Yellow Species Research Articles

Revision of the New World Dohrniphora Dahl species with hind tibial setae (Diptera: Phoridae)

The New World species of Dohrniphora with one or more large hind tibial setae are revised. Prior to our work, the known fauna consisted of 36 described species, including fi ve that are mostly known from specimens lacking hind tibial setae. Fifty-two new species are described, all from the Neotropical Region. Two names, D. anterosetalis Borgmeier & Prado and D. trudiae Disney, are both considered new synonyms of D. anteroventralis Borgmeier. The Dohrniphora species with hind tibial setae are not considered to be a monophyletic group, but some tentative monophyletic groups within this assemblage are proposed. In particular, a large group of small, yellow species is recognized as the probably monophyletic D. pyricornis group.

Simultaneous Determination of Cobalt(II) and Nickel(II) by Fourth-Order Derivative Spectrophotometric Method Using 2-Hydroxy-3-Methoxy Benzaldehyde Thiosemicarbazone

A simple and new simultaneous fourth derivative spectrophotometric method is proposed for the analysis of a two-component system containing cobalt(II) and nickel(II) without separation using 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) as a chromophoric reagent. The reagent reacts with cobalt(II) and nickel(II) at pH 6.0, forming soluble brown and yellow colored species, respectively. Cobalt(II) and nickel(II) present in themixture are simultaneously determined without solving the simultaneous equations bymeasuring the fourth derivative amplitudes at 468.5 nm and 474.5 nm, respectively. The derivative amplitudes obey Beer's law at 468.5 nm and 474.5 nm for Co(II) and Ni(II) in the range 0.059–3.299 μg mL−1 and 0.058–3.285 μg mL−1 respectively. A large number of foreign ions do not interfere in the present method. The present simultaneous method is used for the determination of micro amounts of cobalt in biological samples, nickel in plant samples, and in some alloy steels and soil sample.

The systematic position of some boring sponges (Demospongiae, Hadromerida) studied by molecular analysis

A phylogenetic analysis of some bioeroding sponges of the family Clionaidae (Order Hadromerida) was performed to resolve some taxonomic problems both at the specific and the supraspecific level using the D2 and D3 regions of 28S rDNA. Species belonging to the genera Cliona, Cliothosa, Spheciospongia (fam. Clionaidae) and Diplastrella (fam. Spirastrellidae) from the Mediterranean Sea and Celebes Sea (Indonesia) were analysed. In the phylogenetic tree, the species clustered on two main branches, one comprising Cliona celata, C. rhodensis, C. utricularis, and Cliothosa hancocki, and the other made up of C. viridis, C. nigricans, C. schmidti, C. jullieni, Spheciospongia solida and S. vagabunda. Above the species level, data do not support the separation of the genus Cliothosa from Cliona, while they do support the inclusion of some massive boring species, previously assigned to the genus Spirastrella, in the family Clionaidae. At the species level, data demonstrated the genetic identity of taxa C. viridis and C. nigricans, in spite of their considerable morphological differences. In contrast, the yellow species commonly attributed to C. celata are probably to be considered as a complex of sibling species with a number of distinct taxa present in the Mediterranean. Data also showed the identity of the Mediterranean and Pacific populations of C. schmidti, suggesting the status of a Tethyan relict for this species.

Isolation, characterization, and reactivity of the reaction products of the dimeric, Ti–O–Ti bridged anhydride form of the 1,2-di-titanium(IV)-substituted α-Keggin polyoxometalate with aqueous 30% H 2O 2

The isolation and characterization of the monomeric bis[peroxotitanium(IV)]-substituted α-Keggin polyoxometalate (POM) K 7[α-l,2-PW 10(TiO 2) 2O 38]·8H 2O ( 1) and the monomeric bis[hydroperoxotitanium(IV)]-substituted α-Keggin POM K 5[α-l,2-PW 10(TiOOH) 2O 38]·5H 2O ( 2) are described. The orange solution was prepared by adding an excess amount of aqueous 30% H 2O 2 to the in situ-generated monomeric Keggin species [α-1,2-PW 10Ti 2O 40] 7− in a neutral aqueous solution derived by the hydrolytic cleavage of the dimeric, Ti–O–Ti bridged anhydride form K 10[α-l,2-PW 10Ti 2O 39] 2·18H 2O. Reprecipitation of the orange solution with MeOH gave a thermally stable yellow species containing the peroxo groups (compound 1) whereas reprecipitation with EtOH yielded a relatively unstable orange species that would contain the hydroperoxo groups (compound 2). The characterization of 1 and 2 was accomplished by a complete elemental analysis, TG/DTA, FTIR, UV–vis, solution ( 31P and 183W) NMR and 31P CPMAS NMR spectroscopy, and (for 1 only) X-ray crystallography. Complex 1 did not show any activity for 2-propanol oxidation in the absence of 30% H 2O 2 whereas complex 2 showed an effective activity for the oxidation reaction.

Genetic and Ecological Characterisation of Colour Dimorphism in a Coral Reef Fish

Many recognised species of coral reef fishes exhibit two or more colour variants, but it is unknown whether these represent genetically identical phenotypes, genetic polymorphisms or closely related species. We tested between these alternatives for two colour morphs of the coral reef fish, Pseudochromis fuscus, from Lizard Island (Great Barrier Reef). A molecular analysis using mtDNA did not detect any genetic differentiation between co-occurring ‘yellow’ and ‘brown’ colour morphs. A previous study proposed that these two colour morphs are aggressive mimics of yellow and brown damselfishes. Here, a manipulative field experiment was used to evaluate whether the colour dimorphism in P. fuscus is a phenotypic response to the presence of two different model species. Colonies of either yellow or brown damselfish species were established on different patch reefs, and each of the two different P. fuscus morphs was then placed on the different reefs. Contrary to expectations, all yellow individuals that stayed on the reefs changed to brown, regardless of the model species. No brown individuals changed to the yellow colouration. However, P. fuscus were more likely to emigrate from, or suffer higher mortality on, patch reefs where they were not matched with similarly coloured models. Clearly, yellow and brown P. fuscus are members of a single species with sufficient phenotypic plasticity to switch from yellow to brown colouration.

Mechanism of the Greening Color Formation of “Laba” Garlic, a Traditional Homemade Chinese Food Product

While green discoloration during garlic processing is of a major concern, this greening is desirable and required for the traditional homemade Chinese "Laba" garlic. To obtain insights into the mechanism of color formation, simulation of the greening of "Laba" garlic was carried out in the laboratory by soaking aged garlic in 5% (v/v, pH 2.33) acetic acid solution. After 2 days, the garlic cloves turned green. Up to 4 days, pigment(s) diffused from garlic cloves to the pickling solution. The solution exhibits two maximal absorbances at approximately 440 and approximately 590 nm, corresponding to yellow and blue species, respectively, the combination of which creates the green coloration. With increasing time from 4 to 25 days, the concentration of both yellow and blue species increases at nearly the same rate, while after 25 days, the concentration of the yellow species increases faster than that of the blue species. Interestingly, most thiosulfinates ( approximately 85%) in garlic cloves were converted within 4 days, suggesting that thiosulfinate conversion is proportional to the formation of the pigments. Consistent with this conclusion, alliinase and acetic acid were required for the color formation. UV-vis spectral measurements and pH results suggest that the color formation occurs by two kinds of processes: one enzymatic and the other nonenzymatic. Low pH (2.0-3.0) favors nonenzymatic reactions, while high pH (6.0 or above) is conducive to enzymatic reactions. Thus, the ideal pH for the entire process of garlic greening is between 4.0 and 5.0, which is a compromise of the optimal pH of both the enzymatic and nonenzymatic reactions.

Comparative analysis of the volatiles from flowers and leaves of three Gentiana species

The volatiles from fresh flowers and leaves of Gentiana lutea L., Gentiana punctata L. (yellow Gentiana spp.) and Gentiana asclepiadea L. (Gentianaceae Juss.) were analyzed by GC/MS and 81 compounds identified. The samples studied showed differences in the volatile profiles of flowers and leaves among the species. In the flower-oils straight chain saturated aliphatic hydrocarbons were dominant along with low concentrations of branched saturated aliphatic hydrocarbons and alkylated benzenes. These compounds were not present in the flowers of G. lutea and G. punctata and in the leaves of G. lutea. The branched saturated aliphatic hydrocarbons were the main constituents of the leaf-oil from G. ascleapidea. Terpenes were found in all flower-oils and in the leaf oil from G. punctata. Some of the identified compounds might have allelopathic activity. The results obtained confirm the accepted taxonomical scheme of the genus Gentiana and are also in agreement with the evolutionary less advanced position of the yellow species of Gentiana.

Thermochromatium tepidumPhotoactive Yellow Protein/Bacteriophytochrome/Diguanylate Cyclase: Characterization of the PYP Domain

The purple phototrophic bacterium, Thermochromatium tepidum, contains a gene for a chimeric photoactive yellow protein/bacteriophytochrome/diguanylate cyclase (Ppd). We produced the Tc. tepidum PYP domain (Tt PYP) in Escherichia coli, and found that it has a wavelength maximum at 358 nm due to a Leu46 substitution of the color-tuning Glu46 found in the prototypic Halorhodospira halophila PYP (Hh PYP). However, the 358 nm dark-adapted state is in a pH-dependent equilibrium with a yellow species absorbing at 465 nm (pK(a) = 10.2). Following illumination at 358 nm, photocycle kinetics are characterized at pH 7.0 by a small bleach and red shift to what appears to be a long-lived cis intermediate (comparable to the I(2) intermediate in Hh PYP). The recovery to the dark-adapted state has a lifetime of approximately 4 min, which is approximately 1500 times slower than that for Hh PYP. However, when the Tt PYP is illuminated at pH values above 7.5, the light-induced difference spectrum indicates a pH-dependent equilibrium between the I(2) intermediate and a red-shifted 440 nm intermediate. This equilibrium could be responsible for the sigmoidal pH dependence of the recovery of the dark-adapted state (pK(a) = 8.8). In addition, the light-induced difference spectrum shows that, at pH values above 9.3, there is an apparent bleach near 490 nm superimposed on the 358 and 440 nm changes, which we ascribe to the equilibrium between the protonated and ionized dark-adapted forms. The L46E mutant of Tt PYP has a wavelength maximum at 446 nm, resembling wild-type Hh PYP. The kinetics of recovery of L46E following illumination with white light are slow (lifetime of 15 min at pH 7), but are comparable to those of wild-type Tt PYP. We conclude that Tt PYP is unique among the PYPs studied to date in that it has a photocycle initiated from a dark-adapted state with a protonated chromophore at physiological pH. However, it is kinetically most similar to Rhodocista centenaria PYP (Ppr) despite the very different absorption spectra due to the lack of E46.

Analysis of nrDNA sequences and microsatellite allele frequencies reveals a cryptic chanterelle species Cantharellus cascadensis sp. nov. from the American Pacific Northwest

In the Pacific Northwest, yellow chanterelles have long been referred to as Cantharellus cibarius, synonymous with the European yellow chanterelle. Broad scale genetic surveys of North American chanterelles with C. cibarius-like morphology have demonstrated that the nrDNA internal transcribed spacer exhibits length variability, suggesting that this common morphology masks a species complex. Recently researchers have used morphological and genetic data to identify the yellow chanterelle most frequently harvested from American Pacific Northwest forests as C. formosus, a species once thought to be rare in the region. We present three genetic data sets and one morphological data set that characterize a previously undescribed, species of yellow chanterelle from the central Cascade Mountains of Oregon. Phylogenetic analyses of the nrDNA large subunit and ITS regions show that C. cascadensis sp. nov., along with two other yellow chanterelle taxa (C. cibarius var. roseocanus and European C. cibarius), are more closely related to white chanterelles (C. subalbidus) than they are to C. formosus. Data from five microsatellite loci provide evidence that C. formosus, C. subalbidus, and C. cascadensis sp. nov. do not interbreed when they co-occur spatially and temporally in Douglas fir-western hemlock forests. This demonstrates that these three sympatric chanterelles are biological species with boundaries congruent with those delineated by nrDNA phylogenetic clades. Morphological data indicate that the colour of the pileus and shape of the stipe can be used to separate fresh collections of the two yellow species now known to co-occur in Douglas fir-western hemlock forests in Oregon.

The white potato cyst nematode (Globodera pallida) - a critical analysis of the threat in Britain

Over the last 30 years, there has been an epidemic of the white potato cyst nematode (wPCN, Globodera pallida). It has progressively replaced the yellow species (yPCN, G. rostochiensis) throughout most of England and Wales and is now a widespread problem. As damaging populations of wPCN are enormous (>109 eggs ha−1), several crops of potato cultivars resistant only to yPCN were required to produce this change. The threat it poses is reflected in an increase in the numbers of soil samples being tested and in nematicide use, which has increased to > 25 000 ha of potatoes being treated annually. Computer modelling shows that current management of wPCN is mostly ineffective and populations will continue to increase. The multiplication rate of wPCN is inversely related to its population density at planting and, because of this, modelling shows that sufficient eggs are likely to survive to enable large populations of wPCN to “rebound” following nematicide treatment. This is supported by recent trial results showing that wPCN population increase was almost as great in nematicides-treated plots as in the untreated. Modelling also showed that current rotations (typically potatoes once every 5 or 6 years) are too short to prevent wPCN populations from progressively increasing, even when used in conjunction with a nematicide. Similarly, except with avirulent populations, the partially resistant cultivars currently available will not prevent wPCN from increasing. However, as the effectiveness of partially resistant cultivars is independent of population density, they can be very effective when integrated with a nematicide. Unfortunately, only c. 8% of the potato area is planted with partially resistant cultivars, and much of that is in land not known to be infested with wPCN. Consequently, the current epidemic of wPCN is likely to become progressively more serious. However, many farmers are failing to recognise and respond to this threat until it is too late because of the slow rate of increase of wPCN, the difficulties of detecting small populations and the costs of nematicides. To respond to the current epidemic of wPCN, the greatest priority is to have available an increased number of commercially-attractive partially resistant cultivars.

The white potato cyst nematode (Globodera pallida) – a critical analysis of the threat in Britain

SummaryOver the last 30 years, there has been an epidemic of the white potato cyst nematode (wPCN, Globodera pallida). It has progressively replaced the yellow species (yPCN, G. rostochiensis) throughout most of England and Wales and is now a widespread problem. As damaging populations of wPCN are enormous (>109 eggs ha−1), several crops of potato cultivars resistant only to yPCN were required to produce this change. The threat it poses is reflected in an increase in the numbers of soil samples being tested and in nematicide use, which has increased to > 25 000 ha of potatoes being treated annually. Computer modelling shows that current management of wPCN is mostly ineffective and populations will continue to increase. The multiplication rate of wPCN is inversely related to its population density at planting and, because of this, modelling shows that sufficient eggs are likely to survive to enable large populations of wPCN to “rebound” following nematicide treatment. This is supported by recent trial results showing that wPCN population increase was almost as great in nematicides‐treated plots as in the untreated. Modelling also showed that current rotations (typically potatoes once every 5 or 6 years) are too short to prevent wPCN populations from progressively increasing, even when used in conjunction with a nematicide. Similarly, except with avirulent populations, the partially resistant cultivars currently available will not prevent wPCN from increasing. However, as the effectiveness of partially resistant cultivars is independent of population density, they can be very effective when integrated with a nematicide. Unfortunately, only c. 8% of the potato area is planted with partially resistant cultivars, and much of that is in land not known to be infested with wPCN. Consequently, the current epidemic of wPCN is likely to become progressively more serious. However, many farmers are failing to recognise and respond to this threat until it is too late because of the slow rate of increase of wPCN, the difficulties of detecting small populations and the costs of nematicides. To respond to the current epidemic of wPCN, the greatest priority is to have available an increased number of commercially‐attractive partially resistant cultivars.

Clopyralid effects on yellow starthistle (Centaurea solstitialis) and nontarget species

Yellow starthistle is a problematic invasive plant in the western United States. Attempts to control it often include the use of herbicides although herbicides can have detrimental effects on desired native species. We studied the effect of clopyralid on a native bunchgrass and vernal pool community in the Central Valley of California. Areas invaded by yellow starthistle were treated with clopyralid, and the presence and cover of all species was monitored for 2 yr. There were significant differences in species cover between treated and untreated plots 2 yr after treatment (P 5 0.0001). These included a decline in cover of yellow starthistle and other native and exotic members of the Asteraceae and Apiaceae families in both years and a decline of exotic members of the Fabaceae family in the second year. There also were decreases in the frequency of the Asteraceae (P , 0.0001), Apiaceae (P , 0.05), Fabaceae (P , 0.05), and Polygonaceae (P , 0.05) families 1 yr after treatment, and the Asteraceae (P , 0.05) and Fabaceae (P , 0.05) families 2 yr after treatment. We also observed a significant negative effect of clopyralid on fecundity measures of a native Viola species during the first year of application (P 5 0.0074). This effect did not persist into the second year, when violets were more common and produced more flowers in treated plots (0.02 , P , 0.05).

Biomolecular relationships among isolates ofTomato Yellow Leaf Curl Tanzania Virus

An investigation of the biological properties of the virus causing tomato yellow leaf curl disease in Tanzania was initiated to compare it with other known tomato yellow leaf curl viruses. Properties relating to acquisition and inoculation feeding time, persistence, mechanical inoculation, seed transmission and host range were studied. Results obtained indicate that the virus was transmitted persistently byBemisia tabaci Genn., but it was not mechanically, sap- or seed-transmissible. Minimum acquisition and inoculation feeding time was 30 min.Capsicum annuum, Datura stramonium, Nicotiana glutinosa, N. tabacum andLycopersicon esculentum were found to be hosts of the virus among the plant species tested, whereasPhaseolus vulgaris was not. It is concluded that the properties of the agent causing yellow leaf curl symptoms in tomato plants from different regions in Tanzania are similar to those ofTomato yellow leaf curl Sardinia virus species studied elsewhere.

A nonheme iron(II) complex that models the redox cycle of lipoxygenase.

The air-stable complex [Fe(6-Me3-TPA) (O2CAr)]+ [1; 6-Me3-TPA = tris(6-methyl-2-pyridylmethyl)amine] has been synthesized as a model for the iron(II) site of lipoxygenase. This iron(II) complex reacts with 0.5 equiv ROOH to form a yellow species, which has been formulated as [FeIII(OH)(6-Me3-TPA) (O2CAr)]+ (2) by electrospray mass spectrometry. Addition of more ROOH converts 2 into a purple species, which is characterized by electrospray ionization mass spectrometry and resonance Raman spectroscopy as [FeIII(OOR)(6-Me3-TPA)(O2CAr)]+. The purple species is metastable and decomposes via Fe-O bond homolysis to regenerate the starting iron(II) complex. These metal-centered transformations parallel the changes observed for lipoxygenase in its reaction with its product hydroperoxide.

Spectrophotometric Determination of Some Phenolic Antibiotics in Dosage Forms

A simple and sensitive spectrophotometric method is described for the determination of some phenolic antibiotics namely: cefadroxil, amoxicillin and vancomycin. The method is based on the measurement of the orange yellow species produced when the drugs are coupled with diazotized benzocaine in triethylamine medium. The method is applicable over the range of 0.8–12 μg/ml for cefadroxil, 2–16 μg/ml for amoxicillin and 2–18 μg/ml for vancomycin. The formed compounds absorb at 455 nm for both cefadroxil and amoxicillin and at 442 nm for vancomycin. The proposed method has detection limits of 0.018 μg for cefadroxil, 0.0034 μg for amoxicillin and 0.0156 μg for vancomycin. The stoichiometric ratio for the studied compounds was found to be 1:1 and a proposal of the reaction pathway was made. The proposed method was applied for the analysis of the cited drugs in their pharmaceutical preparations. The results are in good agreement with those obtained by the official methods.

Unusual Oxidative Chemistry ofNω-Hydroxyarginine and N-Hydroxyguanidine Catalyzed at an Engineered Cavity in a Heme Peroxidase

Heme enzymes are capable of catalyzing a range of oxidative chemistry with high specificity, depending on the surrounding protein environment. We describe here a reaction catalyzed by a mutant of cytochrome c peroxidase, which is similar but distinct from those catalyzed by nitric-oxide synthase. In the R48A mutant, an expanded water-filled cavity was created above the distal heme face. N-hydroxyguanidine (NHG) but not guanidine was shown to bind in the cavity with K(d) = 8.5 mM, and coordinate to the heme to give a low spin state. Reaction of R48A with peroxide produced a Fe(IV)=O/Trp(.+) center capable of oxidizing either NHG or N(omega)-hydroxyarginine (NHA), but not arginine or guanidine, by a multi-turnover catalytic process. Oxidation of either NHG or NHA by R48A did not result in the accumulation of NO, NO(2)(-), NO(3)(-), urea, or citrulline, but instead afforded a yellow product with absorption maxima of 257 and 400 nm. Mass spectrometry of the derivatized NHA products identified the yellow species as N-nitrosoarginine. We suggest that a nitrosylating agent, possibly derived from HNO, is produced by the oxidation of one molecule of substrate. This then reacts with a second substrate molecule to form the observed N-nitroso products. This complex chemistry illustrates how the active sites of enzymes such as nitric-oxide synthase may serve to prevent alternative reactions from occurring, in addition to enabling those desired.

Reactivity of sulfur nucleophiles towards S-nitrosothiols

Rate constants have been measured for the reactions of a range of S-nitrosothiols with the following sulfur-centred nucleophiles: sulfite ion, thiourea, thiocyanate ion, thiosulfate ion, thiomethoxide ion and sulfide ion. Many of the reactions were very fast and were followed in a stopped-flow spectrophotometer. For the sulfite reaction the reactive species over the pH range 4–8 was shown to be exclusively SO32−. For two RSNO species the reactivity sequence was established as: SO32− > MeS− > S2O32− ≫ SC(NH2)2 > SCN−. The reaction with sulfide ion was also rapid and generated a fairly stable yellow species (λmax 410 nm), which was probably the nitrosodisulfide ion ONSS−, but the absorbance–time data were too complex for a simple kinetic analysis. This reaction could have some potential as an analytical procedure for the determination of RSNO species. The kinetic results are discussed in terms of the factors affecting nucleophilicity and are compared with the corresponding reactions of other nitrosating species.

Spectrophotometric determination of Sn(II) using palladium chloride in kits for 99mTc radiopharmaceuticals

A method of quantitating Sn(II) suitable for the analysis of kits for 99mTc radiopharmaceuticals, based on a spectrophotometric determination using the Pd(II)–Sn(II) complex (yellow species) is described. The absorbance of the complex is measured at 410 nm and Beer's law is obeyed up to 250 μg Sn (II) in the aqueous phase. Several radiopharmaceutical kits were analyzed for their Sn(II) content. The investigation indicates that the procedure is simple, rapid and accurate for quantitative estimation of Sn(II) in various 99mTc-labelling kits during development, manufacture and storage.

Phenetic distinction between the dwarf yellow water-lilies: Nuphar microphylla and N. pumila (Nymphaeaceae)

Nuphar pumila (Timm) DC. and Nuphar microphylla (Pers.) Fern. are morphologically similar yellow water-lily species that are often regarded as conspecific or recognized as varieties of Nuphar lutea (L.) Sm. This phenetic study analyzes 18 features of vegetative, floral, and fruit morphology scored from North American populations of N. microphylla and Eurasian populations of N. pumila. Morphological similarities among specimens were assessed by univariate statistics, clustering by the unweighted pair group method using arithmetic averages (UPGMA), and ordination by principal components analyses. Means for 17 of the 18 quantitative variables differed significantly between operational taxonomic units (OTUs) of the two species, and an UPGMA phenogram provided good separation of OTUs. Principal components analysis also provided reasonable separation of OTUs, indicating leaf and fruit characters as strong distinguishing features. Multivariate analyses indicate two similar, yet distinct, morphological entities. When coupled with qualitative features, geographical barriers, and putative physiological barriers, morphometric data support the taxonomic recognition of two closely related species. Both species are most closely related to the Japanese endemic Nuphar japonica DC.Key words: Nuphar, Nymphaeaceae, water-lily, taxonomy, phenetics.

Combined removal of SO2, H2S and NOX from gas streams by chemical absorption with aqueous solution of 12-molybdophosphoric acid and its reduced species

Selective removal of SO2, H2S and NOx from gas streams (air or towngas) was investigated using aqueous solutions of 12-molybdophosphoric acid and its reduced molybdenum blue species. The experimental results showed that H2S and SO2 in the gas streams can be removed quantitatively by yellow solution of 12-molybdophosphoric acid. The H2S was oxidized into recoverable elemental sulfur and SO2 into H2SO4, while the yellow solution was reduced into blue species (reduced molybdenum blue). The obtained reduced molybdenum blue solution was then used for the quantitative removal of NOx, which was reduced into N2 and the blue solution was then oxidized back into yellow species. It is possible that the regenration of scrubbing solution is not required and no chemical is consumed during absorption, when NOx, SO2 and/or H2S coexisted in wastegases and the molar ratios of NO2/(SO2 + H2S) is just equal to 1/2, although, in most cases, the ratio in real practical wastegases is not always equal to the value. The absorption mechanism was studied in detail. It was found that only one molybdenum atom in 12-molybdophosphoric acid was reduced from Mo(VI) to Mo(V) by H2S or H2SO3 and the Mo(V) was oxidized back into Mo(VI) in the case of Nox absorption. 12-molybdophsophoric acid used in this work is inexpensive, commercially available, easily regeneratable, relatively nontoxic, and gives no secondary pollutant in the process.