is essential for energy transfer in biological systems and could enhance photosynthetic biohybrid systems.
  • - The semiconductor nanocrystal model system achieves high turnover frequency (TOF) for NADH production, making it one of the most efficient inorganic photosensitizer applications reported so far.
  • - Understanding the charge transfer kinetics in this setup, which ranges from 10 to 10 seconds, is crucial for improving solar energy conversion and developing systems that replicate natural photosynthesis for sustainable chemical production.
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Three new polyketides, including three ester derivatives (, , and ) and a new natural product, which was a benzoquinone derivative, embelin A (), together with nine known ones ( and -), were isolated from the mangrove-derived fungus sp. SCSIO 41411. Their structures were determined by detailed NMR and MS spectroscopic analyses.

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Objective: The neck region is a common site for solitary cystic neck mass (SCNM) of various etiologies, including congenital, inflammatory, and neoplastic. In adults, the primary focus is excluding malignancy. The objective of this study was to retrospectively analyze the accuracy of available diagnostic technologies for the differentiation of benign and malignant SCNM in adult patients.

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The building sector's significant greenhouse gas emissions and energy consumption present added challenges to meeting European climate commitments amidst rapid population growth. In Luxembourg, single-family houses dominate the residential buildings, noticeably contributing to construction waste and CO emissions. This study compares the environmental impacts of a three-story reinforced concrete masonry single-family house and an identical timber building in Luxembourg, emphasizing greenhouse gas emissions and embodied energy.

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A new heptaketide named oryzanigral () was isolated from the fermentation extract of the endophytic fungus isolated from the leaves of , along with five known compounds, ()-mellein, )--methylmellein, (3,4)-4-hydroxymellein, (3,4)-4-hydroxymellein and abscisic acid. The structure of oryzanigral was elucidated by spectroscopic analyses including 2D-NMR. A plausible biosynthetic pathway involving Diels-Alder reaction was proposed for compound and related polyketides previously reported.

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Membrane nanopores are key for molecular transport in biology, portable DNA sequencing, label-free single-molecule analysis and nanomedicine. Transport traditionally relies on barrel-like channels of a few nanometres width, but there is considerable scientific and technological interest for much wider structures of tunable shape. Yet, these nanopores do not exist in nature and are challenging to build using existing de novo routes for proteins.

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Benth is used in Sri Lankan folk medicine as a remedy for inflammatory conditions and microbial infections. Our previous investigations revealed potent 5-lipoxygenase (5-LO) inhibitory activity in lipophilic extracts of this plant, supporting its anti-inflammatory potential. In-depth studies on the antimicrobial activity have not been conducted and the bioactive ingredients remained elusive.

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During the last decades the interest towards natural products containing the tetronic acid moiety augmented significantly, due to their challenging structures and to the wide range of biological activities they display. This increasing enthusiasm has led to noteworthy advances in the development of innovative methodologies for the construction of the butenolide nucleus. This review provides an overview of the progress in the synthesis of tetronic acid as a structural key motif of natural compounds, covering the last 15 years.

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Biological nanopores for single-pore sensing have the advantage of size homogeneity, structural reproducibility, and channel amenability. In order to translate this to clinical applications, the functional biological nanopore must be inserted into a stable system for high-throughput analysis. Here we report factors that control the rate of pore insertion into polymer membrane and analyte translocation through the channel of viral DNA packaging motors of Phi29, T3 and T7.

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Chronic liver inflammation has become a major global health concern. In the absence of clinical surrogate markers to diagnose inflammatory liver disease, the intervention with effective drugs in modern medicine tends to be late. In Sri Lanka, traditional medical practitioners prescribe herbal preparations from for the prevention and treatment of liver disorders.

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Protein post-translational modification (PTM) is crucial to modulate protein interactions and activity in various biological processes. Emerging evidence has revealed PTM patterns participate in the pathology onset and progression of various diseases. Current PTM identification relies mainly on mass spectrometry-based approaches that limit the assessment to the entire protein population in question.

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Single-molecule long-read DNA sequencing with biological nanopores is fast and high-throughput but suffers reduced accuracy in homonucleotide stretches. We now combine the CsgG nanopore with the 35-residue N-terminal region of its extracellular interaction partner CsgF to produce a dual-constriction pore with improved signal and base-calling accuracy for homopolymer regions. The electron cryo-microscopy structure of CsgG in complex with full-length CsgF shows that the 33 N-terminal residues of CsgF bind inside the β-barrel of the pore, forming a defined second constriction.

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Traditional folk medicine in Sri Lanka is mostly based on plants and plant-derived products, however, many of these medicinal plant species are scientifically unexplored. Here, we evaluated the anti-inflammatory and antimicrobial potency of 28 different extracts prepared from seven popular medicinal plant species employed in Sri Lanka. The extracts were subjected to cell-based and cell-free assays of 5-lipoxygenase (5-LO), microsomal prostaglandin E synthase (mPGES)-1, and nitric oxide (NO) scavenging activity.

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The connector channel of bacteriophage phi29 DNA packaging motor has been inserted into the lipid bilayer membrane and has shown potential for the sensing of DNA, RNA, chemicals, peptides, and antibodies. Properties such as high solubility and large channel size have made phi29 channel an advantageous system for those applications; however, previously studied lipid membranes have short lifetimes, and they are frangible and unstable under voltages higher than 200 mV. Thus, the application of this lipid membrane platform for clinical applications is challenging.

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An endophytic fungus Pestalotiopsis microspora isolated from the fruits of Manilkara zapota was cultured in potato dextrose broth media. Chromatographic separation of the EtOAc extract of the broth and mycelium led to the isolation of a new azaphilonoid named pitholide E (1), in addition to previously identified pitholide B (2), pitholide D (3), pestalotin (LL-P880α) (4), PC-2 (5), LL-P880β (6), tyrosol (7) and 4-oxo-4H-pyran-3-acetic acid (8). An endophytic fungus P.

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This study investigated the effect of boiling on the inhibitory action of spices on digestive enzymes. Unboiled extracts of (seed) (25.42%), (seed) (22.

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Sequencing the RNA in a biological sample can unlock a wealth of information, including the identity of bacteria and viruses, the nuances of alternative splicing or the transcriptional state of organisms. However, current methods have limitations due to short read lengths and reverse transcription or amplification biases. Here we demonstrate nanopore direct RNA-seq, a highly parallel, real-time, single-molecule method that circumvents reverse transcription or amplification steps.

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The tea shot-hole borer beetle (TSHB, Euwallacea fornicatus) causes serious damage in plantations of tea, Camellia sinensis var. assamica, in Sri Lanka and South India. TSHB is found in symbiotic association with the ambrosia fungus, Monacrosporium ambrosium (syn.

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Phialemonium curvatum, an endophytic fungus isolated from the leaves of Passiflora edulis was cultured in potato dextrose broth (PDB) media and chromatographic separation of the EtOAc extract of the broth and mycelium led to the isolation of 4-hydroxybenzoic acid (1), 3-indole acetic acid (2), solaniol (3), uracil (4), uridine (5) and glycerol (6). Compound 2 showed a weak antifungal activity against Cladosporium cladosporioides. This is the first report of the isolation of the endophytic fungus P.

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