Coumarin–nucleotide base pairs. Ultraviolet absorption, fluorescence, and photochemical study

1984 ◽  
Vol 62 (10) ◽  
pp. 2006-2010 ◽  
Author(s):  
Grażyna Wenska ◽  
Stefan Paszyc

Bichromophoric compounds containing a nucleotide base and coumarin linked with a polymethylene chain have been synthesized. A hypochromic effect was observed for adenine–coumarin pairs in contrast to the thymine containing compound. The fluorescence intensity of coumarin when bound into these systems was found to be significantly reduced. It has also been demonstrated that excitation energy is transferred from adenine or thymine to the coumarin moiety. Intermolecular dimerization of coumarin residues was observed upon irradiation of an adenine–coumarin pair.

2015 ◽  
Vol 127 (49) ◽  
pp. 14932-14935 ◽  
Author(s):  
Katharina Röttger ◽  
Hugo J. B. Marroux ◽  
Michael P. Grubb ◽  
Philip M. Coulter ◽  
Hendrik Böhnke ◽  
...  

Jurnal MIPA ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Claudius F. Kairupan ◽  
Jantje Pelealu ◽  
Juliet M.E. Mamahit

Daerah Modoinding dan Tomohon di Sulawesi Utara, dikenal sebagai  daerah penghasil sayuran kubis di Indonesia. Sayuran kubis memiliki hama utama yaitu Plutella xylostella. Penyebab serangga ini dapat bertahan hingga saat ini karena adanya sifat resistensi akibat pemberian insektisida yang berlebihan. Penelitian ini dilakukan untuk menganalisis variasi pada gen cytochrome C oxidase IPlutella xylostella yang diperoleh dari dua lokasi yang berbeda, yaitu Modoinding dan Tomohon. Analisis sekuens menunjukkan adanya perbedaan pasang basa nukleotida dari sampel yang berbeda lokasi. Selain itu, variasi juga ditunjukkan pada sampel yang diperoleh dari basis data GenBank dengan adanya perbedaan 1-14 pasang basa nukleotida dengan spesimen pada penelitian ini. Hubungan kekerabatan gen COI P. xylostella keseluruhan sampel tergolong dalam variasi intraspesies dengan nilai jarak genetik berkisar antara 0-0,022 (0-2,20%).Modoinding and Tomohon areas in North Sulawesi, are known as regions in Indonesia that produce a cabbage. The main pest of cabbage, Plutella xylostella. This insect can survive due to its resistance resulted from prolonged insecticide application. This study aims to analyze genetic variation of COI genes in P. xylostella from Modoinding and Tomohon areas. Sequence analysis showed there were differences in nucleotide base pairs between these locations. In addition, variations were also shown in samples obtained from the GenBank database with differences in 1-14 nucleotide base pairs with specimens in this study. The genetic relationship of P. xylostella COI gene in all samples was classified as intraspecific variation with genetic distance values ranging from 0-0,022 (0-2,20%).D aerah Modoinding dan Tomohon di Sulawesi Utara, dikenal sebagaidaerah penghasil sayuran kubis di Indonesia. Sayuran kubis memilikihama utama yaitu Plutella xylostella. Penyebab serangga ini dapatbertahan hingga saat ini karena adanya sifat resistensi akibat pemberianinsektisida yang berlebihan. Penelitian ini dilakukan untuk menganalisisvariasi pada gen cytochrome C oxidase I Plutella xylostella yang diperolehdari dua lokasi yang berbeda, yaitu Modoinding dan Tomohon. Analisissekuens menunjukkan adanya perbedaan pasang basa nukleotida darisampel yang berbeda lokasi. Selain itu, variasi juga ditunjukkan padasampel yang diperoleh dari basis data GenBank dengan adanyaperbedaan 1-14 pasang basa nukleotida dengan spesimen padapenelitian ini. Hubungan kekerabatan gen COI P. xylostella keseluruhansampel tergolong dalam variasi intraspesies dengan nilai jarak genetikberkisar antara 0-0,022 (0-2,20%).


1974 ◽  
Vol 138 (3) ◽  
pp. 499-510 ◽  
Author(s):  
John A. Hunt

By the use of the favoured models defining mRNA synthesis and half-life from the preceding paper (Hunt, 1974) and the known content of globin in a reticulocyte it is possible to estimate the absolute rate of mRNA and globin synthesis and the mRNA and globin content in each type of erythroid cell. The best model requires an mRNA-synthetic rate of 3000 molecules per h/cell. This rate compares favourably with the estimated chain-extension rate of 43 nucleotides/s in Escherichia coli (Manor et al., 1969) provided that the four α- and β-chain cistrons per cell are transcribed by polymerases spaced 50 nucleotide base pairs apart. Similar calculations can be made for erythropoiesis in the chick embryo, where cell times and relative globin content at each mitosis have been measured (Campbell et al., 1971), but where no reliable estimates of mRNA half-life have been made. In this case it was estimated that a constant rate of mRNA synthesis at 10000 molecules per h/cell through six cell divisions is necessary if the mRNA half-life is 15h; after the sixth mitosis the mRNA synthesis would stop and its half-life would increase to approx. 20h. If an mRNA half-life of 4.5h is used, the synthesis rate through the six mitoses would be 21000 molecules per h/cell, ceasing at the sixth mitosis, when the half-life would need to increase to 25h. The chain-elongation rate for the four α- and β-globin cistrons per cell would be 1–2 times higher than in E. coli and would either require a greater rate, polymerases spaced between 25 and 50 nucleotide base pairs apart on the DNA, or limited gene replication. These possibilities are discussed in the light of the low values found for globin cistron multiplicity in ducks and mice.


Jurnal MIPA ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 71
Author(s):  
Era Monalisa ◽  
Feky Recky Mantiri ◽  
Hanry Jefri Lengkong

Penelitian ini bertujuan untuk menganalisis variasi interspesies kelelawar Pteropus sp. dan menjelaskan hubungan filogeni Pteropus sp. dengan spesies Pteropus lain yang terdata di GenBank berdasarkan Gen COI. Analisis sekuens menggunakan Geneious v5.6.4 dan menunjukkan adanya variasi interspesies sekuens gen COI pada ketiga sampel Pteropus sp. yang ditunjukkan oleh adanya perbedaan 5 pasang basa nukleotida pada urutan sekuens sampel nomor 157, 160, 421, 427 dan 652 dengan jarak genetik 0,006. Filogeni Ke-3 sampel kelelawar Pteropus sp. dengan spesies Pteropus lain dilakukan menggunakan MEGAX. Hasil filogeni menunjukkan bahwa sampel yang diteliti merupakan kelelawar dari genus Pteropus tetapi belum dapat dipastikan spesiesnya, karena ketika pohon filogeni dikonstruksikan membentuk satu klaster sendiri. Penjelasan dari proses tersebut adalah penyortiran garis keturunan yang tidak lengkap dan terjadinya hibridisasi, serta diduga bahwa primer yang digunakan kurang mampu dalam membedakan variasi intrespesies terhadap kelelawar genus PteropusThis study aimed to analyze the interspecificvariations of bats from Pteropus sp. and describethe phylogenetic relationship of Pteropus sp. with other Pteropus species recorded inGenBank based on the COI gene. Sequenceanalysis by Geneious v5.6.4 showed interspecificvariations of COI gene sequences in all threesamples of Pteropus sp. which was indicated byvariations in 5 nucleotide base pairs in thesequences number 157, 160, 421, 427 and 652with 0.006 of genetic distance value. Phylogeneticof the 3 bat samples of Pteropus sp. with otherPteropus species was carried out by MEGAX.Phylogenetic analyses showed that the samplesstudied are bats of the genus Pteropus, but theexact species cannot be determined because thesamples were grouped in the same cluster duringphylogenetic tree construction. The most probable explanation for this observation is hybridization between two different Pteropus spesies and also it is assumed that the primersused are not capable to distinguish interspecificvariations of the bats from the Pteropus genusPenelitian ini bertujuan untuk menganalisis variasi interspesies kelelawar Pteropus sp. dan menjelaskan hubungan filogeni Pteropus sp. dengan spesies Pteropus lain yang terdata di GenBank berdasarkan Gen COI. Analisis sekuens menggunakan Geneious v5.6.4 dan menunjukkan adanya variasi interspesies sekuens gen COI pada ketiga sampel Pteropus sp. yang ditunjukkan oleh adanya perbedaan 5 pasang basa nukleotida pada urutan sekuens sampel nomor 157, 160, 421, 427 dan 652 dengan jarak genetik 0,006. Filogeni Ke-3 sampel kelelawar Pteropus sp. dengan spesies Pteropus lain dilakukan menggunakan MEGAX. Hasil filogeni menunjukkan bahwa sampel yang diteliti merupakan kelelawar dari genus Pteropus tetapi belum dapat dipastikan spesiesnya, karena ketika pohon filogeni dikonstruksikan membentuk satu klaster sendiri. Penjelasan dari proses tersebut adalah penyortiran garis keturunan yang tidak lengkap dan terjadinya hibridisasi, serta diduga bahwa primer yang digunakan kurang mampu dalam membedakan variasi intrespesies terhadap kelelawar genus Pteropus


2021 ◽  
Vol 12 ◽  
Author(s):  
Xianjun Chen ◽  
Yan Zhou ◽  
Yundan Cong ◽  
Pusheng Zhu ◽  
Jiayi Xing ◽  
...  

In this study, the protective role of exogenous ascorbic acid (AsA) on salt-induced inhibition of photosynthesis in the seedlings of processing tomatoes under salt stress has been investigated. Plants under salt stress (NaCl, 100 mmol/L) were foliar-sprayed with AsA (0.5 mmol/L), lycorine (LYC, 0.25 mmol/L, an inhibitor of key AsA synthesis enzyme l-galactono-γ-lactone dehydrogenase activity), or AsA plus LYC. The effects of AsA on fast OJIP fluorescence rise curve and JIP parameters were then examined. Our results demonstrated that applying exogenous AsA significantly changed the composition of O-J-I-P fluorescence transients in plants subjected to salt stress both with and without LYC. An increase in basal fluorescence (Fo) and a decrease in maximum fluorescence (Fm) were observed. Lower K- and L-bands and higher I-band were detected on the OJIP transient curves compared, respectively, with salt-stressed plants with and without LYC. AsA application also significantly increased the values of normalized total complementary area (Sm), relative variable fluorescence intensity at the I-step (VI), absorbed light energy (ABS/CSm), excitation energy (TRo/CSm), and reduction energy entering the electron transfer chain beyond QA (ETo/CSm) per reaction centre (RC) and electron transport flux per active RC (ETo/RC), while decreasing some others like the approximated initial slope of the fluorescence transient (Mo), relative variable fluorescence intensity at the K-step (VK), average absorption (ABS/RC), trapping (TRo/RC), heat dissipation (DIo/RC) per active RC, and heat dissipation per active RC (DIo/CSm) in the presence or absence of LYC. These results suggested that exogenous AsA counteracted salt-induced photoinhibition mainly by modulating the endogenous AsA level and redox state in the chloroplast to promote chlorophyll synthesis and alleviate the damage of oxidative stress to photosynthetic apparatus. AsA can also raise the efficiency of light utilization as well as excitation energy dissipation within the photosystem II (PSII) antennae, thus increasing the stability of PSII and promoting the movement of electrons among PS1 and PSII in tomato seedling leaves subjected to salt stress.


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