Need help on natural antimicrobial project ASAP

[deleted-330650]

I was wondering if I should use water or ethanol as a solvent for herb extraction.

[deleted-291782]

Hi Rudra,

The choice of solvent will depend on what it is you are trying to extract. What types of herbs are you using? What types of chemicals are you interested in isolating for your project?

-Pharma

[deleted-330650]

I'm working with herbs such as cinnamon, mint, garlic, and clove. As well as pineapple and honey.

[deleted-330650]

Also I was wondering which is the best way to measure the effectiveness of the agents or herbs. I've seen zone of inhibition, counting the colonies and calculating the colony forming units.

[donnahardy2]

Hi Rudra,

I think Pharma has asked a good question. Can you explain the purpose of your project? The answer to your question depends on what you are trying to accomplish. Ethanol is a polar organic solvent and will extract some molecules from herbs; water will extract the water-soluble compounds.

Also, ethanol is an antimicrobial agent itself, so have you thought about how you would remove the ethanol before you test the extract?

To help explain further, here is a link for an article that compared the results of extraction of 11 different plants with 4 different solvents. The authors found that a water abstract of one plant worked, but the ethanol extract was more effective. You might want to read this paper and adopt the techniques used for your project.

http://scialert.net/fulltext/?doi=jm.2012.59.67

So please let us know what you are trying to do.

Donna Hardy

[deleted-330650]

Do you have an email I could send you my purpose and get more immediate responses please?
I'm trying to find out which natural antimicrobial agent is the most effective against the K-12 Strain of Ecoli. I'd like to extract as much as I can such as cinnamaldehyde from cinnamon. I'm working with herbs such as cinnamon, mint, garlic, and clove. As well as pineapple and honey.

[donnahardy2]

Hi Rudra100,

The best thing to do is to post your purpose on this website; ir if it is more convenient, you can upload it. We will receive messages to our personal e-mail as soon as you make your post.

It would be very helpful to see your purpose and any other information that you might have about your project.


Donna

[deleted-330650]

I will use a mortar and pestle to grind the mint or cinnamon then add ethanol to grind it again. Then filter the liquid out then soak a filter disk in it and wait for the ethanol to dry out. Will this work?
It seems that I receive responses at times when I'm not around my computer, that's why I ask for email so I can also receive messages on my phone.
The purpose of my experiment is to find an effective natural antimicrobial agent that kills the K-12 strain of Escherichia coli. I want to find an easily accessible natural antimicrobial agent that doesn’t contain hazardous chemicals and inhibits any future growth.

[donnahardy2]

Hi,

Yes, your procedure should work. You should define the time that the samples are soaked in the solvent. The reference I found used a 24 hour extraction time for all sample and solvents and the extracts were dried and then resuspended in phosphate buffered saline.

Another important point in planning you experiment will be to quantitate the herbal extracts. The authors used a 10% weight to volume ratio to prepare the extracts and then adjusted the final concentration of 500 mg/mL. It is not clear if the 500 mg/mL is based on the weight before or after extraction, so you would need to define this.

Here's the reference materials and methods section:

Preparation of plant extracts: The prepared powder was soaked in each of water, ethanol, methanol and acetone solvents (plant material to solvent ratio was 1:10, w/v) and extracted for 24 h at room temperature with shaking at 150 rpm. Filtrates of the extracts were dried at 40°C. The dried extracts were resuspended in Phosphate Buffered Saline (PBS) to bring to 500 mg mL-1 concentration.

Another consideration. If you are interested in cinnamaldehyde or other specific compounds, you can check the solvent compatibility on Wikipedia.

https://en.wikipedia.org/wiki/Cinnamaldehyde Cinnamaldehyde is slightly soluble in water and soluble in ether or chloroform (two hazardous solvents). It is described as miscible with alcohols and oils, which means that these will probably not extract the cinnamaldehyde efficiently.

I understand your request for a text message now; this would expedite responses. I recommend that you send a message to the Science Buddies staff to find out if your cell phone can be linked to responses. This is the first request I've had and as far as I know, we have not done this before.

Donna