Found in similar places to: Sea Milkwort [to which it superficially resembles].
Easily confused with : other Scurvygrasses but Danish Scurvygrass is the earliest flowering scurvygrass, and has stem leaves that are stalked, and with the topmost leaves pentagonal (or Ivy shaped). Seed pods egg shaped.
Hybridizes with :
Common Scurvygrass (Cochlearia officinalis) to produce Cochlearia danica × officinalis.
Not to be confused with : Grass-of-Parnassus, Sea Arrow-grass, Marsh Arrow-grass, Sparrowgrass,
Eelgrass, Yellow-Eyed-Grass, Blue-eyed-Grass,
Grass Poly, Grass-Leaved Orache,
Grass-wrack Pondweed or Grass [plants with similar names].
No relation to :
Grass [a plant with similar name].
Danish Scurvygrass is a halophyte (salt-tolerant or salt-loving) and grows in grassland or bare ground, including sand, near the sea. It is also spreading inland along dual carriageways on major roads and motorway verges because of the salt used to de-ice the roads in Winter. The seeds are small and light and easily caught by the turbulence of passing traffic to be carried many yards in one swish, hence its swift progression along major roads. It is annual or biennial and low, less than 6 inches high, tending to sprawl low.
L-ASCORBIC ACID and VITAMIN C
Danish Scurvygrass is rich in L-
Ascorbic Acid, (~Vitamin C), and has been used in the past to cure scurvy, caused by a deficiency of Vitamin C in the body, but the plant also has a rather unpleasantly sharp taste limiting its modern day use as such. It is often reported in the literature that seeds (of many plants) soaked in L-Ascorbic Acid germinate faster, irrespective of whether they are halophytes, and this is due mostly to the anti-oxidant properties of Vitamin C, and only partially due to the salt-induced increase in lipid peroxidation by active oxygen species. Ascorbic Acid may be the key as to Danish Scurvygrasses tolerance to salt, but that does not seem to be a universal trait for halophytes (not all halophytes are rich in Ascorbic Acid or they too would be renown for their ability to cure scurvy). It is possible that Danish Scurvygrass also exudes Vitamin C onto its seeds which helps germination but this would seem to be irrelevant given that it contains so much Vitamin C anyway.
Salt tolerance in other halophyte plants is variously attributed to Salicylic Acid,
Propylpelargonidins, Stilbenes, Lignans,
Flavonoids and combinations thereof etc. See Thrift '
Metallophytes' and 'Heavy Metal Processing within Plants'. But some halophytes are not just salt-tolerant, but rather salt-loving and refuse to grow without salt (however, such plants have usually evolved near salt spray from the sea, and are now so adapted to high salt concentrations that removing them from that environment now kills them). Biochemists should not be surprised to find some natural organohalide compounds within such species. Even Chameleon has a natural organochloride.
Vitamin C is a lactone. The two other -OH groups on the lactone ring can be readily oxidized (by removing two hydrogen atoms and eliminating the double-bond in the lactone ring) yielding DehydroAscorbic Acid, and this is the basis of the ability of Ascorbic Acid to protect other compounds from oxidation; it is easily oxidized and steals the available electrons for its own purposes. The change from one to the other is mediated by a change in pH. The anti-oxidant activity is not related in any way to its vitamic activity, the two are separate properties. Only the L-stereoisomer is present in plants and animals, but the R-stereoisomer is almost inert as a vitamin, but un-diminished in strength as an anti-oxidant. The enzyme activity required for the Vitamin activity is L-stereospecific.
However, Vitamin C is not one specific molecule, but instead refers to a number of vitamers that have Vitamin C activity, L-Ascorbic Acid being only one. Others involved are some of the salts of L-Ascorbic Acid. To work well, these are usually converted to the most active form of the vitamer, Dehydro-Ascorbic Acid within the body.
Anti-oxidants, cancer and food supplements
It is often said that anti-oxidants are good for humans, but a lot of recent research actually points in the other direction; they are usually a bad thing. Those eating a lot of vegetables and fruits containing Vitamin C (and many other anti-oxidants such as the flavones) succumb more easily and often to cancer (of various sorts), whilst those whose diets are poor in anti-oxidants experience up to 30% fewer cancers. The reasoning is that the anti-oxidants prevent cell apoptosis (cell death) - which was assumed to be a good thing. But it turns out that not allowing cell apoptosis to take place normally is preventing the body from destroying those cells which it has labelled as suspect. Allowed to live, some of these cells can go on to become cancerous. Those on diets poor in anti-oxidants fare much better in this regard. It is a good thing to take a few days rest from a diet rich in anti-oxidants to allow cell apoptosis to take place during this interval. It is a bad thing to take anti-oxidant supplements to the diet.
Ascorbic Acid is a
Butenolide of great importance to both mammals and plants better known as Vitamin C (which is not a single compound, but refers to a number of compounds having Vitamin C activity - but to work well, they are converted to the most active form of the vitamer, DehydroAscorbic Acid). Between them, Gibberellic Acid and its antagonist Ascorbic Acid act in anti-concert regarding their roles in seed germination, the first encouraging germination, the second discouraging it. When the relative concentrations of the two tip towards Gibberellic Acid, then the seed sets about germinating, but otherwise if the proportion is tipped towards Ascorbic Acid, then germination is delayed until conditions are just right. A differential mechanism, a balancing act which has far more refined response than that of a trigger point set to the concentration of a single substance. Temperature, rainfall and sunlight-hours could all have their say on the balance between the two mutually antagonistic compounds in ways not yet fully understood.
Danish Scurvygrass contains a total of about 5000µg/g of Calystegines, polyhydroxylated nortropanes, of which roughly 92% is
Calystegine A5, 5% Calystegine A3, and 3%
Calystegine B3. This is more than twice as much of the total content of Calystegines as that of the next highest concentration of Calystegines in members of Cochlearea species, English Scurvygrass (Cochlearia anglica). This is possibly because Danish Scurvygrass has to tolerate a higher concentration of salt.
Polyhydroxylated Hyacinthines of Bluebell, the Calystegines also look similar to sugars, but with a bridging nitrogen atom which makes them alkaloids instead. They can thus put spanners in the works of enzymes within the body meant to process sugars. This makes them poisonous. Calystegines, being related to tropanes, are toxic, but have only been discovered relatively recently. They are present in quite a few Families including the
Brassicaceae and many more Genera. Generally, they are alkaloidal glycosidase inhibitors, and are found not only in many plants but also some fungi. In mammals they inhibit lysosomal glycosidases which are involved in glycoprotein processing. As such they have a lot of potential in chemotherapy against cancer, since oncogene products and cancer-specific proteins sometimes show unique glycosyation patterns.
Your author thinks he has worked out the nomenclature of the Calystegine alphabetic designations; he thinks A has three hydroxyl groups, B four, and C five, etc, but he has no idea how chemists name them when there are only two or fewer hydroxyl groups. There is a further designation, that of N as in
Calystegine N1 where there is an NH2 group substitution for a hydroxyl OH group.