Vobasine is a naturally occurring

monoterpene Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen funct ...

indole alkaloid Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known differe ...

found in several species in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Tabernaemontana ''Tabernaemontana'' is a genus of flowering plants in the family Apocynaceae. It has a pan-tropical distribution, found in Asia, Africa, Australia, North America, South America, and a wide assortment of oceanic islands. These plants are evergreen ...

'' including ''

Tabernaemontana divaricata ''Tabernaemontana divaricata'', commonly called pinwheel flower, crape jasmine, East India rosebay, and Nero's crown, is an evergreen shrub or small tree native to South Asia, Southeast Asia and China. In zones where it is not hardy it is grown a ...

''.

History

Vobasine was first reported by Renner in 1959 after its isolation from ''

Voacanga africana ''Voacanga africana'' is a small tree native to tropical Africa belonging to the family Apocynaceae that grows to in height and bears leaves that are up to in length. The yellow or white flowers are succeeded by paired, follicular, dehiscent f ...

''. The two structurally related compounds, dregamine and tabernaemontanine, where its

alkene In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

(=CHCH₃) sidechain was reduced to

ethyl group In organic chemistry, an ethyl group (abbr. Et) is an alkyl substituent with the formula , derived from ethane (). ''Ethyl'' is used in the International Union of Pure and Applied Chemistry's nomenclature of organic chemistry for a saturated ...

s in two configurations, had their relationship confirmed in the 1970s. Vobasine has been found in many plants of the dogbane (

Apocynaceae Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of the ...

) family including '' Tabernaemontana dichotoma''.

Synthesis

Biosynthesis

As with other

Indole alkaloids Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known differe ...

, the biosynthesis of vobasine starts from the

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

tryptophan Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α- carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic ...

. This is converted into

strictosidine Strictosidine is a natural chemical compound and is classified as a glucoalkaloid and a vinca alkaloid. It is formed by the Pictet–Spengler condensation reaction of tryptamine with secologanin, catalyzed by the enzyme strictosidine synthase. ...

before further elaboration.

Chemical synthesis

The synthesis of alkaloids with the same carbon skeleton as vobasine began in the 1960s and has continued, with some work providing enantiospecific approaches to closely-related compounds.

Natural occurrence

Vobasine is found commonly in the

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

'' and ''

Voacanga ''Voacanga'' is a genus of plants in the family Apocynaceae found in Africa, Southeast Asia, New Guinea, and Australia. the World Checklist of Selected Plant Families recognises 13 species:Search for "Voacanga", ;Species # ''Voacanga africana' ...

'', including the species '' Ervatamia hirta'',

Tabernaemontana elegans ''Tabernaemontana elegans'', the toad tree, is a shrub or small tree in the family Apocynaceae. It is native to eastern Africa. Description ''Tabernaemontana elegans'' grows up to tall, with a trunk diameter of up to . Its fragrant flowers feat ...

, ''

'' and ''Voacanga africana''.

Biochemistry

Plant

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

s have been of interest for their possible

biological activity In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

and alkaloids in particular are major subjects for

ethnobotanical Ethnobotany is the study of a region's plants and their practical uses through the traditional knowledge of a local culture and people. An ethnobotanist thus strives to document the local customs involving the practical uses of local flora for m ...

research. Vobasine has been studied, for example as a potential anti-cancer agent and for its

hypotensive Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dias ...

activity. However, the alkaloid itself has not been developed as a drug.

Toxicity

Very high dose of vobasine at around 300mg/kg may cause death through CNS and respiratory depression.