Sequestration of aristolochic acids by the pipevine swallowtail, Battus philenor (L.): evidence and ecological implications

Summary. It has long been assumed that the North American pipevine swallowtail, Battus philenor (L.) (Papilionidae, Troidini), is protected from natural enemies by aristolochic acids sequestered from its Aristolochia food plants. This study confirmed that populations of B. philenor from Virginia and east Texas sequester these compounds. A comparison of the aristolochic acid profiles of the Virginia butterflies and their A. macrophylla food plants revealed several differences. The aristolochic acid fraction of the foliage was dominated by aristolochic acids I and II, whereas the insects had a much lower proportion of aristolochic acid II and contained, in addition, substantial amounts of aristolochic acids Ia and IVa, which were not detected in the plants. The eggs, larval integument, osmeterial glands, pupal cuticle, and adults (wings and bodies) all contained aristolochic acids. These findings help explain the abundant ecological data indicating that both immature and adult B. philenor are unpalatable and protected from natural enemies. Received 7 April 2000; accepted 31 May 2000     

Predicting bioavailability of metals from sludge-amended soils

We attempted to develop a protocol for fixing the maximum permissible limit of sludge in agricultural lands based on transfer of metals from sludge-amended soils to human food chain. For this purpose, spinach was grown as a test crop on acid and alkaline soils with graded doses of sludge (0, 1.12, 2.24, 4.48, 8.96, 17.9, 35.8, 71.6, 142 and 285 g kg^?1 of soil) in a pot experiment. Biomass yield of spinach was increased due to sludge application in both acid and alkaline soils. Among the chemical extractants, EDTA extracted the highest amount of metals from sludge-amended soil followed by diethylenetriaminepentaacetic acid (DTPA) and CaCl₂. Elevated levels of Zn, Cu, Fe, Mn, Ni, Cd and Pb in spinach were observed due to sludge application over control. Application of sludge was more effective in increasing metal content in spinach grown on acid soil than alkaline soil. Solubility-free ion activity model as a function of pH, organic carbon and extractable metal was far more effective in predicting metal uptake by spinach grown on sludge-amended soils as compared to that of chemical extractants. Risk in terms of hazard quotient (HQ) for intake of metals through consumption of spinach by humans grown on sludge-treated soils was computed for different metals separately. In a 90-day pot experiment, safe rates of sludge application were worked out as 4.48 and 71.6 g kg^?1 for acid and alkaline soils, respectively.     

Application of enzyme-mediated cellulose nanofibers from lemongrass waste for the controlled release of anticancer drugs

Environmental Science and Pollution Research - In the present study, an application of cellulose nanofibers has been established for the controlled release of an anticancer drug, i.e.,...     

Oviposition stimulant for the zebra swallowtail butterfly, Eurytides marcellus, from the foliage of pawpaw, Asimina triloba

Summary. We have isolated a caffeoylcyclohexane-1-carboxylic acid derivative, 3-caffeoyl-muco-quinic acid (3-CmQA), as a contact oviposition stimulant for the zebra swallowtail butterfly, Eruytides marcellus (Papilionidae), from the foliage of its primary host plant, Asimina triloba (Annonaceae). This compound alone was as active in stimulating oviposition by females as were the parent ethanolic plant extract and the host plant itself. Other tested isomers of 3-CmQA, including 5-caffeoylquinic acid (5-CQA or trans-chlorogenic acid), were inactive. We found, however, that experienced female butterflies responded strongly to host volatiles, which enhanced landing rates and hence oviposition.? This is the first report of an oviposition stimulant for a swallowtail butterfly of the tribe Graphiini. We found 3-CmQA to be the major caffeoylcyclohexane-1-carboxylic acid isomer in plants of the genus Asimina. These plants lack appreciable amounts of 5-CQA, which has been shown previously to be one of the oviposition stimulants for certain Rutaceae- or Apiaceae-feeding swallowtails of the related tribe Papilionini.? Our findings, along with earlier results from the tribes Troidini and Papilionini, suggest that responses by swallowtails to hydroxycinnamic acid derivatives as oviposition cues date back at least to the ancestor of the subfamily Papilioninae. Received 24 March 1998; accepted 27 May 1998.     

Assessment of chromium efficacy on germination,root elongation,and coleoptile growth of wheat (Triticum aestivum L.) at different growth periods

The tannery effluents contain a high concentration of chromium (Cr). It drastically reduces the crop yield when used for irrigation purpose. A huge volume of tannery effluents is available as irrigation for crop production. It is negatively affecting germination as well as yield of the crop. The wheat seeds were exposed to five different concentrations of Cr (0, 20, 40, 80, and 100 ppm). In Petri plates, 100 seeds were placed and the germination percent was recorded after 72 hour (h). Root elongation and coleoptile growth were measured at 72, 120, 168, and 240 h. Results showed that the germination percent of the test crop decreased with increasing Cr levels. It decreased by 6, 14, 30, and 37 % under the Cr concentration of 20, 40, 80, and 100 ppm, respectively. The root elongation was more sensitive than the coleoptile growth. The negative correlation was found between Cr levels and root elongation as well as coleoptile growth. These growth parameters were significantly affected up to 80 ppm of Cr level. The wheat growers using tannery effluent as irrigation should be well treated prior to application.     

Carbon capture,storage, and usage with microalgae: a review

Environmental Chemistry Letters - Global warming is induced partly by rising atmospheric carbon dioxide levels, calling for sustainable methods to sequester carbon. Here we review carbon capture,...     

Particle size distribution and its elemental composition in the ambient air of Delhi

This study examines the chemical composition of PM10, the thoracic fraction of the atmospheric particulate matter. An eight-stage Anderson impactor is used to separate the PM10 from other fractions with different aerodynamic behaviour at three different area representative sites in Delhi from February to May 1998. PM10 particulate are subdivided into two fractions, coarse (> 2.1-10 microns) and fine (< 2.1 microns). The concentrations of major heavy metals such as Pb, Zn, Cd, Ni, and Fe are determined by atomic absorption spectrophotometer. The average concentration of coarse fraction of PM10 is found to be 68.3 +/- 17 micrograms/m3 while the fine fraction of PM10 is 71.3 +/- 15 micrograms/m3 for Delhi. Metal concentration (except Fe) in fine fraction exceeds by a factor of up to 6, as compared to that in the coarse fraction. In order to identify the major sources of fine and coarse fraction of PM10, principle component analysis (PCA) was undertaken and three major sources were identified, namely vehicular emissions, industrial emission, and soil resuspension.