Morphological and molecular characterization of somaclonal variations in tissue culture-derived banana plants

AbstractIn this study, 40000 tissue culture-derived banana plants (vitroplants) at different growth stages, i.e. acclimatization, nursery and open field of banana (Musa spp.) cultivar ‘Grand Naine’ were screened for somaclonal variations using morphological investigations and molecular characterization. The total detected variants were grouped into 25 off-types (two of them died) in addition to the normal plant. Random Amplified Polymorphic DNA (RAPD) was carried out to study the differences among the normal cultivar ‘Grand Naine’ and its 23 variants using 17 arbitrary primers. Cluster analysis results revealed that ‘winged petiole’ and ‘deformed lamina’ were more related to the normal plant. However, ‘Giant plant’ and ‘weak plant’ related to each other and clustered with normal plant. According to principal coordinate analysis, most of the variants were aggregated nearly, whereas ‘variegated plant’ was separated apart from the other variants. This may reflect the genetic difference between ‘variegated plant’ and the other variants. The results obtained from both molecular and morphological analyses were in contiguous with better resolution when using the PCOORDA analysis than cluster analysis. Thus, it can be said that molecular markers can be used to eliminate the undesirable somaclonal variants from the lab without additional culture of the vitroplants in the field in order to save time and efforts

Rehybridization dynamics into the pericyclic minimum of an electrocyclic reaction imaged in real-time

Electrocyclic reactions are characterized by the concerted formation and cleavage of both σ and π bonds through a cyclic structure. This structure is known as a pericyclic transition state for thermal reactions and a pericyclic minimum in the excited state for photochemical reactions. However, the structure of the pericyclic geometry has yet to be observed experimentally.We use a combination of ultrafast electron diffraction and excited state wavepacket simulations to image structural dynamics through the pericyclic minimum of a photochemical electrocyclic ring-opening reaction in the molecule α-terpinene. The structural motion into the pericyclic minimum is dominated by rehybridization of two carbon atoms, which is required for the transformation from two to three conjugated π bonds. The σ bond dissociation largely happens after internal conversion from the pericyclicminimum to the electronic ground state. These findings may be transferrable to electrocyclic reactions in general

(E)-1-[5-Methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-3-(4-nitrophenyl)prop-2-en-1-one

The title compound, C19H16N4O3, crystallizes with two molecules (A and B) in the asymmetric unit. In molecule A, the dihedral angles between the triazole ring and the toluyl and nitrobenzene rings are 62.68 (16) and 10.77 (15)°, respectively. The corresponding data for molecule B are 68.61 (17) and 15.59 (15)°, respectively. In the crystal, the B molecules are linked by C—H...N hydrogen bonds to generate [001] chains. Weak C—H...π(benzene) and N—O...π(triazole) contacts are also present

5-Methyl-N'-(5-methyl-1-phenyl-1H-1,2,3-triazole-4-carbonyl)-1-phenyl-1H-1,2,3-triazole-4-carbohydrazide

The asymmetric unit of the title compound, C20H18N8O2, comprises one complete molecule and a half molecule completed by crystallographic twofold symmetry leading to Z = 12. The dihedral angles between the planes of the linked phenyl and methyltriazolyl groups are 69.48 (5) and 44.85 (9)° for the first molecule and 42.88 (9)° for the second. The conformations of the diformyl hydrazyl groups of the molecules are similar as indicated by C—N—N—C torsion angles of −83.4 (2) and −86.4 (3)°. In the crystal, neighbouring molecules are linked by pairs of N—H...O hydrogen bonds to form independent columns propagating parallel to the c-axis direction

4-(4-Bromophenyl)-2-(3-(4-chlorophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)-1,3-thiazole

The asymmetric unit of the title compound, C37H28BrClN8S, comprises one molecule. The molecule consists of two ring systems joined by a C—C bond between the dihydropyrazolyl and pyrazolyl rings of the two extended ring systems. The angles between adjacent ring planes of the tolyl–triazolyl–pyrazolyl–phenyl ring system are 48.2 (1), 12.3 (2) and 22.2 (2)°, respectively, with angles of 19.7 (1), 5.6 (2) and 0.9 (2)° between the rings of the chlorophenyl–thiazolyl–dihydropyrazolyl–bromophenyl set. The pyrazolyl and dihydropyrazolyl rings are inclined at 68.3 (1)° to one another. In the crystal, C—H...Cl interactions form chains of molecules parallel to the b-axis direction

1-{2-Anilino-4-methyl-5-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazole-4-carbonyl]thiophen-3-yl}ethanone

In the title compound, C24H22N4O2S, the dihedral angle between the triazole and thiophene rings is 4.83 (14)°. The dihedral angles between the triazole and tolyl rings and between the thiophene and phenyl rings are 48.42 (16) and 9.23 (13)°, respectively. An intramolecular N—H...O hydrogen bond closes an S(6) loop. In the crystal, molecules are stacked parallel to the a-axis direction with weak π–π interactions between adjacent thiophenyl and triazolyl groups within the stack [centroid–centroid separation = 3.9811 (16) Å]

4-(4-Bromophenyl)-2-(3-(4-chlorophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)-1,3-thiazole

The asymmetric unit of the title compound, C37H28BrClN8S, comprises one molecule. The molecule consists of two ring systems joined by a C—C bond between the dihydropyrazolyl and pyrazolyl rings of the two extended ring systems. The angles between adjacent ring planes of the tolyl–triazolyl–pyrazolyl–phenyl ring system are 48.2 (1), 12.3 (2) and 22.2 (2)°, respectively, with angles of 19.7 (1), 5.6 (2) and 0.9 (2)° between the rings of the chlorophenyl–thiazolyl–dihydropyrazolyl–bromophenyl set. The pyrazolyl and dihydropyrazolyl rings are inclined at 68.3 (1)° to one another. In the crystal, C—H...Cl interactions form chains of molecules parallel to the b-axis direction

Conformer-specific photochemistry imaged in real space and time

Conformational isomers (conformers) of molecules play a decisive role in biology and organic chemistry. However, experimental methods for investigating chemical reaction dynamics are typically not conformersensitive. We report on a gas-phase megaelectronvolt ultrafast electron diffraction investigation of a-phellandrene undergoing an electrocyclic ring-opening reaction. We directly imaged the evolution of a specific set of a-phellandrene conformers into the product isomer predicted by the Woodward-Hoffmann rules in real space and time. Our experimental results are in quantitative agreement with nonadiabatic quantum molecular dynamics simulations, which provide considerable detail of how conformation influences the time scale and quantum efficiency of photoinduced ring-opening reactions. Supplemental files attached

2-(5-Methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-5-phenyl-1,3,4-oxadiazole

The asymmetric unit of the title compound, C17H13N5O, comprises four independent molecules (A–D). The respective interplanar angles between the phenyl/oxadiazole/methyltriazole/phenyl rings for the four independent molecules are A 8.8 (2), 13.0 (2), 22.5 (2)°; B 6.3 (2), 8.9 (2), 29.0 (1)°; C 4.0 (2), 10.0 (2), 24.5 (2)°; D 3.5 (2), 10.1 (2), 27.2 (2)°. In the crystal, molecules form two separate stacks parallel to the b-axis direction: one consists of A and D molecules, and the other of B and C molecules. Aromatic π–π stacking is observed within each stack, with the shortest centroid–centroid separation being 3.552 (2) Å

4-(4-Bromophenyl)-2-(3-(4-bromophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)-1,3-thiazole

In the title compound, C37H28Br2N8S, the dihedral angles between the planes of tolyl–triazolyl–pyrazolyl–phenyl rings are 47.5 (1), 11.4 (2) and 22.4 (2)°, respectively, and the angles between the bromophenyl–thiazolyl–dihydropyrazolyl–bromophenyl rings are 16.0 (2), 5.1 (2) and 0.8 (2)°, respectively. The dihedral angle between the planes of the pyrazolyl and dihydropyrazolyl rings is 67.7 (1)°. In the crystal, weak C—H...Br interactions form chains of molecules propagating in the [010] direction