Novel anti-inflammatory diketopiperazine alkaloids from the marine-derived fungus Penicillium brasilianum.

Diketopiperazine alkaloids have proven the most abundant heterocyclic alkaloids up to now, which usually process diverse scaffolds and rich biological activities. In our search for bioactive diketopiperazine alkaloids from marine-derived fungi, two novel diketopiperazine alkaloids, penipiperazine A (1) and its biogenetically related new metabolite (2), together with a known analogue neofipiperzine C (3), were obtained from the strain Penicillium brasilianum. Their planar structures and absolute configurations were elucidated by extensive spectroscopic analyses, 13C NMR calculation, Marfey's, ECD, and ORD methods. Compound 1 featured a unique 6/5/6/6/5 indole-pyrazino-pyrazino-pyrrolo system, and its plausible biogenetic pathway was also proposed. Additionally, compounds 1-3 have been tested for their inflammatory activities. 1 and 2 significantly inhibited the release of NO and the expression of related pro-inflammatory cytokines on LPS-stimulated RAW264.7 cells, suggesting they could be attracting candidate for further development as anti-inflammatory agent. KEY POINTS: • A novel diketopiperazine alkaloid featuring a unique 6/5/6/6/5 indole-pyrazino-pyrazino-pyrrolo system was isolated from the marine fungus Penicillium brasilianum. • The structure of 1 was elucidated by detailed analysis of 2D NMR data, 13C NMR calculation, Marfey's, ECD, and ORD methods. • Compounds 1 and 2 significantly inhibited the release of NO and the expression of related pro-inflammatory cytokines on LPS-stimulated RAW264.7 cells.

Natural products from marine fungi as a source against agricultural pathogenic fungi.

There are many kinds of agricultural pathogenic fungi, which may belong to pathogenic fungi in different species, such as Fusarium, Alternaria, Colletotrichum, Phytophthora, and other agricultural pathogens. Pathogenic fungi from different sources are widely distributed in agriculture, which threaten the lives of crops around the world and caused great damage to agricultural production and economic benefits. Due to the particularity of the marine environment, marine-derived fungi could produce natural compounds with unique structures, rich diversities, and significant bioactivities. Since marine natural products with different structural characteristics could inhibit different kinds of agricultural pathogenic fungi, secondary metabolites with antifungal activity could be used as lead compounds against agricultural pathogenic fungi. In order to summarize the structural characteristics of marine natural products against agricultural pathogenic fungi, this review systematically overview the activities against agricultural pathogenic fungi of 198 secondary metabolites from different marine fungal sources. A total of 92 references published from 1998 to 2022 were cited. KEY POINTS: • Pathogenic fungi, which could cause damage to agriculture, were classified. • Structurally diverse antifungal compounds from marine-derived fungi were summarized. • The sources and distributions of these bioactive metabolites were analyzed.

Site-selective growth and plasmonic spectral properties of L-shaped Janus Au-Ag gold nanodumbbells for surface-enhanced Raman scattering.

Ligand-mediated interface control has been broadly applied as a powerful tool in constructing asymmetric multicomponent nanoparticles (AMNP), and induces the anisotropic growth with fine-tuning morphology, composition, plasmonic property and functionality. As a new kind of AMNP, the synthesis of Janus Au-Ag nanoparticles with tunable negative surface curvature is still a challenge. Here, we demonstrate that the synergistic surface energy effects between gold nanodumbbells (Au NDs) with a negative surface curvature and 4-mercaptobenzoic acid (4-MBA) can direct the site-selective growth of anisotropic silver domains on gold nanodumbbells (Au NDs@Ag NPs). By adjusting the 4-MBA concentration-dependent interfacial energy, the Au NDs@Ag NPs could be continuously tuned from dumbbell-like core-shell structures, to L-shaped Janus, and then rod-like core-shell structures with directional and asymmetric spatial distributions of resizable Ag domains by site-selective growth. Based on the calculation results of discrete dipole approximation (DDA) method, it has been found that the Au NDs@Ag L-shaped Janus NPs with Ag island domains created polarization orientation-dependent plasmonic extinction spectra and hot spots around the negatively curved waist and Ag domains. The L-shaped Janus Au NDs@Ag NPs exhibited significantly plasmonic spectrum properties with four apparent LSPR peaks that cover from visible to near-infrared range and higher surface-enhanced Raman scattering (SERS) activity compared with the original Au NDs. The best SERS enhancement factor of 1.41 × 107 was achieved. This synergistic surface energy effect-based method involving the asymmetric growth of silver coating on gold nanoparticles with negatively curved surface presents a new method to design and fabricate nanometer optical devices based on asymmetric multicomponent nanoparticles.

Talasteroid, a new withanolide from the marine-derived fungus Talaromyces stollii.

A new withanolide, talasteroid (1), and a known steroid (2), along with eight meroterpenoids (3-10), were obtained from the rice culture of the marine-derived fungus Talaromyces stollii HBU-115. The structure of 1 including its absolute configuration was determined by extensive 1 D and 2 D NMR spectroscopy, and single-crystal X-ray diffraction analysis. Compound 1 represents the first withanolide featuring a 4-substituted 2,3-dimethyl-2-butenolide ring in the side chain. The isolated compounds were evaluated for their antimicrobial and antioxidant activities.

Anti-inflammatory Polyketides from the Marine-Derived Fungus Eutypella scoparia.

Three new polyketides, eutyketides A and B (1 and 2) and cytosporin X (3), along with four known compounds (4-7), were obtained from the marine-derived fungus Eutypella scoparia. The planar structures of 1 and 2 were elucidated by extensive HRMS and 1D and 2D NMR analyses. Their relative configurations of C-13 and C-14 were determined with chemical conversions by introducing an acetonylidene group. The absolute configurations of 1-3 were determined by comparing their experimental electronic circular dichroism (ECD) data with their computed ECD results. All of the isolated compounds were tested for their anti-inflammatory activities on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages. Compounds 5 and 6 showed stronger anti-inflammatory activities than the other compounds, with the inhibition of 49.0% and 54.9% at a concentration of 50.0 µg/mL, respectively.

Marine fungal metabolites as a source of drug leads against aquatic pathogens.

Aquatic pathogens, including Vibrio, Edwardsiella, Pseudomonas, and Aeromonas, which could result in bacterial diseases to aquaculture, have seriously threatened the world aquaculture production. Marine-derived fungi, which could produce novel secondary metabolites with significant antibacterial activity, may be an important source for finding effective agents against aquatic pathogens. In this review, a systematically overview of the harm of several aquatic pathogens, and 134 antibacterial secondary metabolites against aquatic pathogens from 13 genera of marine-derived fungi, were summarized and concluded. The aim of this review is to find out the relationships between activity and structural type, between bioactive compounds and their hosts, and so on. Altogether, 95 references published during 1997-2021 were cited. KEY POINTS: •Aquatic pathogens, which could result in bacterial diseases to aquaculture, were described. •Marine fungal metabolites with activities against aquatic pathogens were summarized. •The distributions of these bioactive marine fungal metabolites were analyzed.

[Development of the certified reference material of mercury in lyophilized human urine].

OBJECTIVE: To develop the certified reference material of mercury in lyophilized human urine. METHODS: Human urine samples from normal level mercury districts were filtered, homogenized, dispensed, lyophilized and radio-sterilized. Homogeneity test, stability inspection and certification were conducted using a atom fluorescence spectrophotometric method. The physical and chemical stability of the certified reference material were assessed for 18 months. The certified values are based on analysis made by three independent laboratories. RESULTS: The certified values are as follows: low level was (35.6 ± 2.1) µg/L, high level was (50.5 ± 3.0) µg/L. CONCLUSION: The certified reference material of mercury in lyophilized human urine in this research reached the national certified reference material requirements and could be used for the quality control.

[Study on the knowledge, behavior and attitude of influenza A (H1N1) among residents in Shuangqiao District, Chengde city].

OBJECTIVE: To understand the the residents' knowledge, behavior and attitude of influenza A (H1N1) in Shuangqiao District of Chengde city, and provide the basis for making proper strategies of health education, prevention and control on influenza A (H1N1). METHODS: 211 residents from 1 community and 1 village of Shuangqiao District were selected to participate the questionnaire interview with multi-stage clustering sampling. RESULTS: 97.6% of the interviewed had received some kind of information on influenza A (H1N1); Total awareness rate of influenza A (H1N1) knowledge was 58.5%, which increased with the level of education and varied among diverse occupations; 48.2% of respondents conceded that their lives was affected by the influenza A ( H1N1) in some degree, and 9% of selected residents believed that there would be a severe pandemicity in this winter, while 7% of respondents didn't consider any form of preventive methods in the future; 78% of respondents expressed their wishes to be vaccinated, but 11.0% of respondents refused to received inoculation explicitly; on the issue of assessment on services provided by governments and health facilities, 93% of respondents expressed their satisfaction hierarchically. Conclusion Residents in Shuangqiao District lacked of comprehensive knowledge of influenza A (H1N1), and some specific health education should be carried out.

[Progress on detection and analysis method of endocrine disrupting compounds].

EDCs are new generation of environmental pollutions which are globally concerned. They may cause adverse effect mainly to the endocrine system and nervous system, etc. To assess the EDCs' hazard to the health exactly, we should know about the distribution and level of EDCs in the environment. In this paper, the technique of pretreatment in different matrices, the method of detection and analysis about EDCs were reviewed, and the future's prospect on the study of detection and analysis method were talked about also.