1.Effects of saline-alkaline stress on benzo[a]pyrene biotransformation and ligninolytic enzyme expression by Bjerkandera adusta SM46.
Andriani A1,2, Tachibana S3, Itoh K4. World J Microbiol Biotechnol. 2016 Mar;32(3):39. doi: 10.1007/s11274-015-2001-4. Epub 2016 Feb 11.
Benzo[a]pyrene (BaP) accumulates in marine organisms and contaminated coastal areas. The biotreatment of waste water using saline-alkaline-tolerant white rot fungi (WRF) represents a promising method for removing BaP under saline-alkaline conditions based on WRF's ability to produce ligninolytic enzymes. In a pre-screening for degradation of polycyclic aromatic hydrocarbons of 82 fungal strains using Remazol brilliant blue R, Bjerkandera adusta SM46 exhibited the highest tolerance to saline-alkaline stress. Moreover, a B. adusta culture grown in BaP-containing liquid medium exhibited resistance to salinities up to 20 g l(-1). These conditions did not inhibit fungal growth or the expression of manganese peroxidase (MnP) or lignin peroxidase (LiP). The degradation rate also became higher as salinity increased to 20 g l(-1). Fungal growth and enzyme expression were inhibited at a salinity of 35 g l(-1). These inhibitory effects directly decreased the degradation rate (>24 %).
2.Design and synthesis of a novel fluorescent benzo[g]imidazo[4,5-c]quinoline nucleoside for monitoring base-pair-induced protonation with cytosine: distinguishing cytosine via changes in the intensity and wavelength of fluorescence.
Siraiwa S1, Suzuki A, Katoh R, Saito Y. Org Biomol Chem. 2016 Apr 28;14(16):3934-42. doi: 10.1039/c6ob00494f. Epub 2016 Apr 5.
A novel fluorescent benzo[g]imidazo[4,5-c]quinoline nucleoside (BIQ)A (1) comprising a 3-deaza-2'-deoxyadenosine skeleton was developed and used to monitor (BIQ)A-C base-pair formation in oligodeoxynucleotide (ODN) duplexes. The newly synthesized (BIQ)A exhibited distinct photophysical properties associated with its protonated/deprotonated forms (monomer: pKa 6.2) via dramatic changes in its absorption and fluorescence spectra. In ODN duplexes, the induced protonation of (BIQ)A occurred, even under alkalescent conditions when cytosine was the opposite base on the complementary strand; the resulting (BIQ)A-C base pairs were stable. By monitoring the protonation of (BIQ)A under neutral and alkalescent conditions, we could clearly discriminate cytosine through spectral changes in absorption and fluorescence. Similarly, we found that the demonstrated 3-deaza-2'-deoxyadenosine (3z)A forms a stable base pair with cytosine via N(1) protonation in ODN duplexes under neutral and acidic conditions (pH < 7.
3.Synthesis of tetracyclic iminosugars fused benzo[e][1,3]thiazin-4-one and their HIV-RT inhibitory activity.
Yin Z1, Zhu M1, Wei S1, Shao J1, Hou Y1, Chen H2, Li X3. Bioorg Med Chem Lett. 2016 Apr 1;26(7):1738-41. doi: 10.1016/j.bmcl.2016.02.049. Epub 2016 Feb 18.
Several aza-C-pseudonucleosides bearing 1,3-benzothiazin-4-one (6 and 7) were prepared by the one-pot three-component condensation from the iminosugar aldehyde 3, amino acid ethyl/methyl ester hydrochlorides 4(a-c), and 2-mercaptobenzoic acid 5. After removal of Boc and the isopropylidene groups, the target novel tetracyclic iminosugars fused benzo[e][1,3]thiazin-4-one 1(a-c) and 2(a-b) were first afforded by the intramolecular cyclo-amidation reaction. Their structures were determined by their (1)H, (13)C NMR, and HRMS (ESI) spectra and X-ray. The tetracyclic iminosugars 1(a-c) and 2(a-b) were examined for their HIV reverse transcriptase (RT) inhibitory activities. The result showed that all compounds could effectively inhibit RT activity. Among them, compound 2a was the best one with the IC50 value of RT inhibitory activity of 0.82μM. Structure-activity relationship analysis suggested that 1'R configuration in the tetracyclic azasugars was of benefit to their anti-HIV RT activity.
4.Diamondoid naphthenic acids cause in vivo genetic damage in gills and haemocytes of marine mussels.
Dissanayake A1, Scarlett AG2,3, Jha AN1. Environ Sci Pollut Res Int. 2016 Apr;23(7):7060-6. doi: 10.1007/s11356-016-6268-2. Epub 2016 Feb 16.
Diamondoids are polycyclic saturated hydrocarbons that possess a cage-like carbon skeleton approaching that of diamond. These 'nano-diamonds' are used in a range of industries including nanotechnologies and biomedicine. Diamondoids were thought to be highly resistant to degradation, but their presumed degradation acid products have now been found in oil sands process-affected waters (OSPW) and numerous crude oils. Recently, a diamondoid-related structure, 3-noradamantane carboxylic acid, was reported to cause genetic damage in trout hepatocytes under in vitro conditions. This particular compound has never been reported in the environment but led us to hypothesise that other more environmentally relevant diamondoid acids could also be genotoxic. We carried out in vivo exposures (3 days, semi-static) of marine mussels to two environmentally relevant diamondoid acids, 1-adamantane carboxylic acid and 3,5-dimethyladamantane carboxylic acid plus 3-noradamantane carboxylic acid with genotoxic damage assessed using the Comet assay.