High-performance liquid chromatographic determination of citropten and bergapten in suction blister fluid after solar product application in humans

Citropten (5,7-dimethoxycoumarin) and bergapten (5-methoxypsoralen) are present in bergamot oil which is used as a tanning cosmetic product. The aim of this study was to quantify, using high-performance liquid chromatography, the amount of citropten and bergapten in the skin after suntan products application (an emulsion and an oil formulation). A suction blister technique performed of the anterior aspect of the forearm permitted the collection of these two accumulated molecules. Fluorometric and ultraviolet detections were used for citropten and bergapten determinations, respectively.     

Silane adsorption onto cellulose fibers: hydrolysis and condensation reactions

The hydrolysis of three alkoxysilane coupling agents, gamma-methacryloxypropyltrimethoxysilane (MPS), gamma-aminopropyltriethoxysilane (APS), and gamma-diethylenetriaminopropyltrimethoxysilane (TAS), was carried out in an ethanol/water (80/20) solution and followed by 1H, 13C, and 29Si NMR spectroscopy, which showed that its rate increased in the order MPS < APS < TAS. The formation of the silanol groups was followed by their self-condensation to generate oligomeric structure. APS and MPS only gave soluble products, whereas colloidal particles precipitated in the medium when TAS was hydrolyzed. Pristine and hydrolyzed MPS were then adsorbed onto a cellulose substrate and thereafter a thermal treatment at 110-120 degrees C under reduced pressure was applied to the modified fibers to create permanent bonding of the coupling agent at their surface.     

Bioactive C15 acetogenins from the red alga Laurencia obtusa

The petroleum ether extract of the red alga Laurencia obtusa afforded three new C(15) acetogenins (cyclic ether enyne): (12Z)-cis-maneonene-D (1), (12E)-cis-maneonene-E (2), and (12Z)-trans-maneonene-C (3), along with one known cis-maneonene-A (4). Blood neutrophils were prepared, cultured, and incubated for 24, 48, and 72 h in medium with and without isolated compounds. Blood neutrophils were prepared, cultured, and incubated for 24, 48 and 72 h in medium with and without the isolated compounds. Both morphology and DNA fragmentation methods assessed the percentage of neutrophils apoptosis in each culture. In the present study, several observations have been made concerning the apoptosis-inducing or inhibiting effect of 1 and 2. Both compounds had no inhibition of apoptosis but apoptosis was enhanced significantly by aging. However, 1 stimulated apoptosis of normal only at the initial 24 h. After that there was no significant difference in apoptosis with or without compound 1, while 2 stimulated apoptosis at all the times. The apoptosis induced by these two compounds was demonstrated by DNA fragmentation assay and microscopic observation. These observations suggest that compounds 1 and 2 may be involved in regulation of programmed death in the initiation and propagation of inflammatory responses.     

Design and synthesis of a new fluorescent tripod for chemosensor applications

A new yellow-green fluorescent tripod based 1,8-naphthalimide has been synthesized and characterised. Its photophysical properties have been investigated in organic solvents of different polarity. The effect that the metal ions (Cd²⁺, Co²⁺, Zn²⁺, Mn²⁺, Mg²⁺, Ni²⁺, Pb²⁺, Cu²⁺, Ba²⁺, Fe³⁺ and Ag⁺) produce upon the fluorescent intensity of acetonitrile solutions of the tripod has been discussed viewing its potential applications as a detector for metal cations. The influence of protons on the fluorescence intensity of the tripod in DMF and methanol–water (1:4 v/v) solutions has also been investigated.     

Synthesis and voltammetric study of some new macrocyclic sulfur compounds for use as chelating agents for separation of arsenic (III) in wastewater and as molluscicidal agents against Biomophalaria Alexandrina Snails

A series of some new nanomeric molecules of cyclic 5- methoxy -5, 6–diaryl -4,5-dihydro -2H-1,2,4–triazin -3-thiones (1-3) has been synthesized. The interaction of compounds 1-3 with HgCl₂ in 1:1 and 1:2 molar ratios was used for the synthesis of the macrocyclic Schiff base [5,6, 11,12 - tetraaryl -1,2,4,7,8,10- hexa-aza cyclododoeca -4,6,10,12- tetraene -3,9-dithione] (4), macrocyclic thioethers 5 and/or complex 6. Chemical structures of the compounds were determined from elemental analysis and spectral measurements. The compounds were screened as molluscicidal agents against Biomophalaria Alexandrina Snails which cause Bilhariziasis. Cyclic voltammetry of selected compounds showed well-defined irreversible electrode couple suggesting application of these compounds as chelating agents for separation of arsenic in industrial wastewater samples. Compound 1 was physically immobilized onto polyurethane foams (PUFs) and was successfully used for complete removal of arsenic (III) & (V) species from wastewater.