Let G = (V;E) be a simple connected graph. The sets of vertices and edges of G are denoted by V = V(G) and E = E(G), respectively. In such a simple molecular graph, vertices represent atoms and edges represent bonds. ...Let G = (V;E) be a simple connected graph. The sets of vertices and edges of G are denoted by V = V(G) and E = E(G), respectively. In such a simple molecular graph, vertices represent atoms and edges represent bonds. The Sanskruti index S(G) is a topological index was defined as where Su is the summation of degrees of all neighbors of vertex u in G. The goal of this paper is to compute the Sanskruti index for circumcoronene series of benzenoid.展开更多
We consider a series of benzenoid isomers obtained by attaching fragments to an mradical. Some of their topological properties, such as the number of Kekule patterns and the maximum number of aromatic π-sextets are e...We consider a series of benzenoid isomers obtained by attaching fragments to an mradical. Some of their topological properties, such as the number of Kekule patterns and the maximum number of aromatic π-sextets are established.展开更多
Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</...Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</sub>(G,x) and Zg<sub>1</sub>(G) of the graph G are defined as Σ<sub>uv∈E(G)</sub>x<sup>(d<sub>u</sub>+d<sub>v</sub>)</sup> and Σ<sub>e=uv∈E(G)</sub>(d<sub>u</sub>+d<sub>v</sub>) respectively. Recently Ghorbani and Hosseinzadeh introduced the first Eccentric Zagreb index as Zg<sub>1</sub>*</sup>=Σ<sub>uv∈E(G)</sub>(ecc(v)+ecc(u)), that ecc(u) is the largest distance between u and any other vertex v of G. In this paper, we compute this new index (the first Eccentric Zagreb index or third Zagreb index) of an infinite family of linear Polycene parallelogram of benzenoid.展开更多
For a Kekulean benzenoid system, we can define the fixed single bonds, fixed double bonds and forcing bounds. The first and second types of bonds can be recognized by efficient algorithms.In this paper, we give an eff...For a Kekulean benzenoid system, we can define the fixed single bonds, fixed double bonds and forcing bounds. The first and second types of bonds can be recognized by efficient algorithms.In this paper, we give an efficient algorithm to recognize the forcing bonds of a benzenoid system.For a cata-condensed benzenoid system we completely determine its forcing bonds. Furthermore,by Polya's theorem we enumerate all cat-condensed benzenoid Systems with forcing bonds.展开更多
In order to study the stability and estimate the resonance energy of benzenoid systems, many chemists agree that some kinds of Kekulé structures are more important than the others. Dewar and Longuet-Higgins, Clar...In order to study the stability and estimate the resonance energy of benzenoid systems, many chemists agree that some kinds of Kekulé structures are more important than the others. Dewar and Longuet-Higgins, Clar, Randi, Randiand Klein gave different kinds of weights to Kekul structures of benzenoid hydrocarbon, respectively. Using their own concept, several approaches are proposed to calculate the resonance energy. In this note we propose an invafiant for benzenoid hydrocarbon, by which展开更多
A benzenoid, or a benzenoid system, is a connected planar graph whose every interiorface is a regular hexagon. A peak (resp. valley) of a benzenoid is a vertex which lies above(resp. below) all its first neighbors. A ...A benzenoid, or a benzenoid system, is a connected planar graph whose every interiorface is a regular hexagon. A peak (resp. valley) of a benzenoid is a vertex which lies above(resp. below) all its first neighbors. A Kekulean benzenoid is a benzenoid with at least oneperfect matching. An essentially disconnected benzenoid is a Kekulean benzenoid which hassome fixed bonds. Essentially disconnected benzenoids have proved to be very useful incertain enumeration techniques for Derfect matching. Hence the problem of recognizing展开更多
Wintersweet(Chimonanthus praecox),a well-known fragrant flowering shrub,is extensively planted for ornamental purpose and production of floral essential oil.Although the tepal color of wintersweet varieties exhibits t...Wintersweet(Chimonanthus praecox),a well-known fragrant flowering shrub,is extensively planted for ornamental purpose and production of floral essential oil.Although the tepal color of wintersweet varieties exhibits the most remarkable diversity,variations in the floral scent traits are also noticeable across different cultivars.In this study,the floral volatile organic compounds(VOCs)in three wintersweet cultivars,‘Yanlingsuxin’,‘Yuxiang’,and‘Hongyun’were detected via GC-MS coupled with OAV.The distinct floral aromas of the three cultivars were primarily attributed to benzyl alcohol(abundant in‘Yuxiang’),linalool(abundant in‘Yanlingsuxin’),(-)-γ-cadinene and eugenol(abundant in‘Hongyun’).Integrated analyses of metabolome and transcriptome showed that an R2R3-MYB transcription factor gene,CpODO1,potentially have a crucial regulatory function in controlling the production of multiple aroma compounds.Overexpression of CpODO1 can enhance the production of benzyl alcohol in transgenic tobacco flowers.Analysis of DAP-seq data,EMSA and dual-luciferase assay revealed that CpODO1 predominantly regulate the expression of CpCYP71,a cytochrome P450 gene encoding a key enzyme in the production of benzyl alcohol,and the transcriptional regulation of CpODO1 is driven by CpEOBII.The identification of polymorphisms in the MYB binding cis-motifs of CpCYP71 and CpODO1 promoters revealed the regulatory mechanism underlying the varied synthesis of benzyl alcohol in three wintersweet cultivars.This study provides new anchor points for floral scent quality improvement breeding of wintersweet,and the profusion of wintersweet germplasm can serve as a material basis for developing various aroma products.展开更多
Jasmine [Jasminum sambac(L.) Ait.], a tropical and subtropical plant emits a sweet, heady fragrance during flower opening. However, the molecular mechanisms underlying this phenomenon remain largely unknown. In the pr...Jasmine [Jasminum sambac(L.) Ait.], a tropical and subtropical plant emits a sweet, heady fragrance during flower opening. However, the molecular mechanisms underlying this phenomenon remain largely unknown. In the present study, integrated Illumina sequencing, Pacbio sequencing, and high-throughput chromatin conformation capture(Hi-C) scaffolding was used to generate a 495.60 Mb genome assembly of J.sambac var. unifoliatum cultivar ‘Fuzhou Single-petal’(JSU-FSP), with contig N50 of 16.88 Mb;96.23% of the assembly was assigned to 13 pseudochromosomes. The genome harbors 30 989 protein-coding genes, and 49.47% of the assembled sequences are repetitive sequences. The analysis of duplication modes showed that 51% of genes were duplicated through dispersed duplication, and expanded gene families are mainly involved in photosynthesis, which may be responsible for the light-loving characteristic specific to jasmine. Transcriptome analysis revealed that at least 35 structural genes involved in the biosynthesis of volatile terpenes(VTs), volatile phenylpropanoid/benzenoids(VPBs),fatty acid-derived volatiles(FADVs), and indole were highly expressed in the flower-opening stage, both preharvest and postharvest, and are proposed to be important in endowing flower aroma. Additionally, at least 28 heat shock protein(HSP) and 11 β-glucosidase(BGLU) genes may be involved in the formation of floral fragrance. These findings provide insights into the formation of the floral fragrance of jasmine and will promote germplasm utilization for breeding improved jasmine varieties.展开更多
文摘Let G = (V;E) be a simple connected graph. The sets of vertices and edges of G are denoted by V = V(G) and E = E(G), respectively. In such a simple molecular graph, vertices represent atoms and edges represent bonds. The Sanskruti index S(G) is a topological index was defined as where Su is the summation of degrees of all neighbors of vertex u in G. The goal of this paper is to compute the Sanskruti index for circumcoronene series of benzenoid.
文摘We consider a series of benzenoid isomers obtained by attaching fragments to an mradical. Some of their topological properties, such as the number of Kekule patterns and the maximum number of aromatic π-sextets are established.
文摘Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</sub>(G,x) and Zg<sub>1</sub>(G) of the graph G are defined as Σ<sub>uv∈E(G)</sub>x<sup>(d<sub>u</sub>+d<sub>v</sub>)</sup> and Σ<sub>e=uv∈E(G)</sub>(d<sub>u</sub>+d<sub>v</sub>) respectively. Recently Ghorbani and Hosseinzadeh introduced the first Eccentric Zagreb index as Zg<sub>1</sub>*</sup>=Σ<sub>uv∈E(G)</sub>(ecc(v)+ecc(u)), that ecc(u) is the largest distance between u and any other vertex v of G. In this paper, we compute this new index (the first Eccentric Zagreb index or third Zagreb index) of an infinite family of linear Polycene parallelogram of benzenoid.
文摘For a Kekulean benzenoid system, we can define the fixed single bonds, fixed double bonds and forcing bounds. The first and second types of bonds can be recognized by efficient algorithms.In this paper, we give an efficient algorithm to recognize the forcing bonds of a benzenoid system.For a cata-condensed benzenoid system we completely determine its forcing bonds. Furthermore,by Polya's theorem we enumerate all cat-condensed benzenoid Systems with forcing bonds.
基金Project supported by the National Natural Sdence Foundation of China.
文摘In order to study the stability and estimate the resonance energy of benzenoid systems, many chemists agree that some kinds of Kekulé structures are more important than the others. Dewar and Longuet-Higgins, Clar, Randi, Randiand Klein gave different kinds of weights to Kekul structures of benzenoid hydrocarbon, respectively. Using their own concept, several approaches are proposed to calculate the resonance energy. In this note we propose an invafiant for benzenoid hydrocarbon, by which
文摘A benzenoid, or a benzenoid system, is a connected planar graph whose every interiorface is a regular hexagon. A peak (resp. valley) of a benzenoid is a vertex which lies above(resp. below) all its first neighbors. A Kekulean benzenoid is a benzenoid with at least oneperfect matching. An essentially disconnected benzenoid is a Kekulean benzenoid which hassome fixed bonds. Essentially disconnected benzenoids have proved to be very useful incertain enumeration techniques for Derfect matching. Hence the problem of recognizing
基金supported by the China National Natural Science Foundation(Grant No.32102417)Henan Key R&D Project,China(Grant No.221111110700)+1 种基金Henan Academy of Agricultural Sciences“Innovation and Utilization of Characteristic Flowers and Trees Germplasm”Team Project(Grant Nos.2023TD35 and2024TD26)Hunan Provincial Natural Science Foundation of China(Grant No.2024JJ6711),Natural Science Foundation of Guangxi(Grant No.2024JJB130300)。
文摘Wintersweet(Chimonanthus praecox),a well-known fragrant flowering shrub,is extensively planted for ornamental purpose and production of floral essential oil.Although the tepal color of wintersweet varieties exhibits the most remarkable diversity,variations in the floral scent traits are also noticeable across different cultivars.In this study,the floral volatile organic compounds(VOCs)in three wintersweet cultivars,‘Yanlingsuxin’,‘Yuxiang’,and‘Hongyun’were detected via GC-MS coupled with OAV.The distinct floral aromas of the three cultivars were primarily attributed to benzyl alcohol(abundant in‘Yuxiang’),linalool(abundant in‘Yanlingsuxin’),(-)-γ-cadinene and eugenol(abundant in‘Hongyun’).Integrated analyses of metabolome and transcriptome showed that an R2R3-MYB transcription factor gene,CpODO1,potentially have a crucial regulatory function in controlling the production of multiple aroma compounds.Overexpression of CpODO1 can enhance the production of benzyl alcohol in transgenic tobacco flowers.Analysis of DAP-seq data,EMSA and dual-luciferase assay revealed that CpODO1 predominantly regulate the expression of CpCYP71,a cytochrome P450 gene encoding a key enzyme in the production of benzyl alcohol,and the transcriptional regulation of CpODO1 is driven by CpEOBII.The identification of polymorphisms in the MYB binding cis-motifs of CpCYP71 and CpODO1 promoters revealed the regulatory mechanism underlying the varied synthesis of benzyl alcohol in three wintersweet cultivars.This study provides new anchor points for floral scent quality improvement breeding of wintersweet,and the profusion of wintersweet germplasm can serve as a material basis for developing various aroma products.
基金supported by the Construction of Plateau Discipline of Fujian Province (Grant No. 102/71201801101)the Construction Project for Technological Innovation and Service System of Tea Industry Chain of Fujian Agriculture and Forestry University (Grant No. K1520005A01)。
文摘Jasmine [Jasminum sambac(L.) Ait.], a tropical and subtropical plant emits a sweet, heady fragrance during flower opening. However, the molecular mechanisms underlying this phenomenon remain largely unknown. In the present study, integrated Illumina sequencing, Pacbio sequencing, and high-throughput chromatin conformation capture(Hi-C) scaffolding was used to generate a 495.60 Mb genome assembly of J.sambac var. unifoliatum cultivar ‘Fuzhou Single-petal’(JSU-FSP), with contig N50 of 16.88 Mb;96.23% of the assembly was assigned to 13 pseudochromosomes. The genome harbors 30 989 protein-coding genes, and 49.47% of the assembled sequences are repetitive sequences. The analysis of duplication modes showed that 51% of genes were duplicated through dispersed duplication, and expanded gene families are mainly involved in photosynthesis, which may be responsible for the light-loving characteristic specific to jasmine. Transcriptome analysis revealed that at least 35 structural genes involved in the biosynthesis of volatile terpenes(VTs), volatile phenylpropanoid/benzenoids(VPBs),fatty acid-derived volatiles(FADVs), and indole were highly expressed in the flower-opening stage, both preharvest and postharvest, and are proposed to be important in endowing flower aroma. Additionally, at least 28 heat shock protein(HSP) and 11 β-glucosidase(BGLU) genes may be involved in the formation of floral fragrance. These findings provide insights into the formation of the floral fragrance of jasmine and will promote germplasm utilization for breeding improved jasmine varieties.
