Synthesis, characterization, and biological activity of selenium nanoparticles conjugated with polysaccharides.

Nanoparticles with unique properties have potential applications in food, medicine, pharmacology, and agriculture industries. Accordingly, many significant researches have been conducted to develop novel nanoparticles using chemical and biological techniques. This review focuses on the synthesis of selenium nanoparticles (SeNPs) using polysaccharides as templates. Various instrumental techniques being used to confirm the formation of polysaccharide-SeNPs conjugates and characterize the properties of nanoparticles are also introduced. Finally, the biological activities of the synthesized SeNPs and the influence of structural factors of polysaccharides on the property of synthetic nanocomposites are highlighted. In general, the polysaccharides functionalized SeNPs can be easily obtained using sodium selenite as precursor and ascorbic acid as reductant. The final products having different particle size, morphology, and selenium content exhibit abundant physiological activities. Structural factors of polysacchairdes involving molecular weights, substitution of functional groups, and chain conformation play determinant roles on the properties of nanocomposites, resulting in different biological performances. The review on the achievements and current status of polysaccharides conjugated SeNPs provides insights into this exciting research topic for further studies in the future.

Chaetochromones A - C, Three New Polyketides from Mangrove Plant Derived Endophytic Fungus Phomopsis sp. SCSIO 41006.

Three new polyketides, chaetochromones A - C (1 - 3), together with a chromone (4), were isolated from the ethyl acetate extract of mangrove-derived fungus Phomopsis sp. SCSIO 41006. Their structures were elucidated by means of spectroscopic techniques (UV, IR, MS, 1D- and 2D-NMR). The absolute configurations of the new compounds were established by CD data.

Asteltoxins with Antiviral Activities from the Marine Sponge-Derived Fungus Aspergillus sp. SCSIO XWS02F40.

Two new asteltoxins named asteltoxin E (2) and F (3), and a new chromone (4), together with four known compounds were isolated from a marine sponge-derived fungus, Aspergillus sp. SCSIO XWS02F40. The structures of the compounds (1-7) were determined by the extensive 1D- and 2D-NMR spectra, and HRESIMS spectrometry. All the compounds were tested for their antiviral (H1N1 and H3N2) activity. Compounds 2 and 3 showed significant activity against H3N2 with the prominent IC50 values of 6.2 ± 0.08 and 8.9 ± 0.3 µM, respectively. In addition, compound 2 also exhibited inhibitory activity against H1N1 with an IC50 value of 3.5 ± 1.3 µM.

Protuboxepin C and protuboxepin D from the sponge-derived fungus Aspergillus sp SCSIO XWS02F40.

Two new diketopiperazine alkaloids, named protuboxepin C (1) and protuboxepin D (2), which contain D-Phe residue and oxepin ring, were isolated from EtOAc extract of sponge-derived fungus Aspergillus sp SCSIO XWS02F40. Their structures were elucidated by 1D, 2D NMR and HRESIMS dates, and their absolute configurations were confirmed by single crystal X-ray diffraction experiments and CD analyses. The in vitro cytotoxicity of these two new compounds was further evaluated using A549 and Hela cell lines.

New phenyl derivatives from endophytic fungus Botryosphaeria sp. SCSIO KcF6 derived of mangrove plant Kandelia candel.

Two new phenyl derivatives (1 and 3), along with two new natural products (4 and 5), and three known compounds (2, 6 and 7), were isolated from an endophytic fungus Botryosphaeria sp. SCSIO KcF6. The structures of these compounds 1-7 were elucidated by the extensive 1D and 2D-NMR and HRESIMS Data analysis, and compared with those of reported data. The absolute configuration of the compounds 1 and 3 were assigned by optical rotation and CD data. The isolated compounds were evaluated for their cytotoxic, anti-inflammatory (COX-2) and antimicrobial activities. Compound 3 exhibited a specific COX-2 inhibitory activity with the IC50 value of 1.12 µM.

Ascomycotin A, a new citromycetin analogue produced by Ascomycota sp. Ind19F07 isolated from deep sea sediment.

A new citromycetin analogue, ascomycotin A (1), together with eight known compounds, wortmannilactone E (2), orcinol (3), orsellinic acid (4), isosclerone (5), (3R,4S)-( - )-4-hydroxymellein (6), diorcinol (7), chaetocyclinone B (8) and 2,5-dimethoxy-3,6-di(p-methoxypheny1)-1,4-benzoquinone (9), was isolated from the fungal strain Ascomycota sp. Ind19F07, which was isolated from the deep sea sediment of the Indian Ocean. The structures of the compounds were established by spectroscopic data including 1D and 2D NMR and HR-ESI-MS. Compounds (1-9) were evaluated for antibacterial activity.