Benzoic acid is a natural ingredient occurring in many foodstuffs and in plant extracts. Benzoic acid, its salts and esters are used as preservatives in cosmetic products, with a maximum concentration of 0.5 %. Benzoic acid and sodium benzoate are on the FDA list of substances that are generally recognized as safe (GRAS). Both may be used as antimicrobial agents, flavouring agents and as adjuvants with a current maximum level of 0.1% in food. Benzoic acid is a constituent of Whitfield Ointment, which is used for the treatment of fungal skin diseases such as tinea, ringworm, and athlete's foot. Adverse effect of Whitfield Ointment: occasionally, a localized mild inflammatory response occurs.

Synthetic glycerophosphates have been known for many years and have been prepared in several ways. The acid may exist in two isomeric forms, alpha and beta. The L-a-acid is the naturally occurring form; the b-acid, present in hydrolyzates of lecithins from natural sources, arises from migration of the phosphoryl group from the a-carbon atom. Dehydrogenation of L-glycerol 3-phosphate produces Dihydroxyacetone phosphate and is part of the entry of glycerol (sourced from triglycerides) into the glycolytic pathway.

Pentobarbital belongs to the class of a short-acting barbiturate is used as sedatives, hypnotics, for the short-term treatment of insomnia, since they appear to lose their effectiveness for sleep induction and sleep maintenance after 2 weeks; preanesthetics and anticonvulsant, in anesthetic doses, in the emergency control of certain acute convulsive episodes, e.g., those associated with status epilepticus, cholera, eclampsia, meningitis, tetanus, and toxic reactions to strychnine or local anesthetics. Pentobarbital binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. All of these effects are associated with marked decreases in GABA-sensitive neuronal calcium conductance (gCa). The net result of barbiturate action is acute potentiation of inhibitory GABAergic tone. Barbiturates also act through potent (if less well characterized) and direct inhibition of excitatory AMPA-type glutamate receptors, resulting in a profound suppression of glutamatergic neurotransmission.

Barium sulfate, an insoluble in water substance, which was approved under the brand name E-Z-HD for use in double-contrast radiographic examinations of the esophagus, stomach and duodenum to visualize the gastrointestinal (GI) tract in patients 12 years and older. Due to its high atomic number, barium is opaque to x-rays and therefore acts as a positive contrast agent for radiographic studies.

Phenobarbital is a barbiturate derivative used to treat insomnia and anxiety, seizures, hyperbilirubinemia in neonates and cholestasis. Phenobarbital promotes binding to inhibitory gamma-aminobutyric acid subtype receptors, and modulates chloride currents through receptor channels.

The alkaloid L-(-)-scopolamine [L-(-)-hyoscine], a belladonna alkaloid, competitively inhibits muscarinic receptors for acetylcholine and acts as a nonselective muscarinic antagonist, producing both peripheral antimuscarinic properties and central sedative, antiemetic, and amnestic effects. Scopolamine acts: i) as a competitive inhibitor at postganglionic muscarinic receptor sites of the parasympathetic nervous system, and ii) on smooth muscles that respond to acetylcholine but lack cholinergic innervation. It has been suggested that scopolamine acts in the central nervous system (CNS) by blocking cholinergic transmission from the vestibular nuclei to higher centers in the CNS and from the reticular formation to the vomiting center. Scopolamine can inhibit the secretion of saliva and sweat, decrease gastrointestinal secretions and motility, cause drowsiness, dilate the pupils, increase heart rate, and depress motor function. Scopolamine is used for premedication in anesthesia and for the prevention of nausea and vomiting (post operative and associated with motion sickness).

Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere. Nitrogen occurs in all living organisms. It is a constituent element of amino acids and therefore of proteins and nucleic acids (DNA and RNA). Nitrogen is found in the chemical structure of almost all neurotransmitters and is a key component of alkaloids. Specific bacteria (e. g. Rhizobium trifolium) possess nitrogenase enzymes which can fix atmospheric nitrogen into a form (ammonium ion) which is chemically useful to higher organisms. Animals use nitrogen-containing amino acids from plant sources, as starting materials for all nitrogen-compound animal biochemistry, including the manufacture of proteins and nucleic acids. Animal metabolism of NO (nitric oxide) results in production of nitrite. Animal metabolism of nitrogen in proteins generally results in excretion of urea, while animal metabolism of nucleic acids results in excretion of urea and uric acid. The characteristic odor of animal flesh decay is caused by nitrogen-containing long-chain amines, such as putrescine and cadaverine. Decay of organisms and their waste products may produce small amounts of nitrate, but most decay eventually returns nitrogen content to the atmosphere, as molecular nitrogen. The circulation of nitrogen from the atmosphere through organics and then back to the atmosphere is commonly referred to as the nitrogen cycle. Nitrogen can be measured in urine with the Kjeldahl method or by spectrophotometric methods (enzymic tests). Total urinary nitrogen is calculated based on urea urinary nitrogen quantified with these methods. Liquid nitrogen (E941) is widely used in food industry as a freezing agent and as a protection against the impact of microorganisms. Nitrogen (E941) extends the period of validity of food and maintains its nutrients and is also used for packing products. In other fields of industry, nitrogen (E941) is useful in suppressing the combustion processes and in creating protective environment in order to avoid oxidation. Medical nitrogen has various medical uses, especially in liquid form when it provides temperatures as low as -196° C. Applications of medical nitrogen in the healthcare environment may include the following: * In cryopreservation for the long-term preservation of blood, blood components, other cells, body fluids or tissue samples. * In cryosurgery for minor surgical procedures in dermatology. * As a component in many gas mixtures. * As a displacement medium for sterile equipment, a non-oxidising displacement medium in pharmaceutical vials and as a propellant in pressurised aerosol dispensers. * As a source of pneumatic pressure to power gas-operated medical devices. * As a coolant for carbon dioxide surgical lasers.

Methenamine is an antibacterial agent for preventing recurrent urinary tract infection. It can be used as methenamine hippurate or methenamine mandelate preparations and is United States Food and Drug Administration-approved. Methenamine exerts its activity because it is hydrolyzed to formaldehyde in acid urine.

Apomorphine (brand names: Apokyn, Ixense, Spontane, Uprima) is indicated for the acute, intermittent treatment of hypomobility, “off” episodes (“end-of-dose wearing off” and unpredictable “on/off” episodes) in patients with advanced Parkinson’s disease. Apomorphine has been studied as an adjunct to other medications. It is a non-ergoline dopamine agonist with high in vitro binding affinity for the dopamine D4 receptor, and moderate affinity for the dopamine D2, D3, and D5, and adrenergic α1D, α2B, α2C receptors. The precise mechanism of action as a treatment for Parkinson’s disease is unknown, although it is believed to be due to stimulation of post-synaptic dopamine D2-type receptors within the caudate-putamen in the brain.

Betaine is a methyl derivative of glycine first isolated from the juice of sugar beets. Betaine is found in many common foods, but concentrated significantly in beets, spinach, wheat foods, and shellfish. In addition, betaine can be synthesized within the human body. Betaine participates in the methionine cycle, which produces vital biomolecules including proteins, hormones, phospholipids, polyamines, and nutrients. Betaine is used as a dietary supplement and has a beneficial effect on the human health. In the USA, FDA approved a betaine-containing drug Cystadane for the treatment of homocystinuria. The drug acts as a methyl group donor in the remethylation of homocysteine to methionine.