Seasonal dependence of cadmium molecular effects on Mytilus galloprovincialis (Lamarck, 1819) protamine-like protein properties

Mussels have a seasonal reproduction and cadmium is a common stressor in estuarine and coastal environments. In previous studies, we have shown that exposure to subtoxic doses of cadmium produced alterations in the properties of winter Mytilus galloprovincialis sperm protamine-like (PL) proteins. In this study, it was analyzed the possibility that these cadmium effects may be seasonal. Winter and summer mussels were exposed to CdCl2 , and it was tested the PL-proteins for cadmium bioaccumulation, electrophoretic pattern, DNA binding, and potentiality to induce DNA oxidative damage. It was found that cadmium exposure did not produce the same effects on PL-proteins of summer mussels that were produced on PL-proteins of winter mussels, that is: cadmium bioaccumulation, alterations in the acetic acid-urea polyacrylamide gels (AU-PAGE) and sodium dodecyl sulfate-PAGE pattern, a reduced DNA binding affinity and the ability to induce DNA oxidative damage. PL-proteins from summer mussels, apart from not being affected by all the abovementioned effects of cadmium, also showed a very low DNA binding affinity, independent of cadmium exposure. This study reveals clock-associated seasonal responses to cadmium in M. galloprovincialis. Understanding the mechanisms through which environmental signals guide biological rhythms is fundamental to understanding the seasonal sensitivity of this bioindicator, to use M. galloprovincialis in appropriate seasonal periods

Various physical-chemical properties of AML and its photodegradation products, and their estimated removal with sewage sludge based on QSAR (EPI Suite).

a<p>Octanol-water partition coefficient (criteria: log K_ow <1 highly soluble in water (hydrophilic);>4 not very soluble in water (hydrophobic)).</p>b<p>Soil organic carbon-water partitioning coefficient (criteria: log K_oc <1.5 negligible sorption to sludge, rapid migration to ground water; 1.5–2.4 low sorption to sludge, moderate migration to ground water; 2.5–3.4 moderate sorption to sludge, slow migration to ground water; 3.5–4.4 strong sorption to sludge, negligible to slow migration to ground water).</p><p>Various physical-chemical properties of AML and its photodegradation products, and their estimated removal with sewage sludge based on QSAR (EPI Suite).</p

Phototransformation of Amlodipine: Degradation Kinetics and Identification of Its Photoproducts

<div><p>Nowadays, monitoring focuses on the primary compounds and does not include degradation products formed during various biological and chemical processes. Transformation products may have the same effects to human health and the environment or sometimes they can be more toxic than the parent compound. Unfortunately, knowledge about the formation of degradation products is still limited, however, can be very important for the environmental risk assessment. Firstly, the photodegradation kinetic of amlodipine was investigated in two experimental conditions: during the exposure to solar radiation and during the exposure to the light emitted by the xenon lamp. In all cases degradation of amlodipine followed a pseudo-first-order kinetics. In the next step, identification of transformation products of amlodipine formed during the exposure to xenon lamp irradiation was performed using ultra high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). As a result sixteen photoproducts were identified, their structures were elucidated and ultimately the transformation pathway was proposed. Fifteen compounds (out of 16 photoproducts) were newly identified and reported here for the first time; some of those compounds were formed from the first photoproduct, amlodipine pyridine derivative. Several analytes were formed only in acidic or basic conditions. Furthermore, the occurrence of amlodipine and its identified degradation products was investigated in environmental waters. Only one out of 16 compounds was found in wastewater effluent. The possibility of the sorption of examined analytes to sewage sludge particles was discussed based on QSAR.</p></div

MS/MS spectrum of AML 2 with proposed structures of each fragment ion.

<p>MS/MS spectrum of AML 2 with proposed structures of each fragment ion.</p

Kinetic curves for AML obtained for various conditions: exposure to xenon lamp irradiation (a) and exposure to natural sunlight including eight different matrices (b).

<p>Kinetic curves for AML obtained for various conditions: exposure to xenon lamp irradiation (a) and exposure to natural sunlight including eight different matrices (b).</p

Proposed photodegradation pathway of amlodipine.

<p>Proposed photodegradation pathway of amlodipine.</p