Aluminum separation from drinking water and serum samples based on djenkolic acid immobilized on the multi walled carbon nanotubes by ultrasound-assisted dispersive micro solid phase extraction

A new method for aluminum extraction from drinking water and human serum samples was used by djenkolic acid (DJKA) immobilized on multi-walled carbon nanotubes (MWCNTs-DJKA). In the optimized study, LOD, LOQ, the linear range, the working range, and the enrichment factor were obtained 0.1 µg L−1, 0.3 µg L−1, 0.3-12.8 µg L−1, 0.3-30.7 µg L−1 and 9.92, respectively (RSD< 5%). The adsorption capacity of the MWCNTs-DJKA and MWCNTs sorbent was achieved 122.6 mg g-1 and 33.7 mg g-1 in the batch system for 20 min, respectively. The mean aluminum in drinking water and serum samples were obtained 48.56 ± 2.92 and 11.64 ± 0.73 which was lower than the reference value in drinking water and human biological samples. The method was validated by spiking samples and standard reference materials (SRM) in water and human biological samples.

Three Different Systems Participate in l-Cystine Uptake in Bacillus subtilis

ABSTRACT The symporter YhcL and two ATP binding cassette transporters, YtmJKLMN and YckKJI, were shown to mediate l-cystine uptake in Bacillus subtilis. A triple ΔyhcL ΔytmJKLMN ΔyckK mutant was unable to grow in the presence of l-cystine and to take up l-cystine. We propose that yhcL, ytmJKLMN, and yckKJI should be renamed tcyP, tcyJKLMN, and tcyABC, respectively. The l-cystine uptake by YhcL (Km = 0.6 μM) was strongly inhibited by seleno-dl-cystine, while the transport due to the YtmJKLMN system (Km = 2.5 μM) also drastically decreased in the presence of dl-cystathionine, l-djenkolic acid, or S-methyl-l-cysteine. Accordingly, a ΔytmJKLMN mutant did not grow in the presence of 100 μM dl-cystathionine, 100 μM l-djenkolic acid, or 100 μM S-methyl-l-cysteine. The expression of the ytmI operon and the yhcL gene was regulated in response to sulfur availability, while the level of expression of the yckK gene remained low under all the conditions tested.

Powder X-ray characterization of djenkolic acid

X-ray powder diffraction data for the orthorhombic natural amino acid djenkolic acid, C7H14N2O4S2, is described in this paper. The orthorhombic cell parameters are: a=8.12 Å, b=12.16 Å, and c=5.38 Å

Synthesis of 35S-labelled djenkolic acid

[no abstract available]