Lactobionic acid (LBA), chemically known as 4-O-β-galactopyranosyl-D-gluconic acid, is a polyhydroxy organic acid obtained by the oxidation of C1 on the lactose glucosyl group of a molecule of galactose and a molecule of gluconic acid linked by an ether bond.
Lactobionic acid, known as a third generation fructic acid, is a naturally occurring acid in the human body with a molecular formula of C12H22O12, a molecular weight of 358.30 g/mol and a pKa of 3.8. Lactobionic acid is an advanced fructic acid that combines repairing, anti-ageing, moisturising, anti-oxidant and promotes the renewal of the organism. Its structure and physical properties give lactobionic acid many applications. Currently, lactobionic acid is widely used in the food industry, pharmaceutical industry, fine chemical industry and cosmetic industry.
The main effect of lactonic acid is to promote the production of collagen, which can play a role in whitening, moisturizing, anti-aging and other effects. The eight hydroxyl group molecules in lactose acid can remove free radicals in the body, and can promote the formation of keratinocytes and remove aging keratinocytes. Most women can use lactonic acid as a topical skin care product, but it is not recommended for people with thin skin or allergies.Today, we will focus on its role in cosmetics.
The role of lactobionic acid:
1. Moisturising
Lactic acid molecular structure with eight groups of hydroxyl groups, can grab a large number of water molecules, the scope of its grasp of water can be from the skin gel matrix to the vaporized water molecules at room temperature, and can be a long time moisture tightly bonded state, moisturizing effect is much greater than glycolic acid, lactic acid, citric acid and gluconic acid. Some experiments show that each unit of lactic acid can absorb about 70g of water, water retention can reach 55g, we commonly used moisturizers such as glycerin, sorbitol, etc., its water retention and water absorption are not as good as lactic acid.
Research results show that 10% and 30% of lactic acid products have a better moisturizing effect on the skin, and there is no statistically significant difference between the two concentrations, lactic acid is an efficient moisturizer.
2. Anti-bacterial acne
It is currently believed that the bacteria mainly associated with acne - Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus - all have a population sensing system, which can regulate the expression of a variety of virulence factors and the formation of biofilms according to different flora densities, which are closely related to the multiple pathogenic stages of acne and the generation of drug resistance in pathogenic bacteria.
The results of the study showed that lactobionic acid has a good inhibitory effect on Staphylococcus aureus. The experiments were carried out using the two-fold dilution method to test the drug sensitivity of lactobionic acid against suspended and perithecia of S. aureus. The test results can be seen from the table that the minimum inhibitory concentration MIC of lactobionic acid against S. aureus was 8mg/mL, the minimum bactericidal concentration MBC was 32mg/mL, the minimum biofilm inhibitory concentration MBIC against S. aureus biofilm was 16mg/mL and the minimum biofilm killing concentration MBBC is greater than 128mg/mL.
3.Anti-aging
Reduce matrix metalloproteinase activity
Matrix metalloproteinases (MMPs), first identified in 1962 as a collagen hydrolase that causes degradation of extracellular matrix EMC proteins, are a class of zinc-dependent endopeptidases. With sun exposure and ageing, matrix metalloproteinases can increase over time, leading to skin laxity.
Lactobionic acid chelates the zinc ions inside matrix metalloproteinases, forming a complex with the metalloproteinases, reducing matrix metalloproteinase activity and reducing collagen loss. Experimental studies have shown that 0.1% lactobionic acid can effectively inhibit the activity of metalloproteinases.
4.Inhibition of lipid peroxidation
Intracellular iron accumulation can generate reactive oxygen species and cause oxidative stress through the Fenton reaction, which promotes lipid peroxidation and leads to regulated cellular necrosis, also known as cellular iron death. Iron death is a regulated form of cell death characterised by the lazy accumulation of iron from lipid peroxidation to lethal levels. When cellular cysteine transport proteins are inhibited, intracellular glutathione is depleted, leading to the eventual accumulation of lipid peroxidation to a level that induces cell death.
Lactobionic acid can chelate trivalent iron ions, inhibit lipid peroxidation and protect unsaturated fatty acid-rich cell membranes and mitochondria from UA damage.
5.Antioxidant
Lactobionic acid acts as an antioxidant by chelating divalent iron ions and slowing down the hydroxyl radicals produced by the Fenton reaction.
In 1893, chemist Fenton discovered that a mixture of hydrogen peroxide (H2O2) and divalent iron ions had strong oxidising properties and could oxidise many organic compounds known at the time, such as carboxylic acids, alcohols and esters, to their inorganic state.
6.Renewal of keratin
Lactic acid, as a type of fructic acid, also has the ability to renew ageing keratinocytes and promote the renewal of keratinocytes. Due to its larger molecular weight compared to other fruit acids, it penetrates relatively slowly and is less irritating. In an irritation experiment with 14 d of continuous use, lactic acid plus gluconic acid caused almost no skin irritation in the experimental group, and cosmetics containing 4% lactic acid and 8% lactone gluconic acid were relatively safe and mild for skin irritation, comparable to saline.
