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Polymorphic DNA G-quadruplex recognition has attracted great interest in recent years. The strong binding affinity and potential enantioselectivity of chiral [Ru(bpy)2(L)]2+ (L=dipyrido[3,2-a:2′,3′-c]phenazine, dppz-10,11-imidazolone; bpy=2,2′-bipyridine) prompted this investigation as to whether the two enantiomers, Δ and Λ, can show different effects on diverse structures with a range of parallel, antiparallel and mixed parallel/antiparallel G-quadruplexes. These studies provide a striking example of chiral-selective recognition of DNA G-quadruplexes. As for antiparallel (tel-Na+) basket G-quadruplex, the Λ enantiomers bind stronger than the Δ enantiomers. Moreover, the behavior reported here for both enantiomers stands in sharp contrast to B-DNA binding. The chiral selectivity toward mixed parallel/antiparallel (tel-K+) G-quadruplex of both compounds is weak. Different loop arrangements can change chiral complex selectivity for both antiparallel and mixed parallel/antiparallel G-quadruplex. Whereas both Δ and Λ isomers bind to parallel G-quadruplexes with comparable affinity, no appreciable stereoselective G-quadruplex binding of the isomers was observed. In addition, different binding stoichiometries and binding modes for Δ and Λ enantiomers were confirmed. The results presented here indicate that chiral selective G-quadruplex binding is not only related to G-quadruplex topology, but also to the sequence and the loop constitution. [ABSTRACT FROM AUTHOR]

To understand the yellow - seed rape collected from Tibet China, variable coefficient and diversity index of 30 phenotypic characteristics of 16 Brassica rapa lines were investigated. Results indicated that except 3 traits ( petiole length, attaching pattern of stem - leaf and branching habits ), the average diversity index of the other 27 phenotypic characteristics was 1. 840, which was higher than 1. 709 as the rest of China. The variation coefficient (3. 92% to 52. 84%) also showed higher diversities. Based on principal component analysis, the ward method cluster analysis was chosen for establishing core collection and the Chi - square average distance was 0. 80. These 16 different yellow - seed lines were divided into 3 groups: Group I the longest pod - length and the most seed numbers per pod; Group II the highest branch height, the most primary branches and effective pod numbers; Group M the lowest branch height, the shortest effective blot length and the least effective pod numbers. In addition, the seed sizes of these yellow - seed materials were extremely large, and the colors of seed coat were rich [ABSTRACT FROM AUTHOR]

Polymorphic DNA G-quadruplex recognition has attracted great interest in recent years. The strong binding affinity and potential enantioselectivity of chiral [Ru(bpy)2 (L)](2+) (L=dipyrido[3,2-a:2',3'-c]phenazine, dppz-10,11-imidazolone; bpy=2,2'-bipyridine) prompted this investigation as to whether the two enantiomers, Δ and Λ, can show different effects on diverse structures with a range of parallel, antiparallel and mixed parallel/antiparallel G-quadruplexes. These studies provide a striking example of chiral-selective recognition of DNA G-quadruplexes. As for antiparallel (tel-Na(+)) basket G-quadruplex, the Λ enantiomers bind stronger than the Δ enantiomers. Moreover, the behavior reported here for both enantiomers stands in sharp contrast to B-DNA binding. The chiral selectivity toward mixed parallel/antiparallel (tel-K(+)) G-quadruplex of both compounds is weak. Different loop arrangements can change chiral complex selectivity for both antiparallel and mixed parallel/antiparallel G-quadruplex. Whereas both Δ and Λ isomers bind to parallel G-quadruplexes with comparable affinity, no appreciable stereoselective G-quadruplex binding of the isomers was observed. In addition, different binding stoichiometries and binding modes for Δ and Λ enantiomers were confirmed. The results presented here indicate that chiral selective G-quadruplex binding is not only related to G-quadruplex topology, but also to the sequence and the loop constitution., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)