Brasilicardin A, a diterpene glycoside isolated from pathogenic actinomycete Nocardia brasiliensis IFM 0406, has become a novel immunosuppressant candidate due to its significant immunosuppressive activity, low toxicity and unique mechanism of action. However, brasilicardin A and its analogues have become a research hotspot to the development of this promising immunosuppressant because of the low-yield production in the natural pathogenic producer and the synthetically challenging skeleton. According to the reported biosynthetic pathway of brasilicardin A, the function of involved diterpene synthase was analyzed by bioinformatics. Then the genes bra1-5 that synthesize the brasilicardin A skeleton were directionally amplified from the pathogenic strain N. brasiliensis IFM 0406, and heterologous expression was achieved successfully in Streptomyces albus R1. The compounds were isolated and purified by using various column chromatographies including silica gel column chromatography and semi-preparative HPLC. Six new brasilicardins were established and named brasilicardin H-M. The activity of brasilicardins was screened using lipopolysaccharide (LPS)-activated mouse primary macrophage inflammation model. Brasilicardin H-M exhibited good inhibitory activity on nitric oxide (NO) release with IC₅₀ values of 28.24 ± 3.70, 37.44 ± 2.00, 39.85 ± 4.02, 26.77 ± 4.40, 65.25 ± 1.48 and 15.24 ± 2.72 μmol·L^-1, respectively (indomethacin as the positive control with IC₅₀ value of 34.28 ± 4.10 μmol·L^-1). The results indicated that six compounds had potential anti-inflammatory activity. This study laid a foundation for the elucidation of the brasilicardin A biosynthetic pathway and evaluation of the structure-activity relationship as well as new drug developments.

Objective To establish a method for the determination of multi-component content of prepared Polygoni Multiflori Radix extract,and to compare the changes of chemical components in the decoction process of prepared Polygoni Multiflori Radix powder decoction pieces and traditional decoction pieces,so as to provide scientific basis for the preparation and clinical application of traditional decoction pieces.Methods The contents of gallic acid,5-hydroxymethylfurfural,2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside,emodin-8-O-β-D-glucoside,physcion-8-O-β-D-glucoside and emodin were determined by high performance liquid chromatography(HPLC).With the extraction rate and alcohol-soluble extract as evaluation indexes,the effects of standard decoction method and non-standard decoction method on the extraction of prepared Polygoni Multiflori Radix powder decoction pieces and original decoction pieces were investigated.Results Non-standard decoction boiling method:the contents of gallic acid,5-hydroxymethylfurfural,2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside,emodin-8-O-β-D-glucoside,physcion-8-O-β-D-glucoside and emodin in the prepared Polygoni Multiflori Radix powder decoction pieces were significantly increased,and the increase ratios were 71.18%,141.67%,146.29%,150.00%,625.00%and 296.00%,respectively.In particular,physcion-8-O-β-D-glucoside increased by 7.25 times.Standard decoction boiling method:the content of the above index components in the prepared Polygoni Multiflori Radix powder decoction pieces was significantly increased,and the increase ratios were 28.09%,10.53%,66.01%,45.45%,316.67%,and 65.85%,respectively.In particular,physcion-8-O-β-D-glucoside increased by 4.17 times.The relative standard deviation(RSD)of each index content of prepared powder decoction by standard decoction boiled method was within 10%.Conclusion The dissolution and quality uniformity of the index components of the prepared Polygoni Multiflori Radix powder decoction pieces are superior to those of the original decoction pieces,which can improve the accuracy of clinical medication and need to be reduced as appropriate.

Objective To explore the effects of glycyrrhizic acid(GA)on neurons injury in traumatic brain injury(TBI)rats and the possible mechanism.Methods The rats were randomly divided into sham-operation group,model group,control group and experimental-L,-M,-H groups,with 20 rats each group.The sham-operation group was only treated with craniotomy;the other 5 groups were used to establish TBI models by extracorporeal shock method.At 0,24 and 48 h after modeling,the experimental-L,-M,-H groups were intraperitoneally injected with 10,50 and 100 mg·kg-1 GA solution,respectively;control group was intraperitoneally injected with 2 mg·kg-1 nimodipine;sham-operation and model groups were intraperitoneally injected with the equal volume of phosphate buffered solution.The degree of neurological dysfunction was evaluated by cerebral edema and modified neurological severity score(mNSS).The apoptosis rates of neurons in rat brain tissue was evaluated by apoptosis staining.Western blot was used to analyze the expression levels of apoptosis-related proteins and aquaporin 4(AQP4)protein.Results The mNSS scores of experimental-M,-H groups,control group,model group,sham-operation group were(6.98±0.82),(5.28±0.37),(5.91±0.52),(13.28±1.59)and(0.36±0.01)points;the degrees of brain edema were(63.27±10.33)％,(60.09±9.38)％,(66.86±9.91)％,(85.92±11.93)％and(52.17±8.53)％;the apoptosis rates of neurons were(6.81±0.73)％,(5.39±0.25)％,(5.87±0.62)％,(15.13±3.29)％and(2.56±0.03)％;the relative expression levels of B cell lymphoma 2(Bel-2)protein were 0.49±0.06,0.68±0.15,0.62±0.03,0.13±0.03 and 0.95±0.13;the relative expression levels of Bel-2 associated X protein were 0.61±0.08,0.55±0.17,0.39±0.09,0.92±0.19 and 0.16±0.02;the relative expression levels of AQP4 protein were 0.69±0.15,0.38±0.03,0.47±0.09,0.86±0.13 and 0.13±0.09,respectively.There were statistically significant differences in the above indexes between the model group and the experimental-M,-H groups and control group(all P＜0.05).Conclusion GA is able to reduce the brain edema degree and neurological dysfunction in TBI rats,and inhibit neuronal damage and apoptosis,and the mechanism of action may be associated with the inhibition of AQP 4 expression.

Objective:The DNA aptamers of lipoprotein-associated phospholipase A2 (Lp-PLA2), a marker of vasculitis, were screened and a visual detection method using unlabeled nucleic acid aptamer-gold nanoparticle (AuNP) probe was established.Method:Lp-PLA2 aptamers were screened through 8 cycles of incubation binding, ssDNA isolation, PCR amplification and single strand recovery by the magnetic bead fixation SELEX technique. The affinity and specificity of the aptamers were validated using surface plasmon resonance technology and flow cytometry, and the secondary structure of the aptamer and its three-dimensional molecular docking with the target protein were simulated by computer software. Subsequently, aptamer-AuNP complex was prepared, and the color change was caused by salt-induced condensation of the AuNP solution by target competitive binding. Then, the target concentration was detected by measuring the absorbance of the solution with a spectrophotometer. The linear relationship between the sample absorbance and concentration of Lp-PLA2 were established under the optimal determine conditions.Results:Three Lp-PLA2 aptamers B76-2, B76-4 and B76-5 with high affinity and strong specificity were obtained, and the dissociation constants were 1.07, 1.26 and 1.75 nmol/L, respectively. Then AuNP colorimetric sensing method based on B76-2 aptamer was successfully constructed. The linear range and detection limit of Lp-PLA2 were 20-500 ng/ml and 78 ng/ml, respectively, and the reaction time was 30 min, which could specifically distinguish the target from other thrombotic markers such as thrombin and myeloperoxidase.Conclusion:A simple, rapid and specific visual detection method for visually detecting Lp-PLA2 was established by using aptamer-AuNP colorimetric assay.

As a biocatalyst, enzyme has the advantages of high catalytic efficiency, strong reaction selectivity, specific target products, mild reaction conditions, and environmental friendliness, and serves as an important tool for the synthesis of complex organic molecules. With the continuous development of gene sequencing technology, molecular biology, genetic manipulation, and other technologies, the diversity of enzymes increases steadily and the reactions that can be catalyzed are also gradually diversified. In the process of enzyme-catalyzed synthesis, the majority of common enzymatic reactions can be achieved by single enzyme catalysis, while many complex reactions often require the participation of two or more enzymes. Therefore, the combination of multiple enzymes together to construct the multi-enzyme cascade reactions has become a research hotspot in the field of biochemistry. Nowadays, the biosynthetic pathways of more natural products with complex structures have been clarified, and secondary metabolic enzymes with novel catalytic activities have been identified, discovered, and combined in enzymatic synthesis of natural/unnatural molecules with diverse structures. This study summarized a series of examples of multi-enzyme-catalyzed cascades and highlighted the application of cascade catalysis methods in the synthesis of carbohydrates, nucleosides, flavonoids, terpenes, alkaloids, and chiral molecules. Furthermore, the existing problems and solutions of multi-enzyme-catalyzed cascade method were discussed, and the future development direction was prospected.
Biological Products/chemistry* ; Catalysis ; Alkaloids ; Biocatalysis

Objective To explore the effect of improving cleaning and disinfection methods on the prevention,con-trol and disinfection of carbapenem-resistant Enterobacterales(CRE)in burn plastic surgery ward.Methods 297 patients who admitted to the department of burn plastic surgery in a hospital from February 1 to August 31,2021 were selected as the control group,and 210 patients who admitted to the hospital from September 1,2021 to Febru-ary 28,2022 after cleaning and disinfection methods improved were selected as the intervention group.Detection rate of CRE from patients,incidence of healthcare-associated infection(HAI)with CRE,and detection rate of envi-ronmental CRE before and after intervention were statistically analyzed and compared.Results The incidence of HAI and detection rate of CRE from patients in the intervention group were 0.95％and 0,respectively,lower than 4.04％and 2.02％in the control group(both P＜0.05).Compared to the control group,qualified rates of detec-tion of air and surface microbiology,adenosine triphosphate(ATP)bioflorescence and fluorescence labeling in the intervention group were all higher(x2=5.52,13.08,6.66,and 15.01,respectively,all P＜0.05).Conclusion Improving cleaning and disinfection method can reduce the incidence of HAI and the detection rate of CRE in burn wards,improve the surface cleanliness of environmental objects,as well as the effectiveness of HAI prevention and control.

Lysine decarboxylase is a key enzyme involved in the upstream biosynthesis of lycopodium alkaloids (LAs) such as huperzine A, contributing to the decarboxylation of lysine to 1,5-pentanediamine (cadaverine). Three lysine decarboxylase genes (HsLDC-L1, HsLDC-L2, HsLDC-L3) were successfully cloned from Huperzia serrata using transcriptomic sequence data mining strategy combined with reverse transcription PCR. The physicochemical properties, secondary and tertiary structures, amino acid identities, and evolutionary relationship of the three LDCs were analyzed by online bioinformatics analysis platforms and DNAMAN, MEGA 7.0 software, revealing that all of these proteins had the conserved PLP binding domain and active site residues were completely conserved in LDCs. Phylogenetic analysis showed that these LDCs were located in the same branch as other known LDCs from LA-producing plants. Accordingly, the ORFs of these three HsLDCs were inserted into different expression plasmids for further expression in E. coli. However, only HsLDC-L1 was successfully expressed in E. coli BL21 (DE3) by inserting into a pCold TF vector. The recombinant protein was purified by Ni²⁺ affinity chromatography purification. HsLDC-L1 contains 469 amino acid residues, with a calculated molecular weight of 50.50 kDa. HsLDC-L1 expectedly catalyzed the decarboxylation of lysine to produce cadaverine. In addition, HsLDC-L1 can also catalyze the generation of putrescine from ornithine. However, it cannot catalyze the decarboxylation of tyrosine, phenylalanine, tryptophan and histidine. The results not only provide insight into the biosynthesis of LAs including huperzine A, but also provide a critical genetic element for the overproduction of Δ¹-piperideine and pelletierine, the essential biosynthetic precursors of LAs, using synthetic biology strategies.

Objective To explore the clinical effect of early intervention of uric acid in elderly high-risk patients with coronary heart disease. Methods Patients who visited the Cardiovascular Department/Cardiology Department of our hospital from January 2017 to December 2019 were screened, and 456 patients who met the criteria were included in the study. The included patients were randomly divided into a control group and an observation group, with 228 cases in each group. The control group was given routine intervention, and the observation group was given early uric acid intervention. The levels of uric acid, cardiac function indexes, 2-year incidence of coronary heart disease and incidence of cardiovascular events were compared between the two groups before and after the intervention. Results After the intervention, the cognitive level of the two groups was significantly improved, and the understanding level of the observation group was significantly higher than that of the control group (P<0.001). Compared with the control group, the abnormal rate of uric acid level in the observation group was significantly lower (P<0.015). After intervention, the ejection fraction, cardiac output and total peripheral vascular resistance in the observation group had no significant changes (P>0.05). In the control group, ejection fraction and cardiac output decreased, total peripheral vascular resistance increased, and the difference was statistically significant (P<0.05). After 2 years of intervention, 94 cases (41.23%) of coronary heart disease in the control group and 48 cases in the observation group had the disease. (21.05%), the difference between the two groups was significant (P=0.002); within 2 years after the intervention, 78 cases/time (34.21%) of cardiovascular events occurred in the control group and 40 cases/time (17.54%) in the observation group, with a difference between the two groups (P=0.007).Conclusion Early intervention of uric acid in elderly high-risk coronary heart disease population can significantly reduce uric acid levels, stabilize cardiac function indicators, and reduce the 2-year incidence of coronary heart disease and cardiovascular events, which can provide a reference for clinical disease intervention in high-risk coronary heart disease populations.

Humans ; Female ; Prevalence ; Breast Neoplasms ; Cancer Survivors ; Non-alcoholic Fatty Liver Disease ; Liver

Objective To forecast the future burden and its attributable risk factors of infective endocarditis (IE). Method We analyzed the disease burden of IE and its risk factors from 1990 to 2019 using the Global Burden of Disease 2019 database and projected the disease burden from 2020 to 2030 using a Bayesian age-period-cohort model. Results By 2030, the incidence of IE will increase uncontrollably on a global scale, with developed countries having the largest number of cases and developing countries experiencing the fastest growth. The affected population will be predominantly males, but the gender gap will narrow. The elderly in high-income countries will bear the greatest burden, with a gradual shift to middle-income countries. The incidence of IE in countries with middle/high-middle social-demographic indicators (SDI) will surpass that of high SDI countries. In China, the incidence rate and the number of IE will reach 18.07 per 100,000 and 451,596 in 2030, respectively. IE-associated deaths and heart failure will continue to impose a significant burden on society, the burden on women will increase and surpass that on men, and the elderly in high-SDI countries will bear the heaviest burden. High systolic blood pressure has become the primary risk factor for IE-related death. Conclusions This study provides comprehensive analyses of the disease burden and risk factors of IE worldwide over the next decade. The IE-associated incidence will increase in the future and the death and heart failure burden will not be appropriately controlled. Gender, age, regional, and country heterogeneity should be taken seriously to facilitate in making effective strategies for lowering the IE disease burden.
Male ; Humans ; Female ; Aged ; Global Burden of Disease ; Bayes Theorem ; Global Health ; Risk Factors ; Cost of Illness ; Endocarditis ; Heart Failure