Lactonic (di-acetylated) Sophorolipids

17-L-[(2′-O-β-D-Glucopyranosyl-β-D-glucopyranosyl)oxy]-cis-9-octadecenoic acid 1′,4″-lactone 6′,6″-diacetate

槐糖脂,

Sophorolipids are a group of lactic acid-derived compounds that have been shown to have synergistic effects in the treatment of oral pathogens. They have been shown to have antimicrobial activity against both bacteria and fungi. Sophorolipids are effective against oral pathogens, such as Streptococcus mutans and Candida albicans, at concentrations of 1 mg/mL or less. This effect is attributed to their surfactant properties, which interfere with the surface tension of water and increase its solubility in fats. The addition of sodium citrate increases their efficacy by inhibiting bacterial adhesion to tooth enamel. Sophorolipids also exhibit antimicrobial activity against human pathogens such as Pseudomonas aeruginosa and Escherichia coli, but not against Staphylococcus aureus or Salmonella enterica serovar Typhimurium.

Lactonic sophorolipid (LSL) is a glycolipid biosurfactant produced via the yeast Candida bombicola. LSL is known for its unique properties, such as excellent interfacial activity, biodegradability, and non-toxicity. LSL has been extensively studied to evaluate its potential applications in various fields of research and industry. In this paper, we will discuss the properties, synthesis, analytical methods, biological properties, toxicity, and safety of LSL, its applications in scientific experiments, current state of research, potential implications in various fields of research and industry, limitations, and future directions.

Definition and Background:

Lactonic sophorolipid is a family of glycolipid biosurfactants made up of a hydrophilic sophorose sugar head and a hydrophobic fatty acid chain. LSLs are distinguished as neutral or acidic based on the presence or absence of a γ-lactone ring in the sugar head. LSLs are structurally similar to biosurfactants such as rhamnolipids, produced by Pseudomonas aeruginosa, and saponins, found in higher plants.

Physical and Chemical Properties:

Lactonic sophorolipid has a molecular weight that ranges from 426 to 994 g/mol, depending on the length of the fatty acid chain and the presence or absence of a cyclic sugar ring. LSLs form micelles in water at concentrations that range from 1 to 10 g/l. The critical micelle concentration (CMC) of LSLs varies between 0.1 and 10 g/l, depending on the molecular weight, the length of the fatty acid chain, and the presence or absence of a cyclic sugar ring. LSLs have a surface tension reduction capability of up to 35 mN/m and show excellent emulsification and solubilization properties. LSLs have a low toxicity.

Synthesis and Characterization:

The synthesis of LSL involves the fermentation of the yeast Candida bombicola using different carbon sources such as glucose, sucrose, lactose, or glycerol, and different nitrogen sources such as peptone, yeast extract, or ammonium sulfate. The bioconversion of the carbon source into sophorolipids occurs through a series of enzymatic reactions. The synthesized LSL can be characterized using various methods such as thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS).

Analytical Methods:

Several analytical methods have been developed to quantitatively and qualitatively determine the presence and quantity of LSLs in different samples. These methods include TLC, HPLC, NMR, MS, Fourier transform infrared spectroscopy (FTIR), and fluorescence.

Biological Properties:

Lactonic sophorolipid possesses several biological properties such as antimicrobial, antifungal, and anti-biofilm activity. Several studies have demonstrated the effectiveness of LSL against various pathogens such as Escherichia coli, Candida albicans, and Staphylococcus aureus. LSLs have also been shown to have wound healing properties.

Toxicity and Safety in Scientific Experiments:

LSLs are considered to be non-toxic and biodegradable, making them a safe option for use in scientific experiments. Several toxicity studies have been conducted, and LSLs have been found to be safe even at concentrations up to 810 µg/ml.

Applications in Scientific Experiments:

Lactonic sophorolipid has a broad range of applications in various fields of research and industry. LSL is used as a biosurfactant, emulsifier, foaming agent, antifoaming agent, and stabilizer in various industries such as food, pharmaceuticals, cosmetics, and agriculture. Apart from these, LSL has potential applications in microbial enhanced oil recovery (MEOR), soil remediation, and bioremediation.

Current State of Research:

Lactonic sophorolipid is an extensively studied glycolipid biosurfactant. Several studies have reported the successful synthesis, characterization, and evaluation of the biological and physicochemical properties of LSLs. The current state of research is focused on optimizing the fermentation process for the production of high yields of LSLs, exploring new applications of LSLs, and developing more efficient and cost-effective methods for the synthesis and characterization of LSLs.

Potential Implications in Various Fields of Research and Industry:

Lactonic sophorolipid has numerous potential implications in various fields of research and industry. LSLs have the potential to replace synthetic surfactants in several applications, including food, pharmaceuticals, and personal care products. LSLs also have the potential to replace toxic and non-biodegradable chemicals used in soil and water remediation. Furthermore, LSLs have been shown to enhance the removal of heavy metals from contaminated water.

Limitations and Future Directions:

Lactonic sophorolipid has several limitations. One of the significant limitations is the high cost of production compared to synthetic surfactants. Another limitation is the low yield of LSLs under industrial fermentation conditions. To overcome these limitations, future directions include optimizing the production process to reduce costs and develop strains with higher productivity. Another future direction is to explore the potential applications of LSLs in various fields, including the development of sustainable and environmentally friendly products.

Future Directions:

The future directions for LSLs are vast. Some of the future directions include exploring the potential of LSLs in drug delivery systems, tissue engineering, and biosensors. To achieve this, researchers can explore the modification of LSL structure to increase its specificity to a particular target and improve its drug delivery efficiency. Furthermore, future directions include developing more accurate and robust analytical methods for the synthesis and characterization of LSL and improving the understanding of the mechanism of action of LSL in various applications.