Metode ekstraksi dan fraksinasi pinostrobin

Summary

This video outlines a practical experiment on the isolation and identification of pinostrobin from the rhizome of Kaempferia galanga. The process involves multiple stages, starting with extraction using a sonicator, followed by fractionation through vacuum liquid chromatography. After the extraction, the concentrated solution is mixed with silica gel for further separation. The fractions are analyzed using Thin Layer Chromatography (TLC) to identify the presence of pinostrobin, with the most promising fractions being selected for isolation. The final step includes an identification process using FeCl3 reagent, ensuring the purity and quality of the isolated compound.

Takeaways

• 😀 The practical session focuses on isolating and identifying pinostrobin from the rhizome of Temu Kunci (Kaempferia pandurata).
• 😀 The session includes three meetings, with the first meeting covering extraction and fractionation techniques.
• 😀 The extraction process involves using a sonicator and ethyl acetate as a solvent to extract pinostrobin from the powdered rhizome.
• 😀 The extraction takes place at 40°C for 30 minutes, followed by filtration to separate the liquid extract from the solid residue.
• 😀 After filtration, the liquid extract is concentrated using a rotary evaporator or traditional evaporation methods to remove the solvent.
• 😀 One gram of concentrated extract is mixed with silica gel for vacuum liquid chromatography (VLC) fractionation.
• 😀 The chromatographic process uses n-hexane and ethyl acetate in varying gradients to separate the extract into fractions.
• 😀 Thin-layer chromatography (TLC) is performed on all fractions, with pinostrobin as the reference standard, to identify which fraction contains the target compound.
• 😀 The fractions that match the RF value of pinostrobin in TLC are isolated for further study.
• 😀 The identification of pinostrobin is confirmed by spraying the fractions with FeCl3, which causes a color change if pinostrobin is present.
• 😀 Fraction number 4 is selected as the best candidate for isolation based on its similarity to the standard pinostrobin and its intensity in the TLC results.

Q & A

What is the main theme of the practical session described in the script?

The main theme is the isolation and identification of pinostrobin from the rhizome of 'temu kunci' using various laboratory techniques.

What is the first step in the process of isolating pinostrobin?

The first step is the extraction of 'temu kunci' powder using ethyl acetate with the assistance of a sonicator.

How long is the extraction process carried out, and at what temperature?

The extraction process lasts for 30 minutes at a temperature of 40°C.

What method is used to filter the extract and separate it from the plant residue?

The filtration is done using a Buchner funnel with filter paper and a vacuum pump.

What is done to concentrate the liquid extract after filtration?

The liquid extract is concentrated using a rotary evaporator to remove the solvent.

What alternative evaporation method is mentioned in the script?

An alternative evaporation method mentioned is using traditional evaporation in a fume cupboard until the solvent evaporates, leaving a thick extract.

What is the next step after obtaining the concentrated extract?

After obtaining the concentrated extract, it is mixed with silica gel in a 1:4 ratio and then subjected to vacuum liquid chromatography for fractionation.

How is the movement phase (mobile phase) used in vacuum liquid chromatography?

The mobile phase is a gradient mixture of n-hexane and ethyl acetate, with the proportion gradually changing from 100% n-hexane to a higher ratio of ethyl acetate.

What is the purpose of performing Thin Layer Chromatography (TLC) on the fractions?

TLC is performed to compare the fractions with a standard pinostrobin sample and identify which fractions contain the compound based on their RF values.

What is the final step after identifying the fraction with the highest similarity to pinostrobin?

The identified fraction is then isolated using preparative TLC, and its purity is confirmed using FeCl3 spraying for identification.