| compound q | <chemical> An extract of a Chinese wild cucumber. It is used in China to induce abortions and treat respiratory viruses. In this country, compound Q has been tried as an anti-HIV treatment. (05 Jan 1998) |
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| compound restoration | A restoration of more than one surface of a tooth. (05 Mar 2000) |
| compound skull fracture | A fracture with laceration of overlying scalp and/or mucous membrane. Synonym: compound skull fracture. (05 Mar 2000) |
| Wintersteiner compound F | Derived from cortisol and with similar physiological actions. (18 Nov 1997) |
| condensation compound | A compound resulting from the combination of two or more simple substances, with the splitting off of some other substance, such as alcohol or water; e.g., a peptide. Compare: conjugated compound. (05 Mar 2000) |
| conjugated compound | A compound formed by the union of two compound's (as by the elimination of water between an alcohol and an organic acid to form an ester) and easily converted to the original compound's (hydrolysis). See: conjugation. Compare: condensation compound. (05 Mar 2000) |
| polar compound | A compound in which the electric charge is not symmetrically distributed, so that there is a separation of charge or partial charge and formation of definite positive and negative poles; e.g., H2O. See also inorganic compound. (05 Mar 2000) |
| cyclic compound | Any compound in which the constituent atoms, or any part of them, form a ring. Used mainly in organic chemistry where: 1) numerous compound's contain rings of carbon atoms (carbocyclic compound's) or carbon atoms plus one or more atoms of other types (heterocyclic compound's), usually nitrogen, oxygen, or sulfur; 2) where the atoms in the ring are all of the same element (homocyclic or isocyclic compound); 3) where the ring is saturated or contains nonconjugated double bonds (alicyclic compound), the compound is similar in properties to the corresponding acyclic compound (e.g., cyclohexane resembles hexane); 4) where the ring contains conjugated double bonds in a closed loop in which there are 4n + 2 (where n is an integer) delocalised π electrons (Huckel's rule) (aromatic compound; e.g., benzene, pyridine), it is more stable than the corresponding saturated ring and exhibits unusual chemical properties characteristic of itself and not of other types of rings or of acyclic compound's. These aromatic compounds have the ability to sustain an induced ring current. Synonym: closed chain compound, ring compound. (05 Mar 2000) |
| heterocyclic compound | Any compound in which the constituent atoms, or any part of them, form a ring. Used mainly in organic chemistry where: 1) numerous compound's contain rings of carbon atoms (carbocyclic compound's) or carbon atoms plus one or more atoms of other types (heterocyclic compound's), usually nitrogen, oxygen, or sulfur; 2) where the atoms in the ring are all of the same element (homocyclic or isocyclic compound); 3) where the ring is saturated or contains nonconjugated double bonds (alicyclic compound), the compound is similar in properties to the corresponding acyclic compound (e.g., cyclohexane resembles hexane); 4) where the ring contains conjugated double bonds in a closed loop in which there are 4n + 2 (where n is an integer) delocalised π electrons (Huckel's rule) (aromatic compound; e.g., benzene, pyridine), it is more stable than the corresponding saturated ring and exhibits unusual chemical properties characteristic of itself and not of other types of rings or of acyclic compound's. These aromatic compounds have the ability to sustain an induced ring current. Synonym: closed chain compound, ring compound. (05 Mar 2000) |
| homocyclic compound | Any compound in which the constituent atoms, or any part of them, form a ring. Used mainly in organic chemistry where: 1) numerous compound's contain rings of carbon atoms (carbocyclic compound's) or carbon atoms plus one or more atoms of other types (heterocyclic compound's), usually nitrogen, oxygen, or sulfur; 2) where the atoms in the ring are all of the same element (homocyclic or isocyclic compound); 3) where the ring is saturated or contains nonconjugated double bonds (alicyclic compound), the compound is similar in properties to the corresponding acyclic compound (e.g., cyclohexane resembles hexane); 4) where the ring contains conjugated double bonds in a closed loop in which there are 4n + 2 (where n is an integer) delocalised π electrons (Huckel's rule) (aromatic compound; e.g., benzene, pyridine), it is more stable than the corresponding saturated ring and exhibits unusual chemical properties characteristic of itself and not of other types of rings or of acyclic compound's. These aromatic compounds have the ability to sustain an induced ring current. Synonym: closed chain compound, ring compound. (05 Mar 2000) |
| nonpolar compound | A compound composed of molecules that possess a symmetrical distribution of charge, so that no positive or negative poles exist, and that are not ionizable in solution; e.g., hydrocarbons. See: organic compound. (05 Mar 2000) |
| surface active compound | <biochemistry> Usually, in biological systems, means a detergent like molecule that is amphipathic and that will bind to the plasma membrane or to a surface with which cells come in contact, altering its properties from hydrophobic to hydrophilic or vice versa. (18 Nov 1997) |
| impression compound | A thermoplastic material usually composed of gum damar and prepared chalk, used especially for making dental impressions. Synonym: impression compound, modeling composition, modeling compound. (05 Mar 2000) |
| inclusion compound | The mechanical trapping of small molecules within spaces between other molecules; e.g., the inclusion of iodine molecules by starch molecules to form the well-known red-to-black "addition compound" (05 Mar 2000) |
| inorganic compound | A compound in which the atoms or radicals consist of elements other than carbon and are typically held together by electrostatic forces rather than by covalent bonds; often are capable of dissociation into ions in polar solvents (e.g., H2O). Compare: organic compound. (05 Mar 2000) |