MolecularDictionary - Maple Help
For the best experience, we recommend viewing online help using Google Chrome or Microsoft Edge.

Online Help

All Products    Maple    MapleSim

Home : Support : Online Help : Toolboxes : Quantum Chemistry : MolecularDictionary




           return the definition of a molecule



Calling Sequence





Calling Sequence





string, integer; name of the molecule as a string, CID number as an integer, or SMILES formula (see below for format)



MolecularDictionary returns a dictionary entry of a molecule from an online database.


The molecule can be a name, CID number, or SMILES formula in the format "smiles=formula".


Kim S, Chen J, Cheng T, Gindulyte A, He J, He S, Li Q, Shoemaker BA, Thiessen PA, Yu B, Zaslavsky L, Zhang J, Bolton EE. PubChem 2023 update. Nucleic Acids Res. 2023 Jan 6;51(D1):D1373-D1380. doi:10.1093/nar/gkac956. PMID: 36305812.



Consider the molecule aspirin


Aspirin: Acetylsalicylic acid is a member of the class of benzoic acids that is salicylic acid in which the hydrogen that is attached to the phenolic hydroxy group has been replaced by an acetoxy group. A non-steroidal anti-inflammatory drug with cyclooxygenase inhibitor activity. It has a role as a non-steroidal anti-inflammatory drug, a non-narcotic analgesic, a platelet aggregation inhibitor, an antipyretic, a cyclooxygenase 2 inhibitor, a cyclooxygenase 1 inhibitor, a prostaglandin antagonist, a teratogenic agent, an anticoagulant, a plant activator, an EC (prostaglandin-F synthase) inhibitor and a drug allergen. It is a member of benzoic acids, a member of salicylates and a member of phenyl acetates. It derives from a salicylic acid. It is a conjugate acid of an acetylsalicylate. -ChEBI
Aspirin: Aspirin is an orally administered non-steroidal antiinflammatory agent. Acetylsalicylic acid binds to and acetylates serine residues in cyclooxygenases, resulting in decreased synthesis of prostaglandin, platelet aggregation, and inflammation. This agent exhibits analgesic, antipyretic, and anticoagulant properties. -NCI Thesaurus (NCIt)

For nitrogen gas we have


Nitrogen: Dinitrogen is an elemental molecule consisting of two trivalently-bonded nitrogen atoms. It has a role as a member of food packaging gas and a food propellant. It is a diatomic nitrogen, a gas molecular entity and an elemental molecule. It is a conjugate base of a diazynium. -ChEBI
Nitrogen: Nitrogen is an element with atomic symbol N, atomic number 7, and atomic weight 14.01. -NCI Thesaurus (NCIt)

while for the Cys-Ser peptide we have


Cys-Ser: Cys-Ser is a dipeptide composed of L-cysteine and L-serine joined by a peptide linkage. It has a role as a metabolite. It is a dipeptide, a secondary carboxamide, a primary alcohol, a primary amino compound, a thiol and a carboxylic acid. It derives from a L-cysteine and a L-serine. -ChEBI

Similarly, we can explore many, many other molecules.  What about the molecule ozone that is sometimes generated before a thunderstorm?


Ozone: Ozone is an elemental molecule with formula O3. An explosive, pale blue gas (b.p. -112###) that has a characteristic, pleasant odour, it is continuously produced in the upper atmosphere by the action of solar ultraviolet radiation on atmospheric oxygen. It is an antimicrobial agent used in the production of bottled water, as well as in the treatment of meat, poultry and other foodstuffs. It has a role as a member of greenhouse gas, a disinfectant, a tracer, an electrophilic reagent, a mutagen, an oxidising agent and an antiseptic drug. It is a member of reactive oxygen species, an elemental molecule, a triatomic oxygen and a gas molecular entity. -ChEBI

Or the molecule ascorbic acid (Vitamin C)?

MolecularDictionaryascorbic acid;

Ascorbic acid: L-ascorbic acid is the L-enantiomer of ascorbic acid and conjugate acid of L-ascorbate. It has a role as a water-soluble vitamin, a vitamin C, a coenzyme, a flour treatment agent, a food antioxidant, a plant metabolite and a cofactor. It is a conjugate acid of a L-ascorbate. It is an enantiomer of a D-ascorbic acid. -ChEBI
Ascorbic acid: Ascorbic Acid is a natural water-soluble vitamin (Vitamin C). Ascorbic acid is a potent reducing and antioxidant agent that functions in fighting bacterial infections, in detoxifying reactions, and in the formation of collagen in fibrous tissue, teeth, bones, connective tissue, skin, and capillaries. Found in citrus and other fruits, and in vegetables, vitamin C cannot be produced or stored by humans and must be obtained in the diet. (NCI04) -NCI Thesaurus (NCIt)

Or that important molecule in coffee?


Caffeine: Caffeine is a trimethylxanthine in which the three methyl groups are located at positions 1, 3, and 7. A purine alkaloid that occurs naturally in tea and coffee. It has a role as a central nervous system stimulant, an EC 3.1.4.* (phosphoric diester hydrolase) inhibitor, an adenosine receptor antagonist, an EC (non-specific serine/threonine protein kinase) inhibitor, a ryanodine receptor agonist, a fungal metabolite, an adenosine A2A receptor antagonist, a psychotropic drug, a diuretic, a food additive, an adjuvant, a plant metabolite, an environmental contaminant, a xenobiotic, a human blood serum metabolite, a mouse metabolite and a mutagen. It is a purine alkaloid and a trimethylxanthine. -ChEBI
Caffeine: Caffeine is a methylxanthine alkaloid found in the seeds, nuts, or leaves of a number of plants native to South America and East Asia that is structurally related to adenosine and acts primarily as an adenosine receptor antagonist with psychotropic and anti-inflammatory activities. Upon ingestion, caffeine binds to adenosine receptors in the central nervous system (CNS), which inhibits adenosine binding. This inhibits the adenosine-mediated downregulation of CNS activity; thus, stimulating the activity of the medullary, vagal, vasomotor, and respiratory centers in the brain. This agent also promotes neurotransmitter release that further stimulates the CNS. The anti-inflammatory effects of caffeine are due the nonselective competitive inhibition of phosphodiesterases (PDEs). Inhibition of PDEs raises the intracellular concentration of cyclic AMP (cAMP), activates protein kinase A, and inhibits leukotriene synthesis, which leads to reduced inflammation and innate immunity. -NCI Thesaurus (NCIt)

The database also contains many more technical molecules such as the antiviral drug remdesivir that was recently repurposed to treat Covid-19.


Remdesivir: Remdesivir is a carboxylic ester resulting from the formal condensation of the carboxy group of N-[(S)-{[(2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl]methoxy}(phenoxy)phosphoryl]-L-alanine with the hydroxy group of 2-ethylbutan-1-ol. A broad-spectrum antiviral prodrug with potent in vitro antiviral activity against a diverse panel of RNA viruses such as Ebola virus, MERS-CoV and SARS-CoV. It is currently in Phase III clinical trials for the treatment of Covid-19 in adults. It has a role as an antiviral drug, a prodrug and an anticoronaviral agent. It is a carboxylic ester, a pyrrolotriazine, a nitrile, a phosphoramidate ester, a C-nucleoside and an aromatic amine. It derives from a GS-441524. -ChEBI
Remdesivir: Remdesivir is a prodrug of an adenosine triphosphate (ATP) analog, with potential antiviral activity against a variety of RNA viruses. Upon administration, remdesivir, being a prodrug, is metabolized into its active form GS-441524. As an ATP analog, GS-441524 competes with ATP for incorporation into RNA and inhibits the action of viral RNA-dependent RNA polymerase. This results in the termination of RNA transcription and decreases viral RNA production. -NCI Thesaurus (NCIt)

Or, using its SMILES formula, melatonin


Melatonin: Melatonin is a member of the class of acetamides that is acetamide in which one of the hydrogens attached to the nitrogen atom is replaced by a 2-(5-methoxy-1H-indol-3-yl)ethyl group. It is a hormone secreted by the pineal gland in humans. It has a role as a hormone, an anticonvulsant, an immunological adjuvant, a radical scavenger, a central nervous system depressant, a human metabolite, a mouse metabolite and a geroprotector. It is a member of acetamides and a member of tryptamines. It is functionally related to a tryptamine. -ChEBI


See Also