lipides dan turunannya

7/24/2019 Lipides Dan Turunannya

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CHAPTER 23LIPIDS

23.1 INTRODCTION

Lipids are compounds of biological origin that dissolve in nonopoler solvents.

Lipids are defined by the physical operation that we use toisolate them.



Lipids include a variety of structure types, For example

H2C

HC

H2C

O C

O C !

O C !!

O

O

O

CH"

OH

CH#CH"$2

CH2OHCH" CH"

CH"

CH"

A fat or oil

#%&'()*+

Menthol#-/01$

Vitamin A

#3*04567+

H2C

HC

H2C

O C

O C !

O 8 OCH2CH2 9:#CH"$"

O

O

O

O;

H

HH"C

H"C

H

H

H

HO

CH"

Choleterol

#<=>? 1$

le!ithin

#@AB)*$



23.2 "ATT# ACIDS AND TRIAC#L$L#CEROLS

Driacylglycerols are the fats and oils of plant or animal origin.

OilsE Driacylglycerols that are liuids at room temperature.FatsE Driacylglycerols that are solids at room temperature.

Game triacylglycerolsE all three acyl groups in triacylglycerolsare the same.

mixed triacylglycerolsE the acyl groups in triacylglycerols are

different.

Hydrolysis of a fat or oil produced a mixture of fatty acids.



H2C

HC

H2C

O C

O C !

O C !!

O

O

O

A fat or oil #%&'()*+

H2C

HC

H2C

OH

OH

OH

:

COOH

!COOH!!COOH

#$ OH; I H2O, heat

#2$ H"O:

$l%!erol# -JK1$

"att% a!i&#)*MN5+

Post of fatty acids have unbrached chains and they have an evennumber of carbon atoms.

Dhe double bonds in unsaturated fatty acids are all cis and not

conQugated. Pany naturally occurring fatty acids contain two orthree double bonds. Driple bond rarely occur in fatty acids.

Gaturated fatty acids have relatively high points and unsaturatedfatty acids have relatively low points.



Driacylglycerols made up of large saturated fatty acids have highmelting points and are solid in room temperature, vice versa.

23.2A H#DRO$ENATION O" TRIAC#L$L#CEROLS

Golid commercial cooRing fats are manufactured by partialhydrogenation of vegetable oils. Completed hydrogenation

of the oil is very hard and brittle. One commercial advantageof partial hydrogenation is to give the fat a longer shelf;life.

23.2' 'IOLO$ICAL "(NCTION O"

TRIAC#L$L#CEROLS

Dhe primary function of triacylglycerols in animal is as anenergy reserve.



7ll of the saturated triacylglycerols of the body, and some of theunsaturated ones, can be synthesiSed from carbohydrates and

proteins.

23.2C SAPONI"ICATION O" TRIAC#L$L#CEROLS

7lRaline hydrolysis of triacylglcerols produces glycerol and a

mixture of salts of long;chain carboxylic acids.

H2C

HC

H2C

O C

O C !

O C !!

O

O

O

H2C

HC

H2C

OH

OH

OH

:

COO; 9a:

!COO; 9a:

!!COO; 9a:

$l%!erol# -JK1$

So&i)m !ar*o+%late #,-./0+

: "9aOHH2O



Dhese salts of long;chain carboxylic acids are soaps and thissaponification reaction is the way most soaps are manufactured.

Goaps are almost completely miscible with water. Goaps micellesin water are usually spherical clusters of carboxylate ions that aredispersed throughout the aueous phase with their negatively

charged carboxylate groups at the surface and with their nonpolarhydrocarbon chains on the interior.

Dhus soap solution are able to separate the dirt particles because

their hydrocarbon chains can TdissolveU in the oil layer.

Gynthetic detergents function in the same way as soapsV they havelong nonpolar alRane chains with polar groups at the end.



CH"#CH2$nCH2GO2O; 9a: CH"#CH2$nCH2OGO2O; 9a:

CH#CH2$nCH2CH": 9a;OO2G

CH"

So&i)m al4%l*en5ene)lfonate #Íé»ù±½»ÇËáÄÆÑÎ£©

So&i)m al4%l )lfate

#Íé»ùÁòËáÄÆÑÎ£©So&i)m al4ane)lonate #Íé»ù»ÇËáÄÆÑÎ£©

Gynthesis of detergents offer an advantage over soapsV theyfunction well in ThardU water.

23.2D REACTIONS O" THE CAR'O6#L $RO(P

O" "ATT# ACIDS



Fatty acids undergo reactions typical of carboxylic acids.they reactwith Li7lHW to form alcohols, with alcohols and mineral acid toform esters, with thionyl chloride to form acyl chloridesE

CH2COOH

#$Li7lHW, diethyl ether

#2$ H2O

CH"OH, H:

GOCl28yridine

CH2CH2OH

CH2COOCH"

CH2COCl

23.2E REACTIONS O" THE AL7#L CHAIN O"

SAT(RATED "ATT# ACIDS

Fatty acids undergo specific halogenation when they are treatedwith bromine or chlorine in the presence of phosphorus.



CH2COOH :#$ X2, 8W

#2$ H2OCHXCOOH : HX

23.2" REACTIONS O" THE AL7EN#L CHAIN O"

(NSAT(RATED "ATT#

Dhe double bonds of the carbon chains of fatty acids undergocharacteristic alRene addition reactions.

CH"#CH2$nCHYCH#CH2$mCO2H

H2

9i

Zr 2CClW

#$ OsOW#2$ 9aHGO"

HZr

CH"#CH2$nCH2 CH2#CH2$mCO2H

CH"#CH2$nCHZrCHZr#CH2$mCO2H

CH"#CH2$nCHOH CHOH#CH2$mCO2H

CH"#CH2$nCH2CHZr#CH2$mCO2H

CH"#CH2$nCHZrCH2#CH2$mCO2H+



23.3 TERPENES AND TERPENOIDS

Hydrocarbons Rnown generally as terpenes and oxygen;containingcompounds called terpenoids are the most important constitutentsof essential oils.

Post terpenes have sReletons of [,\,2[ or "[ carbon atoms and are classified in the following way.

[

\

2[

"[

Ponoterpenes

Gesuiterpenes

]iterpenes

Driterpenes

ecognition of the isoprene unit as a component of the structure of terpenes has been a great aid in elucidating their structures.



Pany terpenes also have isoprene units linRed in rings, andothers#terpenoids$ contain oxygen.

H2C

H2C CHCH2

CHC

CH2

CCH"H"C

H2C

H2CCH

CH

C

H2CC

CHH2C

CH" CH2

CH

CCH"H"C

CH"

or

or



OH

Limonene#^J_ %̀&N$

8Pinene#50$

$eraniol # 1$

Menthol #-/01$

Dhe carotenes are tetraterpenes. Dhey can be thought of as twoditerpenes linRed in tail;to;tail fashion.

CH"

CH"

CH"

CH"

H"C

H"C

CH"CH"

CH"H"C

8Carotene

#/4 @hM 56$



CH"

CH"

CH"

CH"

H"C

H"C

CH"CH"

CH"H"C

8Carotene

#/4 @M 56$

CH"

CH"

CH"

CH"

H"C

H"C

CH"CH"

CH"H"C

8Carotene

#/4 @M 56$

γ

Dhe catotenes all can be converted to vitamin 7 by enSymes inthe liver.



2"."7 97Dj7L jZZk

Dhe isoprene units of natural rubber are all linRed in a head;to;tailfashion and all of the bonds are cis.

CH2

H"C H

CH2

H"C

H2C CH2

H

H2C

H"C H

CH2

etc etc

Nar)ra r)**er

#ÌìÈ»Ïð½º£©

8ure rubber is soft and tacRy, so it must be vulcaniSed by heatingwith sulfur. 7 reaction taRes place that produces cross;linRs

between the cis;polyisoprene chains and maRes the robber muchharder.



23.9 STEROIDS

Gteroids are important Tbiological regulatorsU that nearly always

show dramatic physiological effects when they are administeredto living organisms.

23.9A ATR(CT(RE AND S#STEMATIC

NOMENCLAT(RE O" STEROIDS

Gteroids are derivatives of the following perhydrocyclopentanophenanthrene ring system

CH"

CH"1

2

3

9

:

;

<

=>

1?

11

12

13

19 1:

1;1<

1=

1>

A '

C D



RCH3

CH3

H

H

12

39

:;

<

=>1?

1112

13

191:

1;

1<

1=1>

A 'C D

all rin@ )n!tion are tran

n most steroids the Z, C and C, ] ring Qunctions are trans. Dhe7, Z ring Qunction may be either cis or trans.

1

2

39

:;

<

=>1?

1112

13

19 1:1;

1<

1=

1>

A

'

C D

AB ' rin@ )n!tion i !i

CH"

H

CH"

H

7ngular methyl groupsE Dhe methyl groups that are attached at points of ring Qunction

substituentsE other groups that lie on the same general side of thePolecule as the angular methyl groups.

substituentsE groups that lie on the bottom.



hen and designation are applied to the hydrogen atom at position \,the ring system in which the 7, Z ring Qunction istrans become the \ seriesV and the ring system in which the

7, Z ring Qunction is cis becomes the \ series.

n systematic nomenclature of the group at position determinesthe base name of an individual steroid.

HH"C

H

H

H

CH"

H

1<

1=

1>

For exampleE



;H ;CH2CH"

;CH#CH"$CH2CH2CH"

An&rotane

#q#$& $

Pre@nane

#q& $

Cholane

#<=& $

2? 21

2? 21 22 23 29

CH2CH"HH"C

H

H

H

CH"

H

1<

1=

1>

O

: 8Pre@nan838one #\ ;q;";& +

α

CH#CH"$#CH2$"CH#CH"$2HH"C

H

H

H

CH"

H

1<

1=

1>

O

: 8Cholet818en838one#\ ;<=;;;";& +

α

Dhe following two examples illustrate the way these base names

are used.



23.9' CHOLESTEROL

Cholesterol can be isolated by extraction of nearly all animal tissues. part of the difficulty in assigning an absolute structure to cholesterolis that cholesterol contains eight tetrahedral. For exampleE

C

H

HH"C

H"C

H

H

HHO

CH"

H

Cholesterol is Rnown to serve as an intermediate in the biosynthesisof all of the steroids of the body.



23.9C SE6 HORMONES

Dhe sex hormones can be classified into three maQor groupsE

#$ Dhe female sex hormones, or setrogens.#2$ Dhe male sex hormones, or androgens.#"$ Dhe pregnancy hormones, or progestins.

H"C

H

H

H

HO

OHH"C

H

H

H

HO

O

Etrone

#156& $

Etra&iol

#11$

Dhe first sex hormone to be isolated was an estrogen, estrone.



Dhe examples of the second sex hormonesE

H"C

H

H

H

O

OH"C

H

H

H

HO

OH

Anfroterone #q&w $ Tetoterone #6/& 56$

H

CH" H"C

Destosterone and estradiol are the chemical compounds from whichTmalenessU and TfemalenessU are derived. Dhe differ of their

structure is slightly.

8rogesterone and norethindrone are the most important progestin.



H"C

H

H

H

O

COCH"

H"C

Pro@eterone #'c?z &w $

23.9D ADRENOCORTICAL HORMONES

H"C

H

H

H

O

OH

H"C

Norethin&rone #K{<&w $

C CH

7t least 2| different hormones have isolated from the adrenal cortex.ncluded in this group are the following two steroidsE

H"C

H

H

H

O

COCH2OH

H"C

Cortione

#}0<^50$

OH H"C

H

H

H

O

COCH2OH

H"C

OHHO

Cortiol#~•'€}0<^50+

O



Post of adrenocortical steroids have an oxygen at position .cortisol is the maQor hormone synthesiSed by the human adrenalcortex.

23.9E D VITAMINS

Dhe following reaction can produce vitamin ]2. Dhe photochemical

reaction that taRes place is one in which the dienoid ring Z of ergosterol opens to produce a conQugated triene.

H"C

H

HO

H"C

H"C

H

HO

CH2j light,room tempreature

Vitamin D2

#3* 0456]2£©



23.9" OTHER STR(CT(RE

]igitoxigenin is a cardiac aglycone that can be isolated by

hydrolysis of digitalis.

Cholic acid is the most abundant acid obtained from the hydrolysisof human or oxbile.

H"C

H

H

H

HO

H"C

OH

H

H

HO

CH

H

CH" H"C

H

OO

Di@ito+i@enin#A‚<6'Nƒ„{…'†$

HOH

HO

CH2CH2COOHH"C

Choli! a!i& #<=) 5+



Gtigmasterol is a widely occurring plant steroid that is obeainedcommercially from soybean oil

]iosgenin is obtained from a Mexican vine, cabeza de negro,‡enus Dioscorea. t is used as the starting material for acommercial synthesis of cortisone and sex hormones.

H"C

H

H

H

HO

H"C

OH

H

H

HO

CH"

H"C

O

O

CH"

H"C

Sti@materol&io@enin

# ˆ̀ ‰ˆƒ„{…'†$



23.9$ REACTIONS O" STEROIDS

Dhe stereochemistry of steroid reactions is often uite complex. t

is strongly influenced by the steric hindrance presented at the faceof the molecular methyl groups. Zut many reagent react preferentiallyrelatively at the face #the formula on next page$.

HO

CH"

H

H

O

: B; 8Eo+%!holetan83 8ol

onl% ro&)!t

HCl

HO

CH" H

H

O

H

:

: Cl;;

HO

CH" H

H

OH

:

Cl

hen the epoxide ring of \ ,Š ;kpoxycholestan;" ;ol is opened,7ttacR by chloride ion must occur from the face, but it taRes place at the more open Š position.



H"C

H

H

HHO

CH"

H2, 8t

CŠH\COOOH

#$ DHFE ZH"#2$ H2O2, OH;

HO

CH" H

H

H

39

:

;HO

CH" H

H

O

:

HO

CH" H

H

HOH

: 8Choletan83 8ol D=:8>:F

: B; 8Eo+%!holetan83 8ol Donl% ro&)!t

: 8Choletane83 B; 8&iol D<=F

Choleterol

#<=>? 1$



Dhe relative openness of euatorial groups also influences thestereochemical course of steroid reactions.

HO

H H

CH"

OH

H3

9

:;

C2H\OOCO

H H

CH"

OH

HC2H\OCOCl

#excess$

23.: PROSTA$LANDINS

8rostagRandins are C2?;carboxylic acids that contain a five;

membered ring, at least one double bond, and several oxygen;Containing functional groups. Dwo of the active prostaglandinsare prostaglandin k2 and prostaglandin F1G.



:;CO2H

CH"

O

HO HOH

H

>

11 1:

1

2? CH"

HO

HO HOH

HCO2H

Prota@lan&in E2

DHIJKL.NE2Prota@lan&in "1

DHIJKL.NE2

Dhe biosynthesis of prostaglandins of the 2 series begins with aC2? polyenoic acid, arachidonic acid.

CO2H

CH"

Ara!hi&oni! a!i& #'= 045 ̂5$

2O2cyclooxygenase



CO2H

CH"

O

OH

O2H

H

#'M 1^‹> AŒ'€3• +

P$C2

several steps 8‡k2 and other prostalandins

23.; PHOSPHOLIPIDS AND CELL MEM'RANES

Post phospholipids acid are structurally derived from a glycerolderivative Rnown as a phosphatidic acid.

CH2OCO

CHOCO!

CH2 O 8 OH

OH

O

"rom fatt% a!i&

"rom hohori! a!i&



23.;A PHOSPHATIDES

n a phosphatidic acid, two hydroxyl groups of glycerol are Qoined

in ester linRages to fatty acids and one terminal hyfroxyl group is

Qoined in an ester linRage to phosphoric acid.

n phosphatides, the phosphate group of a phosphatidic acid is boundthrough another phosphate ester linRage to one of the following nitrogen;containing compounds.

HOCH2CH2 9:#CH"$" HO; HOCH2CH2 9H2

HOCH2

9H":

H

CO2;

Choline #<=•$

28Aminoethanol #2;Ž-'†ff1$

L8Serine

#L;5}Ž-5$



Dhe most important phosphatides are the le!ithin, !ehalin,hohati&%l erine, and lamalo@en.

H2C

HC

H2C

O C

O C !

O 8 OCH2CH2N+(CH33

O

O

O

O;

Le!ithin

#@AB)*$

H2C

HC

H2C

O C

O C !

O 8 OCH2CH2 9H":

O

O

O

O;

Cehalin

#^B)*$

H2C

HC

H2C

O C

O C !

O 8 OCH2CH9H":

O

O

O

O;CO2

;

H2C

HC

H2C

O

O C !

O 8 OCH2CH2 9H":

O

O

O;

Plamalo@en

#5ŒK,B)*$

hohati&%l erine

#B)*Œ+5}Ž-5$



LiRe soaps and detergents phosphatides TdissolveU in aueous media by forming micelles.

Dhe hydrophilic and hydrophobic portion of phosphaides form a portion of a structure unit that creates an interface between anorganic and an aueous environment.

23.;' DERIVATIVES O" SPIN$ODINE

7nother important group of lipids is derived from sphingosine.

On hydrolysis, sphingomyelins yield sphingosine, choline, phosphoric acid, and a C29 fatty acid called lignoceric acid.



H"C#H2C$2 H

CHOHH

CH9H2

CH2OH

H"C#H2C$2 H

CHOHH

CH9HCO#CH2$22CH"

CH2O!OCH

2CH

2N+(CH

33

O

O

Shin@oine

#~ Ž̀-1$

Shin@om%elin #~ B̀)*$

23.< A6ES

Post waxes are esters of long;chain fatty acids and long;chainalcohols. axes are found as protective coatings on the sRin,fur, or feathers of animals, and on the leaves and fruits of plants.

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