Granadaene is the

trivial name In chemistry, a trivial name is a non-systematic name for a chemical substance. That is, the name is not recognized according to the rules of any formal system of chemical nomenclature such as IUPAC inorganic or IUPAC organic nomenclature. A ...

of a

polyene In organic chemistry, polyenes are polyunsaturated organic compounds that contain multiple carbon–carbon double bonds (). Some sources consider dienes to be polyenes, whereas others require polyenes to contain at least three carbon–carbon d ...

of non-

isoprenoid The terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeably with "terpene ...

biosynthetic origin, that constitutes the red

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

characteristic of ''

Streptococcus agalactiae ''Streptococcus agalactiae'' (also known as group B streptococcus or GBS) is a gram-positive coccus (round bacterium) with a tendency to form chains (as reflected by the genus name ''Streptococcus''). It is a beta-hemolytic, catalase-negative, an ...

'' (group B streptococcus).

Characteristics

Granadaene contains a

conjugated system In physical organic chemistry, a conjugated system is a system of connected p-orbitals with delocalized electrons in a molecule, which in general lowers the overall energy of the molecule and increases Chemical stability, stability. It is Reson ...

made up of a linear chain of 12 conjugated carbon-carbon double bonds which is connected to the amino acid

ornithine Ornithine is a non-proteinogenic α-amino acid that plays a role in the urea cycle. It is not incorporated into proteins during translation. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency, a disorder of th ...

at one end and the sugar

rhamnose Rhamnose (Rha, Rham) is a naturally occurring deoxy sugar. It can be classified as either a methyl- pentose or a 6-deoxy- hexose. Rhamnose predominantly occurs in nature in its L-form as L-rhamnose (6-deoxy-L- mannose). This is unusual, since mo ...

at the other. Granadaene contains 12 conjugated double bonds, a feature which is unprecedented among non-isoprenoid pigments. Granadaene is dark red, odorless,

insoluble In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solub ...

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

diethyl ether Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

hexane Hexane () or ''n''-hexane is an organic compound, a straight-chain alkane with six carbon atoms and the molecular formula C6H14. Hexane is a colorless liquid, odorless when pure, and with a boiling point of approximately . It is widely used as ...

dimethyl sulfoxide Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula . This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is ...

(DMSO),

acetonitrile Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula and structure . This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanide anion is not class ...

tetrahydrofuran Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water- miscible organic liquid with low viscosity. It is ...

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

, and in most solvents, it is soluble in DMSO–0.1%

trifluoroacetic acid Trifluoroacetic acid (TFA) is a synthetic organofluorine compound with the chemical formula CF3CO2H. It belongs to the subclass of per- and polyfluoroalkyl substances (PFASs) known as ultrashort-chain perfluoroalkyl acids (PFAAs). TFA is not ...

(TFA). Granadaene, can be extracted from cultures of ''S.agalactiae'' in granada broth ( granada medium without

agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from " ogonori" and " tengusa". As found in nature, agar is a mixture of two components, t ...

) with 0.1 M

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

(KOH) and purified by

size-exclusion chromatography Size-exclusion chromatography, also known as molecular sieve chromatography, is a chromatography, chromatographic method in which molecules in Solution (chemistry), solution are separated by their Chemical structure, shape, and in some cases molec ...

Sephadex Sephadex is a cross-linked dextran gel used for gel filtration. It was launched by Pharmacia Pharmacia was a pharmaceutical and biotechnological company in Sweden that merged with the American pharmaceutical company Upjohn in 1995. History ...

LH using DMSO–0.1%TFA. Streptococcus agalactiae in granada broth

Streptococcus agalactiae on Granada medium

The fine-structure of the ultraviolet-visible

absorption spectrum Absorption spectroscopy is spectroscopy that involves techniques that measure the absorption of electromagnetic radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, ...

of the granadaene (in DMSO/TFA) is almost identical to that of a

carotene The term carotene (also carotin, from the Latin ''carota'', "carrot") is used for many related unsaturated hydrocarbon substances having the formula C40Hx, which are synthesized by plants but in general cannot be made by animals (with the ex ...

with a similar conjugated system of 12 double bonds (e.g. alpha-carotene), which is why the GBS pigment was considered to be a

for many years. Non-terpenoid polyenes up to 10 conjugated double bonds are also a bizarre class of biologically natural products (laetiporic acids) found in the basidiomycete '' Laetiporus sulphureus''.

Granadaene and ''S.agalactiae'' detection and identification

Production of the red pigment granadaene is a

phenotypic trait A phenotypic trait, simply trait, or character state is a distinct variant of a phenotypic characteristic of an organism; it may be either inherited or determined environmentally, but typically occurs as a combination of the two.Lawrence, Eleano ...

specific to β-hemolytic GBS, and because of that, detection of red colonies from clinical samples, when cultivated on granada medium, allows the straightforward identification of GBS.

Biological relevance

Granadaene is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

produced by ''S.agalactiae''. It is the product of a

metabolic pathway In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell (biology), cell. The reactants, products, and Metabolic intermediate, intermediates of an enzymatic reaction are known as metabolites, which are ...

similar to that of

biosynthesis Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthe ...

fatty acids In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

. The

enzymes An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as pro ...

necessary for the biosynthesis of granadaene in GBS are coded by a

gene cluster A gene cluster is a group of two or more genes found within an organism's DNA that encode similar peptide, polypeptides or proteins which collectively share a generalized function and are often located within a few thousand base pairs of each othe ...

of 12 genes, the ''cyl''

operon In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splic ...

, Among the cyl operon, the cylE gene is required for pigment production, and transcription of cyl genes is regulated by the CovR/S two-component system, and a pathway for the pigment biosynthesis requiring all the genes of the ''cyl'' operon has been proposed. Like the biosynthesis of the pigment, the hemolytic activity also requires in GBS the 12 genes of the ''cyl'' operon. Moreover,it has been proposed that granadaene is indeed the

hemolysin Hemolysins or haemolysins are lipids and proteins that cause lysis of red blood cells by disrupting the cell membrane. Although the lytic activity of some microbe-derived hemolysins on red blood cells may be of great importance for nutrient acqui ...

of ''S.agalactiae'' The pigment is localized, in GBS, in the

cell membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

, where it could play a role in membrane stabilization, similar to the role of carotenes in other bacterial membranes. In addition to ''S.agalactiae'' the presence of granadaene and the ''cyl'' genes has been reported in pigmented ''Acidipropionibacterium'' spp. (former ''Propionibacterium'') as ''A.jensenii'', ''A.thoenii'', and ''A.virtanenii'',Deptula P, Loivamaa L , Smolander OP, Laine P , Roberts RJ, Piironen V, Paulin L, Savijoki K, Auvinen P, Varmanen P (2019). "Red-Brown Pigmentation of Acidipropionibacterium jensenii Is Tied to Haemolytic Activity and cyl-Like Gene Cluster". ''Microorganisms'' 7: 512. https://doi.org/10.3390/microorganisms7110512 , https://pmc.ncbi.nlm.nih.gov/articles/PMC6920887/, where it can cause defects such as red spots in some cheeses. Probably granadaene is also present in other related species such as ''Pseudopropionibacterium rubrum''. Granadaene is also produced by strains of ''Lactocococcus garvieae/petaury/formosensis'' group where the ''cyl'' cluster is also present. The ''cyl'' genes have been cloned in ''Lactococcus lactis'' (a non-hemolytic non-pigmented Gram-positive bacterium) and the expression of the GBS cyl operon conferred hemolysis, pigmentation, and cytotoxicity to ''Lactococcus lactis''. Proving that the expression of the genes of the ''cyl'' operon is sufficient for Granadaene production in a heterologous host.

Granadaene and GBS Virulence

The hemolytic activity of granadene is strongly linked to the length of its polyene chain. It has been proposed that granadaene is indeed the

of ''S.agalactiae'', the GBS hemolysin is a broad-spectrum

cytolysin Cytolysin refers to the substance secreted by microorganisms, plants or animals that is specifically toxic to individual cells, in many cases causing their dissolution through lysis. Cytolysins that have a specific action for certain cells are ...

able to destroy many

eukaryotic The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...

cells, including platelets. Because of this, granadaene is considered an important

virulence factor Virulence factors (preferably known as pathogenicity factors or effectors in botany) are cellular structures, molecules and regulatory systems that enable microbial pathogens (bacteria, viruses, fungi, and protozoa) to achieve the following: * c ...

for GBS. Nevertheless, 1–5% of GBS strains are non-hemolytic and do not produce pigment. These non-hemolytic and non-pigmented GBS strains (lacking pigment and hemolysin) are considered less virulent because of that.

References

{{Reflist Rhamnosides Polyenes Biological pigments