Licorice extract is derived from the root of the Glycyrrhiza glabra plant, commonly known as licorice. It has been used for centuries in traditional medicine and is now a popular ingredient in skincare products due to its beneficial properties. Chemical Properties: 1. Active Compounds: o Glycyrrhizin (or Glycyrrhizic Acid): This is the primary active compound in licorice extract, making up 2-25% of the extract by weight. Glycyrrhizin is responsible for many of the extract's therapeutic effects, including its anti-inflammatory and skin-brightening properties. o Liquiritin and Licochalcone: These are additional active compounds found in licorice extract. Liquiritin has skin-brightening effects and can help to disperse melanin, while Licochalcone has anti-inflammatory and antioxidant properties. 2. Chemical Structure: o Glycyrrhizin: Chemically, glycyrrhizin is a saponin glycoside with the formula C₁₈H₂₁O₁₀. It consists of a glycyrrhetic acid moiety and a glycyrrhizinic acid moiety linked by a glucuronic acid unit. o Liquiritin: It is a flavonoid glycoside, with a structure featuring a flavone backbone linked to glucose. o Licochalcone: This is a flavonoid with a structure that includes a chalcone backbone, which contributes to its anti-inflammatory effects. 3. Physical Properties: o Licorice extract is usually a brown or yellowish-brown powder or liquid, depending on its preparation. It is soluble in water and can be used in aqueous-based skincare formulations. 4. Stability: o Licorice extract is generally stable in formulations, but its effectiveness can be influenced by factors such as pH and temperature. Proper storage in a cool, dark place can help maintain its potency.

Azelaic Acid is a naturally occurring dicarboxylic acid found in grains like wheat, barley, and rye. It is widely used in dermatology and cosmetics for its multifunctional benefits, particularly in treating acne, rosacea, and hyperpigmentation. Azelaic acid is known for its anti-inflammatory, antimicrobial, and skin-brightening properties. Chemical Properties of Azelaic Acid: 1. Chemical Structure: o Molecular Formula: C9H16O4 o Molecular Weight: 188.22 g/mol o Structure: Azelaic acid is a saturated, straight-chain dicarboxylic acid with the chemical structure HOOC-(CH2)7-COOH. It has two carboxylic acid groups (-COOH) at either end of the nine-carbon chain, which contribute to its acidic nature and reactivity. 2. Physical Appearance: o Form: Azelaic acid is typically a white, odorless, crystalline powder. o Solubility: It is sparingly soluble in water but more soluble in alcohol and organic solvents, making it suitable for a variety of formulations, including creams, gels, and serums. 3. Stability: o pH Stability: Azelaic acid is stable in formulations with a pH range of about 4 to 5. This slightly acidic environment is optimal for maintaining its effectiveness. o Temperature Stability: It is stable under normal storage conditions but should be kept away from excessive heat and light to prevent degradation. 4. Mechanism of Action: o Antimicrobial: Azelaic acid inhibits the growth of bacteria like Propionibacterium acnes (associated with acne) and Staphylococcus epidermidis, helping to reduce acne-related inflammation and breakouts.

Kojic acid is a naturally occurring compound with notable applications in skincare due to its skin-brightening and pigment-reducing effects. Here's an overview of its chemical properties and functions: Chemical Properties: 1. Chemical Structure: o Kojic acid (C₆H₆O₄) has a chemical structure featuring a 5-hydroxy-2-hydroxymethyl-4-pyrone ring. This structure is crucial for its biological activity. o The molecule contains two hydroxyl groups (-OH) and a carbonyl group (C=O) within the pyrone ring. 2. Physical Properties: o Kojic acid appears as a white to off-white crystalline powder. o It is soluble in alcohol and slightly soluble in water. Its solubility in aqueous solutions can be improved by adjusting the pH. 3. Stability: o Kojic acid is relatively unstable in the presence of light and air. It is sensitive to oxidation and may degrade over time, especially in formulations exposed to air and light. o To enhance stability, it’s often incorporated into formulations with antioxidants or kept in opaque containers. Function and Uses: 1. Mechanism of Action: o Kojic acid primarily functions as an inhibitor of the enzyme tyrosinase. Tyrosinase is a key enzyme in the melanin synthesis pathway, responsible for the production of pigment in the skin. o By inhibiting tyrosinase activity, kojic acid reduces melanin production, leading to lighter skin and diminished hyperpigmentation. 2. Skin Brightening: o Its ability to interfere with melanin production makes kojic acid effective in treating hyperpigmentation, such as dark spots, age spots, and melasma. It helps even out skin tone and brighten the complexion. 3. Antioxidant Activity: o Kojic acid has antioxidant properties, which means it can neutralize free radicals and reduce oxidative stress in the skin. This can help protect the skin from environmental damage and contribute to a more youthful appearance. 4. Applications in Skincare: o Kojic acid is used in a variety of skincare products, including creams, serums, masks, and lotions. It is typically formulated in concentrations ranging from 0.5% to 2% to balance

Arbutin is a naturally occurring compound found in various plants, notably in the leaves of bearberry, pear, and cranberry plants. It is widely used in the cosmetic industry as a skin-brightening agent due to its ability to inhibit melanin production, which can help reduce the appearance of dark spots and hyperpigmentation. Chemical Properties of Arbutin: 1. Chemical Structure: o Molecular Formula: C12H16O7 o Molecular Weight: 272.25 g/mol o Structure: Arbutin is a glycosylated hydroquinone, meaning it consists of a hydroquinone molecule linked to a glucose molecule. This structure allows it to be more stable and less irritating than hydroquinone itself. 2. Forms: o Alpha-Arbutin: A synthetic form of arbutin that is more stable and effective than its natural counterpart. It has better solubility and is used in more advanced formulations. o Beta-Arbutin: The naturally occurring form found in plants. It is less stable compared to alpha-arbutin but still widely used in skincare products. 3. Physical Appearance: o Form: Arbutin typically appears as a white, crystalline powder. o Solubility: It is soluble in water and alcohol, which makes it easy to incorporate into various cosmetic formulations. 4. Stability: o pH Stability: Arbutin is stable in a pH range of 3.5 to 6.5, which is compatible with the pH levels of most skincare products. o Temperature Stability: It is stable at lower temperatures but can degrade when exposed to high temperatures for extended periods, which may reduce its effectiveness

Hydroquinone is an aromatic organic compound that is widely used in the cosmetic industry, particularly in skin-lightening products. It is also used in photographic development and as an antioxidant in various industrial applications. Hydroquinone is known for its ability to inhibit melanin synthesis, making it effective in treating hyperpigmentation.