Astaxanthin as a King of Ketocarotenoids: Structure, Synthesis, Accumulation, Bioavailability and Antioxidant Properties.

Astaxanthin (3,3-dihydroxy-ß, ß-carotene-4,4-dione) is a ketocarotenoid synthesized by Haematococcus pluvialis/lacustris, Chromochloris zofingiensis, Chlorococcum, Bracteacoccus aggregatus, Coelastrella rubescence, Phaffia rhodozyma, some bacteria (Paracoccus carotinifaciens), yeasts, and lobsters, among others However, it is majorly synthesized by Haematococcus lacustris alone (about 4%). The richness of natural astaxanthin over synthetic astaxanthin has drawn the attention of industrialists to cultivate and extract it via two stage cultivation process. However, the cultivation in photobioreactors is expensive, and converting it in soluble form so that it can be easily assimilated by our digestive system requires downstream processing techniques which are not cost-effective. This has made the cost of astaxanthin expensive, prompting pharmaceutical and nutraceutical companies to switch over to synthetic astaxanthin. This review discusses the chemical character of astaxanthin, more inexpensive cultivating techniques, and its bioavailability. Additionally, the antioxidant character of this microalgal product against many diseases is discussed, which can make this natural compound an excellent drug to minimize inflammation and its consequences.

Quality of life after coronary artery bypass graft & percutaneous transluminal coronary angioplasty: A follow up study from India.

Coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) are treatments of choice for coronary artery disease. Quality of life (QoL) is an important factor in determining optimum treatment. This study was aimed to compare changes in QoL, six months post procedure, between CABG and PTCA, and to understand the confounding effect of various contributing factors. Thirty stable angina patients each in CABG and PTCA groups, were followed up for six months. QoL was assessed with WHO-QoL-BREF. Depression was rated on the Hamilton Depression Rating Scale. Changes in QoL and depression within and between CABG and PTCA groups were compared. Multinomial logistic regression was used to measure the predictive strength of treatment type (CABG and PTCA) on QoL, controlling for significant confounders. Although scores of QoL and depression significantly changed over time in both the groups, time×group interaction did not reach to a significance. Significant confounding effects of diabetes (P<0.01), hypertension (P<0.05) and diet restriction (P<0.05) were found. Controlling for confounding effects of these factors, group distribution to PTCA, compared to CABG, significantly predicted greater improvements in QoL (P<0.01).

Conformational order of n-alkyl modified silica gels as evaluated by Fourier transform infrared spectroscopy.

The conformational behaviour of non-deuterated and selectively deuterated alkyl modified silica gels in the dry state is examined by variable temperature FT IR spectroscopy. In the present study, three systems are considered, which are distinguished by the length of the tethered alkyl chains (C9Hl9-, C18H37-, C22H45-). The desired information is obtained by the analysis of various conformational-sensitive IR bands, including CH2 wagging, CD2 stretching and CD2 rocking bands. The analysis of the CH2 wagging bands provides the relative amounts (i.e., integral numbers over the whole chain) of the kink/gauche-trans-gauche, double-gauche and end-gauche conformers in the tethered alkyl chains. From the analysis of the CD2 stretching and CD2 rocking bands information about the conformational order at a specific deuterated methylene segment is available. Here, the CD2 rocking band data are used to determine the amount of gauche conformers at the deuterated carbon positions C-4 and C-6, and C-12. It is found that the conformational order critically depends on the actual alkyl chain length, chain position and sample temperature. Particular emphasis is given to the impact of the external pressure during sample preparation on the alkyl chain conformations, about which so far no information is available. It is observed that the samples prepared as KBr pellets, which experienced a pressure of about 10 kbar, are characterised by a lower amount of gauche conformers. This substantial increase of conformational order is attributed to better alkyl chain packing along with a gain of intermolecular chain interactions.