γδ T cell antigen receptor polyspecificity enables T cell responses to a broad range of immune challenges.

γδ T cells are essential for immune defense and modulating physiological processes. While they have the potential to recognize large numbers of antigens through somatic gene rearrangement, the antigens which trigger most γδ T cell response remain unidentified, and the role of antigen recognition in γδ T cell function is contentious. Here, we show that some γδ T cell receptors (TCRs) exhibit polyspecificity, recognizing multiple ligands of diverse molecular nature. These ligands include haptens, metabolites, neurotransmitters, posttranslational modifications, as well as peptides and proteins of microbial and host origin. Polyspecific γδ T cells are enriched among activated cells in naive mice and the responding population in infection. They express diverse TCR sequences, have different functional potentials, and include the innate-like γδ T cells, such as the major IL-17 responders in various pathological/physiological conditions. We demonstrate that encountering their antigenic microbiome metabolite maintains their homeostasis and functional response, indicating that their ability to recognize multiple ligands is essential for their function. Human γδ T cells with similar polyspecificity also respond to various immune challenges. This study demonstrates that polyspecificity is a prevalent feature of γδ T cell antigen recognition, which enables rapid and robust T cell responses to a wide range of challenges, highlighting a unique function of γδ T cells.

Coronavirus disease 2019: Repeated immersion of chlorine-containing disinfectants has adverse effects on goggles.

Introduction: During COVID-19, some front-line personnel experienced varying degrees of eye discomfort due to the use of goggles repeatedly disinfected with chlorine-containing disinfectant. Methods: The eye damage information of 276 front-line personnel who used goggles in a hospital from October 1, 2021, to December 1, 2021, was collected by filling out a questionnaire. To study the effect of chlorinated disinfectants on goggles, we immersed the goggles in the same volume of water and chlorinated disinfectant buckets. We tested the light transmittance, color and texture, and airtightness of the goggles at different times (1, 3, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, 216, 240, and 268 h). In addition, we detected where chlorinated disinfectant remained in the goggles by using disinfectant concentration test paper. Results: 60 (21.82%) people experienced dry eyes, stinging pain, photophobia and tearing, conjunctival congestion, eyelid redness, and swelling. After treatment or rest, the patient's ocular symptoms were significantly relieved within 3 days. With the extension of disinfection time, the light transmission of the lenses gradually decreased, and the light transmission reduced when immersion occurred at 216 h. After 72 h of disinfection, the color of the goggle frame began to change to light yellow, the texture gradually became hard and brittle, and the color became significantly darker at 268 h of disinfection. The airtightness of the goggles began to decrease after 168 h of disinfection, the airtightness decreased substantially at 268 h, and the shape changed significantly. In addition, the concentration test paper results show that the disinfection solution mainly resides in the goggle frame seam and goggles' elastic bands' bundle. Conclusions: Repeated chlorine disinfectant disinfection will reduce the effectiveness of goggles protection and damage front-line personnel's eye health.

Strategies to evaluate potential effector function of glycan variants: a case study of ordesekimab (AMG 714 or PRV-015).

The potential for effector functions of therapeutic antibodies, including antibody-dependent cell-mediated cytotoxicity (ADCC), is a biological activity of interest for characterization, regardless of if ADCC is an intended primary pharmacological effect. The composition of the conserved antibody Fc glycan can vary as a function of post-translational processing which may affect the binding affinity to Fc receptors, leading to a change of effector activity. Ordesekimab (AMG 714 or PRV-015), a fully human immunoglobulin G1-kappa anti-interleukin (IL)-15 monoclonal antibody, is in clinical development for celiac disease. The binding of ordesekimab to IL-15 inhibits the interaction of IL-15 with the IL-2Rß and common γ chain of the IL-15 receptor complex, but not with the IL-15Rα chain. Therefore, the simultaneous binding of ordesekimab to the Fcγ receptor (R) IIIα expressed on natural killer (NK) cells and to the IL-15/IL-15Rα complex on cells such as monocytes may theoretically enable ADCC toward the IL-15Rα-expressing cells. The high mannose (HM) levels on the Fc glycan were found to vary in different lots of ordesekimab resulting from refinements to the manufacturing process, and the impact on ordesekimab-mediated ADCC activity was evaluated in in vivo and in vitro studies. A review of nonclinical and clinical data found no evidence of ordesekimab-induced depletion of monocytes, or cytotoxicity in organs with wide IL-15Rα expression, suggesting a lack of in vivo ADCC activity. In addition, in vitro peripheral blood mononuclear cells-based ADCC assay did not reveal any cytolytic effect of ordesekimab with various levels of HM content when cocultured with recombinant human IL-15. Taken together, these data demonstrate that ADCC is not a potential liability for ordesekimab and does not contribute to the reduction of IL-15-mediated inflammation, the intended pharmacological effect.

Characterization of an Anti-CD70 Half-Life Extended Bispecific T-Cell Engager (HLE-BiTE) and Associated On-Target Toxicity in Cynomolgus Monkeys.

Bispecific T-cell engager (BiTE) molecules have great potential to treat cancer. Nevertheless, dependent on the targeted tumor antigen, the mechanism of action that drives efficacy may also contribute to on-target/off-tumor toxicities. In this study, we characterize an anti-CD70 half-life extended BiTE molecule (termed N6P) which targets CD70, a TNF family protein detected in several cancers. First, the therapeutic potential of N6P was demonstrated using in vitro cytotoxicity assays and an orthotopic xenograft mouse study resulting in potent killing of CD70+ cancer cells. Next, in vitro characterization demonstrated specificity for CD70 and equipotent activity against human and cynomolgus monkey CD70+ cells. To understand the potential for on-target toxicity, a tissue expression analysis was performed and indicated CD70 is primarily restricted to lymphocytes in normal healthy tissues and cells. Therefore, no on-target toxicity was expected to be associated with N6P. However, in a repeat-dose toxicology study using cynomolgus monkeys, adverse N6P-mediated inflammation was identified in multiple tissues frequently involving the mesothelium and epithelium. Follow-up immunohistochemistry analysis revealed CD70 expression in mesothelial and epithelial cells in some tissues with N6P-mediated injury, but not in control tissues or those without injury. Collectively, the data indicate that for some target antigens such as CD70, BiTE molecules may exhibit activity in tissues with very low antigen expression or the antigen may be upregulated under stress enabling molecule activity. This work illustrates how a thorough understanding of expression and upregulation is needed to fully address putative liabilities associated with on-target/off-tumor activity of CD3 bispecific molecules.

Brain transcriptome analysis reveals genes involved in parental care behaviour in discus fish (Symphysodon haraldi).

Parental care is common in mammals and allows offspring to obtain milk, a substance rich in a range of nutritional and non-nutritional factors crucial to the survival of newborns. The discus fish Symphysodon spp., an Amazonian cichlid, shows an unusual behaviour: Free-swimming fry bite on their parents' skin mucus for growth and development during the first month after hatching. This is similar to the breastfeeding behaviour of mammals, but little is known about the regulatory mechanism by which discus secrete 'milk' and the related genes involved in parental care. Here, transcriptome sequencing was performed by using the brain tissues of female discus fish in parental and non-parental care. The results showed that a total of 86 differentially expressed genes (71 up-regulated genes and 15 down-regulated genes) were obtained by comparing parental with non-parental discus fish, including up-regulated LAPTM, FOXB, SOX1S, OTX2 and NR1F2, and down-regulated EDNRB, PRKCD, H1-5 and HBE. Through functional enrichment analysis, a total of 20 pathways were identified, e.g., estrogen signaling pathway, inflammatory mediator regulation of TRP channels, vascular smooth muscle contraction, GnRH signaling pathway, neurotrophin signaling pathway, NOD-like receptor signaling pathway, Jak-STAT signaling pathway, Fc gamma R-mediated phagocytosis, serotonergic synapse, autophagy-animal and cytokine-cytokine receptor interaction. These pathways and related genes might play important roles in the regulation of discus 'milk' secretion.

Development of a BiTE®-mediated CD8+ cytotoxic T-lymphocyte activity assay to assess immunomodulatory potential of drug candidates in Cynomolgus macaque.

The immunotoxic potential of drug candidates is assessed through the examination of results from a variety of studies and endpoints. While the functional assessment of CD8+ cytotoxic T-lymphocytes (CTL) is well-characterized in the clinic, the lack of a robust macaque CTL functional assay has been an important hurdle in evaluating and accurately quantifying cell-mediated CD8+ T-cell effector responses in the nonclinical setting. This paper describes the development of an assay to measure CTL activity in peripheral blood mononuclear cells (PBMC) isolated from Cynomolgus macaques. A human EGFR/CD3 Bispecific T-cell Engager (BiTE®) was used to mount a robust CD8+ T-cell response in the presence of target-expressing cells. Upon target engagement, degranulation of CD107a and production of interferon (IFN)-γ both reliably indicated a robust functional response in CD8+ T-cells. The BiTE®-mediated stimulation method proved to be favorable when compared to other methods of stimulation in the absence of target cells. These studies demonstrated acceptable longitudinal variability of the functional assay and sensitivity to dexamethasone-mediated immunosuppression. Taken together, the results indicated an assay leveraging CD3-bispecific antibodies and target-expressing cells can provide a robust approach to the in vitro or ex vivo assessment of CTL function in Cynomolgus macaques. Because the impairment of CTL activity by immunomodulators is recognized to be an important contributor to decreased antiviral defense and increased carcinogenicity risk, we believe that this novel assay to be a valuable addition to the immunotoxicology assessment of therapeutic drug candidates.

Microbiota-activated CD103+ DCs stemming from microbiota adaptation specifically drive γδT17 proliferation and activation.

BACKGROUND: IL-17-producing γδT cells (γδT17) promote autoinflammatory diseases and cancers. Yet, γδT17 peripheral regulation has not been thoroughly explored especially in the context of microbiota-host interaction. The potent antigen-presenting CD103+ dendritic cell (DC) is a key immune player in close contact with both γδT17 cells and microbiota. This study presents a novel cellular network among microbiota, CD103+ DCs, and γδT17 cells. METHODS: Immunophenotyping of IL-17r-/- mice and IL-17r-/- IRF8-/- mice were performed by ex vivo immunostaining and flow cytometric analysis. We observed striking microbiome differences in the oral cavity and gut of IL-17r-/- mice by sequencing 16S rRNA gene (v1-v3 region) and analyzed using QIIME 1.9.0 software platform. Principal coordinate analysis of unweighted UniFrac distance matrix showed differential clustering for WT and IL-17r-/- mice. RESULTS: We found drastic homeostatic expansion of γδT17 in all major tissues, most prominently in cervical lymph nodes (cLNs) with monoclonal expansion of Vγ6 γδT17 in IL-17r-/- mice. Ki-67 staining and in vitro CFSE assays showed cellular proliferation due to cell-to-cell contact stimulation with microbiota-activated CD103+ DCs. A newly developed double knockout mice model for IL-17r and CD103+ DCs (IL-17r-/-IRF8-/-) showed a specific reduction in Vγ6 γδT17. Vγ6 γδT17 expansion is inhibited in germ-free mice and antibiotic-treated specific pathogen-free (SPF) mice. Microbiota transfer using cohousing of IL-17r-/- mice with wildtype mice induces γδT17 expansion in the wildtype mice with increased activated CD103+ DCs in cLNs. However, microbiota transfer using fecal transplant through oral gavage to bypass the oral cavity showed no difference in colon or systemic γδT17 expansion. CONCLUSIONS: These findings reveal for the first time that γδT17 cells are regulated by microbiota dysbiosis through cell-to-cell contact with activated CD103+ DCs leading to drastic systemic, monoclonal expansion. Microbiota dysbiosis, as indicated by drastic bacterial population changes at the phylum and genus levels especially in the oral cavity, was discovered in mice lacking IL-17r. This network could be very important in regulating both microbiota and immune players. This critical regulatory pathway for γδT17 could play a major role in IL-17-driven inflammatory diseases and needs further investigation to determine specific targets for future therapeutic intervention.

Stabilizing Cr species in incinerator fly ashes with/without kaolin addition through a firing process: a molecular study on heated Cr.

Cr speciation in Cr-sorbing washed incinerator fly ash (IFA) after heating up to 1100°C is temperature dependent. Higher temperature leads to a greater level of chemical reduction of Cr(VI) that is considerably more toxic than Cr(III). Most Cr(VI) sorbed washed IFA is effectively transformed into Cr(III) after heating to 1100°C for 2 h, as indicated by the disappearance of hexavalent pre-edge peak of Cr K-edge X-ray absorption near edge structure (XANES) spectrum. After heating the Cr-sorbing IFA to 100°C and 500°C for 2 h, water-soluble CaCrO4 is determined to be the principal Cr species due to the chemical reaction between the sorbed Cr(VI) and CaO components of washed fly ash, based on the comparison between sample and reference XANES spectra. Replacing half of the washed fly ash with kaolin could effectively reduce all Cr(VI) after heating to ≧ 900°C for 2 h.

A Highly Focused Antigen Receptor Repertoire Characterizes γδ T Cells That are Poised to Make IL-17 Rapidly in Naive Animals.

Interleukin (IL)-17 plays a key role in immunity. In acute infections, a rapid IL-17 response must be induced without prior antigen exposure, and γδ T cells are the major initial IL-17 producers. In fact, some γδ T cells make IL-17 within hours after an immune challenge. These cells appear to acquire the ability to respond to IL-1 and IL-23 and to make IL-17 naturally in naïve animals. They are known as the natural Tγδ17 (nTγδ17) cells. The rapidity of the nTγδ17 response, and the apparent lack of explicit T cell receptor (TCR) engagement for its induction have led to the view that this is a cytokine (IL-1, IL-23)-mediated response. However, pharmacological inhibition or genetic defects in TCR signaling drastically reduce the nTγδ17 response and/or their presence. To better understand antigen recognition in this rapid IL-17 response, we analyzed the antigen receptor repertoire of IL-1R(+)/IL-23R(+) γδ T cells, a proxy for nTγδ17 cells in naïve animals directly ex vivo, using a barcode-enabled high throughput single-cell TCR sequence analysis. We found that regardless of their anatomical origin, these cells have a highly focused TCR repertoire. In particular, the TCR sequences have limited V gene combinations, little or no junctional diversity and much reduced or no N region diversity. In contrast, IL-23R(-) cells at mucosal sites similar to most of the splenic γδ T cells and small intestine epithelial γδ lymphocytes expressed diverse TCRs. This remarkable commonality and restricted repertoire of IL-1R(+)/IL-23R(+) γδ T cells underscores the importance of antigen recognition in their establishment/function.

Gamma delta T cells recognize haptens and mount a hapten-specific response.

The ability to recognize small organic molecules and chemical modifications of host molecules is an essential capability of the adaptive immune system, which until now was thought to be mediated mainly by B cell antigen receptors. Here we report that small molecules, such as cyanine 3 (Cy3), a synthetic fluorescent molecule, and 4-hydroxy-3-nitrophenylacetyl (NP), one of the most noted haptens, are γδ T cell antigens, recognized directly by specific γδ TCRs. Immunization with Cy3 conjugates induces a rapid Cy3-specific γδ T cell IL-17 response. These results expand the role of small molecules and chemical modifications in immunity and underscore the role of γδ T cells as unique adaptive immune cells that couple B cell-like antigen recognition capability with T cell effector function.

The Split Virus Influenza Vaccine rapidly activates immune cells through Fcγ receptors.

Seasonal influenza vaccination is one of the most common medical procedures and yet the extent to which it activates the immune system beyond inducing antibody production is not well understood. In the United States, the most prevalent formulations of the vaccine consist of degraded or "split" viral particles distributed without any adjuvants. Based on previous reports we sought to determine whether the split influenza vaccine activates innate immune receptors-specifically Toll-like receptors. High-dimensional proteomic profiling of human whole-blood using Cytometry by Time-of-Flight (CyTOF) was used to compare signaling pathway activation and cytokine production between the split influenza vaccine and a prototypical TLR response ex vivo. This analysis revealed that the split vaccine rapidly and potently activates multiple immune cell types but yields a proteomic signature quite distinct from TLR activation. Importantly, vaccine induced activity was dependent upon the presence of human sera indicating that a serum factor was necessary for vaccine-dependent immune activation. We found this serum factor to be human antibodies specific for influenza proteins and therefore immediate immune activation by the split vaccine is immune-complex dependent. These studies demonstrate that influenza virus "splitting" inactivates any potential adjuvants endogenous to influenza, such as RNA, but in previously exposed individuals can elicit a potent immune response by facilitating the rapid formation of immune complexes.

Detoxification of hazardous dust with marine sediment.

Hazardous electric arc furnace dust containing dioxins/furans and heavy metals is blended with harbor sediment, fired at 950-1100 °C to prepare lightweight aggregates. Dust addition can lower the sintering temperature by about 100 °C, as compared to a typical industrial process. After firing at 950 °C and 1050 °C, more than 99.85% of dioxins/furans originally present in the dust have been removed and/or destructed in the mix containing a dust/sediment ratio of 50:100. The heavy metals leached from all fired mixes are far below Taiwan EPA legal limits. The particle density of the lightweight aggregates always decreases with increasing firing temperature. Greater addition of the dust results in a considerably lower particle density (mostly <2.0 g cm(-3)) fired at 1050 °C and 1100 °C. However, firing at temperatures lower than 1050 °C produces no successful bloating, leading to a denser particle density (>2.0 g cm(-3)) that is typical of bricks.

Recycling steel-manufacturing slag and harbor sediment into construction materials.

Mixtures consisting of harbor sediment and slag waste from steel industry containing toxic components are fired to produce non-hazardous construction materials. The fired pellets become lighter as firing temperature increases. At a sintering temperature of ≦1050°C, the fired pellets are in a form of brick-like product, while at 1100°C, they become lightweight aggregates. Calcium silicate, kyanite, and cristobalite are newly formed in the pellets after firing, demonstrating that calcium oxide acts as a flux component and chemically reacted with Si- and/or Al-containing components to promote sintering. Dioxin/furan content present in the pure slag is 0.003ng I-TEQg(-1) and, for the fired pellet consisting of slag and sediment, the content appears to be destructed and diminishes to 0.0003ng I-TEQg(-1) after 950°C-firing; while it is 0.002ng I-TEQg(-1) after firing at 1100°C, suggesting that dioxins/furans in the 950°C-fired pellets have a greater chance to escape to atmosphere due to a slower sintering reaction and/or that construction of dioxins/furans from molten chloride salts co-exists with their destruction. Multiple toxicity characteristic leaching procedure extracts Cu, Cr, Zn, Se, Cd, Pb, Ba, As, and Hg from all fired products at negligible levels.

Tracking of arsenics during the thermal stabilization of an AsH3 scrubber sludge.

Toxic arsenics in an AsH(3) scrubber sludge were thermally stabilized in the temperature range of 973-1,373 K. To better understand how the high-temperature treatments can stabilize arsenics in the sludge, their synchrotron X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra of arsenics were determined. It is found that the reduced arsenic leachability may be associated with the formation of As(2)O(5) (51-59%) and embedded As(V) within the Ca(3)(PO(4))(2) matrix (41-49%) in the stabilized sludge. In addition, the As-O bond distances in the stabilized As(2)O(5) are much less than that of normal As(2)O(5) by 0.05-0.07 Å. The shorter As-O bond distances accompanied with the higher bonding energy also have a contribution to the thermal stabilization of arsenics.

Docosahexaenoic acid inhibition of inflammation is partially via cross-talk between Nrf2/heme oxygenase 1 and IKK/NF-κB pathways.

We examined the underlying mechanisms involved in n-3 docosahexaenoic acid (DHA) inhibition of inflammation in EA.hy926 cells. The present results demonstrated that pretreatment with DHA (50 and 100 µM) inhibited tumor necrosis factor-alpha (TNF-α)-induced intercellular adhesion molecule 1 (ICAM-1) protein, mRNA expression and promoter activity. In addition, TNF-α-stimulated inhibitory kappa B (IκB) kinase (IKK) phosphorylation, IκB phosphorylation and degradation, p65 nuclear translocation, and nuclear factor-κB (NF-κB) and DNA binding activity were attenuated by pretreatment with DHA. DHA triggered early-stage and transient reactive oxygen species (ROS) generation and significantly increased the protein expression of heme oxygenase 1 (HO-1), induced nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus and up-regulated antioxidant response element (ARE)-luciferase reporter activity. Moreover, DHA inhibited Nrf2 ubiquitination and proteasome activity. DHA activated Akt, p38 and ERK1/2 phosphorylation, and specific inhibitors of respective pathways attenuated DHA-induced Nrf2 nuclear translocation and HO-1 expression. Transfection with HO-1 siRNA knocked down HO-1 expression and partially reversed the DHA-mediated inhibition of TNF-α-induced p65 nuclear translocation and ICAM-1 expression. Importantly, we show for the first time that HO-1 plays a down-regulatory role in NF-κB nuclear translocation, and inhibition of Nrf2 ubiquitination and proteasome activity are involved in increased cellular Nrf2 level by DHA. In this study, we show that HO-1 plays a down-regulatory role in NF-κB nuclear translocation and that the protective effect of DHA against inflammation is partially via up-regulation of Nrf2-mediated HO-1 expression and inhibition of IKK/NF-κB signaling pathway.

γδ T cells recognize a microbial encoded B cell antigen to initiate a rapid antigen-specific interleukin-17 response.

γδ T cells contribute uniquely to immune competence. Nevertheless, how they function remains an enigma. It is unclear what most γδ T cells recognize, what is required for them to mount an immune response, and how the γδ T cell response is integrated into host immune defense. Here, we report that a noted B cell antigen, the algae protein phycoerythrin (PE), is a murine and human γδ T cell antigen. Employing this specificity, we demonstrated that antigen recognition activated naive γδ T cells to make interleukin-17 and respond to cytokine signals that perpetuate the response. High frequencies of antigen-specific γδ T cells in naive animals and their ability to mount effector response without extensive clonal expansion allow γδ T cells to initiate a swift, substantial response. These results underscore the adaptability of lymphocyte antigen receptors and suggest an antigen-driven rapid response in protective immunity prior to the maturation of classical adaptive immunity.

Preparation of low water-sorption lightweight aggregates from harbor sediment added with waste glass.

A harbor sediment is successfully recycled at 1150 °C as low water-absorption lightweight aggregate via addition of waste glass powder. Sodium content in the waste glass is responsible for the formation of low-viscosity viscous phases during firing process to encapsulate the gases generated for bloating pellet samples. Water sorption capacity of the lightweight products can be considerably reduced from 5.6% to 1.5% with the addition of waste glass powder. Low water-absorption property of lightweight products is beneficial for preparing lightweight concrete because the water required for curing the cement would not be seized by lightweight aggregate filler, thus preventing the failure of long-term concrete strength.

Study of chromium modified TiO2 nano catalyst under visible light irradiation.

Visible light active photocatalysts were successfully prepared by incorporating chromium into anatase TiO2 at two Cr/Ti atomic ratios (0.03% and 0.11%) by the use of a modified sol-gel process. Results show that the size of the chromium modified TiO2 particles is approximately 14-25 nm. As indicated by diffuse reflectance ultra violet/visible absorption spectra, heavier chromium dosage tends to result in greater absorption in both ultra violet and visible light. The simulation results from Cr K-edge X-ray absorption spectra suggest that Cr(0) and Cr(III), accounting for approximately 25% and 75% of total Cr, respectively, coexist in the TiO2 catalyst doped with 0.11% Cr. Cr dopant is suggested to be responsible for the phenomenon of enhanced light absorption in both ultra violet and visible regions. Further, Cr(0) can act as an electron remover because of the formation of the Schottky barrier between Cr(0) and TiO2, thus reducing the possibility of electron hole recombination. Photo-catalytic degradation of methylene blue under irradiation of blue light (with peak flux at 460 nm wavelength and a small flux near 367 nm) was considerably enhanced under appropriate reaction time (12 and 24 h) as small amount of Cr was doped into anatase titanium dioxide catalyst. After prolonged reaction time, Cr(0) was suggested to be poisoned and/or oxidized by SO4(2-), one of the final products of mineralizing methylene blue, thus loosing the capability of the electron hole separation.

Thermal enrichment and speciation of copper in rice husk ashes.

Copper(II) was considerably enriched in the residual ash via thermal treatment of copper-sorbed rice husk at 700-1100°C for 2h, and the copper speciation was quantitatively determined with X-ray absorption spectroscopy. After the thermal process, the resulting ash only represents by weight 18.7-26.4% of the pre-heated samples. Copper content in the ashes is >7% which is far above the required minimum copper content in copper ores for the copper smelting sector, 0.5%. Crystalline SiO(2) is observed only in the ash generated at 1100°C, with more copper in this ash being available for leaching in acidic solution. It is suggested that this is due to the considerable dissimilarity in crystalline structure between copper compounds and crystalline SiO(2). No chemical reaction between copper and SiO(2) is observed in any ash. In fact, we suggest that the SiO(2) crystalline phase repels copper during the thermal process; this would make it easy to extract copper from the ashes. For copper speciation in the ashes, CuO merely represents 0-12% of the total copper, while Cu(2)O and Cu(0) represent 34-42% and 46-63%, respectively. The lower copper oxidation state would be beneficial for the copper smelting process due to less usage of coke.

Antituberculosis agents and an inhibitor of the para-aminobenzoic acid biosynthetic pathway from Hydnocarpus anthelminthica seeds.

Investigation on the extracts of Hydnocarpus anthelminthica seeds led to the isolation of three new compounds, anthelminthicins A-C (1-3, resp.), and two known ones, namely chaulmoogric acid (4) and ethyl chaulmoograte (5). Their structures were determined mainly by using spectroscopic techniques. The absolute configuration at the cyclopentenyl moiety of compound 2 was rationalized by quantum calculations. Base hydrolysis, followed by optical-rotation comparison, allowed assignment of the configuration of chaulmoogric-acid moiety of compounds 3 and 5. Biological assays revealed that compounds 1-5 significantly inhibit Mycobacterium tuberculosis (MTB) growth with MIC values of 5.54, 16.70, 4.38, 9.82, and 16.80 microM, respectively. Compound 3 was found to inhibit the pathway between chorismate and para-aminobenzoic acid (pAba) with a MIC value of 11.3 microM, representing a new example of pAba inhibitor isolated from a natural source. All compounds were not toxic to Candida albicans SC5314 at a concentration up to 100 microM.