PRAKTIKUM FARMAKOGNOSI-IDENTIFIKASI ALKALOID

Summary

This video demonstrates a pharmacognosy practical session focused on the identification of alkaloids in soursop leaf powder (simplisia). The process begins with ethanol extraction, followed by filtration, heating, and drying. Afterward, two chemical tests are conducted: the Meyers test and the Dragendorff test. The Meyers test looks for the formation of a white precipitate to indicate alkaloids, while the Dragendorff test shows an orange color change. These tests help confirm the presence of alkaloids, providing a practical insight into the identification of chemical compounds in plant material.

Takeaways

• 😀 The demonstration is about pharmacognosy, specifically identifying alkaloid compounds in herbal powder.
• 😀 The powder sample used is derived from soursop leaves (Daun Sirsak).
• 😀 Ethanol (70%) is used as a solvent to extract the chemical compounds from the herbal powder.
• 😀 The herbal powder and ethanol are mixed in an Erlenmeyer flask and left to stand for about 30 minutes for extraction.
• 😀 The mixture is then filtered to separate the liquid extract, which is placed in a porcelain dish.
• 😀 The extract is heated using a water bath to evaporate the solvent, leaving behind a dry extract.
• 😀 After the heating process, diluted hydrochloric acid (HCl) is added to the dry extract to dissolve it.
• 😀 The solution is filtered once again to ensure purity before proceeding with tests.
• 😀 The first test conducted is the Mayer’s reagent test, which detects alkaloids based on the formation of a white precipitate.
• 😀 The second test is the Dragendorff’s reagent test, which produces an orange color when alkaloids are present.
• 😀 Both tests indicate the presence of alkaloid compounds in the soursop leaf powder sample.

Q & A

What is the main purpose of the demonstration in the script?

The demonstration aims to show the process of identifying alkaloid chemical compounds in a powdered simplisia sample using a pharmacognosy practical.

What material is used to perform the alkaloid identification?

The material used for the alkaloid identification is the powdered simplisia of soursop leaves.

Which solvent is used for extracting the compounds from the simplisia?

Ethanol 70% is used as the solvent to extract the compounds from the simplisia.

How long should the mixture of simplisia and ethanol be left to allow proper extraction?

The mixture of simplisia and ethanol should be left for about 30 minutes to allow the compounds to be fully extracted.

What step follows after the extraction of the simplisia in ethanol?

After extraction, the solution is filtered, and the filtrate is transferred to a porcelain dish to be heated.

What method is used to heat the solution after filtering?

The solution is heated over a water bath to evaporate the solvent and obtain the dried extract.

Why is hydrochloric acid (HCl) added to the dried extract before testing?

Hydrochloric acid (HCl) is added to help dissolve the dried extract before performing the chemical tests.

What is the first test conducted on the extract, and what is its purpose?

The first test is the Mayer's reagent test. It is used to check for the presence of alkaloids by observing the formation of a white precipitate.

What does the appearance of a white precipitate indicate in the Mayer's test?

The appearance of a white precipitate after adding Mayer's reagent indicates the presence of alkaloids in the sample.

What is the second test performed, and what is the expected result?

The second test is the Dragendorff reagent test. It is used to confirm the presence of alkaloids by observing an orange color formation after adding the reagent.

What does the orange color formed after the Dragendorff reagent test indicate?

The orange color indicates a positive result for alkaloids, confirming the presence of these compounds in the sample.