I am working in a company extracty soy isoflavones (genistein,
daidzein and glycetien) we are going now for a patent. Since we began
extracting soy isoflavones in 1996 I would like to know whether there
is some documentation proving that soy isoflavones were extracted in
the year prior to 1995.

Hello

Soy isoflavone extraction definitely pre-dates 1995-1996.


According to United States Patent No. 6,171,638:

"The isoflavone, genistin, was first isolated from soybean meal in
1931 by Walz (Justus Liebigs Ann. Chem 489, 118) and later confirmed
in 1941 by Walter (J. Amer. Chem. Soc. 63, 3273). Patents have
described the production of isoflavone enriched soy-protein products
(WO 95/10512, WO 95/10529; WO 95/10530), genistin malonate and daidzen
malonate (U.S. Pat. No. 5,141,746), pharmaceutical-type compositions
containing isoflavones (U.S. Pat. Nos. 5,424,331; 4,883,788), and
isolation and modification of isoflavones from tempeh (U.S. Pat. Nos.
4,390,559; 4,366,248; 4,366,082; 4,264,509; 4,232,122; 4,157,984)."

Source:
United States Patent No. 6,171,638
Inventors: 	Gugger; Eric (Decatur, IL); Grabiel; Richard (Decatur, IL)
Assignee: 	Archer Daniels Midland Company (Decataur, IL) 
Appl. No.: 	478751
Filed: 	January 6, 2000
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=/netahtml/search-adv.htm&r=46&p=1&f=G&l=50&d=ft00&S1=(isoflavone+AND+soy)&OS=isoflavone+and+soy&RS=(isoflavone+AND+soy)


Also take a look at United States Patent 5,141,746  (filed in 1990)
which described a process for extracting genistin malonate and daidzin
malonate:
"We claim: 
1. A process for obtaining genistin malonate and daidzin malonate
comprising:
extracting ground soya bean with a solvent selected from the group of
solvents consisting of methanol and ethanol to obtain an extract;
buffering the extract with an aqueous buffer solution to obtain an
aqueous solution having a pH of from 6 to 9;
extracting the buffered aqueous solution with a water-immiscible
organic solvent and recovering an aqueous phase therefrom;
acidifying the recovered aqueous phase to a pH of from 2 to 5.4; 
extracting the acidified aqueous phase with a water-immiscible organic
solvent and recovering an organic phase therefrom;
neutralizing the recovered organic phase to a pH of from 6.8 to 7.2;
and
separating genistin malonate and daidzin malonate from the neutralized
organic phase."
Source: 
United States Patent 5,141,746 
Inventors: 	Fleury; Yvette (Boncourt, CH); Magnolato; Daniele (La
Tour-de-Peilz, CH)
Assignee: 	Nestec S.A. (Vevey, CH) 
Appl. No.: 	598247
Filed: 	October 16, 1990
http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5141746


Also see these journal articles regularly cited in patent applications
relating to isoflavone extraction:

Walz, "Isoflavon-und Saponin-Glucoside in Soja hispida", Justus
Liebigs Ann. Chem., vol. 489, pp. 118-155, 1931.

Walter, "Genistin (an Isoflavone Glucoside) and its Aglucone,
Genistein, from Soybeans", The Journal of The American Chemical
Society, vol. 63, pp. 3273-3276, 1941.

Isoflavones and Their Conjugates in Soy Foods: Extraction Conditions
and Analysis by HPLC--Mass Spectrometry; Barnes, Stephen et al.:
Agric. Food Chem.; vol. 42, No. 11, pp. 2466-2474 (1994).


I hope this helps.

While not an exhaustive source for information on "prior art" with
regard to patents, the US Patent and Trademark Office is often the
best place to look for information regarding prior art:
http://patft.uspto.gov
They have a good searchable database.

I would refer you to patent # 5,141,746, "Process for obtaining
genistin malonate and daidzin malonate", dated August 25, 1992.

It does not appear that there is any patent regarding the extraction
of glycetien, however.