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Four rare isotachin-derived, isotachins E-H (1-4), together with two known biogenetically related isotachin derivatives (5 and 6) were isolated from the solid rice fermentation of a fungus Penicillium tanzanicum ZY-5 obtained from a medicinal plant Dasymaschalon rostratum collected from the Changjiang County, Hainan Province, China. Their structures were elucidated using comprehensive spectroscopic methods. The single-crystal X-ray diffraction of compound 5 was determined. Compounds 1-4 have a trans-3-(methylthio)-acrylic acid fragment, which are rare in nature. The inhibitory activities of all compounds against the nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro were evaluated.

Five undescribed triene derivatives, pinophols B-F (2-6), together with one known compound, pinophol A (1), were obtained from the mangrove endophytic fungus Penicillium herquei JX4. The structures of compounds 1-6 were elucidated using IR, HR-ESI-MS, and NMR methods. The absolute configurations of compounds 1-6 were confirmed by comparing their experimental or calculated ECD spectra. Pinophols C and D (3 and 4) showed inhibitory activities against LPS-induced NO production.

Two new sesquiterpenes, litseachrandaevanes C and D (1 and 2), together with five known sesquiterpenes (3 − 7), were isolated from the stems of Fissistigma glaucescens (Hance) Merr. Their structures were elucidated using comprehensive spectroscopic methods. The inhibitory effect of all compounds on the proliferation of primary synovial cells was evaluated. Compound 3 showed inhibitory effect on the proliferation of synoviocytes, with an IC50 value of 12.5 μM.

A new cytochalasin derivative xylarisin B (1), together with four known compounds astropyrone (2), guaidiol (3), xylaropyrone B (4), and xylaropyrone C (5), were isolated from the fermentation broth of Xylaria sp. HNWSW-2. Their structures were elucidated by spectroscopic data. Among them, compounds 2 and 3 at a concentration of 50 μg/ml showed weak inhibitory activity against AChE with inhibition rates of 10.4 and 12.9%, respectively. In addition, compound 2 also exhibited inhibitory activity against α-glycosidase with inhibition rate of 77.0% at a concentration of 0.25 mg/ml.

Two novel aporphine-derived alkaloids, aporaloids A and B (1 and 2), together with eight known biogenetically related alkaloids (3−10), two known isoquinoline alkaloids (3 and 4), and six known aporphinoid alkaloids (5–10) were isolated from the stems of Fissistigma glaucescens. Their structures were elucidated using comprehensive spectroscopic methods. Compounds 1 and 2 represent the rare example of a six-membered lactone ring aporphine-derived alkaloids from natural products. The inhibitory activities of all compounds against four cancer cell lines were evaluated. Aporaloids A and B (1 and 2) showed broad spectrum cytotoxic activities.

Three new phenylpropanoid derivatives, dasymaroacid A (1), dasymaroesters B and C (2 and 3), and one new polyoxygenated 6H-dibenzo[b,d]pyran-6-one derivative dasymarolactone D (4), together with seven known compounds (5-11), were isolated from the stems of Dasymaschalon rostratum Merr. Compounds 1 and 2 are unusual phenylpropanoid derivatives with a polymethyl substituted cyclopentene conjugated diketone as a substituent, and 3 is a unique cinnamic acid detective with a polymethyl substituted cyclohexene conjugated triketone as a substituent. Their structures were elucidated by extensive spectroscopic methods and chemical method, and 4 was further confirmed by the single crystal X-ray diffraction method. Compounds 1-4 and 7 showed weak anti-HIV-1 activities with EC50 values ranged from 16.44 to 25.91μM.

In an effort to identify novel, small molecules which can affect the proliferation of lung cancer cells, F-01A, a polyether antibiotic isolated from the fermentation broth of Streptomyces was tested.F-01A was tested for its antitumor properties on the lung cancer cell line SPC-A-1, at six doses (0.1, 0.5, 1, 2.5, and 5 μmol·L(-1)), using various cellular assays. Cell viability was measured by the MTT assay, Hochest 33258 was used to study nuclear morphology; DNA ladder and the loss of mitochondrial membrane potential were also evaluated.F-01A induces apoptosis against SPC-A-1 cells in a dose-dependent manner. The IC50 is 0.65 μmol·L(-1), and the inhibition at 5 μmol·L(-1) is 87.89%. Further, JC-1 staining indicates F-01A could induce the loss of mitochondrial membrane potential, and the DNA fragment is evident.Mechanistic analysis showed that F-01A induced apoptosis of cancer cells probably in the mitochondrial pathway. The antitumor actions of F-01A involve activation of the apoptotic pathway against SPC-A-1 cells, and it may be valuable for further drug development.

Two novel epimer pairs of acetaminophen derivatives penicilquei A-D (1-4) were isolated from Penicillium herquei JX4. Their structures were elucidated using comprehensive spectroscopic methods. The absolute configurations of penicilquei A-D (1-4) were determined by modifified Mosher's method, and comparing their experimental and calculated electronic circular dichroism (ECD) spectra. Penicilquei A-D (1-4) are the first example of acetaminophen derivatives featuring an unprecedented carbon skeleton. The inhibitory activities of all compounds against nine phytopathogenic fungi and α-glucosidase were evaluated. Penicilquei A-D (1-4) showed strong inhibitory activities against at least eight phytopathogenic fungus.

Five new clerodane diterpenoids, polylauiester A (1), (4→2)-abeo-2,13-diformyl-cleroda-2,12E-dien-14-oic acid (2) and polylauiamides B-D (3-5), together with 11 known clerodane diterpenoids (6-16), were isolated from the roots of Polyalthia laui. Among them, polylauiester A (1) represents the first example of a novel norclerodane diterpenoid only containing 17 carbon atoms on the carbon skeleton, and polylauiamide B (3) is an unusual diterpenoid with a p-substituted benzene ring as a substituent. Their structures were elucidated by extensive spectroscopic methods, and the relative configuration of polylauiamide B (3) was further confirmed by the single crystal X-ray diffraction method. Biological evaluation of new compounds against human Hela, MCF-7 and A549 human cancer cell lines showed that all compounds displayed weak cytotoxicities against various human cancer cell lines in the range of IC50 at 25.01-39.31μM.

A novel lumazine peptide, aspergilumamide A (1), as well as a known analog penilumamide (2), were isolated from the mycelia of a marine-derived fungus Aspergillus sp. (33241), obtained from the mangrove Bruguiera sexangula var. rhynchopetala collected from the South China Sea. The structure of 1 was identified by comprehensive spectroscopic analysis, including 1D- and 2D-NMR, ESI-MS, and MS/MS experiments. The absolute configuration of 1 was determined by Marfey's method.

Streptococcus dysgalactiae is a significant pathogen associated with bovine mastitis in lactating and nonlactating dairy cows, causing a severe inflammatory response of the mammary gland, which results in major economic losses to the dairy industry. Two proteins from S. dysgalactiae strain SDG8 were tested for their protective capacity against a homologous bacterial challenge in a dry cow model. The first was a bovine plasmin receptor protein (GapC), which shares 99.4% sequence identity to the plasmin-binding Plr protein of group A streptococci. The second protein product was Mig, a α2-M-, IgG-, and IgA-binding protein present on the cell surface of SDG8. We investigated the efficacy of immunization with purified recombinant forms of GapC and Mig by measuring the number of somatic cells and assessing the presence of the challenge strain in mammary secretions following challenge. In this model, we found that, although the number of quarters containing SDG8 was significantly reduced in the GapC- but not in the Mig-immunized animals, the somatic cell counts from teat secretions were significantly decreased in both the GapC and Mig vaccinates.Key words: Streptococcus dysgalactiae, bovine mastitis, Mig, GapC, GAPDH.

The fragmentation of 23S rRNA of 23 Haemophilus influenzae strains and eight strains belonging to other Haemophilus species was investigated. Instead of intact molecules, the 23S rRNA molecules were found to be cleaved into two to five smaller conserved fragments in most strains examined, especially in H. influenzae type b (5/6) and nontypeable strains (5/5). One or two conserved potential cleavage sites were identified by PCR analysis of the strains showing a fragmented 23S rRNA pattern. The relevant nucleotide sequences were determined and compared to H. influenzae Rd, which contains intact 23S rRNA molecules. An identical 112bp long intervening sequence (IVS) at position 542 and a conserved 121-123bp IVS sequence at position 1171 were found in two H. influenzae type b strains and one nontypeable strain. Among the strains with fragmented 23S rRNA, nearly half showed a heterogeneous cleavage pattern due to the dispersion of IVSs among different 23S rRNA operons. The localization of the conserved H. influenzae IVSs coincided well with the extensively studied IVSs among other bacteria, but differed in nucleotide sequence from any other reported IVSs. Therefore, the IVSs of Haemophilus 23S rRNA may originate from a common source that is independent of other bacteria.

The presence of a functional glpT gene in Haemophilus influenzae could be questioned, since there is only what appears to be a truncated glpT (HI0686, 143 nt in the 5'-end) available in the H. influenzae Rd genome database (Fleischmann et al. , 1995). For cloning of the glpT gene from H. influenzae type b strain Eagan, an isogenic glpT, rec-1 double mutant and a selective medium for detection of the glpT mutant strains were constructed. The recombinant plasmid carrying glpT was able to complement the isogenic glpT mutant to wild-type levels of G3P uptake and permitted growth on a selective medium with G3P as a major carbon source. The nucleotide sequences of the glpT gene were determined both directly from PCR products and from the cloned DNA insert of strain Eagan. An identical 1440 bp open reading frame with 480 deduced amino acids, highly homologous to other bacterial G3P permeases, was identified. A Northern blot analysis showed that the glpT genes in both Eagan and Rd strains were transcribed on a RNA of approximately 1.4 kb in size. Thus, it is likely that HI0686 sequence originates from a mutated glpT clone in Escherichia coli.

Optimized conditions are developed for the desilylation of the starting alkynes and subsequent cycloaddition with aromatic azides to produce triazoles regioselectively.

Background Highly active anti-retroviral therapy (HAART) is the current HIV/AIDS treatment modality. Despite the fact that HAART is very effective in suppressing HIV-1 replication and reducing the mortality of HIV/AIDS patients, it has become increasingly clear that HAART does not offer an ultimate cure to HIV/AIDS. The high cost of the HAART regimen has impeded its delivery to over 90% of the HIV/AIDS population in the world. This reality has urgently called for the need to develop inexpensive alternative anti-HIV/AIDS therapy. This need has further manifested by recent clinical trial failures in anti-HIV-1 vaccines and microbicides. In the current study, we characterized a panel of extracts of traditional Chinese medicinal herbal plants for their activities against HIV-1 replication. Methods Crude and fractionated extracts were prepared from various parts of nine traditional Chinese medicinal herbal plants in Hainan Island, China. These extracts were first screened for their anti-HIV activity and cytotoxicity in human CD4+ Jurkat cells. Then, a single-round pseudotyped HIV-luciferase reporter virus system (HIV-Luc) was used to identify potential anti-HIV mechanisms of these extracts. Results Two extracts, one from Euphorbiaceae, Trigonostema xyphophylloides (TXE) and one from Dipterocarpaceae, Vatica astrotricha (VAD) inhibited HIV-1 replication and syncytia formation in CD4+ Jurkat cells, and had little adverse effects on host cell proliferation and survival. TXE and VAD did not show any direct inhibitory effects on the HIV-1 RT enzymatic activity. Treatment of these two extracts during the infection significantly blocked infection of the reporter virus. However, pre-treatment of the reporter virus with the extracts and treatment of the extracts post-infection had little effects on the infectivity or gene expression of the reporter virus. Conclusion These results demonstrate that TXE and VAD inhibit HIV-1 replication likely by blocking HIV-1 interaction with target cells, i.e., the interaction between gp120 and CD4/CCR5 or gp120 and CD4/CXCR4 and point to the potential of developing these two extracts to be HIV-1 entry inhibitors.

Bioassay-guided isolation studies of the extract of Canthium horridum Bl. stem led to the isolation of ten compounds: (+)-syringaresinol (1), scoparone (2), scopoletin (3), 3′-methoxy-4′-hydroxy- trans-cinnamaldehyde (4), sinapic aldehyde (5), syringic acid (6), mannitol (7), vanillic acid 4- O-β-D-glucopyranoside (8), β-daucosterol (9), and β-sitosterol (10). Compounds 1-10 were reported for the first time from this species, and compounds 1, 4, 5, 6, and 8 from the genus. The antimicrobial activities of the isolated compounds were studied; 6 had the highest activity against Bacillus subtilis, but 1 showed good activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Compounds 2, 4 and 6 also inhibited the growth of these three bacteria. None of the compounds demonstrated inhibitory activity against Aspergillus niger.

Background Streptococcus pneumoniae infection starts from colonization of the host respiratory tract where interaction with host respiratory tract epithelial cells occurs. To investigate pneumococcal genes that are involved in the early stage of interaction with host epithelial cells, transcriptional responses of an encapsulated pathogenic pneumococcal strain TIGR4 upon exposure to human lung epithelial cells A549 for 0.5 h and 1 h time periods were investigated by using TIGR (JCVI) microarray technology. Gene expression changes were validated by quantitative real-time PCR (qRT-PCR) analysis. Findings We observed different transcriptional profiles at two incubation time periods in which most gene expressions were down-regulated at 0.5 h but up-regulated at 1 h. Many genes associated with ribonucleotide biosynthesis were down-regulated at both time points, whereas the genes associated with cell envelope, energy metabolism, transport and protein synthesis were mostly up-regulated at 1 h. Furthermore, these profiles were compared to the transcriptomes of a TIGR4-derived strain in response to human macrophages for the same time periods. We found one set of genes that exhibited similar expression changes upon exposure to both types of host cells, including cell envelope-associated bgaA (SP0648) and nanA (SP1693), and uncharacterized gene clusters such as SP1677–SP1680 and SP1688–SP1690. Conclusion These data indicate that at the early stage of interaction with host epithelial cells, a complex gene regulation and expression change occur in bacteria. Some of them might play an essential role during pathogen-host interactions and for the establishment of infection.

In eubacteria Escherichia coli and Bacillus subtilis, the glpTQ operon is involved in utilization of glycerol3phosphate (G3P) as a carbon source, and the glpT and glpQ genes transcribe as a single unit. In Haemophilus influenzae, we have previously characterized the glpT and glpQ homologues encoding glycerol-3-phosphate permease and glycerophosphodiester phosphodiesterase, respectively. The protein encoded by glpQ is also called Protein D and is involved in pathogenesis. In this study, we analysed the glpTQ transcripts in one H. injluenzae type b (Hib) and one nontypeable (NTHi) strain, and characterized potential function of the 1.4 kb glpTQ intergenic region that exists in most Hib strains but not in NTHi strains. In Northern blot and RT-PCR analysis, the glpT and glpQ genes in the Hib strain transcribed separately, whereas a co-transcribed glpTQ was found in the NTHi strain. It suggests that the 1.4 kb glpTQ intergenic region in Hib strains partially blocks the glpTQ operon transcription. When an isogenic mutant strain where the 1.4 kb region was replaced with a kanamycin cassette in the chromosome of the wildtype strain was tested, the blockage of the glpTQ transcription disappeared. We therefore conclude that due to the existence of the 1.4 kb glpTQ intergenic region in Hib strains, the glpTQ operons between Hib and NTHi strains transcribed differently. Based on a much lower G+C content (26 %) of the 1.4 kb DNA coding region than an overall G+C content of 38 % for the H. influenzae genome, we speculate that the 1.4 kb region might have been acquired by lateral transfer from an organism with a lower G+C content.