Many similarities to : Sun Spurge (Euphorbia helioscopia). see captions for differentiating from other similar spurges.
It is a glabrous or hairy archaeophyte and annual plant growing to 80cm high. The stem is hollow and contains a toxic milky latex, as do most (all?) other Spurges.
The diterpenoids obtained from Broad-leaved Spurge are four Jatrophanes similar to those isolated from Upright Spurge (Euphorbia stricta (Previously known as E. serrulata), which is of taxonomic importance enabling a botanical similarity between the two species to be established. It also contains Abietane diterpenoids (unless these are the same as the Jatrophanes???)
Jatrophanes selectively bind to and inhibit the ATP-dependent efflux pump P-glycoproten (Pgp). As such, they may be valuable in treating multi-drug resistant cancers which are common encountered. Unforyunately, to make new Jatrophane type diterpenoids for testing, several routes to synthesize them in the laboratory are required, but only a few routes have been found.
In most Jatrophanes, the cyclo-Pentane ring is fused to a larger ring which in turm is fused to another large ring; three fused rings in all. But in these Jatrophanes, the second two rings are broken resulting in a single large 12-membered ring with a broken bridge. In the case of the first 3 shown here, the bridging moiety is still present, but broken.
Jatrophane diterpenoids with a macrocyclic ring occur exclusively in both the Spurge Family (Euphorbiaceae) and Mezereon Family (Thymelaeaceae) families. Some of these compounds are of profound interest due to their cytotoxicity and antitumour properties, as well as their anti-viral and their ability to reverse multi-drug resistance. Jatrophane diterpenoids are found in nature, such as plants like thse, in their partly oxidised forms, mainly as polyesters (those side-groups sticking out - not polyester the plastic).
Similar, but not identical, Jatrophane diterpenoids to those found in Broad-leaved Spurge are to be found in Upright Spurge (Euphorbia stricta) (old name Euphorbia serrulata).
There are two totally different compounds with the same common name:
Pubescenol, one a Jatrophane Diterpenoid, the other a
Withanolide. Only the Jatrophane Pubescenol is present in Broad-leaved Spurge.
Withanolide version of
Pubescenol is not present in any Spurge, but instead in Chinese Lantern (Physalis pubescens) [which should not be confused with another plant with the same common name: Chinese Lantern (Abutilon pictum) which belongs in a differing family (Malvaceae)]. As you can see, the two are totally different, which fact had your Author completely puzzled when he tried to look up the chemical structural formula for Pubescenol and ended up with a totally unexpected structural formula.
Altotibetin, as its name may imply, was first found in Euphorbia altotibetic which some Chinese scientists observe. They may mean Euphorbia altotibetica? In fact they found not one, but 4 new Jatrophanes in this Spurge which they named
Altotibetin D; a fifth was named
Altotibetin E by another group of researchers. It is not known which, if any, of these Altotibetins it is that is also found in Broad-leaved Spurge. One presumes the 'A' version.
Pl-3 is yet another jatrophane-type diterpenoid found in Broad-leaved Spurge. Both Pl-3 and Pl-4 have a benzene ring moiety as a side group attached to the cyclopentane ring. Altotibetin has the benzene ring side-group attached to the main 12-membered ring instead, whilst Pubescenol lacks it altogether.
Pl-4 is yet another jatrophane-type diterpenoid found in Broad-leaved Spurge. Pl-4 has two double-bonds in the 12-membered ring, all the others have but one. All four have at least 4 (most have 5) acetoxy side-groups, which is what is meant by the 'polyester' moniker.
Broad-leaved Spurge also contains four Cerebrosides, Cerebroside 1 to Cerebroside 4, the first 3 (Cerebroside 1 to 3) which are the 1-O-β-D-Glycosides of PhytoSphingosines. In Cerebroside 1-3 the PhytoShingosides comprise of the same long-chain base, a 2-AminoOctadec-8-ene-1,3,4-triol while that last of a 2-AminoOctadeca-4,8-Diene-1,3-Diol; but all are terminated by 2-Hydroxy Fatty Acids of various chain lengths (C16:0, C24:0, C26:1 and C28:1 which is linked to the amino group. Those with a number other than zero after the colon, :, are Singly UnSaturated Fatty Acids.
The C16:0 is Palmitic Acid (aka
HexaDecanoic Acid), CH3(CH2)14)COOH.
The C18:0 is Stearic Acid (aka
OctaDecanoic Acid), CH3(CH2)16)COOH and is found in tallow (candle-wax) and cocoa butter the ester of which is used to make soap, shampoos and shaving cream.
Whilst the following are singly un-saturated fatty acids:
The C16:1 is
Palmitoleic Acid, CH3(CH2)5CH=CH(CH27)COOH which is found in Macadamia Nuts.
The C24:1 is
Nervonic Acid (aka
SelaCholeic Acid), CH3(CH2)7CH=CH(CH213)COOH, which is found in the seeds of Flax, sesame Seed, and Macadamia nuts.
The C26:1 is
HexaCosenoic Acid. [Your Author has failed to find the long formula for this one]
These large compounds are all amines, containing a single Nitrogen atom (in the top chain)
Broad-leaved Spurge accumulates complex SphingoGlycoLipids such as these.
This has only recently been found in Broad-leaved Spurge but was previously known in Mediterranean Spurge (Euphorbia characias ssp. wulfenii); the other 3 constituents have been known about for some time and they have also been identified in the rare
Purple Spurge (Euphorbia peplis)