Total synthesis of dryocrassin ABBA and its analogues with potential inhibitory activity against drug-resistant neuraminidases.

The stems of Dryopteris crassirhizoma, one of the main components of Lianhua-Qingwen Formula (LQF) was traditionally used for heat-clearing and detoxifying. Dryocrassin ABBA is a key antiviral component in the herbal medicine while the compound is hard to get in large amounts with the features of homologous compounds, polyphenol groups, and low contents. Therefore, the present work aims to seek influenza H7N9 virus inhibitors from natural source by synthesis of dryocrassin ABBA and its analogues. As a result, total synthesis of the compound was achieved in nine steps with an over-all yield of 4.6%. Neuraminidases (NAs) inhibitory activities of the synthesized product and its analogues were evaluated afterward. Comparing with the positive control, OSV (9.6 µM), it was very exciting that dryocrassin ABBA and its analogues (b5 and e2) showed better NAs inhibitory activity against Anhui H7N9 with IC50 values of 3.6 µM, 2.5 µM and 1.6 µM. For the highly resistant Shanghai N9, these compounds can also show medium inhibitory activities. Docking results indicated the direct interaction of synthesized 3 hits with the key K294 by hydrogen bonds, but no direct interaction of OSV with the key K294 was observed in Shanghai N9. This study suggested that dryocrassin ABBA and its analogues especially AB, which consisted of polyphenol groups may have beneficial effects on treating avian influenza H7N9 virus.

Characterization of a protein-bound polysaccharide from Herba Epimedii and its metabolic mechanism in chronic fatigue syndrome.

OBJECTIVES: Herba Epimedii is one of the famous Traditional Chinese Medicines used to treat the chronic fatigue syndrome (CFS). The polysaccharides are the main active components in H. epimedii. The aim of this study is to discover the therapeutic effect and metabolic mechanism of H. epimedii polysaccharides against CFS. METHODS: The polysaccharide conjugates named HEP2-a were isolated from the leaves of H. epimedii using a water extraction method, and the general physicochemical properties of HEP2-a were analysed. In addition, a CFS rat model was established, and then, urinary metabonomic studies were performed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) in combination with multivariate statistical analysis. RESULTS: The physicochemical properties revealed that HEP2-a had an average molecular weight of 13.6×104Da and consisted of mannose (4.41%), rhamnose (5.43%), glucose (31.26%), galactose (27.07%), arabinose (23.43%), and galacturonic acid (8.40%). The amino acids in HEP2-a include glutamate, cysteine, leucine, tyrosine, lysine, and histidine. Molecular morphology studies revealed many highly curled spherical particles with diameters of 5-10µm in solids and 100-200nm for particles in water. Five metabolites in the HEP2-a group were oppositely and significantly changed compared to the CFS model group. CONCLUSION: Two metabolic pathways were identified as significant metabolic pathways involved with HEP2-a. The therapeutic effects of HEP2-a on CFS were partially due to the restoration of these disturbed pathways.

[Preparation and Identification of High Immunogenic A/PR/8/34 Maternal Strain HA Protein for Influenza Virus Classical Reassortment].

Preparation of maternal strain A/PR/8/34 HA antiserum for influenza virus classical reassortment. A/PR/8/34 virus was digested by bromelain after inactivation and purification. 5%-20% sucrose continuous density gradient centrifugation method was used to purify HA protein. SIRD method was used to select the target protein. SDS-PAGE method was used to identified HA protein. High Immunogenic A/PR/8/34 HA protein was successfully prepared and HI titer reached 10240. High purity HA antiserum was identified by SIRD method. The key reagent in the classical reassortment of influenza virus was prepared, and the complete set of technical methods were explored, which laid the foundation for the independent research and development of seasonal influenza vaccine strains of China.

[Effects of ulinastatin on cognitive function in patients with coronary artery bypass grafting].

OBJECTIVE: To investigate the effects of ulinastatin(UTI) on postoperative cognitive function in patients undergoing coronary artery bypass grafting. METHODS: One hundred and twenty-seven patients undergoing elective coronary artery bypass surgery were randomly divided into three groups:high-dose UTI group(16000 U/kg i.v.), low-dose UTI group(8000 U/kg i.v.) and control group(normal saline). The levels of plasma cortisol were measured before and one day after surgery. The level of IL-6, IL-10, TNF-α and S100ß were measured before operation(T0), at open chest(T1), end of operation(T2), 6 h(T3)and 24 h(T4) after operation. A neuropsychological test scale was to evaluate the cognitive function 1 day before operation, 1 week and 3 months after operation. RESULTS: Ninety-three patients completed the study. There was no significant difference in general information of patients among three groups(P>0.05). The level of plasma cortisol one day after operation was significantly higher than that before operation in control group(P<0.01). The levels of plasma cortisol in high-dose UTI group and low-dose UTI group were lower than that of control group(P<0.01). In all groups, the level of plasma IL-6, IL-10, TNF-α and S100B increased remarkably at T2, T3, T4 compared to those at T0(all P<0.05). The level of plasma IL-6, TNF-α(at T2, T3, T4)and S100ß(at T3)in high-dose UTI group and low-dose UTI group were all lower than those of control group(P<0.05),while there were no significant differences between high-dose UTI group and low-dose UTI group(P>0.05). The incidence of postoperative cognitive dysfunction in POCD 1 week after operation in high-dose UTI and low-dose UTI groups(25.8% and 23.3%)was lower than that in control group(50.0%), while there were no significant difference 1 month after operation between high-dose UTI group(12.9%) or low-dose UTI group(16.7%)and control group(28.1%). The level of plasma S100ß at T2 of POCD patients(n=31)was higher than that of non-POCD group(n=62)(P<0.05). CONCLUSION: Ulinastatin can reduce the incidence of postoperative cognitive dusfunction 1 week after coronary artery bypass surgery, which might be associated with inhibition of inflammation and S100ß expression.

Invasive Robinia pseudoacacia in China is nodulated by Mesorhizobium and Sinorhizobium species that share similar nodulation genes with native American symbionts.

The aim of this work is to describe the diversity of potentially symbiotic bacteria associated with the invasive introduced legume Robinia pseudoacacia in China. Thirty-three isolates from 33 separate trees and nodules were characterized using restriction length fragment polymorphism and sequencing of 16S rRNA, nodA, nodC and nifH genes. Their 16S rRNA gene patterns and sequences placed them in three clades: 85% of isolates were related to the Mesorhizobium mediterraneum/temperatum group, whereas the remaining were similar either to Mesorhizobium amorphae or to Sinorhizobium meliloti. However, despite their diverse taxonomic positions, the nodA, nodC and nifH genes' phylogenies indicated that these R. pseudoacacia symbionts share similar symbiosis genes, implying gene transfers and a degree of host specificity. Comparison of R. pseudoacacia symbiotic diversity in native and other invaded areas suggests that most Chinese symbionts may not have arrived with the seed but were local bacteria that acquired specific symbiotic genes from native American rhizobia.