Frequency tripled semiconductor disk laser with over 0.5 W ultraviolet output power.

Semiconductor disk lasers can produce high output power and good beam quality simultaneously. The high intracavity circulating power of about hundreds of watts, along with the flexibility of tailorable emitting wavelengths, make it an attractive light source for obtaining ultraviolet (UV) radiation from near-infrared lasers through nonlinear frequency conversion. This work reports a frequency tripled 327 nm semiconductor disk laser with record output power and wavelength tuning range by using a type-I phase-matched LiB3O5 (LBO) crystal and a type-I phase-matched ß-BaB2O4 (BBO) crystal as the frequency-doubling and -tripling crystals respectively. Thanks to the obviously larger nonlinear coefficient of the type-I phase-matched BBO compared to the commonly used type-II phase-matched LBO, as well as the small spot size specifically designed at the crystal location, the maximum output power of UV lasers reaches 538 mW, corresponding to an optical-to-optical conversion efficiency from pump to UV laser of about 1.14%. A wavelength tuning range of about 8.6 nm and good power stability with a standard deviation of about 0.94 are also achieved.

New Helvolic Acid Derivatives with Antibacterial Activities from Sarocladium oryzae DX-THL3, an Endophytic Fungus from Dongxiang Wild Rice (Oryza rufipogon Griff.).

Three new helvolic acid derivatives (named sarocladilactone A (1), sarocladilactone B (2) and sarocladic acid A (3a)), together with five known compounds (6,16-diacetoxy-25-hy- droxy-3,7-dioxy-29-nordammara-1,17(20)-dien-21-oic acid (3b), helvolic acid (4), helvolinic acid (5), 6-desacetoxy-helvolic acid (6) and 1,2-dihydrohelvolic acid (7)), were isolated from the endophytic fungus DX-THL3, obtained from the leaf of Dongxiang wild rice (Oryza rufipogon Griff.). The structures of the new compounds were elucidated via HR-MS, extensive 1D and 2D NMR analysis and comparison with reported data. Compounds 1, 2, 4, 5, 6 and 7 exhibited potent antibacterial activities. In particular, sarocladilactone B (2), helvolinic acid (5) and 6-desacetoxy-helvolic acid (6) exhibited strongly Staphylococcus aureus inhibitory activity with minimum inhibitory concentration (MIC) values of 4, 1 and 4 µg/mL, respectively. The structure-activity relationship (SAR) of these compounds was primarily summarized.

Transcriptome analysis of the dimorphic transition induced by pH change and lipid biosynthesis in Trichosporon cutaneum.

Trichosporon cutaneum, a dimorphic oleaginous yeast, has immense biotechnological potential, which can use lignocellulose hydrolysates to accumulate lipids. Our preliminary studies on its dimorphic transition suggested that pH can significantly induce its morphogenesis. However, researches on dimorphic transition correlating with lipid biosynthesis in oleaginous yeasts are still limited. In this study, the unicellular yeast cells induced under pH 6.0-7.0 shake flask cultures resulted in 54.32% lipid content and 21.75 g/L dry cell weight (DCW), so lipid production was over threefold than that in hypha cells induced by acidic condition (pH 3.0-4.0). Furthermore, in bioreactor batch cultivation, the DCW and lipid content in unicellular yeast cells can reach 21.94 g/L and 58.72%, respectively, both of which were also more than twofold than that in hypha cells. Moreover, the activities of isocitrate dehydrogenase (IDH), malic enzyme (MAE), isocitrate lyase (ICL) and ATP citrate lyase (ACL) in unicellular cells were all higher than in the hyphal cells. In the meanwhile, the transcriptome data showed that the genes related to fatty acid biosynthesis, carbon metabolism and encoded Rim101 and cAMP-PKA signaling transduction pathways were significantly up-regulated in unicellular cells, which may play an important role in enhancing the lipid accumulation. In conclusion, our results provided insightful information focused on the molecular mechanism of dimorphic transition and process optimization for enhancing lipid accumulation in T. cutaneum.

Isolation, diversity and acetylcholinesterase inhibitory activity of the culturable endophytic fungi harboured in Huperzia serrata from Jinggang Mountain, China.

Huperzia serrata has many important medicinal properties with proven pharmacological potential. Some of these properties may be mediated by its endophytic fungi. To test this hypothesis, in the present study, we provided a first insights into evaluating the species composition and acetylcholinesterase (AChE) inhibitory activity of the culturable endophytic fungi of H. serrata from the regional at Jinggang Mountain in southeastern China. A total number of 885 fungal isolates distributed across 44 genera and 118 putative species were obtained from 1422 fragments of fine H. serrata roots, stems and leaves base on ITS-rDNA sequences BLAST analysis. The endophytic fungi were phylogenetically diverse and species-rich, with high rate of colonization and isolation. The assemble of endophytic fungi consisted mainly of Ascomycota (97.15%), followed by Basidiomycota (1.92%) and unknown fungal species (0.90%). Colletotrichum (64.29%), Phyllosticta (3.39%), Hypoxylon (2.81%), Xylaria (2.25%) and Nigrospora (2.04%) were the most abundant genera, whereas the remaining genera were infrequent groups. Although, roots yielded low abundance strains, the diverse and species-rich were both higher than that of stems and leaves. In addition, out of the 247 endophytic fungi strains determinated, 221 fungal extracts showed AChE inhibition activities in vitro. Among them, 22 endophytic fungi strains achieved high inhibitory activity (≥50%) on AChE which belongs to 13 genera and five incertae sedis strains. Four endophytic fungi designated as JS4 (Colletotrichum spp.), FL14 (Ascomycota spp.), FL9 (Sarcosomataceae spp.) and FL7 (Dothideomycetes spp.) were displayed highly active (≥80%) against AChE, which the inhibition effects were even more intense than the positive control. Our findings highlight that H. serrata grown in Jinggang Mountain harbors a rich and fascinating endophytic fungus community with potential AChE inhibitory activity, which could further broaden the natural acetylcholinesterase inhibitors resources used for Alzheimer's disease treatment.

Loss of RTN3 phenocopies chronic kidney disease and results in activation of the IGF2-JAK2 pathway in proximal tubular epithelial cells.

Reticulon 3 (RTN3) is an endoplasmic reticulum protein that has previously been shown to play roles in neurodegenerative diseases, but little is known about its function in the kidneys. The aim of the present study was to clarify the roles of RTN3 in chronic kidney disease (CKD) and kidney fibrosis. In this study, RTN3 levels were measured in kidney tissues from healthy controls and CKD or kidney fibrosis patients. An RTN3-null mouse model was generated to explore the pathophysiological roles of RTN3 in the kidneys. The underlying mechanisms were studied in primary proximal tubular epithelial cells and HEK293 cells in vitro. The results showed that (1) a reduction in RTN3 in mice induces CKD and kidney fibrosis; (2) decreased RTN3 expression is found in patients with CKD; (3) RTN3 plays critical roles in regulating collagen biosynthesis and mitochondrial function; and (4) mechanistically, RTN3 regulates these phenotypes by interacting with GC-Rich Promoter Binding Protein 1 (GPBP1), which activates the IGF2-JAK2-STAT3 pathway. Our study indicates that RTN3 might play crucial roles in CKD and kidney fibrosis and that a reduction in RTN3 in the kidneys might be a risk factor for CKD and kidney fibrosis.

Rational design and synthesis of potent aminoglycoside antibiotics against resistant bacterial strains.

Based on the structural information of biomacromolecule-aminoglycoside complexes, a series of kanamycin B analogues were rationally designed and synthesized. A convenient approach to the construction of kanamycin derivatives, in which the C4'-position on ring I of neamine moiety was modified, was developed. Most synthetic analogues exhibited good to excellent antibiotic activity against some typical drug-resistant bacteria. The disclosed results suggested that the C4'-position of aminoglycosides such as kanamycin may be an ideal site for modification to gain new modifying enzyme-resistant aminoglycoside antibiotics.

Isolation and characterization of endophytic huperzine A-producing fungi from Huperzia serrata.

Huperzia serrata is a producer of huperzine A (HupA), a cholinesterase inhibitor (ChEI). Over 120 endophytic fungi were recovered from this plant and screened for Hup-A and nine were found. These nine represented seven different fungal genera with the most significant producer being Shiraia sp. A total of 127 endophytic fungi isolates obtained from the root, stem, and leaf segments of H. serrata were grouped into 19 genera based on their morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in H. serrata are diverse and abundant. Aspergillus, Podospora, Penicillium, Colletotrichum, and Acremonium were the frequent genera, whereas the remaining genera were infrequent groups. Overall, 39 endophytic fungi isolates showed acetylcholinesterase (AChE) inhibition in vitro. Nine endophytic fungi isolates from seven distinct genera were capable of producing HupA verified by thin-layer chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). Among the HupA-producing fungi, the yield of HupA produced by the Shiraia sp. Slf14 was 327.8 µg/l in potato dextrose broth, and the fungal HupA was further validated by mass spectrometry (ESI-MS). The present study demonstrated that H. serrata was a fascinating fungal reservoir for producing HupA and other ChEIs.

(±)-4a-(4-Nitro-benz-yl)-2,3,4,4a-tetra-hydro-1H-carbazole.

The title mol-ecule, C(19)H(18)N(2)O(2), is built up from three fused rings, viz. phenyl, pyrrole and cyclo-hexane, linked to a nitro-benzyl group. The C atom bearing the nitro-benzyl group is chiral and the compound is a racemate (R/S). The dihedral angle between the nitro-benzyl and indole rings is 57.49 (5)°. The cyclo-hexane ring adopts a slightly distorted chair conformation.

1,2-Bis(4-nitro-benz-yl)diselane.

The title compound, C(14)H(12)N(2)O(4)Se(2), is not chiral, but the mol-ecules assume a chiral conformation in the solid state and crystallize as an aggregate. The central C-Se-Se-C torsion angle is 90.4 (2)°, while the two Se-Se-C-C fragments assume gauche conformations with values of -59.4 (5) and 67.5 (4)°. The dihedral angle between the two benzene rings is 80.74 (14)°.

trans-3,3',4,5'-Tetra-meth-oxy-stilbene.

The title compound, C(18)H(20)O(4), was synthesized by a Wittig-Horner reaction of diethyl 3,4-dimeth-oxy-benzyl-phosphate and 3,5-dimeth-oxy-benzaldehyde. In the crystal, the dihedral angle between the two aromatic rings is 2.47 (12)°. All the meth-oxy groups are almost coplanar with the aromatic ring to which they are attached [C-C-O-C torsion angles = -2.8 (3), -5.2 (4), -176.3 (2) and -178.0 (2)°].

Enzymatic acylation of lutein with a series of saturated fatty acid vinyl esters and the thermal stability and anti-lipid oxidation properties of the acylated derivatives.

Lutein was enzymatically acylated with saturated fatty acid vinyl esters of different lengths of carbon chain (C6 -C14 ) under the action of Candida antarctica lipase B (Novozyme 435). The acylation reaction was optimized by considering substrate molar ratio, reaction solvent, type of enzyme, and reaction time. The highest yield (88%) was obtained using the Novozyme 435 to catalyze the acylation reaction of lutein and vinyl decanoate (lutein/vinyl decanoate molar ratio of 1/10) for 16 h in methyl tert-butyl ether. Ten lutein esters were synthesized, isolated, and purified, which were characterized by Fourier-transform infrared spectroscopy, high-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy. We found that the acylation of lutein improved its antioxidant capacity in lipid system and thermal stability. Our study extended the potential application of lutein in lipophilic food, cosmetic, and pharmaceutical industries. Practical Application: Enzyme acylation of lutein improved its antioxidant capacity in lipid system and thermal stability, extended its potential application in food, cosmetic, and pharmaceutical industries. In addition, our study also provided a new perspective and cognition for the further development and utilization of lutein.

Enzymatic acylation of rutin with benzoic acid ester and lipophilic, antiradical, and antiproliferative properties of the acylated derivatives.

Rutin (3',4',5,7-tetrahydroxy-flavone-3-rutinoside) was enzymatically acylated with benzoic acid and its esters (methyl benzoate and vinyl benzoate) using Thermomyces lanuginosus lipase (Lipozyme TLIM). The acylation reaction was optimized by varying the reaction medium, reaction temperature, acyl donor, substrate molar ratio, and reaction time. The highest conversion yield (76%) was obtained in tert-amyl alcohol (60 °C, 72 hr) using vinyl benzoate (molar ratio of 1:10) as acyl donor. The acylation occurred at the 2'''-OH and 4'''-OH of the rhamnose unit and the 2''-OH position of the glucose moieties. Three novel rutin acylated derivatives (compounds 1-3) were purified and characterized by HR-MS and 1D and 2D NMR spectroscopy. We found that acylation significantly improved lipophilicity, capacity to inhibit lipid peroxidation, anticancer capacity and substantially maintained the antioxidant activity of rutin. This research provides important insights in the acylation of flavonoids with different glycosyl moieties. PRACTICAL APPLICATION: In this study, three novel rutin derivatives were successfully synthesized and the highest conversion yield (76%) was obtained by reacting the rutin and vinyl benzoate at molar ratio of 1:10 in tert-amyl alcohol for 72 hr at 60 °C. Introducing a benzoic acid substituent into rutin molecule significantly improved their lipophilicity and inhibition of lipid peroxidation in lipophilic system. Furthermore, this study demonstrated that acylation significantly improved anticancer capacity and substantially maintained the antioxidant activity.

C-geranylated flavanones from YingDe black tea and their antioxidant and α-glucosidase inhibition activities.

YingDe black tea is produced from crude tea prepared from leaves of Camellia sinensis var. assamica. In this work, we isolated and identified five novel flavanones, namely, amelliaone A-E (1-5), along with seven known compounds 6-12 from the ethanol extract of YingDe black tea. The structures of these five novel phenolic compounds were determined using extensive 1D and 2D nuclear magnetic resonance spectroscopy experiments. The compounds were further evaluated for antioxidant, α-glucosidase inhibitory, and cytotoxic activities. Compound 1 exhibited higher α-glucosidase inhibitory activity with a half-maximum inhibitory concentration value (IC50) of 10.2µM compared with acarbose (18.2µM).

Phylogenetic diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff), detection of polyketide synthase gene and their antagonistic activity analysis.

The biodiversity of plant endophytic fungi is enormous, numerous competent endophytic fungi are capable of providing different forms of fitness benefits to host plants and also could produce a wide array of bioactive natural products, which make them a largely unexplored source of novel compounds with potential bioactivity. In this study, we provided a first insights into revealing the diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff.) from China using rDNA-ITS phylogenetic analysis. Here, the potential of fungi in producing bioactive natural products was estimated based on the beta-ketosynthase detected in the polyketide synthase (PKS) gene cluster and on the bioassay of antagonistic activity against two rice phytopathogens Thanatephorus cucumeris and Xanthomonas oryzae. A total of 229 endophytic fungal strains were validated in 19 genera. Among the 24 representative strains, 13 strains displayedantagonistic activity against the phytopathogens. Furthermore, PKS genes were detected in 9 strains, indicating their potential for synthesising PKS compounds. Our study confirms the phylogenetic diversity of endophytic fungi in O. rufipogon G. and highlights that endophytic fungi are not only promising resources of biocontrol agents against phytopathogens of rice plants, but also of bioactive natural products and defensive secondary metabolites.

Characterization of phenolic constituents inhibiting the formation of sulfur-containing volatiles produced during garlic processing.

Garlic (Allium sativum L.), which is a widely distributed plant, is globally used as both spice and food. This study identified five novel phenolic compounds, namely, 8-(3-methyl-(E)-1-butenyl)diosmetin, 8-(3-methyl-(E)-1-butenyl)chrysin, 6-(3-methyl-(E)-1-butenyl)chrysin, and Alliumones A and B, along with nine known compounds 6-14 from the ethanol extract of garlic. The structures of these five novel phenolic compounds were established via extensive 1D- and 2D-nuclear magnetic resonance spectroscopy experiments. The effects of the phenolic compounds isolated from garlic on the enzymatical or nonenzymatical formation of sulfur-containing compounds produced during garlic processing were examined. Compound 12 significantly reduced the thermal decomposition of alliin, whereas compound 4 exhibited the highest percentage of alliinase inhibition activity (36.6%).

Mutant ubiquitin-mediated beta-secretase stability via activation of caspase-3 is related to beta-amyloid accumulation in ischemic striatum in rats.

Previous studies have demonstrated that ischemic stroke increases beta-amyloid (Abeta) production by increasing beta-secretase (BACE1) through activation of caspase-3, and stimulates generation of mutant ubiquitin (UBB(+1)) in rat brains. In this study, we examined whether caspase-3 activation participates in the regulation of UBB(+1) generation and UBB(+1)-mediated BACE1 stability in ischemic injured brains. The results showed that UBB(+1) and activated caspase-3-immunopositive-stained cells were time dependently increased in the ipsilateral striatum of rat brains after middle cerebral artery occlusion. UBB(+1)-immunopositive cells could be co-stained with caspase-3, Abeta (UBB(+1)-Abeta), and BACE1 (UBB(+1)-BACE1). BACE1 protein could also be pulled down by immunoprecipitation with UBB(+1) antibody. Z-DEVD-FMK (DEVD), a caspase-3 inhibitor, significantly decreased the level of UBB(+1) protein and the number of UBB(+1)-Abeta and UBB(+1)-BACE1 double-stained cells in the ischemic striatum, as well as the level of UBB(+1)/BACE1 protein complex. We conclude that activation of caspase-3 might be upstream of UBB(+1) formation and that excessive UBB(+1) could bind to BACE1 and increase the stability of BACE1, thereby increasing Abeta in ischemic injured brains. These results suggest new biological and pathological effects of caspases and regulation of the ubiquitin-proteasome system in the brain. Our results provide new therapeutic targets to prevent further neurodegeneration in patients after stroke.

[Effects of vegetation recovery practices on the characteristics of soil nematode communities on seriously degraded grasslands in Songnen Plain].

In this paper, the data of soil nematodes on the seriously degraded grasslands in Songnen Plain under different vegetation recovery practices were collected from May to October, 2005, and the community structure and its seasonal changes of the nematodes were studied by using the community parameters of generic richness, abundance, diversity index, and functional group index. The results showed that both fencing enclosure and planting Puccinellia chinampoensis could improve the nematode communities substantially. The nematode abundance and diversity were significantly higher in planting P. chinampoensis than in fencing enclosure, whereas the generic richness and evenness had no significant difference between these two vegetation recovery practices. The functional group index indicated that fencing enclosure and planting P. chinampoensis altered the ratio of rho- and kappa- choice of plant parasite nematodes. Compared with free-living nematodes, plant parasite nematodes were more sensitive to the vegetation recovery practices. On the seriously degraded grasslands in Songnen Plain, planting P. chinampoensis could be more favorable to the restoration of soil nematode communities than fencing enclosure.