Aldose reductase inhibitory compounds from extracts of Dipsacus asper

Amethanolic extract of Dipsacus asper, having anti-diabetic activity, was examined as a possible aldose reductase (ALR2) inhibitor, a key enzyme involved in diabetic complications. Bioactivity guided fractionation led to the isolation of ten compounds, ursolic acid (1), oleanolic acid-3-O-α-L-arabinopyranoside (2), daucosterol (3), hederagenin-3-O-α-L-arabinopyranoside (4), sweroside(5), caffeic acid (6), esculetin (7), protocatechualdehyde (8), loganin (9), and vanilic acid (10) from the ethyl acetate fraction of D. asper methanol extract. Among them, compounds 4, 6, 7, and 8 exhibited inhibitory effects on aldose reductase, with IC₅₀ values of 23.70, 16.71, 34.36, and 21.81 μM, respectively. This is the first report on the isolation of these compounds from D. asper, and the ALR2 inhibitory activity of hederagenin-3-O-α-L-arabinopyranoside. These results suggest the successful use of the extract of D. asper for ameliorating diabetic complications.     

Insecticidal activity of recombinant baculovirus co-expressing Bacillus thuringiensis crystal protein and Kunitz-type toxin isolated from the venom of bumblebee Bombus ignitus

To improve the insecticidal activity of Autographa californica nucleopolyhedrovirus (AcMNPV), using co-expression of Bacillus thuringiensis crystal protein and a Kunitz-type toxin isolated from bumblebee Bombus ignitus venom, a recombinant AcMNPV, ApPolh5-3006BiKTI, expressing Bi-KTI under the control of early promoter from Cotesia plutellae bracovirus (CpBV) was constructed. In this recombinant virus, B. thuringiensis cry1-5 crystal protein gene was introduced into the genome by the fusion of polyhedrin-cry1-5 under the control of polyhedrin gene promoter. RT-PCR analysis indicated that both Bi-KTI and polyhedrin-cry1-5 fusion protein were successfully expressed from the infected cells. In addition, SDS-PAGE revealed that polyhedrin-cry1-5 fusion protein expressed by recombinant viruses was occluded into the polyhedra. ApPolh5-3006BiKTI showed an improved insecticidal activity against larvae of Plutella xylostella and Spodoptera exigua. At low dosage rates, it was more effective against S. exigua than on P. xylostella, but more rapid insecticidal activity was shown in P. xylostella. These results strongly suggest that co-expression of Bt toxin and Kunitz-type toxins could be successfully applied to improve the insecticidal activity of baculoviruses.     

Sublingual administration of bacteria-expressed influenza virus hemagglutinin 1 (HA1) induces protection against infection with 2009 pandemic H1N1 influenza virus

Influenza viruses are respiratory pathogens that continue to pose a significantly high risk of morbidity and mortality of humans worldwide. Vaccination is one of the most effective strategies for minimizing damages by influenza outbreaks. In addition, rapid development and production of efficient vaccine with convenient administration is required in case of influenza pandemic. In this study, we generated recombinant influenza virus hemagglutinin protein 1 (sHA1) of 2009 pandemic influenza virus as a vaccine candidate using a well-established bacterial expression system and administered it into mice via sublingual (s.l.) route. We found that s.l. immunization with the recombinant sHA1 plus cholera toxin (CT) induced mucosal antibodies as well as systemic antibodies including neutralizing Abs and provided complete protection against infection with pandemic influenza virus A/CA/04/09 (H1N1) in mice. Indeed, the protection efficacy was comparable with that induced by intramuscular (i.m.) immunization route utilized as general administration route of influenza vaccine. These results suggest that s.l. vaccination with the recombinant non-glycosylated HA1 protein offers an alternative strategy to control influenza outbreaks including pandemics.     

Isolation and characterization of a mycovirus in Lentinula edodes

A mycovirus was isolated from an edible mushroom, Lentinula edodes, that was suffering from a severe epidemic. Fractionation of the diseased cell extract by isopycnic centrifugation with 50% CsCl revealed that the diseased mushroom was infected by Lentinula edodes spherical virus (LeSV), a new spherical virus with a diameter of 55 nm. The particle of LeSV encapsidated the 12 kb RNA genome by a 120 kDa coat protein. BLAST analysis of the partially sequenced LeSV genome showed 95% sequence identity with a putative RNA-dependent RNA polymerase (RdRp) gene of the mycovirus HKB, which was previously reported as being a double-stranded RNA (dsRNA) element. In contrast to HKB, the RNA genome in LeSV is encapsidated by the 120 kDa coat protein. To confirm that the LeSV coat protein is encoded by the viral genome, the N-terminal amino acid sequence of the coat protein was determined. The resulting N-terminal amino acid sequence, N-SALDVAPVVPELYFXXLEV-C, was found to be located in the middle of the HKB ORF1, suggesting that the LeSV coat protein was indeed encoded by the virus. To detect LeSV in L. edodes, a primer set targeting the RdRp gene was designed based on the partial sequence of the LeSV genome. RT-PCR analysis showed that 56 of the 84 commercially available dikaryotic cultivars carry LeSV. The transmission pattern of the virus was determined by analysing basidiospores from LeSV-infected and LeSV-free fruiting bodies. Nine out of 10 basidiospores from the LeSV-infected cultivars contained the virus while the spores from the LeSV-free parent were free of LeSV, suggesting that vertical transmission is the primary mode of LeSV propagation.     

Sunxiuqinia dokdonensis sp. nov., isolated from deep sub-seafloor sediment

A novel facultatively anaerobic strain DH1^T was isolated from deep sub-seafloor sediment at a depth of 900 m below the seafloor off Seo-do (the west part of Dokdo Island) in the East Sea of the Republic of Korea. The new strain was characterized using polyphasic approaches. The isolate was Gram-stain-negative, motile by gliding, non-spore-forming rods, oxidase-negative, and catalase-positive; and formed colonies of orange-red color. The NaCl range for growth was 0.5–7.0% (w/v) and no growth was observed in the absence of NaCl. The isolate grew optimally at 30°C, with 2% (w/v) NaCl and at pH 7. The cell-wall hydrolysates contained ribose as a major sugar. The DNA G+C content was 40.8 mol%. The closest related strains are Sunxiuqinia faeciviva JAM-BA0302^T and Sunxiuqinia elliptica DQHS-4^T (97.9 and 96.3% sequence similarity, respectively). The level of DNA-DNA relatedness between strain DH1^T and S. faeciviva JAM-BA0302^T was around 41% (but only 6% between DH1T and S. elliptica DQHS-4^T). The major cellular fatty acids of the isolate were contained iso-C_15:0 (25.9%), anteiso-C_15:0 (16.7%), and summed feature 9 (comprising C_16:0 3-OH and/or unknown fatty acid of dimethylacetal ECL 17.157; 13.2%). The predominant menaquinone was MK-7. On the basis of polyphasic evidence from this study, the isolate was considered to represent a novel species of the genus Sunxiuqinia, for which the name Sunxiuqinia dokdonensis sp. nov. is proposed; the type strain is DH1^T (=KCTC 32503^T =CGMCC 1.12676^T =JCM 19380^T).     

Female sex pheromone components of the box tree pyralid,Glyphodes perspectalis,in Korea: Field test and development of film-type lure

The box tree pyralid, Glyphodes perspectalis, is the most destructive pest of the box tree in Korea and was recently introduced into Europe. The previously known as EAG active components of this moth, (Z)-11-hexadecenal (Z11-16:Ald), (E)-11-hexadecenal (E11-16:Ald), and (Z)-11-hexadecenol (Z11-16:OH) have been detected from the extracts of female abdomen. The ratios of these three compounds identified in female moth were 5.2:1:0.2 in 2010 and 6.5:1:0.2 in 2011. During field bioassays, it was found that the male moths were not attracted to Z11-16:Ald or E11-16:Ald when used alone; however, they were attracted to a mixture of the above. The most effective ratios of Z11-16:Ald to E11-16:Ald were 5:1 and 7:1. A small amount of Z11-16:OH inhibited male moth attraction in field bioassays. Further, a uni-trap was found to be more effective in catching the moth than delta and wing traps were. In field bioassays using 2 different types of lures, significantly more male G. perspectalis were caught to film-type lures (50.5 ± 4.4/trap) than those to rubber septum lures (35.8 ± 5.2/trap).     

Change of arthropod abundance in burned forests: Different patterns according to functional guilds

Forest fires are one of the most frequent and important causes of forest disturbances, the occurrence of which is globally increasing due to the effects of climate change. This study aimed to determine the impacts of fire and human activity on arthropod communities in affected forests. Twelve study sites in three burned areas were selected for this study. Intensities of disturbance in the study sites were characterized as follows: Disturbance Degree (DD) 0 (no fire), DD 1 (surface fire), DD 2 (crown fire), and DD 3 (crown fire followed by reforestation). Arthropods were collected using pitfall traps. Fourteen arthropod taxa (families, orders or classes), which are relatively homogeneous in their feeding habits and abundant, were analyzed. Depth of litter layer was selected as an environmental indicator for disturbance intensity, as it decreases linearly as the degree of disturbance increased. Changes of arthropod abundance in response to disturbance differed among functional guilds. As disturbance intensity increased, the abundance of detritivores decreased, but the abundance of herbivores increased. However, the abundance of predators varied between taxa. Formicidae and Araneae increased in disturbed sites, whereas Carabidae and Staphylinidae did not change. The abundance of Thysanura and Diptera was highly correlated with disturbance intensity, and may be suitable as a bioindicator for forest disturbance. Arthropod communities were more heterogeneous in forests of intermediate disturbance.     

Combination of 1,4-naphthoquinone with benzothiazoles had selective algicidal effects against harmful algae

A series of naphthoquinone-benzothiazole conjugates were synthesized as algicides, and their efficacies against harmful algal blooming species, such as Chattonella marina, Heterosigma akashiwo and Cochlodinium polykrikoides, were examined. The introduction of substituted benzothiazole at the C2 position of 1,4-naphthoquinone (compounds 1–9) resulted in higher algicidal activity against C. polykrikoides than the C6 conjugates (compounds 10–20). On the other hand, of the C6 conjugates, compounds 11 and 12 exhibited better algicidal activity against H. akashiwo, C. marina, and C. polykrikoides than the C2 conjugates. Further structure-activity analysis indicated that a replacement of the methoxy groups with hydroxyl groups (compounds 21–26) decreased the algicidal activity significantly. Among the various synthetic naphthoquinonebezothiazole conjugates tested, compound 12 was found to affect the most significant decrease in the level of C. polykrikoides growth, with an IC₅₀ of 0.19 μM. Compound 11 was found to be the most potent inhibitor against H. akashiwo and C. polykrikoides, with IC₅₀ values of 0.32 and 0.12 μM, respectively. Overall, these results highlight a possible method for controlling and inhibiting red tide forming algae using NQ derivatives.