is the anion [OSCN]-
and the conjugate base of hypothiocyanous acid. It is an organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
part of the thiocyanates as it contains the functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
SCN. It is formed when an oxygen is singly bonded to the thiocyanate
Thiocyanate is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates...
group. Hypothiocyanous acid (HOSCN) is a fairly weak acid as its acid dissociation constant is 5.3
Hypothiocyanite (also named hypothiocyanate) is formed by peroxidase catalysis of hydrogen peroxide and thiocyanate:
- H2O2 + SCN- → OSCN- + H2O
As a bactericide
Hypothiocyanite occurs naturally in the antimicrobial immune system of the human respiratory tract in a redox reaction catalyzed by the enzyme lactoperoxidase
Lactoperoxidase is a peroxidase enzyme secreted from mammary, salivary, and other mucosal glands that functions as a natural antibacterial agent. Lactoperoxidase is a member of the heme peroxidase family of enzymes. In humans, lactoperoxidase is encoded by the LPO gene.Lactoperoxidase catalyzes...
. It has been researched extensively for its capabilities as an alternative antibiotic as it is harmless to human body cells while being cytotoxic to bacteria. Of late, the exact processes for making hypothiocyanite have been patented as such an effective antimicrobial has many commercial applications. Whether or not this antimicrobial compound comprises the entirety of the immune system of the respiratory tract remains to be seen.
Mechanism of action
Lactoperoxidase-catalysed reactions yield short lived intermediary oxidation products of SCN-
, providing antibacterial activity.
The major intermediary oxidation product is hypothiocyanite OSCN-
, which is produced in an amount of about 1 mol per mol of hydrogen peroxide. At the pH optimum of 5.3, the OSCN-
is in equilibrium with HOSCN. The uncharged HOSCN is considered to be the greater bactericidal of the two forms. At pH 7, it was evaluated that HOSCN represents 2% compare to OSCN-
The action of (OSCN)- against bacteria is reported to be caused by sulfhydryls (SH) oxidation.
The oxidation of -SH groups in the bacterial cytoplasmic membrane results in loss of the ability to transport glucose and also in leaking of potassium ions, amino acids and peptide.
has also been identified as an antimicrobial agent in milk, saliva, tears, and mucus.
is considered as safe product as it is not mutagenic.
Relation to cystic fibrosis
Initially, this particular lactoperoxidase-catalyzed compound was originally discovered while viewing the specific environment of cystic fibrosis
Cystic fibrosis is a recessive genetic disease affecting most critically the lungs, and also the pancreas, liver, and intestine...
patients' weakened respiratory immune system against bacterial infection.
Symptoms of cystic fibrosis include an inability to secrete sufficient quantities of SCN-
which results in a shortage of necessary hypothiocyanite, resulting in increasing mucous viscosity, inflammation and bacterial infection in the respiratory tract.
Lactoferrin , also known as lactotransferrin , is a multifunctional protein of the transferrin family. Lactoferrin is a globular glycoprotein with a molecular mass of about 80 kDa that is widely represented in various secretory fluids, such as milk, saliva, tears, and nasal secretions...
with hypothiocyanite has been granted orphan drug
An orphan drug is a pharmaceutical agent that has been developed specifically to treat a rare medical condition, the condition itself being referred to as an orphan disease...
status by the EMEA
The European Medicines Agency is a European agency for the evaluation of medicinal products. From 1995 to 2004, the European Medicines Agency was known as European Agency for the Evaluation of Medicinal Products.Roughly parallel to the U.S...
and the FDA.
Naturally, the discovery correlated with studies exploring different methods seeking to further gain alternative antibiotics, understanding that most older antibiotics are decreasing in effectiveness against bacteria with antibiotic resistance.
OSCN, which is not an antibiotic, has proved efficacy on superbugs including MRSA reference strains, BCC, Mucoid PA
Schema of LPO/SCN-
in human lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
Non exhaustive list of microorganisms
Bacteria (+Gram, -Gram)
• Acinetobacter species
• Aeromonas hydrophila
• Bacillus brevis
• Bacillus Cereus
• Bacillus megaterium
• Bacillus subtilis
• Burkholderia cepacia
• Campylobacter jejuni
• Capnocytophaga ochracea
• Corynebacterium xerosis
• Enterobacter cloacae
• Escherichia coli
• Haemophilus influenzae
• Helicobacter Pylori
• Klebsiella oxytoca
• Klebsiella pneumoniae
• Listeria monocytogenes
• Micrococcus luteus
• Mycobacterium smegmatis
• Mycobacterium abscessus
• Neisseria species
• Pseudomonas aeruginosa
• Pseudomonas pyocyanea
• Salmonella species
• Selenomonas sputigena
• Shigella sonnei
• Staphylococcus aerogenes
• Staphylococcus Aureus
• Streptococcus agalactiae
• Streptococcus faecalis
• Streptococcus mutans
• Wolinella recta
• Xanthomonas campestris
• Yersinia enterocolitica
• Herpes simplex virus, HSV
• Immunodeficient virus, HIV
• Respiratory Syncytial virus, RSV
• Echovirus 11
• Influenza virus
Yeast and mould
• Candida albicans
• Aspergillus niger
• Colletotrichum musae
• Colletotrichum gloeosporioide
• Botryodiplodia theobromae
• Fusarium monoliforme
• Fusarium oxysporum
• Rhodotula rubra
• Byssochlamys fulva