Hesperidin,520-26-3

### I. Physical Properties

* Appearance and Properties: Pure product is a white or light yellow, fine, needle-like crystalline powder.
* Melting Point: 258°C to 262°C (begins to soften at 250°C).
* Optical Rotation: [α]²⁰_D = -76° (in pyridine).
- Special dissolution behavior: Slightly soluble in hot water; soluble in dilute alkaline solutions (due to the presence of phenolic hydroxyl groups, which form salts and increase solubility, though it is prone to ring-opening hydrolysis under strong alkaline conditions).

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### II. Chemical and Industrial Uses

#### 1. API and Healthcare Product Raw Materials
* Maintaining Normal Capillary Permeability: As a vitamin P-like substance, hesperidin reduces capillary fragility and permeability. It is commonly used as an adjuvant treatment for hypertension and hemorrhagic capillary diseases.
* Formula Combinations: Frequently co-formulated with Diosmin in a 1:9 ratio (such as the classic clinical drug "Purified Flavonoid Fraction") to treat chronic venous insufficiency, varicose veins, and acute hemorrhoidal attacks.
* Anti-inflammatory and Antioxidant: Possesses significant free-radical scavenging capabilities, demonstrating strong biological activities in anti-inflammatory, antiviral, and immune-system regulation.

#### 2. Raw Material for Fine Chemical Synthesis (Derivatization)
Due to its natural flavonoid skeleton, hesperidin serves as a crucial precursor for synthesizing various high-value compounds:
* Synthesis of Diosmin: Industrially, hesperidin is commonly converted into diosmin via iodination/dehydrogenation reactions.
* Synthesis of Methyl Hesperidin: Through methylation modification, methyl hesperidin is produced with excellent water solubility, widely used in liquid pharmaceuticals and cosmetics.
* Synthesis of Neohesperidin Dihydrochalcone (NHDC): Hesperidin can be hydrolyzed to obtain neohesperidin, which is then hydrogenated to synthesize NHDC, a high-intensity sweetener (approximately 1,500 to 1,800 times sweeter than sucrose) used in food and feed additives.

#### 3. Cosmetics and Personal Care
* Whitening and Spot-Fading: Inhibits tyrosinase activity, thereby reducing melanin production.
* Microcirculation Improvement: Used in eye creams or facial skincare products to help reduce dark circles and diminish facial redness (telangiectasia).

#### 4. Food Additives
* Natural Antioxidant: Utilizes its polyphenol structure as a lipid preservative and antioxidant in the food industry.