L

•

"

..

mnesota 559~.= USA into-their

enantiomersby thin-layerchtomato-_ ..

od isalsoapplicabie-totb~ separationof enan-

g •~!i::t

id 1,2.alkanediols derived from diestez waxes of rot skin have a~dsand boctadecanediol is.preferentially utilized,by myeiinatingrat phosphoUpZs h.ving a ],2, t;do an mot backbone. Dfat ~bon:2 Of 2-acyl-1,2-alkanediol phosphocholine cor-

r~":J--:responds ' to me conxt

carbOn'2of 1,2-diacyl,sn,gly cero-3-phosphocholine.

i ~ng-chain alkanediols are major constituents of mammalian and avian surface lipids [q' 1,2.~kanediols [2] occUr mainly as diester waxes in mammalian skin Hpids [3,4] !andinuropygial glands of certain birds [5,6]. They appear to be struc:tutaliy [2~] and metabolically [6] related to the corresponding 2-hydroxy fatty :acids; Dieste~sof long-chain 2,3.alkanediols have been found only in avian uropy-

Sa! glands [7-9],

i

~ii:iilWei~vepre~O~sly shown that.~in developing rat brain, long,chain 1,2-alkane' yone carbon atom, but they are .....shot ~ terb~ :-:ii I!!diiolsa~e!nbt~ylme~abouzedtofatty aci[ds ~ 6 oXid~ed to ~:~xoalkanOlsand~corporat0d into phospholipids to form both 1-O~'~ " ' ............ : ~ " ~ :"'" " ~ " I glycerophosphatides [I0-131-~!, ~ ~.~:t,~,',~.Ib~,.Lg~.~1 and 1~,2 .oxoalkyl-2-acy . _ . -.

:i:":~a

iiperimentswith microsomal preparations ~alkanediol may substitute for 1,2-diacyl : diacylglyceroli cholinephosphotransferase ~I,2-alkanediols are necessary f o r experiments acylation and deacylation, and for their use . . . . . . . . '----*---lipid biosyntheparation o. enanLtion of enantio-

267

!i ¸! ~ .i

chased

: ..'

,

.

:,.

'~

.:"

:, i

:: :ii • • :::~ .~

.,.. .

~. •

.

.

269

(hexane-

descfibehere the prepara[ona small ~¢ale:.

screw-ca[,:testtUbeand

'i ~:"

elylc--ofide:-[18]iin:25 ~i?f:,drYbenzeneand stored pyridi,e~ia~e.ad~]ed; ~e:~xture iskept at room tem!ter, 5 :~i ~fbenZene are added iandthe solution i s ~.eaChof 5% aque0us HCI. 5% aqueous NaHCO3, d.::Witheach•washing, the test tube is shaken vigorously. hase is withdrawn with-a disposable,-pipette. Finally, iedunder:a-Stream :0f nitrogen it: a water bath at 40°C, ,:anq .

.....

iik:i/• .'; Sep~affon of enantiomers .

.

.

'

.

-

: The separation of bis-Dacetylmandelates of 2D, and 2L-1,2-hexadecanediol is accomplished by T ~ :using freshlyactivated layers of Silica Gel G (Merck) 0.5 mm 'thick. :~e C~omatoplate~: developed three times with benzene-diethyl ether, 97:3,in a tank lined with filter paper, In order to achieve separation, it is important tO avoid overloading the chromatogram. When the sample is applied along a starting neparative separation, the bis-Lfrom the adsorbent with water-sa~canediolsare obtained by methaneor 3 hr followed by TLC (Silica Gel

. .

-re.ReSUlts-

dkanediols, hydroxy fatty acids and secondary

yields diols. :nanecon-

I

of

lien-

.._. ,. ".'., .~

~ :l ;~nnfiourationand that . . . . . . .

'mr:skin

to

~ l o w e d by TLC and

e ~_):~'r~eS

itlt'~:upper(L) and :10wer(D) fractions (fig. l a) ~thyl 2-~a:toxy heXadecanoates followed by ending 2L- and2D,l,2'hexadecane(~ols. Their ier (fig. I e) andiower (fig. I f) TLC fraction, re-

the natural rl,2~lkanediols of rat skin (fig. I c) i~:theVwere:assijmed the D-configuration. I

B

1c

I o ,i!'-'-" -

.~ .. ....

.:

D

Origin-

2 0 0 ~ 4 0 0 :.600:

cpm

500 .

.

.

.

1000 .

.

.

.

.

.

.

.

.

.

.

c;)m '-----'-Iates of 1,2-alkane-

myelinating rat brain I [i 3], B: Free 1,2)rain 24 hr after in,nzene-diethyl ether, [lek radioactivity ~ebis-L-acetylmande.

- . . .

.

"

..

!.ii ~i~i'

~--by tli¢.:~O~dfi~¢

/

..

"

o. :~o~..o,, 0~

. . . .

[

-

IV.Discussion

• I

'

•

'

;i::!I:, -..

:

int~. i i::

'~i:¸i i¸ ~i/i! :.

,.-i/!

~ L:-..vi: ¸ ./

; ° ,..,:

~ ~'.

•

:i!rl

in~lkanea!Ols ~

," " ::~,:!273

ent rates

.:.,.

both of iculties

;rivatives.

.%

:~

~iOn.of.:~,~-diglyce~des or a,mOnoglycerides b y re- Ce~idehYde obtainabie by oxidation 0f the primary sphoricaCids were assigned their configurations in des, ThUs, natural el..glycerophosphoric acid ("L~[phospholipidS were assigned the L,configuration [33] empl0yed the same prefixes m a somewhat dif-phosphoric acid',). The present system of stereospets for the fact that the two primary carbinols of gly~cher projections of glycerolipids and 1,2-alkanediol

•

- .:

°nthe assignment of absolute configurations of other ale analysis of secondary alcohols should alsobe of of alkan,2-ols have recently been discovered [35] as uropygial lipids. -

.

- .

Acknowledgments -,

•

.

-

•

: ~ s investigation was supported by PHS Research Grants Nos. NS 10013, CA :the Program Projects Branch; Exitute~ and by the Hormel Foundaskin diester waxes.

(1953) 3533 11968) 294 70) 299 if2) 164 ) 1376 267 398 ~(1972) 365 ;(197'3) 265

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