The differences between Sea Spurge and Portland Spurge.
Like Portland Spurge, Sea Spurge grows near the sea. Both have lower stems that tend to redden. Both have the mid part of the stem covered in narrowish leaves. Where they differ is that the stem leaves of Portland Spurge also tend to be both narrower and red, and they also have a prominent mid-rib absent from the stem leaves of Sea Spurge. The flowerheads of Portland Spurge have very long crescent-shaped horns, whereas those in Sea Spurge the horns are much shorter and not crescent-shaped. Also unlike Portland Spurge, Sea Spurge does not have minutely pointed leaves. Sea Spurge has rougher fruits.
Sun Spurge contains toxic and irritant
Phorbol esters. The milky sap is caustic to the skin and can cause dermatitis. Besides the compounds detailed below, Sun Spurge contains a whole series of complex tannins collectively known as Euphorbins, but individually named as Euphorbin-A, -B, -C, -D and Euphorbin-E as well as several steroidal terpenoids: 0.2% β-Sitosterol, 0.12% Ursolic Acid, 0.23% β=
Amyrin, 0.01% Uvaol and 0.03% Betulin. Hyperoside, the galactoside of Quercetin is present at 0.12%. It also contains diterpene esters called
Paralinone A and Paralinone B, which obtain their name from Sun Spurge (Euphorbia paralias.
The specific epithet paralias does not mean that Sun Spurge will paralyse you (although the sap is toxic) but rather is derived from the Greek 'paralos' meaning 'maritime' sometimes used in the sense 'blue-green like the sea', which it is also.
Another Ingenane series diterpenoid found in Sea Spurge is Ingenol 3-,20-dibenzoate. OBz is the abbreviation for benzoate.
A diterpenoid belonging to the Tigliane Series found in Sea Spurge, Phorbol 12-Tigliate 13-Decanoate has medical applications as an anti-viral drug against lymphomatic leukaemia and HIV. Note the strained cyclo-propane ring shown in red. A similar drug called Prostratin (12-deoxyphorbol 13-acetate) is used to treat prostrate cancer. Phorbols are named after the Spurge Family (Euphorbiaceae).
A very similar compound (with the only two differences being that the decanoate group is moved to the 12-position from the 13-position shown above, and a smaller acetate group on the 13-position) is known variously as TPA or PMA. TPA is used both in the biological laboratory to activate protein kinase C, and therapeutically as a pharmacological drug in myolectic leukaemia patients. This happens because Phorbol esters resemble
DiAcylGlycerol (DAG) which is a signalling molecule within mammals which activates protein kinase C (PKC). PKC is important in the human body and anything which inhibit it will trigger many usually harmful cellular responses, including cell division. TPA is found naturally in some Spurges, but it is unclear whether it is found in Sea Spurge.
A diterpenoid belonging to the Paraliane Series (which are named after Sea Spurge (Euphorbia paralias in which they were first discovered) is Paraliane itself. The Paraliane series have three 5-membered rings and one of six.
Euphorbol are steroidal terpenoids found in Sun Spurge. They are both derived from the universal plant steroid and pre-cursor, Cycloartenol. They are named after the Spurge Family (Euphorbiaceae).
Betulin is a lupane triterpene found in Sea Spurge at 0.03% and in the bark of
Birch trees where it comprises up to 35% of the dry weight. Indeed, the Birch Tree Family, Betula is where it derives its name. Betulin is directly related to Betulinic Acid, which is the more biologically active of the two. Betulin can be easily converted to the more effective Betulinic Acid in the laboratory. Both possess anti-malarial, anti-retroviral, hepatoprotective and anti-inflammatory properties. Betulinic Acid is also effective against tumours of various sorts. Betulin has been known of for 200 years, but its almost miraculous healing properties were only recently re-discovered. Both are available as extracts from Birch Bark from alternative therapy shops. Other derivatives of Betulinic Acid are now made in the laboratory from Betulin (using Birch bark, rather than Sea Spurge, which contains far less) for pharmaceutical uses. Betulinic Acid is related to Oleanolic Acid.
See Menyanthoside, a glycoside based upon Betulinic Acid.
Hybridizes with: Portland Spurge.