Diuretics: Introduction and Chemical Classification
Hello guys welcome to my today’s lecture on sar of five sulfur mild amino benzoic acid derivatives as loop directive agents i’m sure that you might have seen my last two videos in which i had discussed the sr of thiazides and sl sulfonamides as diuretic agents and if you have missed those videos i suggest you should watch them before watching today’s video
As there are certain structural features which are common in the sar of all diuretic agents so without wasting time let’s start the sar of 5 sulfur oil amino benzoic acid derivative as loop diuretic agents so the parent skeleton for the sar is five sulfur oil amino benzoic acid and this is required for the diuretic activity on the basis of the position of
The amino group there are two series when this amino is at the second position then these are five sulfur oil two amino benzoic acid derivative when this amino group is at the third position then these are five sulfam oil three amino benzoic acid derivative so we will first see the sar for five sulfur oil two amino benzoic acid derivatives this is the parent
Skeleton which i had just discussed these are five sulfum oil benzoic acid derivatives with amino substituent at second position and x substituent at fourth position so we’ll see the sar position wise starting with the position number one so the sar suggests that at position number one the substituent which is present it must be acidic in nature and out
Of various acids carboxylic group shows the most favorable diuretic activity however in certain drugs like esosimide this carboxylic group is replaced with the tetrazole and it shows the good diuretic activity in this series coming to the position number two at position number two substituted amino group is there where substitution is r so r can be perforal
Benzyl thionyl methyl out of this perforal group at this position shows the maximum diuretic activity followed by benzyl group then thianil methyl group when this r substituent is perforal then the drug name is furasamide which is the most active loop diuretic of the category and it is also called high ceiling loop diuretic because it cause maximum dialysis
Acting on the thick ascending limb of henle coming to the position number four the substituent x is present now at at position four substituent x can be activating groups like chloro alkoxy analino benzyl or benzoyl group presence of these group at position 4 increase the diuretic activity so if we change these activating groups by deactivating groups then
The activity is reduced coming to the sulfur oil group at position number five this group is essential for diuretic activity if we replace this group with any other group then the diuretic activity is lost sulphur boil group then we see the sar of all the diuretic agent this is the group which is commonly present in the diuretics and it is required for the
Diuretic activity coming to the sar of 5 alpha boil 3 amino benzoic acid derivatives at the third position the amino group is there at the first position carboxyl group at the fifth position sulfur oil group and at the fourth position substituent x is there position one and five as well as the four it is same as that of the five sulfur oil 2 amino benzoic
Acid only change is there at the position of the amino group it is here and the third position substituted amino group is placed at the third position coming to position number one here again the substituent at the position one must be acidic and carboxyl group is the most favorable group at this position for the diuretic activity coming to the position
Three where substituted amino group is there and substituent r here can be butyl in case of bumatinide so it is a butyl amine group at the third position and this is the most active drug of this category showing very good diuretic activity if we replace this butyl group with the perforal group which we have seen in the structure of furosemide this perforal
Group then there is decrease in the diuretic activity at position 3 if we incorporate cyclic amines like parallel denial group then also there is increase in the diuretic activity coming to the position number 4 at position number 4 when x is phenoxy group for example in the drug bumatinide x is phenoxy and r is butyl this drug bumatinide is 50 times more
Active as compared to furosemide so phenoxy group at fourth position increases the diuretic activity other substituent which can be tolerated and which can give good diuretic activity at this position are analino group and phenyl sulfide group coming to position number five here sulfur oil group is essential for the diuretic activity and if we replace this
Group with any other group the diuretic activity is lost so you can understand that the position one and position five the sar is same as in we have seen in five sulforamine two amino benzoic acid derivatives only there is change at the third and the fourth position substituent nature this is all for today’s lecture thank you
Transcribed from video
SAR of Loop diuretics (5-Sulfamoylamino benzoic acid derivatives) By Pharma Success