Porphyran is a sulfated

Sulfation

Sulfation in biochemistry is the enzyme-catalyzed addition of sulfate to another molecule. It often refers to a phase II enzyme reaction. This biotransformation process uses its cosubstrate 3'-phosphoadenosine-5'-phosphosulfate to transfer sulfate to a xenobiotic...

 carbohydrate

Carbohydrate

A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

 dervied from red algae

Red algae

The red algae are one of the oldest groups of eukaryotic algae, and also one of the largest, with about 5,000–6,000 species  of mostly multicellular, marine algae, including many notable seaweeds...

 of the genus Porphyra

Porphyra

Porphyra is a foliose red algal genus of laver, comprising approximately 70 species. It grows in the intertidal zone, typically between the upper intertidal zone and the splash zone in cold waters of temperate oceans. In East Asia, it is used to produce the sea vegetable products nori and gim ,...

.

Composition

Porphyran is a complex sulphated

Sulfation

Sulfation in biochemistry is the enzyme-catalyzed addition of sulfate to another molecule. It often refers to a phase II enzyme reaction. This biotransformation process uses its cosubstrate 3'-phosphoadenosine-5'-phosphosulfate to transfer sulfate to a xenobiotic...

 carbohydrate

Carbohydrate

A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

. It is a highly substituted agarose with a linear backbone consisting of 3-linked

Glycosidic bond

In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....

 beta-D-galactosyl

Galactose

Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

 units alternating with either 4-linked alpha-L-galactosyl 6-sulfate or 3,6-anhydro-alpha-L-galactosyl units. The composition includes 6-O-sulphated L-galactose

Galactose

Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

, 6-O-methylated D-galactose, L-galactose, 3,6-anhydro-L-galactose, 6-O-methyl D-galactose and ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 sulphate. Some of the ester is present as 1-4-linked L-galactose 6-sulphate. The precise composition of porphyran shows seasonal

Season

A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

 and environmental

Natural environment

The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

variations. In Porphyra haitanensis, the L-residues are mainly composed of alpha-L-galactosyl 6-sulphate units, and the 3,6-anhydro-galactosyl units are minor. In Porphyra capensis, The ratio of alpha-L-galactose-6-sulphate and the 3,6-anhydrogalactose is 1.2:1.