Compound Isolation - Science topic

I see some researchers doing some isolation of already known and available compounds!

Does this isolation still meaningful?

For an adoptive transfer would like to isolate CD8 T cells that express granzyme K and EOMES from the spleen. Is it possible to first isolate CD8 T cells with an isolation kit, followed by the use of antibodies for granzyme K and EOMES?

I have to isolate and then properly purify some of azo pigment compounds.

i have done TLC and column chromatography of these pigments but ending up with the seperation of thier isomers only.

i believe that my pigment compounds still have some side products and impurities that i am unable to separate out.

suggestions required for highly efficient isolation and purification of the following pigment compounds attached.

My study involves establishing chronic nicotine addiction in mice and I would to check the cotinine level in mice urine using HPLC but currently protocols I found are done using human urine. Bioassays and GC are expensive, and I would like to use urine as the sample. Thus, how do I modify the HPLC protocol for mice urine?

Greetings,

May someone make a suggestion where I can get the standard of carpaine compound (usually extracted from the carica papaya) for my HPLC study? Thanks

Hi every one,

In drinking mineral water treatment we just check the water micro biologically for Ecoli, fecal coliform, Total coliform and TVC, and some times Pseudomonas.

How we detect viruses in water?

how to isolate viruses from water?

How to Characterize them?

I am planning to isolate certain compounds from plants. Will you please give me possible factors that I should consider before proceeding to work. Thank you for your response. 

I would like to know the procedure for isolation,purification and characterisation of bio active compounds from plant extract.I have to isolate the major consitutent of my sample.

I am working on the isolation and identification of flavonoids. I have different fractions of ethyl acetate extract of a plant. I got those fractions after doing chromatography on silica gel. The second fraction is a yellowish powder. It is to some extent soluble in methanol but it is more soluble in chloroform and ethyl acetate. It is not 100% soluble in either of the above solvents. I took the dissolved portion of the extract in ethylacetate, and did tlc on silica gel (chloroform and ethyl acetate (9:1) as solvent system). It showed three spots. I am now in a dilemma about how to proceed for isolation. If I do silica then I need to apply the sample in dry form as the sample is not 100% soluble in the solvents I do have. Could anybody suggest a better alternative for the isolation?

We are investigating the effects of plant extracts on human cancer cells. For one of our projects,  we want to isolate a certain compound from the extract. We are looking for researchers who could help us with the isolation step. We are willing to work together for this part of the project. If you know a researcher/team or you are one of them, would you kindly help us on the matter?

I fractionated an extract of plant and I took 15mg in 20ml solvent of a fraction and injected to HPLC, got a sharp peak with good resolution,

and I injected a standard compound of concentration 5mg/10ml got the same sharp peak and the same RT

I need to calculated the concentration of the compound that matched the same peak of the Std.

I used the equation conc. of sample = [Area sample/Area Std ] * conc. of Std and according to that equation the calculation showed to be

[16957864/171987]*0.5 = 49.3 mg/ml .. I am not sure if this is correct or not ?

please any confirmation for this calculations ? any comments and suggestions ?

I am confused about this results

I got the equation from this link

Thank you for your help

i have work on pure compound isolation of different phyto-chemicals, i need different solvent system for hit and trial methods?

I was performing fractionation for a plant extract, i was perplexed by the answers i found on the internet as "denser solvent is the lower portion" .

however, another answered the separation is done based on the molecular weight, in this case chloroform is the lower portion.

Can anyone confirm this? your help will be appreciated, Thank you

Dear all, Good day, currently I am practicing extracting total DNA using different fungi. My main purpose is to extract total DNA and send the extracted DNA for 16S Amplicon sequencing (ITS-1 and ITS-4)

Dear all,

Recently I started collaborating with a chemistry group to synthesize a sugar derivative with isobutyric acid sticking out. The synthesis went well, however the final product has a huge amount of lithium acetate (10:1 Li ac:sugar).

This makes my enzymatic work impossible.

Does anyone know any method by which we could remove LiAc from the solution?

NB:

the compound is soluble in both water and ethanol

I will isolate cyanidin compounds from local fruits. we try to get pure cyanidin which is free from the 3-glucoside chain. if you have the right and effective method to get this compound, please share with us.

Thank you

Hi, I'm on research in developing inhibitor of virus enzyme from natural chemical compounds with molecular docking and molecular dynamics. Finally, the result is that there are few chemical compounds that have potential activity to inhibit the enzyme. i want to examine the inhibitory activity from that chemical compound through in vitro assay to complete my research. where is the place to buy natural chemical compounds that has been isolated? For example the chemical compound is Nigellidine from Nigella Sativa, I want to buy the isolated compound. I choose to buy, because I need the chemical compound as soon as possible. Any suggestion can help

Thanks

I need some information that can help me to design my experiment. the first thing i want to know is that there is any membrane that can permeate just organic compound from bulk liquid, or any selective membrane for organic compound that can permeate from bulk liquid.

The synthesis of sulfated compounds is intricate to achieve and percentage yield of the product is low. The reaction leads to formation of many conjugates thereby making it difficult to isolate sulfated compound from the reaction mixture. Moreover most of sulfated compounds are water soluble compounds, therefore to purify these compounds becomes very difficult. What are the different ways to purify sulfated compounds other then RP-HPLC?

I used ethylacetate but yield was very less please suggest me what solvent system i can use for extraction. 

I am running ethyl acetate extract on silica gel column using hexane and ethyl acetate as mobile phase ( by stepwise-gradient increase of polarity). When the compound elutes, I run in the same polarity until that compound disappears (or completely eluted out). When I increase the polarity, new compound elutes out along with the previous compound ( or even two compounds previous to that) yielding mixtures. How to overcome this problem?

I'm looking a method for crystallization in hexane extracts for purification of high molecular weigh compounds like sterols...

Thank you in advance!!

I have got 2 pure compounds both 0.8mg. One is a white powder-like substance while the other is clear and gooey-like. I had isolated them using HPLC and wanted to know if they can be analysed by NMR even though their masses are quite low. Both are able to dissolve in MeOH.

Any suggestions please? 

Anyone has a guide book etc in which the identified fungal secondary metabolites characterized by chromatography, MS, NMR etc. Please, I very need it.

I am testing estrogen in plant leaves. For color removal, I am trying GCB contained column but afraid maybe estrogen will retained in this column. Is there anyone suggest me best chemical for elution.

I will isolate of growth factors from product metabolite human mesenchymal stem cell.

I need to quantify the alkaloid, so it needs to be separated from the liquid medium.or can we quantify the medium as such..

I try to establish a GC-FAIMS method for different volatile substances.

Hi, I am working on isolation of Phenolic compounds form plant extract. I need polyamide for the fractionation and isolation of phenolics. Please suggest any supplier who can spare the polyamide as a Gift sample.

what is the best method to reduce sample loss during purification process?I did column by using silica gel to remove unwanted compound. but, the yield of the compound is about 30% of the starting material. 

is there any suggestion for the purification process rather than by using silica gel column chromatography (solid phase extraction) to reduce the loss of target compound. 

my compound is extracted from the natural product.

how to remove residual peaks of solvent from NMR ?

I have synthesized two different compounds. However, what a coincident both nmr spectrum showed an unknown peak (singlet, very intense) at the region of 2.4 - 2.6 ppm in proton nmr, 28 - 30 ppm in carbon NMR which doesn't belong to my synthesized compounds, solvent impurities or catalyst been used. i have checked through the list of solvent impurities as well but still unable to figure out what is that. 

Both compounds purified using column chromatography. Solvent system used is hexane, dcm and methanol.  

Anyone of you have encountered before or do you have any idea about it? i will be much appreciated for your precious opinions.  

We are working on characterization and pharmacological activities of Plant Extract and compound material against Leishmania Tropica (Cutaneous Leishmaniasis). Now, we want to proceed this work via Joint work project to do Antileishmanial activities of compounds isolated from natural resources, like Lawsonia inermis etc If someone is interested in doing Joint research work, then please let me know.

Hi there,

I need some opinion. I've conducted my research project using bioassay- guided method. Out of three sample crude extract I've used, only two of them showed an activity. I've further fractionated the two of it using packed column. Unfortunately, none of the fraction showed any activity. What I can conclude is that the activity happens because of the synergistic interaction between phytochemical present in crude. Do I still need to isolate those compound? Or should I just proceed to identify what compound contain in each fraction using NMR perhaps? For the information, I did screening those fraction using TLC and in each fraction, there were one or two spots developed under UV 365 nm.

What is the best method for protease enzyme isolation from some fruit juices?

Is there any other source to obtain carnosic acid(rosmary extract) except Sigma Aldirsh?

Is there anyone who can suggest me about isolation and purification of a specific compound. After running a column (solvent Ethyl acetate), I am getting a lot of compound in the same fraction. If i want to ZERO down on a specific mass, Is there anyone who can help me to know "HOW TO PURIFY that specific spot". 

Thank you

I am preparing a text for students.Thanks.

Dear All,

The compounds I am working with are highly hydrophobic, containing  long hydrocarbon chains, neutral and the only functional group was derivatised with Fmoc amino acid. I am trying to develop a RP method using C18 column. The compounds are strongly retained on C18, are not eluted with 100% MeOH or ACN, and can be eluted with 50% IPA in MeOH or 30% EthAcet in MeOH. The problem is that I am not getting any separation between the samples components most likely due to their highly similar structure. Very long and shallow gradients are not effective nor addition of water. I also tried CN, Amide, and PFP column chemistries with no luck although the C18-PFP column showed some promise but nowhere near to acceptable resolution. I have not tried the C8 yet, however I am somewhat reluctant due to possibility of lesser retention due to shorter chains of the stationary phase. I would welcome any ideas or a good discussion.

Thanks

I am curious on how to determine the percent impurity of an isolated unknown compound without using any standard. Could experts please share your ideas and experiences in this regard?

how to isolate Highly water soluble organic/inorganic compounds, with out it's salt formation?

Anybody has any idea about this retrosynthetic analysis of this compound?

I need guidelines for the isolation of bioactive compounds from fish. 

I have isolated a compound. As i isolated through silica gel column, it its was crystalline suggested me that its pure latter on it turned amorphous when i checked via TLC showed me 4 bands mixed together. suggest me how i can separate them to get pure compound? quantity approx 55mg

Hello all

I prepared new transition metal complexes and i need for free XRD software for pc to analyze the new compounds (unknown) to give many parameters such as the structures, unit cell, lattice parameters, miller constants and other. 

Thank you all

what is the best source (book or internet source) to classify different type of given compounds? like we have certain number of compound names and we put a compound name directly to the source and it gives the exact clas for the specified name?

How to find the best compatible carrier for such a compound.

There are tens of volatile aromatic compounds isolated from Artemisia vulgaris but I do not clearly know which one or ones  are the main aroma attribute's of the common mugwort. If some one knows about it pleas help me. Thanks. 

I put my reduction reaction in the presence of pd/C, h2S04 in methanol. Actually my starting compound contains free NH and dione group. My aim is reduce that dione group. After completion of my reaction, filtered the catalyst and vacue the fitrate to get brown gel type residue.Then i washed with ethyl acetate and recrtaliized by acetone. after recrystalization i got white solid compound. But, i hope that is in the salt form. how to get my compound as free base.

Which one is best for CV studies of metal complexes with same type of Aromatic ligand environment.

I have encountered an compound which turns red when dissolved in DCM and turns to yellow when dissolved in methanol. What can be the nature of the compound.

Is there any reliable institute that analyse the extract for isolation and characterization of bioactives? I have found chloroform fraction (through kupchan protocol) of plant the most toxic one against seed germination and seedling growth in four weeds in wheat crop. Now I want to point out the toxic compounds in that fraction. What are different possibilities for me for analysis of my sample?

To perform any bio-assay with different organic fractions of a plant part, mostly methanol crude extract is partitioned with different solvents in increasing order of polarity using a separating funnel, is not it better to extract the tissue separately with all solvents? If you have availability of plant in excess, what protocol should be preferred? 

I want to isolate plant constituents using paper chromatography. Is i need to use different types of paper for different constituents. kindly suggest me  the type of commercial whatman papers available for paper chromatography with use? 

i m working on osteoarthritis, i want to isolate the active compound which is responsible for preventing arthritis

I have tested different organic fractions of crude methanol extract of Parthenium hysterophorus leaves. Ethyl acetate fraction showed highest toxic activity. Now I would like to find out the most toxic compound form this fraction. I have LC-MS, FT-IR and TLC in access. What sequence should I adopt to identify and quantify the responsible compound?

LC-MS or FT-IR or both in combination?

If some one wants to check certain activity, say for example antimicrobial, for 4 or 5 different plants with aim to perform chemical characterization for plant showing highest activity, is this necessary to check all organic fractions (methanol, ethyl acetate, n-hexane, chloroform etc.) for the same activity or plant can be selected based on activity shown by initially prepared methanol extract?

I found a lot of literature in which researchers prepared all organic fractions of different parts (leaves, roots, fruits etc.) for all interested species (3, 4 or 5) and then selected single fraction for compound isolation. On contrary few papers represent methodology in which single plant was selected for detailed analysis based on activity shown by methanol extract for different parts (leaves, roots, fruits etc.) of different species (say for example 4). Methanol extract showing highest activity is then selected for fractionation and sub fraction with highest activity is chemically analyzed?

I think the second method is more time consuming and economic. Being an expert what do you suggest? 

HI,

  We are purifying the antibacterial compounds produced by one bacillus strains. we have successfully purified all compounds that are assumed to be produced by that strains as a single peak and confirmed by Mass spectroscopy. But there are still two peaks with unknown compounds that showed antibacterial activity. We are not able to further purify those peaks as MS analysis shows that these peaks are comprised of more than one compound. Would you please help me or suggest me to use other techniques to purify these peaks. We are using Grace Vydac C18 238TP52 (5 μm) column and tried many elution conditions and some other similar kinds of columns but these compounds still elute as a single peak.

thanks

See above

I have isolated an antifungal compound isolated from lactic acid bacteria. I have carried out LC-MS and there I got 11 peaks with different m/z values. Can any one help me how to intrepret the results??? (Its a crude sample)

I would like to analyse CO using a mass spec however I do have CO2 gas present. So I'm interested in efficient and reliable CO2 filters that eliminate CO2 without affecting CO. Other suggestions are also welcomed. 

Thank you!

I have isolated a novel compound from fraction library and there is a slight impurity which is detected using LC/MS analysis, where a small ion peak is detected besides the molecular ion peak. Thus, I am hoping to get some opinion from RG members for whether purification work should be done now or shall I proceed to NMR analysis for structural disclosure before any further purification? As such minor impurity in the main compound might not have a significant effect on NMR spectra measurement. FYI, the amount of the compound I obtained is less than 2 mg.

I would greatly appreciate for any advice, suggestions or comments. Thanks in advance. 

We have isolated lignans and alkaloids with alpha-glucosidase activities from our labs

Does molecular weight determine the size of the particle? What is the correlation between molecular weight and size of the particle? Suppose molecular weight of the compound is approximately MW 320 then what would be the size of the particle? 

I had a reviewers comments regarding calculation of drug dose from cell culture to mouse and then human equivalent dose. I did both in vitro and in vivo (mouse) experiments for specific single compounds isolated from bread crust. The question is: How can I calculate the equivalent dose for humans?

Thanks in advance everyone share your suggestions...    

Hello everyone,

I intend to isolate total protein from bacterial cells (in terms of both quality and quantity). My protein is basically an enzyme and hence I will be analyzing its activity. It would be a help if anyone can provide me with a manual protocol for isolation of total protein with intact activity.

I want to study about protective effect of some compound isolated from medicinal plant on mpp induced cytotoxicity in pc12 cells. Many before studies showed that mpp+  induced cytotoxicity in this cell line but when I exposed pc12 cells with mpp ( 1mM) it is not able to induce cytotoxicity. please help me

Sometimes, we extract organic compounds with similar Ko/w values and structure from aqueous phase to the organic solvent, but we obtain different PF.

I am working on endophytic fungi.

I have isolated a few fatty acid derivatives recently. After taking all NMR measurement, I have assigned the planar structures but I am unsure whether these fatty acids are of novel or known compounds. I have checked through Scifinder as well, but could not find similar structures. Please advise me on this matter. I would greatly appreciate your professional advice and suggestions regarding my doubts.

Major portion of shilajit is very polar.

I have isolated around 10 compounds by column chromatography. The quantity is very low, all ranging from 10-25 mg. I need to get chemical characterization by using IR, MS, and NMR . The problem is that I am not sure about purity of compounds. They may be a mixture of similar kinds of compounds. I could not go for further with purification as the quantity is low. Can anyone suggest the possible way to sort out this problem?

I have used sucrose powder. Before doing so I have checked the conc of the protein by SDS-PAGE. To make it further concentrate, I used Dialysis tubing to keep my samples. I wash the tubing first with tap water and then lukewarm distilled water to get rid of any salt etc. Followed by tying one end with thread, and then transfer the sample followed by tying another end. Placed the tube in beaker containing sucrose powder. After few hours the volume reduced to half. I checked this in same way, but conc decreased. What could be the reason?

I get lesser yields when performing LiHMDS reaction. I have a doubt how I could judge when all nBuLi converted HMDS into LiHMDS.

And, if I am using acetonitrile: water as mobile phase under isocratic elution

It seems my compound of interest tightly bound to the Alumina column. Most of my impurities in the fraction had been eluted out but still no elution of my compound of interest even after 30% methanol in chloroform. Did anyone have an experience with Alumina column?

I want to separate two compounds from a mixture; one contains an amide functional group and the other contains a nitrile functional group in it.

I can use chromatography methods, such as LC (silice) or HPLC. Any suggestions?