CA1303619C - Alkoxy derivatives of ginkgolides, their preparation and therapeutic compositions containing the same - Google Patents

Abstract

ABSTRACT

This invention relates to 1-alkoxy or 10-alkoxy substituted Ginkgolides or mixtures of the same, to a preparation process of these compounds consisting in reacting a dioxan solution of the selected Ginkgolide on a diethyl ether solution of diazoalkane in excess, at room temperature for 1 to 10 hours and to therapeutic compositions containing the same.

Description

13~?3~19 RS CAS_147 ~ he invontlon relata~ to GinX~olid~ d~rivAtlv ~, to met~o~ for their prep~r~tlon, and to phAr~ceu~l~al ~ompo~ltion~ oontalnlng t~em.

The lnvention provldes l-~lkoxy derivatlve~ of Glnkgollde~ A,~,C,J and M and further provl~-s 10-~lkoxy aerl~Atives o~ the ~ald GinXgol~des. Th~ pre~errod al~oxy groups are ~e~hoxy and othoxy groups.

rhe ln~entlon al~o provid~ a ~ethod ~or the preparation o~ l-alXoxy derlvative~ of Gin~olld-~ A,B,C,J
lo and M and o~ 10-alkoxy derivativoe o~ the ~ald Glnkgollds~, the method co~prl-ing reactlng, ln ~olution, Glnkgolide A,B,C, J or M w~tb an exc~ss o~ d$~zoalkAne ~nd -parating the re~ultant ~lYtur- o~ l-alkoxy-Glnkgol~de and 10-alkoxy-Glnkgolla~.

In a pre~err-a proceduro, the ~oloet-d ~lnXgollde i6 dl~solved ln dloxan, ~uita~ly at ~ concontratlon Or lg per 100 ml, an~ the sel-ote~ dlazo~lkan~ 1~ di-~ol~ed in die~hyl other. ~he olutlon ~ontalnlng th~ al~oalkAn~ iB
slowly a~d-d to that contalnlng the Glnkgolld~, allowing ten sgu~val~nto o~ ala~oal~an~ per ~qul~ nt of Glnkqolld~. Iho ~lxed olution i8 toad at a~b~ont t-mperA~ur~ ~or ~ro~ 3 to B ~ours, yl~lding ~ mlxture o~
l-alkoxy-GlnXgollde and 10~ oxy-Glnkgolldo. The ~opara-tlon o~ thQ two proaucts ~rom the r~lnlng non-r-~ct-d Glnkgollde ~ay u~t~bly be achle~ed by ~porAtlng o~ the ~olvent~ and ~lut~ng the rocldue e~rou~ a ~llioa g~l column u~ing thyl acet~te : hex~ne 1:1 hy volu~e ~
elu-nt.~he resultlng oolutlon 1~ ovapor~t~d o~ and tronted .

RS CAS 1~7 13~3 ~y ohloro~orm which di-~olve~ lO-alkoxy d-r~v~tlv-. The ~aid lO-al~oxy ~oriv~t~ve i~ r-cov-r-d ~om thl0 chlororor~lo olutlon and the r-malnln~ ~olutlon 1O the~
treateid wlth dlethyl ether w~lch glvo~ the l-alkoxy dorlv~tlve.
~ he ~lkoxy-Glnk~oll~o~ o~ th- lnvontlon ar- o~
~ntere~t ln th~ treat~ont ? PAF-Aooth-r lnduced ~ladie~, and the lnvent~on accordln~ly al80 provlde- a phaxmaaeutlaal composlt~on comprl~ln~ a l-~lkoxy dcrlvAtlv~
of Ginkgolldo A,B,C,J or M or lO-~lkoxy dorl~atlv- o~ one of the ald Glnkgolld-- or ~ ~lxturo o~ two o~ ~ore o~ ~ld l-Alkoxy ~nd/or ~d lO-alkoxy derlvatlve- ln admlxture wit~ a phar~acoutlcally ~oceptable dllu-nt or c~rrior.
ThB lnvent~on i~ lllu~trate~ by the ~ollowin~
15 exa~ple~ :
Exam~le 1 l-MethoxY-G~n~soll~e B and lO-M t~oxY-Glnkaolld- B
~ o ~ olution of Glnkgollde a ln dloxan ~lOg~l) WAB
slowly add-d lO oqul~al-nt- of a olutlon of diazo~ thane ln di-thyl eth-r. I~ ~lxtur wa- tood at a~bi-nt to~poraturo for ~ hour~, and t~ n -parAt d followlng the preferr~d -paration procedux4 d -crlb~d ~bove.
l-methoxy-aln~g~lldo ~, t~o otructur o~ whlch W~E
conflrmed by HPLC, wa- obtain d in 66.1 % yiel~ and 2S lo-~Qthoxy-Gin~gollae B wa- obteinoa ln Z4.4 % yl-ld.

r~

RS CAS 1~7 ~ 3~3~

Example 2 l-E~hoxy-Gink~ollde B ~nd 10-E~hoxY-Cln~qolld- ~

~ollDw~n~ the proc~dure de~crlb~d ln Ex~pl~ 1, but using dlazo4thane ln pl~ce Or ~l~zon than~
(duration ~ houx~), l--t~oxy-Gln~golld- ~ wa- Dbtaln~d ln 63 2 % yleld and ~o-othoxy-alnkgolid~ ~ wa~ obtaine~ ln 25,7 ~ ylel~

Proceedlng a~ ~bov~, but wlth Glnkgollde~ A ~md c, th~ ~ollowlng yi-ld~ w-re obt~ln-~:

=~

¦ Ginbgolld ~ ¦ 72 - ~ ¦ 20 1 ¦ Ginbqol~de C 59 2 % 30 4 %

TW~ICI~f The toxlcity of th~ compounds of tho lnventlon has b--n lS ~sured on ~1¢- by oral rout~

No death W~B not~ce~ ~t ma~lmu~ ad~ niotrat~on do~ to mlc~

PNM~CO~aY
-A proof of the ph~r~aooutlcal lnt-r--t of th~
2 0 compounds of tho lnv-ntion ha~ been o-tabll-hod by tho following pbarma¢-utlcal experl~ont~tlon~

~3tJ~

1) - Inhibition of the platelets aqqreqation on N w Zealand rabbits.

The experimentation was conducted on platelets with plasma of New Zealand rabbits.
Blood samples were taken from auricular artery and placed in a citrate buffer (3.8 % ; pH 7.4) ; blood was further centrifugated for 15 mn at 1200 RPM.
The tested sample was prepared in DMSO, then poured on platelets rich plasma for 1 mn, then a dose of 2.5 nM of PAF was added.
The determination is made on a Cronolog Coultronics apparatus which determines the transmission percentage corresponding to the maximum height of the peak before the desaggregation.

The percentage of variation of the inhibition with respect to the transmission percentage is calculated (control :
pure DMSO).
This method was described in detail in LABORATORY
INVESTIGATIONS, Vol. 41, No. 3, p. 275, 1979, JEAN-PIERRE
CAZENAVE, Dr. MED., JACQUES BENVENISTE, Dr. MED., AND
J. FRASER MUSTARD, M. D., "Aggregation of Rabbits Platelets by Platelet-Activating Factor is independent of the Release Reaction and the Arachidonate Pathway and inhibited by Membrane-Active Drugs".

The results demonstrate that the compounds inhibit the aggregation induced by 2.5 nN of PAF. Five tests made on 5 different rabbits allowed us to calculate the ICso of the various compounds using the linear regression test.

The values for ICso on platelets have been found as follows :

13~

Ginkgolide type and substitution - OCHJ - OC2H5 position , ~
B 1- 6.6 10-7 1.1 1o~6 B 10- 2.9 10-7 7.2 1o~6 C 1- 4.2 1o~6 8.5 1o~6 C 10- 3 0 10-6 9.~ 10-6 A 1- 4.6 10-6 8.7 1o~6 A 10- 1.3 10-5 6.2 10-4 2) - AnaPhYlactic bronchoconstriction of a Passively ~ sensitized nuinea-piq Passive heterolog sensitizing ________________ ___________ Male Hartley guinea-pigs (400-500g) were sensitized by an intravenous injection (IV) of an antiovalbumin immune-serum rabbit (Cooper Biomédical, U.S.A.). To obtain a satisfactory anaphylactic response, 24 hours later, the following conditions of use were fixed : injection into the penis of a diluted serum (to half concentration 0.05 ml/100 g).

Bronchoconstriction measure Guinea-pigs were anesthetized with urethan (2 g/kg IP), then tracheotomized and ventilated by mean of a respiratory pump (UG0 BASILE) : stroke volume 1 ml/100 g, 60 strokes/mn.

~, ~ , . . .

` ~3~36~3 A pneumothorax wa- don- to abollsh spontaneous r-splratlon Th- initlal reslstanc- was kept constant at 10 c~ watsr pressur- accordlng to the method o~ Konzett and Ro~lcr and th- cxcess o~ alr volume wa~ measur-d with a bronchospa~
tranduc~r ~UG0 BASI~E) connected to a UC0 ~ASI~ r-cord-r "Gemlnin~ Th- ~ugular veln was cathet-rlzed for lntravenous ln~ections Th- anaphylactlc shock was lnduced by an intravenou- ln~ection of 0 7S mg/kg ot heterolog pa~slve of ovalbu~ine Products wer- given by oral rout-, 1 hour before the antiqenlc stimulation ln the fora of a qu~my water suspenslon, at th- dose of 25 mq/kg ~e~ult~
_______ Th- bronchoconstriction induced by ovalbumin was xpressed ln p-rcentag- of maxlual bronchoconstriction lS given by clamping of the trachea Tbe results are reported in th- following table Glnkgollde type and sub~t~tutlon - OSH, - OC,H, po~itlon _ .
B 1- - 49 7 - 38 3 ~*

C 1- - 40 1 ~ - 39 8 *~
C 10- - 30 6 * - 23 1 *

NS Non Significative Slqnificative ~ *~ Very Slgnificativs 114~ **~ ~ighly Signi~lcative . .
.
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~3~3~1~

POSOLOGY

In human therapy, usual doses for per as administration are 0.5 to 1 g per diem, in tablets or gelatine capsules for one month.

In I.V. administration, three weekly injections at 0.05 to 0.2 g in isotonic solution, for one month are recommended.

~,

Claims (3)

1) 1-alkoxy or 10-alkoxy substituted Ginkgolides or mixtures of the same.

2) A preparation process of the Ginkgolides derivatives according to claim 1 consisting in reacting a dioxan solution of the selected Ginkgolide on a diethyl ether solution of diazoalkane in excess, at room temperature for 1 to 10 hours.

3) A therapeutic composition of matter for the treatment of PAF-Acether induced maladies comprising, as an essential ingredient therein, a sufficient amount of a compound according to claim 1, together with an appropriate diluent or carrier.