Triterpenes - Science topic

Thank you, Dr. Yannick

Hi Shaimaa Heider is there any chance that you have respiration rates available for cut foliage Fatsia japonica?

Dear Arthur Kaneps many thanks for your interesting technical question. I agree with the previous abswers provided by Christian Gege, Thomas Mayer-Gall and M Venkata Krishna Reddy in that esterification with acyl chlorides or carboxylic acid anhydrides in the presence of pyridine or triethylamine is a safe bet. Unfortunately you did not disclose in your original question which acyl chloride you are planning to use.

I found two relevant articles in the chemical literature about the esterifcation of allobetulin in which the use of the free carboxylic acids R-COOH is reported. For example, allobetulon reacts directly with benzoic acid, phthalic acid, and succinic did in the melt (5 min at 230 °C) to give the corresponding esters:

Similarly, a series of allobetulin esters with R = CClH₂, CF₃, CClF₂, and CCl₃ have been synthesized through acylation of allobetulin with the free haloacetic acids R-COOH in CHCl₃ at 70°C.  The resulting esters were obtained in high yields, and the reactions did not require the use of a catalyst:

Rasayan Journal of Chemistry, 2019, 12, 1032-1037

Unfortunately I don't have access to this rather exotic journal, but I think the general indormation given in the Abstract is already quite useful.

Good luck with your research! 👍

I have prepared 10mM stock solution of betulin and betulinic acid in DMSO. It was the highest concentration possible to make. However, the compounds required dissolving for the long time (even 1hour) with occasional vortexing and warming at 37 Celcius degrees to obtain lucid solution. The stock was further diluted up to 1uM and lower in cell culture medium. In this, there were no problems with solution clarity (stock solution was dissolved substantially).

Hi

study this link

The squalene and triterpenoids is oil-soluble, it is can dissolved in fat, and I add whole milk powder after boiled.

The first question to address is whether the instrument abnormal operation is a current situation or an issue in the past. Look at data acquired during instrument install by the vendor,. There must be a MS/MS of reserpine or some other compound. Also you'll find fragmentation parameters.

Try to reproduce it. The outcome will point on further troubleshooting.

Best of luck! 

Dear Bilal,

Salkowski Test is another method for detection of phytosterols in plant extract. To 1 ml of extract solution prepared in chloroform, few drops (3-4) of conc. sulphuric acid is added. from the sides of the test tubes. Appearance of reddish brown colour in chloroform layer indicates presence of phytosterols 

you can perform hydrolysis of these saponins by boiling them with Lemon juice, it is a safe and non toxic method for food processing, you have to ensure the complete hydrolysis of saponins by simple TLC analysis, if the acidic taste in not accepted you can add sodium bicarbonate to neutralize the acidity of citric acid.

Mr Gill. I do not yet really have an answer to your question but please kindly post a reference material that provides information on the basis for your question. I am very interested in this, thanks

It is not even sure whether these act through any of these receptor, or rather through signalling cascades, such as MAPK. In addition, some of them have been shown to directly work on pathogens. See attachments.

Thanks dear Roa ...

Dear Dr. Ibrahim

You may like to follow this link where you will find many interesting and informative responses from several RG members concerning the compounds you are likely to find in an hydrodistilled essential oil:

Good luck.

1. Extract and filter in 4C.

2. If already extracted:

-. Freeze in -80 C/ -20 C O/N and then filter in cold.

- Bilayer Liq-liq extraction in cold Dicholoromethane/ chloroform for the ethanolci extract will remove some.

- centrifuge in cold after -20 C few hours storage.

-run preparative TLC with mobile phase specific for triterpenoids and then re-elute molecules you are interested in.

These are more cidal to micro-organisms in vitro when we compare with the drugs, But in vivo so many  cleaving enzymes, inhibitors, digestors and solibilizers effect their activity. Second in vivo no compound is absorbed more than 50% and for absorption if carriers are no supplied antimicrobials will not reach to its target sites. These usually occur in trace amounts hence, MIC can not lonely interpret their activity well in a living system.

The only people I know of who have attempted the synthesis of these compounds are; Lothar Bore, Tadashi Honda and Gordon Gribble. J. Org Chem, 2000, 65(19) pp 6278-6282. You could try finding out if they are still active in research and where they are based and contact them directly for advice if the above reference is not suitable to your needs. Failing that, as you have hinted in your question, most of the accessible journal articles deal with the extraction, isolation and medical effects of these pentaterpenes. I suspect that neither the synthesis or the extraction and purification are particularly straight forward.

Triterpenes can be soluble in methanol also and these fact cannot be overlooked. First make yourself sure about the solubility profile of triterpenes you are expecting. 

For triterpene analysis, GC on a capillary column with FID (or selective mass detector) has a much greater resolution and sensitivity than HPLC . The MS quality matching of the peak you are analyzing (lupeol) is also an indication of its purity. On the other hand, triterpenoids frequently appear poorly resolved or co-elute with other  lipidic material in reversed phase HPLC where the UV detector should be fixed at a wavelenght where most compounds show a significant end absorption  that could cause biased response factor. Corroborate by collecting the HPLC "lupeol" peak  of several successive runs , evaporate solvent, weigh residue and analyze (GC-MS, NMR, etc.) 

Dr: R.S,

No, i don't test another adsorbent

thanks for mentioned a different way to separation

Dear Xavier,

EI-MS is better choice than ESI.

I guess by ESI that you are use LCMS with ESI source.

Each class of pentacyclic triterpenes have particular mass fragments, proton shifts and numbers of methyl groups.

this can be find from literature survey.

Make a table of Proton shift and J values from data collected by literature search.

From that exercise you will be able to identify the different class of pentacyclic triterpenes as well as point of difference.

Kown triterpenoids easily identify by EI-MS and Proton NMR.

hope this is helpful to you.

Firstly you should evaporate methanol if you used 70% or 80% methanol: dist. Water you evaporate methanol with rota vapor apparatus then add acetone to viscous aqueous extract (5:1) & leave it till precipitation the mix of triterpenes

after that use silica for backing column & use mobile phase with low polar solvent at the beginning like (chloroform: methanol) then gradually increase polarity till reach 100% methanol