广西姑婆山及邻近地区大型真菌物种多样性

姑婆山紧邻南岭生物多样性保护优先区，孕育了丰富的生物资源。为了解该区域大型真菌物种多样性，该文采用随机踏查法对广西姑婆山自治区级自然保护区(以下简称姑婆山)及邻近地区大型真菌资源进行调查采集，并结合形态学和分子生物学方法进行物种鉴定。结果表明：(1)共发现348种大型真菌，隶属于2门6纲17目69科175属，其中包含食用菌40种、药用菌42种、毒菌7种。(2)对该区的物种组成分析表明，优势科为蘑菇科(Agaricaceae)、牛肝菌科(Boletaceae)、粉褶蕈科(Entolomataceae)和锈革菌科(Hymenochaetaceae)等9科；优势属为鹅膏属(Amanita)、靴耳属(Crepidotus)、毛皮伞属(Crinipellis)和粉褶蕈属(Entoloma)等11属。(3)共发现2个中国特有属，即脆孔菌属(Fragiliporia)和臧氏牛肝菌属(Zangia);11个中国特有种，即厚集毛菌(Coltricia crassa)、魏氏集毛菌(C.weii)、丛生粉褶蕈(Entoloma caespitosum)、极细粉褶蕈(E.praegracile)、近薄囊粉褶蕈...     

Synthesis and properties of triplex-forming oligonucleotides containing 2′-O-(2-methoxyethyl)-5-(3-aminoprop-1-ynyl)-uridine

2′-O-(2-Methoxyethyl)-5-(3-aminoprop-1-ynyl)-uridine phosphoramidite (MEPU) has been synthesized from d-ribose and 5-iodouracil and incorporated into triplex-forming oligonucleotides (TFOs) by automated solid-phase oligonucleotide synthesis. The TFOs gave very high triplex stability with their target duplexes as measured by ultraviolet/fluorescence melting and DNase I footprinting. The incorporation of MEPU into TFOs renders them resistant to degradation by serum nucleases.     

Discovery and structural optimization of pyrazole derivatives as novel inhibitors of Cdc25B

Structural optimization and preliminary structure–activity relationship studies of a series of N-substituted maleimide fused-pyrazole analogues with Cdc25B inhibitory activity, starting from a high-throughput screening hit, are illustrated. A simplified 3,5-diacyl pyrazole analogue was obtained as the most potent compound (118, IC₅₀ = 0.12 μM) with a 270-fold increase in potency.     

Discovery of novel sphingosine kinase-1 inhibitors. Part 2

Building on our initial work, we have identified additional novel inhibitors of sphingosine kinase-1 (SK1). These new analogs address the shortcomings found in our previously reported compounds. Inhibitors 51 and 54 demonstrated oral bioavailability in a rat PK study.     

Maternal diabetes and oocyte quality

Maternal diabetes has been demonstrated to adversely affect preimplantation embryo development and pregnancy outcomes. Emerging evidence has implicated that these effects are associated with compromised oocyte competence. Several developmental defects during oocyte maturation in diabetic mice have been reported over past decades. Most recently, we further identified the structural, spatial and metabolic dysfunction of mitochondria in oocytes from diabetic mice, suggesting the impaired oocyte quality. These defects in the oocyte may be maternally transmitted to the embryo and then manifested later as developmental abnormalities in preimplantation embryo, congenital malformations, and even metabolic disease in the offspring. In this paper, we briefly review the effects of maternal diabetes on oocyte quality, with a particular emphasis on the mitochondrial dysfunction. The possible connection between dysfunctional oocyte mitochondria and reproductive failure of diabetic females, and the mechanism(s) by which maternal diabetes exerts its effects on the oocyte are also discussed.     

Using embryonic stem cells to form a biological pacemaker via tissue engineering technology

Biological pacemakers can be achieved by various gene‐based and cell‐based approaches. Embryonic stem cells (ESCs)‐derived pacemaker cells might be the most promising way to form biological pacemakers, but there are challenges as to how to control the differentiation of ESCs and to overcome the neoplasia, proarrhythmia, or immunogenicity resulting from the use of ESCs. As a potential approach to solve these difficult problems, tissue‐engineering techniques may provide a precise control on the different cell components of multicellular aggregates and the forming of a construct with‐defined architectures and functional properties. The combined interactions between ESC‐derived pacemaker cells, supporting cells, and matrices may completely reproduce pacemaker properties and result in a steady functional unit to induce rhythmic electrical and contractile activities. As ESCs have a high capability for self‐renewal, proliferation, and potential differentiation, we hypothesize that ESCs can be used as a source of pacemaker cells for tissue‐engineering applications and the ambitious goal of biological cardiac pacemakers may ultimately be achieved with ESCs via tissue‐engineering technology.     

Enhancement of erythromycin A production with feeding available nitrogen sources in erythromycin biosynthesis phase

Effects of feeding different available nitrogen sources from 80 h in erythromycin biosynthesis phase on the erythromycin A (Er-A) production were investigated in 50 l fermenter. Feeding corn steep liquor and yeast extract, the Er-A production was enhanced, while the biotransformation from erythromycin C (Er-C) to Er-A had no increase. When ammonium sulphate was fed at high feeding rate, the maximal Er-A production and ratio of Er-A to Er-C were 7953 U/ml and 98.18:1 at 184 h, respectively, which were higher than that of the control (6742 U/ml and 5.47:1). The feeding ammonium sulphate process was successfully scaled up from 50 l to 25 m³ fermenter. The maximal Er-A production reached 7938 U/ml at 203 h, which was enhanced by 22.1% compared with the control (6501 U/ml at 192 h). The ratio of Er-A to Er-C was 24.05:1, which was higher than that of the control (4.77:1).     

Secondary Metabolites from Aspergillus fumigatus,an Endophytic Fungus from the Liverwort Heteroscyphus tener (Steph.) Schiffn.

Three new metabolites, asperfumigatin ( 1 ), isochaetominine ( 10 ), and 8′‐O‐methylasterric acid ( 21 ), together with nineteen known compounds, were obtained from the culture of Aspergillus fumigatus, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph.) Schiffn. Their structures were established by extensive analysis of the spectroscopic data. The absolute configurations of 1 and 10 were determined by analysis of their respective CD spectra. Cytotoxicity of these isolates against four human cancer cell lines was also determined.     

New Labdane Diterpenes and Their Glycoside Derivatives from the Roots of Isodon adenantha

Two new labdane‐type diterpenes (adenanthic acids A and B; 1 and 2 , resp.) and three new labdane diterpene glycosides (adenanthosides A–C; 3 – 5 , resp.) were isolated from the roots of Isodon adenantha, together with 23 known constituents including seven diterpenoids ( 6 – 12 ), eight triterpenoids ( 13 – 20 ), one lignan glycoside ( 21 ), six steroids ( 22 – 27 ), and one ceramide ( 28 ). Their structures were elucidated by spectroscopic methods including extensive 2D‐NMR techniques. Cytotoxicity and antibacterial activities of the samples were measured by the MTT method and the filter paper disc agar diffusion method. But none of them showed significant activities.     

Lupane‐ and Friedelane‐Type Triterpenoids from Celastrus stylosus

Two new triterpenoids, 30‐hydroxylup‐20(29)‐ene 3β‐caffeate ( 1 ) and 24‐nor‐friedelan‐6α,10‐dihydroxy‐1,2‐dioxo‐4,7‐dien‐29‐oic acid ( 2 ), together with eight known compounds 3 – 10 , were isolated from the roots of Celastrus stylosus. The structures of these compounds were elucidated on the basis of spectroscopic analyses. To the best of our knowledge, this represents the first study on the chemical constituents of C. stylosus. The antiproliferative activities of the triterpenoids against six human cancer cell lines (PANC‐1, A549, PC‐3, HepG2, SGC‐7901, and HCCLM3) were evaluated. Compounds 3, 4 , and 10 exhibited comparable activities against PC‐3 and HCCLM3 cell lines as the positive control taxol.