carbohydrates (mcm chapt 25) glucose: c 6 h 12 o 6 = c 6 (h 2 o) 6 monosaccharides / simple...
DESCRIPTION
Monosaccharides - Reactions (McM chapt 25.7) Functional groups: Alchohols, aldehydes/ketones, hemiacetals React like ROHTRANSCRIPT
Carbohydrates (McM chapt 25)
Glucose: C6H12O6 = “C6(H2O)6”
Monosaccharides / Simple carbohydrates:Can not be hydrolyzed to simpler carbohydrates
D-shugars
H OHCH2OH
OH
H OHCH2OH
OH
(R) Glyceraldehyde / D-glyceraldehyde
H OHH OH
CH2OHH OH
OH
RiboseAldopentose
Aldehyde 5 C
CH2OHO
HO HH OHH OH
CH2OH
FructoseKetohexose
Ketone 6 C
Open and cyclic forms
H OHHO H
H OHH OH
CH2OH
OH
Aldehyde
HO
OH
OH
CH2OH
OHOH O
OHOH
OH
CH2OH
OH
H
Hemiacetal
HO
OH
OH
CH2OH
OHOH
O
OHOH
HOHO
HOH2C
α-D-glucopyrαnose
O
OH
HOHO
HOH2C
OH
β-D-glucopyrαnose
Monosaccharides - Reactions (McM chapt 25.7)Functional groups: Alchohols, aldehydes/ketones, hemiacetals
React like ROH
O
O
OPyridine
H3COCO OCOCH3
O OCOCH3H3COCO
CH3IAg2O
OCH3 OCH3
O OCH3H3CO
OH OH
O OHHO
β-D-riβofurαnose
OH OH
O OHHO
β-D-riβofurαnose
CH3OHαcid
OH OH
O OCH3HO
+
OH OH
O
OCH3
HO
hem iαcetαl αcetαl
Methyl β-D-riβofurαnoside
Glycoside
Glycosides in natureN
N N
NNH2
O
OHHO
HO
Adenine(Vit. B4)
N
N N
NNH2
O
ORHO
OP
O
OOH
P
OO
OHHO
N
OHO
O
NH2
N
N N
NNH2
O
ORHO
OP
O
OOH
P
OO
OHHO
N
OHO
O
NH2
NADH
H H
Nicotinamid adenine dinucleotide
NADR=H
R=Phosphate: NADP+, NADPH
N
N
N
NHH3C
H3C
O
O
H OHOHOHH
H
O P OO
OH
O
OHO O
HO OH
N
N
N
N
NH2
FAD
N
HN
N
NHH3C
H3C
O
ORFADH2
Flavin adenine dinucleotide
DNA / RNA
OHO
OHOHOH
OH
Glucose
OCO2H
OHOOH
OH
UDP-Glucuronate
P P O
HO OH
N
NO
O
RXH
OCO2H
OHOH
OH
XR
More hydrophilic metaboliteof RXH
Metabolism
O
O
OOH
CO2H
OH
HOOHHOOHO
O
OHNH2
OH
HO
OH
Amfotericin B(Legemiddel mot soppinfeksjon)
O
O
O
HOO
O
NHO
HOHO
O
OO
OH
Erytromycin (Antibiotikum)
CO2H
H
OH
H
O
HO
O
OHCO2H
O
O
CO2HOH
HO
HO
Aglycone
GlycyrrhizinSaponin from liquorice (lakris) rootexpectorants (slimløsende) respir. tract infect.
From microorganisms:
Stereoselectivity in glycoside syntheses
+
HO
OH
OH
CH2OH
OHOH
O
OHOH
HOHO
HOH2C
α-D-glucopyrαnose
Minor
β-D-glucopyrαnose
MαjorH
O
OH
HOHO
HOH2C
O
OH
HOHO
HOH2C
Stereochem icαl info lost
R -OH
AB
O
OOH
HOHO
HOH2C
Alkyl α-D-glucopyrαnoside
Mαjor
O
OH
HOHO
HOH2C
O
Alkyl β-D-glucopyrαnoside
Minor
R
R
O
OH
HOHO
HOH2C
OH
The anomeric effect
O
O
OO
R
R
No lone-pair repulsjonAxial subst
Lone-pair repulsjonequatorial subst subst
Stereoselective synthesis of β-glycisides - Koenigs Knorr react
OOAc
OAc
AcOAcO
OAcHBr O
BrOAc
AcOAcO
OAc
O
OAcO
AcO
OAc
OH3C
O
O
AcOAcO
OAc
OH3C
R-OH
OO
OAcAcO
AcO
OAc
R
Reduction of carbonyl:
HO O
OH
HO OH
OH
D-glukose
HO OH
OH
HO O
OH
D-glukose
NaBH4 HO OH
OH
HO OH
OH
D-glusitol(sorbitol)
Oxidative reactions:“Reducing shugars”: Easily oxidized (most often aldeh. - acid)
HO O
OH
HO OH
OH
HO OH
OH
HO O
OH
D-glucose
mild oxHO
CO2HOH
OH
HO
OH
HO O
OH
HO O
OH
CH3 no ox. under mild condNot "reducing shugar"
Hemiacetal Aldehyde
Acetal •Tollens•Fehling•Benedict [old diabetes (glucose) test]
Tests (visual results)Not used in synthesis (preparative scale)
Ketoses as “reducing shugars”
CH2OHOHHOHHHHOO
CH2OH
Fructoseketo - tautomer I
Base
CH2OHOHHOHHHHOOH
enol - tautomer
HO
Base
CH2OHOHHOHHHHO
O H
OH
keto - tautomer II
mild ox
CH2OHOHHOHHHHO
O OH
OH
Synthetically useful oxidations
OH
OH
An aldose
Aldehyde
prim alchohol
HNO3
OHO
OHO
Diacid
Br2
H2O, pH 6
OHO
OH
Only aldehyde oxidized
Chain Lengthening and Shortening
OH
An aldose
HCN
CN
H OH1) H2 / cat.2) Hydrol. imine
CH OH
H O
n C-atoms n+1 C atoms
H2N-OH
CH OH
H NOH- H2O
Strong base
Monosaccharides / Simple carbohydrates:Can not be hydrolyzed to simpler carbohydrates
Disaccharides (McM chapt 25.9)
Complex carbohydrates: Disacch., polysacch.Can be hydrol. to monosacch. (cleav. of acetal / hemiacetal)
O
OHHO
HO
OH
O
OHOHHO
O
OH
Maltose
1,4'-α-glycosideGlucose + glucose
1
α 4'
O
OHHO
HO
OHO
OHOHHO
O
OH
Celloβiose
1,4'-β-glycosideGlucose + glucose
1β
4' O
OHHO
OH OHO
OHOHHO
O
OH
Lαctose
1,4'-β-glycosideGαlαctose + glucose
1β
4'
hem iαcetαl αldehyde ; "reducing shugαr"
O
OHHO
HO
OH
O
Sucrose
1,2'-α-glycosideGlucose + fructose
1
α 2'O
OH
HO
OH
OH
No hem iαcetαl fuctionNot "reducing"
Milk intolerance
O
OHHO
OH OHO
OHOHHO
O
OH
Lactose
1,4'-β-glycosideGαlαctose + glucose
1β
4'
Not αβsorβet from intestinesAccum ulαtion - diαrrheα etc
Lαctαse
O
OHHO
OH OHO
OHOHHO
OH
Often m issingαdults
HO
OH
gαlαctαse glucose
norm αl m etαβolism
No isom erisαtion:gαlαctosem iαSevere m ilk intolerαnce (even kids)Mentαl retαrdαtion
Polysaccharides (McM chapt 25.10)
CelluloseLong chains (>1000 monosachh.)H-bond between chainsStructural material - plantsβ-glycoside link., not digested humans
Starch: Amylose and amylopectin
O
OHHOO
OHO
O
OHHO
O
OH
1β
4'O
O
OHHO
OH
O
OHHOO
OH
O
OHHO
O
OH1α 4'
O
OOHHO
O
OH
Amylose ca 20%
O
OHHOO
OH
O
OHHO
O
1α 4'
O
OOHHO
O
OH
O
OHHOO
OH
O
1
α
6'
Brαnches(cα every 25. gluc.)
Amylopectin ca 80%
Energy storage plantsα-glycoside link., digested humans
Glycogen ≈ amylopectin, larger, more branchesEnergy storage animals
Synthesis Di- and Polysaccharides
Building from monosaccharides - Challenges•Regioselectivity•Stereoselectivity•Stability
O
HO
OH OHO
HO
OH OH
OHOH
Galactose Glycal from galComm. avail.
Cl Si
Base O
HO
OH OSi
O-silylationPrim OH
O
N NNN
Prot. as carbonate ester
O
O
OO
Si
O
epoxidationi.e.mCPBA
O
O
OO
Si
O
O
O
O
OOH
O
TBAF
ZnCl2
O
O
OO
Si
O
OH
O
O
O
OO
1,6' β
Other carbohydrates (McM chapt 25.11-12)
OH OH
O OHHO
β-D-riβofurαnose
H OHOHH
H OHOH
H O
OH OH
O
NHO
N
O
NH2
RNA nucleosidei.e . cytidine
riβose
OH
O OHHOH H
OHHH OH
OH
H O
OH
O
NHO
N
O
NH2
DNA nucleosidei.e . deoxycytidine
Deoxyriβose
O
O
NH3
H
Aminoglycoside antibiotics
O
OH
O
OO
HN
OH
OHHO
NH
H2
N
NH
H2
N
NH
HO
O
NH
HO
HO
Streptomycin
N-Metylglucosamin
L-Streptose
Streptidin
(sykloheksander.)
O
OHO
OHO
O
OH
NH2
NH2
HO
O
HO
NH2
NH2
OH
O
OH
NH2
H2N
Neomycin C
ÿ Basic, water solubile salts phys. pH
ÿ -Glykosides (= acetals) stabile acidic media because of protonated
amino subst.
NH
R'R
O
SOH
HOOH
N
O
R= H, R'=Cl: Klindamycin
R=OH, R'=H: Linkomycin,
Lincomycin antibiotics
Glycoproteins / Glycopeptides
Neuraminidase InhibitorsEffect on influenza virus A and B(?)Inhib. neuraminidase (enzyme that breaks bonds between HA* in newly HA in formed virus and host cell)Prevents release of virus
HA: Hemaglutinin, (glycoprotein)important for bonding between influenza virus and host
O
CO2H
OGlycopeptide
HO
HN
O
OHHO
HO
NeuraminidaseHO
GlycopeptideO
CO2H
OHHO
HN
O
OHHO
HO
+
Sialic acid≈ SN1
≈ TS‡
ZanamivirRelenza®
OseltamivirTamiflu®
O
CO2H
OGlycopeptide
HO
HN
O
OHHO
HO
Sialic acid
OCO2H
HO
HN
O
OHHO
HO
OH2
O
CO2HHO
HN
O
OHHO
HO
Lead compound Neuramidinase Inhib. (not selective for viral NA)
DANA
First selective drug Carbocyclic drug
CO2HH2N
HN
O
OO
CO2HHO
HN
O
OHHO
HO
O
CO2HHN
HN
O
OHHO
HO
HN NH2