Phytochemical investigation of the roots and stems of Illigera luzonensis afforded two new aporphine alkaloids (1) and (2), one new bisdehydroaporphine alkaloid (3), and one new benzenoid (4), along with 28 known structures. The structures of new compounds were elucidated by spectral and MS analysis. Among the isolated compounds, (1) and (4-13) were subjected into the examination for their inhi...

We make use of the classical correspondence between Kekulé structures and lattice paths to obtain explicit formulas for the Pauling bond order of edges in benzenoid parallelograms. These formulas are further used to establish the average π-electron content of hexagonal rings in such benzenoids. We then compare this quantity with the atom-based π-electron content of rings, and study the local an...

Chemical investigation of the EtOH extract of the fresh stem of Aquilaria sinensis collected in Hainan Province of China resulted in the isolation of a new benzenoid, named aquilarin A (1), together with two known compounds balanophonin (2) and (+)-lariciresinol (3). Their structures were elucidated by a study of their physical and spectral data. Compounds 2 and 3 exhibited cytotoxicity against...

let $r$ be a commutative ring with identity. let $g(r)$ denote the maximal graph associated to $r$, i.e., $g(r)$ is a graph with vertices as the elements of $r$, where two distinct vertices $a$ and $b$ are adjacent if and only if there is a maximal ideal of $r$ containing both. let $gamma(r)$ denote the restriction of $g(r)$ to non-unit elements of $r$. in this paper we study the various graphi...

We consider a family of structurally closely related fully-benzenoid hydrocarbons of increasing number of fused benzene rings. Local and global aromatic properties of such molecules are investigated with a particular interest in investigating the role of the finite size of such molecules in modelling the high-polymer or even graphite. An interesting alternation of local properties for benzene r...

The atom-bond connectivity (ABC) index is a recently introduced topological index, defined as ABC(G) = ∑ uv∈E(G) √ du+dv−2 dudv , where du (or dv) is the degree the vertex u (or v). The ABC index of benzenoid systems and phenylenes are computed, a simple relation is established between the atom-bond connectivity index of a phenylene and the corresponding hexagonal squeeze in this paper. Mathema...

Kekule structures are transformed into the subspace of their double bonds to yield the correspondilng factor graphs, orig.inally called submolecules (8. E 1Bas i 1, Internat. J. Quantum Chem. 21 (1982) 771). A graiph-theoretical analysis of factor graphs is presented for certain classes o,f benzeno1i:d hydrocarbons. Such an analysis led to expressions for .the construction of sextet polynomials...

The title compound, C(20)H(32)N(2)O(2)S(2), has been synthesized by the reaction of α-methyl-sulfanylcyclo-dodeca-none and p-toluene-sulfonyl-hydrazine. In the crystal structure, the conformation of the non-benzenoid ring is [3333] and the methyl-sulfanyl group is in the α-side exo position. The mol-ecules are linked by inter-molecular N-H⋯S hydrogen bonds.