Home > Community > How to calculate Total flavonoid content from extract ?
Upvote

25

Downvote
+ Extraction of natural products
+ Phenolic acids
+ Anthocyanins
+ Phenolic compounds
Posted by
Alec Cawley

How to calculate Total flavonoid content from extract ?

Ashfaq Ahmad Shah  Follow
The total phenolic content can be calculated as natural compound  (gallic acid) equivalent (GAE) by the following equation: T= C XV/M  . T is the total phenolic content in mg·g–1 of the extracts as GAE, C is the concentration of gallic acid established from the calibration curve in mg·ml–1, V is the volume of the extract solution in ml and M is the weight of the extract in g. Gallic acid is  used as a standard compound and the total phenols were expressed as mg/g gallic acid equivalent using the standard curve equation: y = 0.0061x + 0.0396, R2 = 0.9991, Where y is absorbance at 760 nm and x is total phenolic content in the different extracts.
A control is prepared by mixing 0.5 ml distilled water and 2.5 ml 0.1 mM DPPH solution. The samples are shaken well and keep in dark for 30 minutes at room temperature. The absorbance is measured at 517 nm against the blank solution
consisting 2.5 ml MeOH and 0.5 ml distilled water. The radical scavenging activity is expressed as the radical scavenging percentage using the equation where; AS
= absorbance of sample solution, Ab= absorbance of blank and AC = absorbance of control % scavenging = (As-Ab/ Ac) X 100, IC50 value is the concentration of sample require to scavenge 50% of DPPH free radical and is calculated from the graph of radical scavenging activity against the concentration of extracts. Statistically, the correlation between antioxidant activity and total phenolic content is  determined by plotting IC50 (µg/ml) against TPC (mg/g). 
More
Upvote

1

Downvote
Azizi Gill  Follow

Thank you all for your comments which I find helpful. This is my question, am I going to calculate the total flavonoid content for one concentration or for different concentration and then calculate the average

More

Upvote

VOTE

Downvote
Bright Odohofre  Follow

thank you Sujan Bhowmick ·

More

Upvote

VOTE

Downvote
Daniel Silvers  Follow

Hi Vaibhavi,
From the equation you can calculate the value of X (conc. of QE extract in ug/ml).
Now, to simplify the calculation forget about the conc. and consider the content, I mean to say the quantity. Let me explain it for you.
As you have used 1 ml of extract (conc. was 2 mg/ml) it means there was 2 mg of extract in the reaction mixture. You got X ug of QE in 1 ml that was actually in 2 mg extract. So, X ug QE/ 2 mg extract or (X÷2) ug QE/ mg extract. Suppose it is P ug QE/mg extract. Multiply both side with 1000 and you will get Q mg QE/gm of extract.
You did not mention the yield of extract from 300 gm dry powder. Now you have to do back calculation to get back to the amount of QE/ gm of dry powder.
Let me know if you need further explanation. Best wishes!

More

Upvote

VOTE

Downvote
Morgan Falk  Follow

First you need to use your calbiration curve. The calibration curve that you can formulate by preparing quercetin solutions at concentrations 10 to 100 μg/ml in methanol. For example the equation becomes, y =11.924x - 0.0307
Now to calculate the value of x, you need the value of y
Where y = Absorbance of your test sample (say 0.342)
x = concentration from the calibration curve
This implies that x = y + 0.0307/11.924
x = 0.0313mg/mL
Therefore, TFC can be calculated as follows
TPC = cV/m
Where c= concentration from calibration curve
V= Volume of the extract used
m= Mass of the extract used
Therefore, TPC = cV/m
TPC = 0.0313x1/0.01
TPC = 3.13mg of Q/ g of extracted compound

Regards
Ashfaq Ahmad Shah
Graphic Era University, Dehradun

More

Upvote

VOTE

Downvote
Barry Walden  Follow

In the linear equation obtained from the standard curve, Y is the absorbance of the sample obtained from UV-visible spectrophotometer. X is the concentration of Standard from calibration curve. From the value of X, the total Flavonoid content (mg/g) C can be calculated using following equation.
                                                   C = X x V/N
where: V=volume of extract taken in mL: N=weight of plant extract in g
In your case V = 1mL and N = 0.002 g (2mg)
and the value of X can be calculated from standard curve

More

Upvote

VOTE

Downvote
Alapa Osayande Wisdom  Follow

from 300 gm dry powder i got 10 gm extract.

More

Upvote

VOTE

Downvote
Chaudhary Haziq  Follow

I am working on ACE inhibition properties of my plant extract which contain 1 of the flavonoid quercetin. but for my initial study i want to know what is total flavonoid content of plant as there are other flavonoid too..other than quercetin in my plant


More

Upvote

VOTE

Downvote
Bob Mouk  Follow

17
In the linear equation obtained from the standard curve, Y is the absorbance of the sample obtained from UV-visible spectrophotometer. X is the concentration of Standard from calibration curve. From the value of X, the total Flavonoid content (mg/g) C can be calculated using following equation.
C = X x V/N
where: V=volume of extract taken in mL: N=weight of plant extract in g
In your case V = 1mL and N = 0.002 g (2mg)
and the value of X can be calculated from standard curve

More

Upvote

VOTE

Downvote
Derek Williams  Follow

Dear Vaibhavi,
I am working with i.v. form of Q for 20 years. We study Q in patients with AMI and Acute Heart Failure. We have good result first of all for limitation of infarct size and many other aspect. Now we continue to study drug Quercetin in RCT. Could you tell me what is your interest in investigations drug with cardioprotective property? Thanks a lot! 

More

Upvote

VOTE

Downvote
Annmarie Wilson  Follow

17
In the linear equation obtained from the standard curve, Y is the absorbance of the sample obtained from UV-visible spectrophotometer. X is the concentration of Standard from calibration curve. From the value of X, the total Flavonoid content (mg/g) C can be calculated using following equation.
C = X x V/N
where: V=volume of extract taken in mL: N=weight of plant extract in g
In your case V = 1mL and N = 0.002 g (2mg)
and the value of X can be calculated from standard curve

More

Upvote

VOTE

Downvote
Blaine Childress  Follow

Then calculate the amount of flavoniod in 10 gm of extract which is equal to the amount of total flavonoid in 300 gm of dry powder.
Thank you..

More

Upvote

VOTE

Downvote