'Pyrans' are heterocyclic organic compounds containing a six-membered ring with one oxygen atom and five carbon atoms, which can be found in various natural substances and synthesized compounds, and may have potential applications in medicinal chemistry.

Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

Copolymer of divinyl ether and maleic anhydride that acts as an immunostimulant with antineoplastic and anti-infective properties. It is used in combination with other antineoplastic agents.

A pyrano-acridone alkaloid found in RUTACEAE plants.

Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).

Lip diseases refer to various medical conditions that primarily affect the lips, causing symptoms such as inflammation, pain, dryness, discoloration, or abnormal growths, which may result from infectious, autoimmune, genetic, traumatic, or neoplastic causes.

A barbiturate that is effective as a hypnotic and sedative.

A double-stranded polyribonucleotide comprising polyadenylic and polyuridylic acids.

A group of 20-member macrolactones in which there are three remotely substituted pyran rings that are linked by a methylene bridge and an E-disubstituted alkene, and have geminal dimethyls at C8 and C18 carbons. Some interact with PROTEIN KINASE C.

Leukemia induced experimentally in animals by exposure to leukemogenic agents, such as VIRUSES; RADIATION; or by TRANSPLANTATION of leukemic tissues.

A group of compounds consisting in part of two rings sharing one atom (usually a carbon) in common.

The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

Polynucleotides are long, multiple-unit chains of nucleotides, the monomers that make up DNA and RNA, which carry genetic information and play crucial roles in various biological processes.

Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)

The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.