Isolation of new compounds related to xyloketals biosynthesis implies an alternative pathway for furan-fused-chromene formation.

In fungi, there is a rare group of natural products harboring the 2,3,3a,9a-tetrahydro-4H-furo[2,3-b]chromene skeleton, represented by xyloketal B, which display a wide range of biological activities and have drawn significant attention. In this work, four new analogues simpliketals A-D (1-4), as well as two other new compounds simplilactones A and B (5 and 6), were isolated from Simplicillium sp. AHK071-01. Their structures were elucidated by extensive NMR spectroscopic methods, 13C NMR calculation, single-crystal X-ray diffraction, and ECD calculation. In addition, five known compounds (7-11) including alboatrin (7) were also obtained. Based on the structural similarity of the above compounds, we inferred that compounds 5, 6, and 8-11 might be biosynthetically related with 1-4 and 7, which allowed us to propose an alternative biosynthetic route to generate the furan-fused chromene skeleton of this class of compounds, instead of a previously presumed polyketide-terpenoid hybrid pathway. Finally, cytotoxicity assays showed that 1-4 exhibited weak inhibitory activity on PANC-1 cells and that 2 and 3 possessed moderate activity against SH-SY5Y cells.

Astramalabaricosides A-T, Highly Oxygenated Malabaricane Triterpenoids with Migratory Inhibitory Activity from Astragalus membranaceus var. mongholicus.

Twenty new malabaricane triterpenoids, astramalabaricosides A-T (1-20), were isolated from the roots of Astragalus membranaceus var. mongholicus (Astragali Radix). Their structures were determined by spectroscopic analysis, and the use of the circular dichroism exciton chirality method, quantum chemical calculations, and chemical methods. Malabaricane triterpenoids, an unusual group with the 6-6-5-tricyclic core, are distributed in plants (e.g., Simaroubaceae, Polypodiaceae, and Fabaceae), a marine sponge, and fungi, and their number obtained to date is limited. Compounds 1-20 were characterized as glycosides with a highly oxygenated side chain, and 13-20 were the first cyclic carbonate derivatives among the malabaricane triterpenoids. The stereocluster formed from the continuous hydroxylated chiral carbons in each highly oxygenated side chain and the 6-6-5-tricyclic core system were entirely segregated, and the independent identification of their stereoconfigurations required considerable effort. The migratory inhibitory and antiproliferative activities of 1-20 were evaluated by wound-healing and cell-viability assays, respectively. Most compounds showed significant migratory inhibitory activity, and a preliminary structure-activity relationship was developed. Malabaricane triterpenoids are being reported in the genus Astragalus for the first time.

[Study on hereditary susceptibility genetic markers to anti-tuberculosis drug induced liver injury in Chinese population].

To systematically study the susceptible genetic markers for liver injury induced by anti-tuberculosis drugs in the Chinese population, 109 genes related to drug metabolism, transport and immunity were captured by Haloplex capture technique from DNA samples of 41 patients with liver injury induced by anti-tuberculosis drugs and 39 healthy controls, and sequenced completely. Association study was conducted using Plink software. To verify the significant candidate SNPs, the χ 2 study was expanded to the control group from the 1000-person Genome Project of the East Asian population. SIFT and Polyphen2 software were used to predict the functional significance of the associated SNPs. Our results identified the UGT1A4 rs2011404 (χ 2 = 4.6809, P = 0.0305) as a susceptible genetic marker for liver injury induced by anti-tuberculosis drugs, and rs2011404 mutation might contribute to UGT1A4 protein dysfunction. This study has provided a potentially useful reference for establishing the precision medicine in rational uses of anti-tuberculosis drugs in the clinic.

Sinulaspirolactam A, a novel aza-spirocyclic valerenane sesquiterpenoid from soft coral Sinularia sp.

A novel valerenane sesquiterpenoid sinulaspirolactam A (1), together with five known compounds, was isolated from the soft coral Sinularia sp. Their structures were determined by spectroscopic analyses. The absolute configuration of 1 was established by ECD calculation. Compound 1 was the first example of valerenane sesquiterpenoid bearing an aza-spiro[4.5] ring moiety, the plausible biogenetic pathway of which was proposed. Cytotoxic activities of these compounds were also evaluated.

Inhibition of TRAF3 expression alleviates cardiac ischemia reperfusion (IR) injury: A mechanism involving in apoptosis, inflammation and oxidative stress.

Ischemia reperfusion (IR) injury is known as a major issue in cardiac transplantation and various pathogenesis are involved in myocardial IR injury. Here, we show that tumor necrosis factor receptor-associated factor 3 (TRAF3) was increased in hearts of mice with cardiac IR injury and in cardiomyocytes incubated with lipopolysaccharide (LPS) and H2O2. Reducing TRAF3 expression in vivo markedly reduced the infacrted area, attenuated the histological changes, improved cardiac dysfunction and injury in mice subjected to IR injury. Functional study further indicated that TRAF3 knockdown inhibited apoptosis in murine hearts of mice with cardiac IR injury and in LPS and H2O2-cotreated cardiomyocytes, as evidenced by the decreased expression of cleaved Caspase-3 and poly (ADP-ribose) polymerases (PARP). In addition, inflammatory response and oxidative stress observed in hearts of mice with IR operation were significantly alleviated by TRAF3 knockdown through inhibiting nuclear factor-κB (NF-κB) and xanthine oxidase (XO) signaling pathways, and similar results were detected in LPS and H2O2-cotreated cardiomyocytes in vitro. Moreover, the loss of TRAF3 also restrained the phosphorylated c-Jun N-terminal protein kinase (JNK) activation following cardiac IR injury. Importantly, blocking JNK activation, as TRAF3 knockdown, greatly reduced apoptosis, inflammation and reactive oxygen species (ROS) production in LPS and H2O2-cotreated cardiomyocytes. In contrast, TRAF3 knockdown-reduced apoptosis, inflammatory response and oxidative stress were significantly rescued by promoting JNK activity in LPS and H2O2-cotreated cardiomyocytes. In summary, the results of our study indicated that repressing TRAF3 expression could be served as essential therapeutic target for protection against cardiac IR injury through restraining JNK-meditated apoptosis, inflammation and the production of ROS.

Phenylisotertronic acids from the TCM endophytic fungus Phyllosticta sp.

Four new phenylisotertronic acids (1a/1b, 2a, and 3a) were isolated from a TCM endophytic fungal strain Phyllosticta sp. J13-2-12Y obtained from the leaves of Acorus tatarinowii, along with two known ones (2b and 3b). Compounds 1-3 all existed as mixtures of enantiomers, and their corresponding optically pure enantiomers were successfully isolated by chiral HPLC. The structures of isolated compounds were determined by comprehensive spectroscopic analyses and X-ray diffraction. Their absolute configurations were determined by ECD experiments and quantum chemical calculations. In addition, the antimicrobial activities and the cytotoxicities of these three pairs of optically pure enantiomers (1a/1b, 2a/2b, and 3a/3b) had been evaluated.

Dimericbiscognienyne A: A Meroterpenoid Dimer from Biscogniauxia sp. with New Skeleton and Its Activity.

Dimericbiscognienyne A (1), an unusual diisoprenyl-cyclohexene-type meroterpenoid dimer, was isolated from Biscogniauxia sp. together with three new monomeric diisoprenyl-cyclohexene-type meroterpenoids (2-4) and one new isoprenyl-benzoic acid-type meroterpenoid (5). All structures were determined by extensive NMR spectroscopic methods, quantum chemical calculations, chemical derivatization, and X-ray crystallography. The formation of 1 is related to a unique intermolecular redox coupling Diels-Alder adduct reaction. Their cytotoxicities and short-term memory enhancement activities against Alzheimer's disease were assessed.

Quantitative assessment of the association between rs2046210 at 6q25.1 and breast cancer risk.

Genome-wide association studies (GWAS) have identified several genetic susceptibility loci for breast cancer (BC). One of them, conducted among Chinese women, found an association of rs2046210 at 6q25.1 with the risk of BC recently. Since then, numerous association studies have been carried out to investigate the relationship between this polymorphism and BC risk in various populations. However, these have yielded contradictory results. We therefore performed a meta-analysis to clarify this inconsistency. Overall, a total of 235003 subjects based on 13 studies were included in our study. Significantly increased BC risk was detected in the pooled analysis [allele contrast: OR = 1.13, 95%CI = 1.10-1.17, P(Z) <10(-5), P(Q) <10(-4); dominant model: OR = 1.21, 95%CI = 1.14-1.27, P(Z) <10(-5), P(Q) <10(-4); recessive model: OR = 1.18, 95%CI = 1.12-1.24, P(Z) <10(-5), P(Q) = 0.04]. In addition, our data revealed that rs2046210 conferred greater risk in estrogen receptor (ER)-negative tumors [OR = 1.27, 95%CI = 1.15-1.40, P(Z) <10(-5), P(Q) <10(-4)] than in ER-positive ones [OR = 1.18, 95%CI = 1.09-1.28, P(Z) <10(-4), P(Q) = 0.0003]. When stratified by ethnicity, significant associations were found in Caucasian and Asian populations, but not detected among Africans. There was evidence of heterogeneity (P<0.05), however, the heterogeneity largely disappeared after stratification by ethnicity. The present meta-analysis demonstrated that the rs2046210 polymorphism may be associated with increased BC susceptibility, but this association varies in different ethnicities.

HLA-B*58:01 allele is associated with augmented risk for both mild and severe cutaneous adverse reactions induced by allopurinol in Han Chinese.

AIM: Allopurinol is widely used as an effective urate-lowering drug and is one of the most frequent causes of cutaneous adverse drug reactions (cADRs). Recently, a strong association of HLA-B*58:01 with allopurinol-induced severe cADRs was identified. This study investigated the predisposition to different types of allopurinol-cADRs conferred by HLA-B*5801 in a Han population from mainland China. PATIENTS & METHODS: HLA-B genotyping was performed on 38 Chinese patients with different types of allopurinol-cADRs from 2008 to 2011. RESULTS: All the allopurinol-cADR patients carried HLA-B*58:01, in contrast with only 11.11% (7/63) in the allopurinol-tolerant patients (odds ratio [OR] = 580.07; p < 0.0001) and 13.99% (80/572) in a Han Chinese population from the human MHC database (dbMHC; OR: 471.09; p < 0.0001) carried the genotype. Each type of allopurinol cADRs revealed a statistically significant association with HLA-B*58:01. In particular, the risk of allopurinol-induced maculopapular eruption was significantly higher in patients with HLA-B*58:01 (OR: 339.00; p < 0.0001). CONCLUSION: The strong association of both the mild and severe types of allopurinol cADRs with the HLA-B*58:01 allele were observed. The results indicated that the prospective use of a genetic test of HLA-B*58:01 might reduce the prevalence of allopurinol-induced cADRs. Original submitted 7 March 2012; Revision submitted 21 May 2012.

Chemical-protein interactome and its application in off-target identification.

Drugs exert their therapeutic and adverse effects by interacting with molecular targets. Although designed to interact with specific targets in a desirable manner, drug molecules often bind to unexpected proteins (off-targets). By activating or inhibiting off-targets and the associated biological processes and pathways, the resulting chemical-protein interactions can influence drug reaction directly or indirectly. Exploring the relationship between drug and off-targets and the downstream drug reaction can help understand the polypharmacology of the drug, hence significantly advance the drug repositioning pipeline and the application of personalized medicine in understanding and preventing adverse drug reaction. This review summarizes works on predicting off-targets via chemical-protein interactome (CPI), an interaction strength matrix of drugs across multiple human proteins aiming at exploring the unexpected drug-protein interactions, with a variety of computational strategies, including docking, chemical structure comparison and text-mining etc. Effective recall on previous knowledge, de novo prediction and subsequent experimental validation conferred us strong confidence in these methods. Such studies present prospect of large scale in silico methodologies for off-target discovery with low cost and high efficiency.

The sugar-binding ability of human OS-9 and its involvement in ER-associated degradation.

Misfolded glycoproteins are translocated from the endoplasmic reticulum (ER) into the cytoplasm for proteasome-mediated degradation. OS-9 protein is thought to participate in ER-associated glycoprotein degradation (ERAD). The recombinant biotinylated mannose 6-phosphate receptor homology (MRH) domain of human OS-9 (OS-9(MRH)) together with six kinds of mutated OS-9(MRH) were prepared and mixed with R-phycoerythrin (PE)-labeled streptavidin to form tetramers (OS-9(MRH)-SA). The PE-labeled OS-9(MRH)-SA bound to HeLaS3 cells in a metal ion-independent manner through amino acid residues homologous to those participating in sugar binding of the cation-dependent mannose 6-phosphate receptor, and this binding was greatly increased by swainsonine, deoxymannojirimycin, or kifunensine treatment. N-Acetylglucosaminyltransferase I-deficient Lec1 cells, but not Lec2 or Lec8 cells, were also strongly bound by the tetramer. OS-9(MRH)-SA binding to the cells was strongly inhibited by Manalpha1,6(Manalpha1,3)Manalpha1,6(Manalpha1,3)Man and Manalpha1,6Man. To further determine the specificity of native ligands for OS-9(MRH), frontal affinity chromatography was performed using a wide variety of 92 different oligosaccharides. We found that several N-glycans containing terminal alpha1,6-linked mannose in the Manalpha1,6(Manalpha1,3)Manalpha1,6(Manalpha1,3)Man structure were good ligands for OS-9(MRH), having K(a) values of approximately 10(4) M(-1) and that trimming of either an alpha1,6-linked mannose from the C-arm or an alpha1,3-linked mannose from the B-arm abrogated binding to OS-9(MRH). An immunoprecipitation experiment demonstrated that the alpha1-antitrypsin variant null(Hong Kong), but not wild-type alpha1-antitrypsin, selectively interacted with OS-9 in the cells in a sugar-dependent manner. These results suggest that trimming of the outermost alpha1,2-linked mannose on the C-arm is a critical process for misfolded proteins to enter ERAD.

[Preparation and application of gel chip].

A new method for manufacturing three-dimensional gel film-coated chips was described in this paper and its advantages were evaluated by its application. A patch of polyacrylamide gel (15mm x 15mm x 20 microm) was fixed on the glass surface with Bind-Silane treatment, then activated by glutaraldehyde. The aldehyde groups in gel provided reactive sites that allowed covalent immobilization of molecules containing amino groups. Oligonucleotides were mechanically spotted by GMS 417 Arrayer. After hybridization with Cy-3 labeled probes, fluorescence signals of perfect binding can be discriminated from mismatched ones. Compared with two-dimensional glass chip, the capacity of oligonucleotides immobilized on gel film-coated chip is over 100 times. And the gel film-coated chip have lower background and shorter hybridization time. Monoclonal antibodys of cytokine IL-4, IL-5, IL-6, IL-7, ANG, I-309 and VEGF were also immobilized on the gel film-coated chips to make protein microarrays. After incubation with serum of breast cancer patients or normal persons, the microarray reacted with biotin-labeled second antibodys of cytokines and Cy-3-labeled streptavidin sequentially. Results show IL-4, IL-5, I-309 and VEGF of patients have higher expression level than normal persons. This kind of protein microarrays can be potentially helpful to clinical diagnosis. Furthermore different oligonucleotides or proteins can be performed in parallel in a single reaction with minimal amount of binding reagents. Such gel film-coated chips can be used widely in the fabrication of oligonucleotides and proteins microarrays.