The anthocyanins of sunflower

The extraction process of red pigments from the husks of a cultivar of sunflower has been studied. It has been shown that a fraction containing circa 80% of the starting pigments could be obtained by grinding. Best extractions were obtained with distilled water-organic solvent mixtures of intermediate polarity values. The extraction yields are strongly influenced by the pH and the solvent/powder ratio and reach the maximum after about 2 hr.
The experimental data showed that the greater part of the pigments, readily precipitable by acidification to pH 2.0, are bonded to a macromolecule, probably of protein nature, as confirmed by electrophoresis.     

Anthocyanins of Sunflower (Helianthus annuus)

The presence of anthocyanins in the achenes of some varieties of sunflower was ascertained for the first time. The two major pigments were identified as Pn-3-divanillylsambubioside and Cy-3-vanillylsambubioside. For two other pigments present in smaller quantities, a tentative identification awaiting confirmation was made and the constituents were identified. Traces were found of five other pigments for which chromatographic data are presented.     

Purification and Characterization of α-Galactosidase from Feijão bean Phaseolus vulgaris

α-Galactosidase is an important enzyme which degrades galactooligosaccharide in legumes. α-Galactosidase from feijão beans was purified and its characteristics established. The purified enzyme exhibits multiple forms –enzymes I and II with molecular weights of 140,000 and 49,000 daltons, respectively. Optimum pH was 5.5 for enzyme I and 6.0 for enzyme II. Optimum temperature for both was 55°C. Kinetically, enzyme I is more reactive. Heavy metal ions completely inhibited both enzymes I and II. Galactose is a potential inhibitor for both enzymes.     

Characterization of the Porous CaO Particles Formed by Decomposition of CaCO3 and Ca(OH)2 in Vacuum

The solid products of decomposing CaCO₃ powder in vacuum at 510°C (sr-CaO) and of decomposing Ca(OH)₂ powder at 320°C in vacuum (h-CaO) are particles which have approximately the same exterior dimensions as the parent CaCO₃ or Ca(OH)₂ particles. N₂ adsorption and desorption isotherms show that sr-and h-CaO have high internal surface areas which for sr-CaO have cylindrical symmetry, with the most common diameters being ∼ 10 nm, and for h-CaO are slit-shaped, with the most common slit width being ∼ 2.7 nm. The conclusions reached in earlier investigations, i.e that these decomposition reactions in vacuum initially yield a form of CaO which has the same unit cell dimensions as the parent solid, were in error, probably because water vapor converts much of the CaO to poorly crystalline Ca(OH)₂ before XRD measurements can be completed in air. From the volume of N₂ adsorbed by the porous powders, the porosity of h-CaO is calculated to be 36±5% and of sr-CaO 41.5±5%. These porosities imply that the linear dimensions of the 1 to 20 μm particles of h-CaO and sr-CaO are ∼5% smaller than those of the parent particles. XRD measurements made as a function of time show that particle shrinkage must occur by cooperative, diffusionless movement of crystallites of sr-CaO or h-CaO as they form.     

Contact X‐ray microscopy of living cells by using LiF crystal as imaging detector

In this paper, the use of lithium fluoride (LiF) as imaging radiation detector to analyse living cells by single‐shot soft X‐ray contact microscopy is presented. High resolved X‐ray images on LiF of cyanobacterium Leptolyngbya VRUC135, two unicellular microalgae of the genus Chlamydomonas and mouse macrophage cells (line RAW 264.7) have been obtained utilizing X‐ray radiation in the water window energy range from a laser plasma source. The used method is based on loading of the samples, the cell suspension, in a special holder where they are in close contact with a LiF crystal solid‐state X‐ray imaging detector. After exposure and sample removal, the images stored in LiF by the soft X‐ray contact microscopy technique are read by an optical microscope in fluorescence mode. The clear image of the mucilaginous sheath the structure of the filamentous Leptolyngbya and the visible nucleolus in the macrophage cells image, are noteworthiness results. The peculiarities of the used X‐ray radiation and of the LiF imaging detector allow obtaining images in absorption contrast revealing the internal structures of the investigated samples at high spatial resolution. Moreover, the wide dynamic range of the LiF imaging detector contributes to obtain high‐quality images. In particular, we demonstrate that this peculiar characteristic of LiF detector allows enhancing the contrast and reveal details even when they were obscured by a nonuniform stray light.