Dear Agnieszka,

try this one:

http://www.massbank.jp/index.html?lang=en

kind regards,

Lars

http://www.massbank.jp/index.html?lang=en

Hi,

I would recommend you using this database

http://spectra.psc.riken.jp/menta.cgi/respect/search/fragment

Hi,

try this one:

http://gnps.ucsd.edu/

You can analyse your MSMS data, or search for specific compound spectra filtering here

http://gnps.ucsd.edu/ProteoSAFe/gnpslibrary.jsp?library=all 

Dear all,

Thank you for yours helpful suggestions. But still I have a problem with one compound, namely with this of the exact mass 655, and fragments 316, 331, 493. Who knows what is it?

On mass bank, gnp and metlin you can input the information of your compound (exact mass and fragments, with relative intensity) and search. Other option is

http://msbi.ipb-halle.de/MetFrag/

That will provide possible structures...

Yes, but unfortunately found compounds don't match to those occurred in juniper extract.

3 of your m/z (without 331) gave the following hit in the MassBank (ESI-MS positive mode):

3,5-Bis(beta-D-glucopyranosyloxy)-7-hydroxy-2-(4-hydroxy-3,5-dimethoxyphenyl)-1-benzopyrylium

......

http://www.massbank.jp/jsp/Dispatcher.jsp?type=disp&id=PR100346&site=1&mz0=655&tol0=0.3&int0=100&mz1=493&tol1=0.3&int1=100&mz2=331&tol2=0.3&int2=100&num=3

Hi,

You will definitely need intensities of these peaks to have a match. Could you please tell which one of three MS2 peaks is a base peak or give intensities of all the three peaks, type of instrument and CID/HCD parameters. 

Hope this is usefull for you!

http://pubs.sciepub.com/jfnr/2/11/4/index.html

Dear Charandeep,

Intensities are as follows: peak 331 , intensity: 7.78e+0.004; peak 493, intensity: 6.54e+0.004. I look forward to hearing from you.

Best regards,

Agnieszka

Thanks a lot Dimitra .

Dear Agnieszka,

From the intensity list you gave your compound seems to be Malvin chloride.

Please go to http://spectra.psc.riken.jp/menta.cgi/respect/index

and enter PS083803 accession number.

In negative mode?

no its positive mode. If you have done this experiment in negative mode then I will have to search again. Could you please also provide me MS parameters CID collision energy and did you use QqQ instrument?

No, it is MS LTQ Velos mass spectrometer (ThermoScientific) equipped with an ESI interface and controlled by Excalibur software.

Agnieszka you acan also check on phenol explorer. Please find attached the link

http://phenol-explorer.eu/compounds/classification

Dear Agnieszka,

I have used this instrument. I am also using Thermo QExactive instrument at the moment So, you mean its negative mode and exact mass is available. So could you then could you please give me exact m/z values upto 4 decimal places. you can do this in Xcalibur Qual browser. Go to a particular MS2 scan and press on a button on the extreme right. Right click on button and then press spectrum list.

Find below a research paper. I think would be very useful for your purposes

Best regards.

Fabio

Angerosa F., D'Alessandro N., Konstantinou P., Di Giacinto L.

GC-MS evaluation of phenolic compounds in virgin olive oil

(1995) Journal of Agricultural and Food Chemistry, 43 (7), pp. 1802-1807. Cited 140 times.

Istituto Sperimentale per la Elaiotecnica, Contrada Fonte Umano 37, Pescara, Italy

Abstract

A new gas chromatographic method for detection of phenolic compounds in virgin olive oils was developed. Identification of chromatographic peaks was made by mass selective detection. The presence of a main peak at m/z 192 or at m/z 280, related only to tyrosol and hydroxytyrosol, evident in the mass spectra of linked phenols, was very profitable for assigning the phenolic nature to minor polar compounds extracted by methanol from virgin olive oil. Twelve structures are possible, and some of them are deemed more likely on the basis of the chemical behavior of the compounds studied. The presence of a ligstrosid aglycon containing no carbomethoxy group and of oleuropein aglycon derivatives was evidenced. © 1995 American Chemical Society.

Author Keywords

Mass spectroscopy; Phenolic compounds; Virgin olive oil

Correspondence Address

Angerosa F.; Istituto Sperimentale per la Elaiotecnica, Contrada Fonte Umano 37, Pescara, Italy

ISSN: 00218561

Language of Original Document: English

Document Type: Article

Source: Scopus

Can you help me please in identification of compounds. I have ran my sample on LC-MS,ESI-MS in positive mode. How can I compare my data to confirm my compounds?

Take a look on GnPS

http://pubs.acs.org/doi/abs/10.1021/np400413s

http://gnps.ucsd.edu/

Why you do not use a spectral library to identify phenolic compounds or perhaps try to find a software for identification