[Latin Name] Hypericum perforatum

[Plant Source] From China

[Appearance] Brown fine powder

[Specifications] 0.3% Hypericin

[Particle size] 80 Mesh

[Loss on drying] ≤5.0%

[Heavy Metal] ≤10PPM

[Pesticide residue] EC396-2005, USP 34, EP 8.0, FDA

[Storage] Store in cool & dry area, keep away from the direct light and heat.

[Package] Packed in paper-drums and two plastic-bags inside.

[What is St. John's wort]

St. John’s wort (Hypericum perforatum) has a history of use as a medicine dating back to ancient Greece, where it was used for a range of illnesses, including various nervous disorders. St. John’s wort also has antibacterial, antioxidant, and antiviral properties. Because of its anti-inflammatory properties, it has been applied to the skin to help heal wounds and burns. St. John’s wort is one of the most commonly purchased herbal products in the United States.

In recent years, St. John’s wort has been studied extensively as a treatment for depression. Most studies show that St. John’s wort may help treat mild-to-moderate depression, and has fewer side effects than most other prescription antidepressants.

[Functions]

1. Anti-depressive and sedative properties;

2. Effective remedy for the nervous system, relaxing tension, and anxiety and lifting the spirits;

3. Anti-inflammatory

4. Improve capillary circulation

Biology Biomolecules Plants part 9 (Polysaccharides) CBSE class 11 XI

Iodine and Starch Experiment | Iodine Experiment | Starch Experiment | Science experiments for kids

Simple and easy experiment to demonstrate the iodine with starch reaction!

For this test you will need:
• Two test tubes
• Soluble starch powder
• Iodine solution
• Water
• Dropper
Procedure:
• Put some starch powder into a test tube and fill the test tube with water.
• Mix the starch in the test tube well until the starch dissolves in the water.
• Fill the other test tube with normal water.
• Place both the test tubes in a test tube stand.
• Using a dropper take iodine solution.
• Put some drops in each test tube.
• Observe that the test tube with starch solution turns to purple black color.
• The other test tube with normal water retains the color of iodine i.e orange or yellow.
Explanation:
Starch is a mixture of amylose and amylopectin, which are different forms of glucose/starch.
Amylose in starch is responsible for the formation of a deep blue black color.
Amylase is long polymer chains of glucose units connected by an alpha acetal linkage and looks much like a coiled spring.
However iodine is a potassium iodide reagent and it is not very soluble in water.
So, iodine is prepared by dissolving it in water in an aqueous solution of potassium iodide. This results in a linear tri-iodide ion (I3−) complex in iodine which is soluble.
This tri-iodide ion (I3−) slips into the coil of the starch causing an intense or deep blue-black color.