polymeronearth.Itcomprises20–35%oft

polymeronearth.Itcomprises20–35%ofthedryweightof
plant cellwall,dependingonthebiomasssource(Galbeand
Zacchi, 2007). Softwoodsgenerallycontainmorelignin(25–
35%) thanhardwoods(20–25%)(Faravellietal., 2010). Lignin
is predominantlyconcentratedinthemiddlelamellaandprimary
cellwall.Itsurroundsandcrosslinksthecellulose–hemicellulose
matrixthroughlignin–carbohydratenetworkstructuresthatpro-
videstiffnesstothecellwallsandgluethecellstogetherthereby
shieldingthepolysaccharidesagainstmicrobialdegradation.Asa
hydrophobicpolymer,ligninalsoservesasabarrieragainstwater
penetration.Allthesebiologicalfunctionsofligninmakethis
uniquebiopolymeroneofthemostrecalcitrantnaturallyoccur-
ringcompound(Ruiz-DueñasandMartínez, 2009). Thelignin
macromoleculecontainsfunctionalgroupssuchasmethoxyl,phe-
nolic hydroxyl,alcoholichydroxyl,andcarbonylgroupsthathave
a profoundimpactonitsreactivity.
Ligniniscomposedofphenylpropanoidunits,knownasmono-
lignolsorligninprecursors,whicharelinkedtogetherthrough
carbon–carbonandcarbon–oxygenbondswithavaryingdegree
ofmethoxylation(Adler, 1977; Karhunenetal., 1995) (Figure1).
Themonolignolshavebeenidentifiedas p-coumaroyl,confin-
eryl,andsinapylalcohols,whicharetherespectiveprecursors
of p-hydrophenyl(H),guaiacyl(G),andsyringyl(S)unitsin
lignin(Zhang etal., 2003). Usually,plantcellwalllignification
is accomplishedthroughoxidativecouplingandchemicallycon-
trolledpolymerizationofthethreeligninprecursorsindifferent
proportions.Forexample,softwoodligninisbuiltupmainlyfrom
G-units (upto95%)withsmallamountsofH-units,whereashard-
woodligninhasbothS-andG-unitsinproportionsfrom1:1to
1:3, withtracesofH-units.Allthreeligninunitsarepresentin
annualplants(Sjostrom, 1993; Brunow, 2001; Kangetal., 2012).
Ligninbiosynthesisproceedsthroughoxidativecouplingreac-
tionsofradicalsgeneratedbylaccasesandperoxidasesthatlead
toformationofagrowingpolymerlinkedbycarbon–carbonand
etherbonds.Theresonance-stabilizedphenoxyradicalspolymer-
izeinavarietyofmonomer–oligomerandoligomer–oligomer
couplingcombinationsthrough b-O-4, a-O-4, b-5, b-1, b-b, 5-5,
dibenzodioxocin,and4-O-5 linkages,someofthemdepictedin
Figure2. Themostabundantstructureinligninisthearylglycerol-
b-aryletherstructurewiththe b-O-4 linkagesaccountingforup
to60%ofthetotalinter-unitbondsinlignin(Balakshinetal.,
2009) whereasthecarbon–carbonbondsinligninareamongthe
most resistanttowardbreakage(Capanemaetal., 2004). However,
it shouldbenotedthatdespitethenumerousstudiesonlignin
that followedthepioneeringworkofFreudenbergandco-workers
(FreudenbergandHübner, 1952; Freudenberg, 1959, 1962, 1965;
FreudenbergandNeish, 1968) morethansixdecadesago,its
structureisstillnotcompletelyunderstood.

ผลลัพธ์ (ไทย) 1:

polymeronearth Ofthedryweightof Itcomprises20 – 35%พืช cellwall, dependingonthebiomasssource (GalbeandZacchi, 2007) Softwoodsgenerallycontainmorelignin(25–35%) thanhardwoods(20–25%) (Faravellietal. 2010) ลิกนิเป็น predominantlyconcentratedinthemiddlelamellaandprimarycellwall Itsurroundsandcrosslinksthecellulose – hemicellulosematrixthroughlignin – carbohydratenetworkstructuresthatpro -videstiffnesstothecellwallsandgluethecellstogethertherebyshieldingthepolysaccharidesagainstmicrobialdegradation Asahydrophobicpolymer, ligninalsoservesasabarrieragainstwaterเจาะ Allthesebiologicalfunctionsofligninmakethisuniquebiopolymeroneofthemostrecalcitrantnaturallyoccur-ringcompound (รูอิซ-DueñasandMartínez, 2009) Theligninmacromoleculecontainsfunctionalgroupssuchasmethoxyl เพ-ไฮดรอก nolic, alcoholichydroxyl, andcarbonylgroupsthathaveprofoundimpactonitsreactivityLigniniscomposedofphenylpropanoidunits, knownasmono-lignolsorligninprecursors, whicharelinkedtogetherthroughคาร์บอน – carbonandcarbon – oxygenbondswithavaryingdegreeofmethoxylation (Adler, 1977 Karhunenetal., 1995) (Figure1)Themonolignolshavebeenidentifiedas p-coumaroyl, confin-eryl, andsinapylalcohols, whicharetherespectiveprecursorsของ p-hydrophenyl (H), guaiacyl (G), andsyringyl (S) unitsinลิกนิ (เตียว etal., 2003) โดยปกติ plantcellwalllignificationคือ accomplishedthroughoxidativecouplingandchemicallycon-trolledpolymerizationofthethreeligninprecursorsindifferentสัดส่วน โดย softwoodligninisbuiltupmainlyfromG-หน่วย (upto95%) withsmallamountsofH-หน่วย whereashard-woodligninhasbothS-andG-unitsinproportionsfrom1:1to1:3, withtracesofH-units.Allthreeligninunitsarepresentinannualplants (Sjostrom, 1993 Brunow, 2001 Kangetal., 2012)Ligninbiosynthesisproceedsthroughoxidativecouplingreac-tionsofradicalsgeneratedbylaccasesandperoxidasesthatleadtoformationofagrowingpolymerlinkedbycarbon – carbonandetherbonds Theresonance-stabilizedphenoxyradicalspolymer -izeinavarietyofmonomer – oligomerandoligomer – oligomercouplingcombinationsthrough b-O-4, a-O-4, b-5, b-1 บีบี 5-5dibenzodioxocin เชื่อมโยง and4-O-5, someofthemdepictedinFigure2 Themostabundantstructureinligninisthearylglycerol-b aryletherstructurewiththe b-O-4 linkagesaccountingforupto60% ofthetotalinter-unitbondsinlignin(Balakshinetal.,whereasthecarbon – carbonbondsinligninareamongthe 2009)ส่วนใหญ่ resistanttowardbreakage (Capanemaetal. 2004) อย่างไรก็ตามมัน shouldbenotedthatdespitethenumerousstudiesonligninfollowedthepioneeringworkofFreudenbergandco-พนักงาน(FreudenbergandHübner ค.ศ. 1952 Freudenberg, 1959, 1962, 1965FreudenbergandNeish, 1968) morethansixdecadesago ของstructureisstillnotcompletelyunderstood

ผลลัพธ์ (ไทย) 2:

polymeronearth.Itcomprises20-35% ofthedryweightof
cellwall พืช dependingonthebiomasssource (Galbeand
Zacchi 2007) Softwoodsgenerallycontainmorelignin (25-
35%) thanhardwoods (20-25%) (Faravellietal., 2010) ลิกนิน
เป็น predominantlyconcentratedinthemiddlelamellaandprimary
cellwall.Itsurroundsandcrosslinksthecellulose-เฮมิเซลลูโลส
matrixthroughlignin-carbohydratenetworkstructuresthatpro-
videstiffnesstothecellwallsandgluethecellstogetherthereby
shieldingthepolysaccharidesagainstmicrobialdegradation.Asa
hydrophobicpolymer, ligninalsoservesasabarrieragainstwater
penetration.Allthesebiologicalfunctionsofligninmakethis
uniquebiopolymeroneofthemostrecalcitrantnaturallyoccur-
ringcompound (Ruiz-DueñasandMartínez 2009) Thelignin
macromoleculecontainsfunctionalgroupssuchasmethoxyl, ปรากฏการณ์
nolic ไฮดรอก, alcoholichydroxyl, andcarbonylgroupsthathave
profoundimpactonitsreactivity ได้.
Ligniniscomposedofphenylpropanoidunits, knownasmono-
lignolsorligninprecursors, whicharelinkedtogetherthrough
คาร์บอน carbonandcarbon-oxygenbondswithavaryingdegree
ofmethoxylation (Adler 1977. Karhunenetal, 1995). (รูปที่ 1)
Themonolignolshavebeenidentifiedas P-coumaroyl, confin-
eryl, andsinapylalcohols, whicharetherespectiveprecursors
ของ P-hydrophenyl (H), guaiacyl (G), andsyringyl (S) unitsin
ลิกนิน (Zhang etal., 2003) โดยปกติ plantcellwalllignification
เป็น accomplishedthroughoxidativecouplingandchemicallycon-
trolledpolymerizationofthethreeligninprecursorsindifferent
proportions.Forexample, softwoodligninisbuiltupmainlyfrom
G-หน่วย (upto95%) withsmallamountsofH-หน่วย whereashard-
woodligninhasbothS-andG-unitsinproportionsfrom1: 1 ใน
1: 3, withtracesofH-units.Allthreeligninunitsarepresentin
annualplants (Sjöström 1993; Brunow 2001 .. Kangetal 2012)
Ligninbiosynthesisproceedsthroughoxidativecouplingreac-
tionsofradicalsgeneratedbylaccasesandperoxidasesthatlead
toformationofagrowingpolymerlinkedbycarbon-carbonand
etherbonds.Theresonance-stabilizedphenoxyradicalspolymer-
izeinavarietyofmonomer-oligomerandoligomer-โอลิโก
couplingcombinationsthrough BO-4, AO-4, B-5, B-1, BB, 5-5,
dibenzodioxocin, and4 -O-5 เชื่อมโยง someofthemdepictedin
Figure2 Themostabundantstructureinligninisthearylglycerol-
B-aryletherstructurewiththe BO-4 linkagesaccountingforup
to60% ofthetotalinter-unitbondsinlignin (Balakshinetal.,
2009) whereasthecarbon-carbonbondsinligninareamongthe
resistanttowardbreakage มากที่สุด (Capanemaetal., 2004) แต่
มัน shouldbenotedthatdespitethenumerousstudiesonlignin
ที่ followedthepioneeringworkofFreudenbergandco งาน
(FreudenbergandHübner 1952; Freudenberg 1959 1962 1965;
FreudenbergandNeish, 1968) morethansixdecadesago มัน
structureisstillnotcompletelyunderstood

ผลลัพธ์ (ไทย) 3:

polymeronearth itcomprises20 – 35% ofthedryweightof .ของแบคทีเรีย พืช dependingonthebiomasssource ( galbeandzacchi , 2007 ) softwoodsgenerallycontainmorelignin ( 25 )35% ) thanhardwoods ( 20 - 25 % ) ( faravellietal . , 2010 ) ลิกนินเป็น predominantlyconcentratedinthemiddlelamellaandprimaryitsurroundsandcrosslinksthecellulose –เฮมิเซลลูโลสของแบคทีเรีย .matrixthroughlignin carbohydratenetworkstructuresthatpro - จำกัดvidestiffnesstothecellwallsandgluethecellstogethertherebyshieldingthepolysaccharidesagainstmicrobialdegradation เย้hydrophobicpolymer ligninalsoservesasabarrieragainstwater ,allthesebiologicalfunctionsofligninmakethis การเจาะuniquebiopolymeroneofthemostrecalcitrantnaturallyoccur -ringcompound ( รู เนื่องจาก asandmart í nez 15 , 2009 ) theligninmacromoleculecontainsfunctionalgroupssuchasmethoxyl เพ -nolic ไฮดรอกซิล alcoholichydroxyl andcarbonylgroupsthathave ,เป็น profoundimpactonitsreactivity .ligniniscomposedofphenylpropanoidunits knownasmono - ,lignolsorligninprecursors whicharelinkedtogetherthrough ,คาร์บอน– carbonandcarbon – oxygenbondswithavaryingdegreeofmethoxylation ( Adler , 1977 ; karhunenetal . , 1995 ) ( figure1 )p-coumaroyl จำกัด - themonolignolshavebeenidentifiedas ,eryl andsinapylalcohols whicharetherespectiveprecursors , ,ของ p-hydrophenyl ( H ) , ไกวซิล ( G ) andsyringyl ( s ) แคลิกนิน ( จางคณะ . , 2003 ) โดยปกติ plantcellwalllignificationaccomplishedthroughoxidativecouplingandchemicallycon - คือtrolledpolymerizationofthethreeligninprecursorsindifferentสัดส่วน เช่น softwoodligninisbuiltupmainlyfromg-units ( upto95 % ) หน่วย withsmallamountsofh whereashard - ,woodligninhasboths-andg-unitsinproportionsfrom1:1to1 : 3 , withtracesofh-units.allthreeligninunitsarepresentinannualplants ( sjostrom , 1993 ; brunow , 2001 ; kangetal , 2012 )ligninbiosynthesisproceedsthroughoxidativecouplingreac -tionsofradicalsgeneratedbylaccasesandperoxidasesthatleadtoformationofagrowingpolymerlinkedbycarbon คาร์บอนและจำกัดetherbonds.theresonance-stabilizedphenoxyradicalspolymer -izeinavarietyofmonomer – oligomerandoligomer –โอลิโกเมอร์couplingcombinationsthrough b-o-4 a-o-4 B-5 B-1 , , , b-b 5-5 , , ,dibenzodioxocin and4-o-5 someofthemdepictedin , ลิงค์ภาพที่ 2 . themostabundantstructureinligninisthearylglycerol -b-aryletherstructurewiththe b-o-4 linkagesaccountingforupto60 % ofthetotalinter unitbondsinlignin ( balakshinetal .2009 – carbonbondsinligninareamongthe ) whereasthecarbonresistanttowardbreakage ที่สุด ( capanemaetal . , 2004 ) อย่างไรก็ตามมัน shouldbenotedthatdespitethenumerousstudiesonligninที่ followedthepioneeringworkoffreudenbergandco คนงาน( freudenbergandh ü bner 1952 ; ฟร เดนเบิร์ก 1959 , 1962 , 1965 ;freudenbergandneish , 1968 ) morethansixdecadesago ของมันstructureisstillnotcompletelyunderstood .