The concentration is selected by the target of which compound class you are isolating. For example, for mono and sesquiterpenoids 96% ethanol, for flavonoids 40% and 70% ethanol for alkaloids, 80% ethanol is ideal.

Hi Lerato,

Why dont you used Hot- soxhlet sequential extraction like Hex> EtOH or MeOH> Aqeous. This will give you much yield. For getting 100mg/ml, there is no magic, you have extract more. For phytochem test, you can perform sample powder itself.

You can also try accelerated solvent extraction. This method give you much high amount of extract in small sample quantity then other classical method like soxhlet.

Prepare a different concentration series (1, 5, 10, 25, 50, 75, 100 mg/ml or as you comfortable) for phytochemical tests then you will get better result.  

Dear Lerato

Prepare a serie of different concentrations from 0.1 to 10 mg/mL from the concentrated and dried extract (you could arrange to have 4 or 5 runs in this range). Then perform the test again on each of those concentrations. It is hard but you will be proud of you at the end. It will permit you not only to have a result but also to calculate the IC50 of each of your extracts.

Regards!

NOBOSSE.

The answer to your question is : it depends on what you are hoping to extract and whether you are extracting fresh material or dried material. Tulbaghias contain the same kinds of compounds as garlic. If you are hoping to extract the garlic-like compounds, you then need to decide whether you want the original sulfur-containing amino acids as present in the intact plant, or whether you want to extract allicin and various sulfides released by the enzyme alliinase when the plant material is damaged.  Each of these scenarios would change your choice of solvent.

If you do not need too much of extract, try microwave assisted extraction.

Protocol can  be found in the attached papers.

If u need optimization then prepare different concentration other  it depend upon your plant that how much amount you have for example if you have 1 kg plant material in powder form then put it in 2-3 liter of solvents but make sure that the plant deep well in the solvents

Dear Lerato,

Your question is not very easy to answer. At a first glance, hexane is not a good candidate for the main extraction procedure, because most important secondary metabolites are rather polar and hexane is a low polar solvent. Hexane is used mostly for the preliminary extraction only, to liberate a botanical sample from chlorophyll and lipidic compounds, usually of little interest with curative / medicinal plants and obscuring the results of the important analyses (either spectrophotometric, or chromatographic)..

Now then, there is nothing like an ideal concentration of the extractant, because it depends on the plant itself, whether it is fresh or dried, whether it is relatively hard or soft, whether it is pulverized or less finely morcelated etc.

Nowadays, it is advisable that the selection of the optimal extraction conditions is carried out chemometrically, with use of the experiment planning approach. All other approaches belong to the so-called trial-and-error strategy, which usually does not lead to an optimum solution and is regarded as of lesser value.  An example of such a chemometrical approach of selecting the proper concentration of methanol - water (presented from start to end) is contained in the attached paper. It is noteworthy that a very efficient extraction outperforming the Soxhlet extraction is that known as ASE (accelerated solvent extraction, ASE).

Answering your question regarding solvents themselves, methanol is performing in plant analysis the best, although it does not represent modern "green chemistry".

My best,

Teresa Kowalska

Dear Lerato

Concentrations of solvents depends upon the type of analysis. however, 100mg/ml extract concentration is too high. Concentration of extract vary according to the experiments. Result of experiments depends upon the amount of metabolites present in that particular plant.  Firstly, you make extract 1mg/ml concentrations. However, 70% ethanol, methanol is best but you can try other conc. also.

You can find your answer in this paper also.

Reetika Singh

Thank you all so much for the feedback, truly helped a lot. I worked with Water and Ethanol extracts and obtained good results from your suggestions

Lerato

The concentration is selected by the target of which compound class you are isolating. For example, for mono and sesquiterpenoids 96% ethanol, for flavonoids 40% and 70% ethanol for alkaloids, 80% ethanol is ideal.