Small RNAs are important regulators of genome function, yet their prediction in genomes is still a major computational challenge. Statistical analyses of pre-miRNA sequences indicated that their 2D structure tends to have a minimal free energy (MFE) significantly lower than MFE values of equivalently randomized sequences with the same nucleotide composition, in contrast to other classes of non-coding RNA. The computation of many MFEs is, however, too intensive to allow for genome-wide screenings.
Granular starch was cross-linked with 1,3-di-O-acetyl-2-nitro-1,3-propanediol (1), 1,3-di-O-pivaloyl-2-nitro-1,3-propanediol (2), 2-nitro-3-O-pivaloyl-1-propene-3-ol (3), 1,3-di-O-acetyl-aci-2-nitro-1,3-propanediol (4), 1,3-di-O-pivaloyl-aci-2-nitro-1,3-propanediol (5) and 1,6-di-O-acetyl-2,5-dinitro-1,6-hexanediol (6). The bifunctional precursors for the nitro-alkenes 1, 2, 3, and 4 were readily synthesized in high yields from nitromethane, paraformaldehyde and acetic anhydride (1, 3) or pivaloyl chloride (2, 4), respectively. The reaction rate for the cross-linking was very high, and for 1 and 3, the reaction reached completion within 1 h (at room temperature). The swelling capacities of the products obtained when starch was cross-linked with precursors for the nitroalkenes 1-4 and 6 were lower in comparison to epichlorohydrin cross-linked starch. These results indicate a high reaction efficiency at low degrees of substitution. Cross-linked 2-nitroalkyl starch ethers were synthesized in a one-pot synthesis by addition of 1 or 3 and 2-nitroalkyl acetates to granular suspensions of starch. Copyright (C) 1998 Elsevier Science Ltd.
Production of dry encapsulated forms of anthocyanins from tulip petals with high antioxidant activity and their utilization in lipsticks.Anthocyanins (of the Greek anthos = flower and kianos = blue) are the most important pigments of the plants. These pigments are responsible of the shiny orange, pink, red, violet and blue colors in the flowers and fruits of some plants. The most interesting substances of the waste material are anthocyanins as natural water soluble antioxidants with a great health benefit besides the coloring properties. Tulip is a perennial bulbous plant which is popular worldwide and especially in the Holland due to the showy flowers of the great variety of colors and shades. It was found that for flowers of different colors biosynthesis of anthocyanins of the three anthocyanidin backbones may occur. Thus, pelargonidin (Pg), cyanidin (Cy) and delphinidin (Dp) derivatives, are responsible for tulip flowers color.
