UV and FTIR Interpretation

8/17/2019 UV and FTIR Interpretation

1/10

UV-spectrum was used to determine the purity of lignin and monitor the lignin distribution

among various tissues of lignocellulosic material with respect to the concentration. In this

study spectra the typical UV spectra of lignin fraction were illustrated in Fig. ,,,,,. The region

of UV spectrum was 2-! nm. The nine lignin fractions showed the characteristic pea"s

within 2# to $%nm, however all lignin fraction were demonstrated the absorption at

2&'#. First absorption at 2$'# nm was found in the al"ali lignin ()*+#, )*+2, )*+$,and )*+ and methanolic lignin ()+. The all lignin fractions were showed the shoulder

pea"s in the )*+#, )*+2, )*+$, )*+, )*+, )/+ and )0+ at $&nm, $#nm, $#2nm,

$##nm, $#nm, $nm and $#nm respectively. The ma1imum absorbance at 2& nm could

be originated to non-conugated phenolic groups in the lignin. The absorption at 2& nm,

corresponding to the 3→34 electronic transition in the aromatic ring of the unconuated

phenolic units, is indicative of free and etherified hydro1yl groups. This result was consistent

with the relatively high proportion of guaiacyl units in lignin characteri5ed with other

analysis. This result was consistent with the relatively high proportion

of guaiacyl units in lignin characteri5ed with other analysis. 6oftwood lignin is mainly

composed of guaiacylpropane units and gives an absorption ma1imum at a wavelength of 2&

nm, whereas hardwood lignin is a mi1ture of guaiacylpropane and syringylpropane units invarying ratios resulting in a shifted pea" ma1imum towards 2!&72! nm (Fergus and 8oring,

#9!a: Fu"a5awa and Imagawa, #9: Fengel and ;egener, #9&9: Ta"abe et al.,

#992:


2/10

&n this stud8,t8pical 34 spectra of lignin fractions are illustrated in Fig. *. Thesi9 lignin fractions shoed to characteristic absorptions at *6(and (*+ n2. The 7rst absorption at *6( n2 could be assigned tothe nonconugated phenolic groups in lignin. The second one at(*+ n2, corresponded to the n transition in lignin units containing% = ? group and = transition in lignin units containing% = % = lin@ages conugated to the aro2atic ring, as indicati5e of ferulic and p-cou2aric acids )Seca et al., *+++. Further2ore, if the a5elength of the second absorption is shorter than (*+ n2,it 2eans that esteri7ed p-cou2aric acid is the 2ain co2ponent)Aen et al., *+1+. &n this stud8, the second absorption of MAL is at(1; n2, conseBuentl8, it could be concluded that MAL contained2ore esteri7ed p-cou2aric acid than etheri7ed ferulic acid, hichas con7r2ed b8 the al@aline nitrobenzene o9idation results.Meanhile, it could further con7r2 that esteri7ed p-cou2aricacid indeed e9isted in MAL. %o2paring ith CL and MAL,lignin fractions prepared ith DM&MCc and aterEorganic sol5entsFig. 2. 34 spectra of lignin fractions )CL, MAL, LMCc, LMF, LMS?, and LG*?.

pretreat2ents had loer absorption coeHcients, hich ere inthe order of LMS? I LMCc I LMF I LG*?. This as in agree2entith the results of carboh8drates anal8sis. The higher 5alue of theabsorption coeHcient of LMS? re5ealed that LMS? had 2ore phenolicgroups and % = ? and % = % = lin@ages conugated ith thearo2atic ring )Seca et al., *+++. Cccording to the results obtained

b8 Sun and To2@inson )*++*, the lo absorption coeHcient asprobabl8 due to the relati5el8 higher a2ounts of other co-e9tractednon-lignin 2aterials.

The 34 spectra of ba2boo lignin fractions shoed si2ilar bands to thoseof other annual plants )Seca et al. 1;;6, *+++ )Fig. *, hich arecharacterized b8 a sharp 2a9i2u2 at *+ n2, a shoulder at *( n2, andto lo 2a9i2a at *6* and (1* n2, respecti5el8. The absorption at *+n2 is assigned to the J→J> transition in the aro2atic ring. &n addition, theabsorption at *6* n2, corresponding to the J→J> electronic transition inthe aro2atic ring of the unconuated phenolic units, is indicati5e of free

and etheri7ed h8dro98l groups. This result as consistent ith therelati5el8 high proportion of guaiac8l units in lignin characterized ithother anal8sis. The absorption at (1* n2, assigned to the n→J> transitionin lignin units containing %K? groups and J→J> transition in lignin unitsith %K% lin@ages conugated to the aro2atic ring, is indicati5e of ferulicand p-cou2aric acids t8pe structures )Sun et al. *++(, hich as inagree2ent ith the FT &$ spectra. The higher 5alue of e9tinctioncoeHcients at *6* and (1* n2 of 1. and 10.0 L g/1 c2/1 re5ealed thatthe lignin had 2ore phenolic groups and %? and %K% lin@agesconugated ith the aro2atic ring, hich as in agree2ent ith pre5iousresearch on MAL of ba2boo )Tai et al. 1;;+ and other stras )?li5eira et

al. *++; Seca et al. *+++.

PDD$-$D4&DAD C$T&%LD bioresources.comLi et al. )*+1+ . O%haracterization of ba2boo lignin, BioR esources )(, 10*-16.

10*

CHARACTERIZATION OF EXTRACTED LIGNIN OF BAMBOO(NEOSINOCALAMUS AFFINIS ) PRETREATED WITH SODIUMHYDROXIDE/UREA SOLUTION AT LOW TEMPERATUREMing-Fei Li,a !ong-Ming Fan,a $un-%ang Sun, a,b,> and Feng "u a,c,>

The se5en acid-insoluble lignin preparations e9hibitedthe basic 34 spectru2 of t8pical lignins ith a 2a9i2u2at *6+ n2, originating fro2 the non-conugated


3/10

phenolic groups )aro2atic ring in the lignin and being@non to be characteristic of a do2inant guaiac8l ligninQ1+R. Fig. * shos the 34 spectra of the acidinsolublelignin fractions obtained b8 treat2ent of thedea9ed barle8 stra ith 1. G*?* at pG 1*.+ for 1'h at ' =% under the e9tractant to stra ratios of 1+:1)spectru2 F1, 16:1 )spectru2 F', *+:1 )spectru2 F,

and (+:1 )spectru2 F. D5identl8, as shon in thespectra, the absorption coeHcient increased slightl8 iththe incre2ent of e9tractant to stra ratios, indicatingthat 2ore ether lin@ages beteen lignin and he2icellulosescould be clea5ed hen a relati5el8 higher a2ountof al@aline pero9ide e9tractant as used. &n contrast, therelati5el8 loer absorptions in the lignins fractions beteenF1 and F', e9tracted ith lo ratios of e9tractantto stra, are presu2ed to due to the slightl8 highera2ounts of bound he2icelluloses and co-precipitatedother non-lignin 2aterials such as ash and salt. The2uch loer absorption at (1+/(*+ n2 in all the ligninpreparations stated that the al@aline pero9ide treat2entsunder the conditions gi5en clea5ed 2ost of the ester or

ether lin@ages beteen lignin or he2icelluloses and h8dro98cinna2icacids, such as p-cou2aric and ferulicacids.

Structural and ph8sico-che2ical characterization ofligninssolubilized during al@aline pero9ide treat2ent ofbarle8 stra$.%. Sun a,b,>, ".F. Sun c, P. Foler b, . To2@inson b

The UVspectrum of the guaiacyl compounds in chloroform e1hibits a λma1 at 2B& nm and a λminat around 2%% nm, which are in accordance with the values reported by )ew G2#H, andthat for the syringyl compounds is 2!# and 2% nm respectively. The FTI spectrum of

each component showed the presence of all the functional groups for guaiacyl and syringylcompounds (Table and also matches with the FTI spectra for guaiacol and syringol of the*ldrich FTI library. Thus, by using a series of complementary techniEues the separationand complete identification of guaiacyl and syringyl groups of the walnut shell oil has beenattained. The 68 (syringylguaiacyl ratio of the oil using the values from the 8=76analysis of the initial petroleum-ether fraction was calculated to be #.#. This value appears

to be well in line with that for hard wood lignin. )yrolysis methods by far have proved to be the most accurate methods to determine lignin content, and since the complete pyrolysisof the walnut shells occurs during the e1traction process of the oil, the lignin present is

completely converted to its mar"ers, thus ma"ing this study representative for the lignincontent in the oil.

UV-6pectra of al"ali (*+#, *+2 *+$ *+ and acidic (*J lignin with ligno-sulphate (+6

as a standard are depicted in Fig. # (a. In the spectrum (Fig. #a, the pea"s were shown at the

region of 2#'# nm and 2&'# nm. UV-6pectra absorbance at 2#'# nm is assigned to

the 3@34 in the aromatic ring and at 2&'# nm is obtained to the 3@34 electronic

transition in the aromatic ring of the unconugated phenolic units. It is indicative of free and

etherified hydro1yl group (+i et al., 2#. UV-Vis characteristic absorbance pea"s of

polyphenol obtained from all samples is highlighted in Fig. #(a.UV- Visible spectrum

absorbance of organosolve (*+, /+, +, )+ and hot water lignin with ligno-sulphate as a

standard revealed in the Fig. #(b. The spectrum of e1tracted lignin samples wascharacteri5ed by absorption at 2$ nm and high intense pea" at 2& nm. The ma1imum


4/10

absorbance at 2& nm originated due to the presence of non-conugated phenolic group in the

lignin (6he et al., 2#, and also 3@34 electronic transition in the aromatic ring of the

unconugated phenolic units. *fter the study of UV-6pectra, high intense pea" at 2& nm was

determined in organosolve lignin (which is responsible for electronic transition of non-

conugated aromatic ring. UV-6pectra of al"ali (*+#, *+2 *+$ *+ and acidic (*J lignin

with ligno-sulphate (+6 as a standard are depicted in Fig. # (a. In the spectrum (Fig. #a, the pea"s were shown at the region of 2#'# nm and 2&'# nm. UV-6pectra absorbance at

2#'# nm is assigned to the 3@34 in the aromatic ring and at 2&'# nm is obtained to the

3@34 electronic transition in the aromatic ring of the unconugated phenolic units. It is

indicative of free and etherified hydro1yl group (+i et al., 2#. UV-Vis characteristic

absorbance pea"s of polyphenol obtained from all samples is highlighted in Fig. #(a.UV-

Visible spectrum absorbance of organosolve (*+, /+, +, )+ and hot water lignin with

ligno-sulphate as a standard revealed in the Fig. #(b. The spectrum of e1tracted lignin

samples was characteri5ed by absorption at 2$ nm and high intense pea" at 2& nm. The

ma1imum absorbance at 2& nm originated due to the presence of non-conugated phenolic

group in the lignin (6he et al., 2#, and also 3@34 electronic transition in the aromatic ring

of the unconugated phenolic units. *fter the study of UV-6pectra, high intense pea" at 2&nm was determined in organosolve lignin (which is responsible for electronic transition of

non-conugated aromatic ring. UV-6pectra of al"ali (*+#, *+2 *+$ *+ and acidic (*J

lignin with ligno-sulphate (+6 as a standard are depicted in Fig. # (a. In the spectrum (Fig.

#a, the pea"s were shown at the region of 2#'# nm and 2&'# nm. UV-6pectra

absorbance at 2#'# nm is assigned to the 3@34 in the aromatic ring and at 2&'# nm is

obtained to the 3@34 electronic transition in the aromatic ring of the unconugated phenolic

units. It is indicative of free and etherified hydro1yl group (+i et al., 2#. UV-Vis

characteristic absorbance pea"s of polyphenol obtained from all samples is highlighted in

Fig. #(a.UV- Visible spectrum absorbance of organosolve (*+, /+, +, )+ and hot water

lignin with ligno-sulphate as a standard revealed in the Fig. #(b. The spectrum of e1tracted

lignin samples was characteri5ed by absorption at 2$ nm and high intense pea" at 2& nm.

The ma1imum absorbance at 2& nm originated due to the presence of non-conugated

phenolic group in the lignin (6he et al., 2#, and also 3@34 electronic transition in the

aromatic ring of the unconugated phenolic units. *fter the study of UV-6pectra, high intense

pea" at 2& nm was determined in organosolve lignin (which is responsible for electronic

transition of non-conugated aromatic ring. UV-6pectra of al"ali (*+#, *+2 *+$ *+ and

acidic (*J lignin with ligno-sulphate (+6 as a standard are depicted in Fig. # (a. In the

spectrum (Fig. #a, the pea"s were shown at the region of 2#'# nm and 2&'# nm. UV-

6pectra absorbance at 2#'# nm is assigned to the 3@34 in the aromatic ring and at 2&'#

nm is obtained to the 3@34 electronic transition in the aromatic ring of the unconugated

phenolic units. It is indicative of free and etherified hydro1yl group (+i et al., 2#. UV-Vischaracteristic absorbance pea"s of polyphenol obtained from all samples is highlighted in










spectrum (Fig. #a, the pea"s were shown at the region of 2#'# nm and 2&'# nm. UV-6pectra absorbance at 2#'# nm is assigned to the 3@34 in the aromatic ring and at 2&'#


5/10


phenolic units. It is indicative of free and etherified hydro1yl group (+i et al., 2#. UV-Vis




lignin samples was characteri5ed by absorption at 2$ nm and high intense pea" at 2& nm.The ma1imum absorbance at 2& nm originated due to the presence of non-conugated










characteristic absorbance pea"s of polyphenol obtained from all samples is highlighted inFig. #(a.UV- Visible spectrum absorbance of organosolve (*+, /+, +, )+ and hot water







transition of non-conugated aromatic ring.UV-6pectra of al"ali (*+#, *+2 *+$ *+ and













pea" at 2& nm was determined in organosolve lignin (which is responsible for electronictransition of non-conugated aromatic ring.

6eparation and characteri5ation of lignin

compounds from the walnut ( Juglans regia shell oil

using preparative T+=, 8=76 and #0 K /.V. athias a, b, U.). 0al"ar a

Na2e ofthe

Aa5elength)n2

(+-#cm-#ɛ

CPL *00 111.*

(1+ 6'.'CPL1 * (*6.(


6/10

(11 *+.0*(' (6.(

CPL* *6+ *6;.(16 *1.*( (;1.'

PCL( *6* 1''.((16 1(.'*1'

PCL' *6+ 1'6.6(1; 1*.1*1'

PDL *06 1(*.0(*+ 6.6

PGL ** 11*.*(1* ;.6

PPL ** 6*.;

TC *6( (;0.+*0; (;.0**0

PML *0 1+0.+**

Fourier transform infrared spectroscopy has been proven to be a useful approach to study

physicochemical and conformational properties of lignin in which various functional groups

and structural fragments can be characteri5ed. The FT-I spectra of the acid-insoluble ligninfractions )*+#, )*+2, *)+$ and *)+, organosolve lignin )*+, )/+, )+ and ))+ and hot

water lignin (0+ are shown in Fig. $(a .+ignin contains various types of functional groups

depending on the wood species and isolation procedure. 6oftwood lignin, often referred to as

guaiacyl lignin is primarily comprised of coniferyl alcohol units, which ma"e up more than

9%L of the structural units in the lignin, with the remainder consisting mainly of p-coumaryl

alcohol-type units. 6oftwood lignin, often referred to as guaiacyl lignin is primarily

comprised of coniferyl alcohol units, which ma"e up more than 9%L of the structural units in

the lignin, with the remainder consisting mainly of p-coumaryl alcohol-type units. 6pectral

differences between different e1tracted paddy lignin were observed in the fingerprint region

(#& and & cm-#. The maor pea"s in the Fig. ,,,,,,,, of all samples show up in the spectra

were the broad bandMs at near about $2BcmN#, as attributed to hydro1yl groups in phenolicand aliphatic structures, and all samples spectrum band ( Table no. # at 29!-29#B were

predominantly arising from =-0 stretching in the aliphatic =-0 (6un et al., 2#2.The

aromatic metho1yl groups was assigned at 2&! cm-# (


7/10

#,#%# cm-#,#%92 cm-#, #%9 cm-#, #B2$ cm-# and #%9$ cm-# of );, );2,)*+2, )*+,

)0+, )/+, )*+ and ))+ respectively (Teado et al., 2!. In the al"ali treated paddy and

methanolic e1tracted lignin were not shown any band at this region due toPPPPPP . The strong

band at #%% cm-#, #BB cm-#, #B$ cm-#, #%& cm-# and #% cm-# of );#, )*+2, )*+,

)/+ and ))+ were attributed to the asymmetric vibration (asymmetric in methyl, methylene

and metho1y groups (Qahan et al., 2!. The band at near #2% cm-# was shown in allsamples e1cept untreated paddy straw, which was originated by =-0 in plane deformation in

the guaiacyl ring. In the various previous study softwood lignins also called as guaiacyl lignin

(


8/10

Lignin is created b8 enz82atic pol82erisation of three 2ono2ers, called conifer8lalcohol, s8nap8l alcohol and p-cou2ar8lalcohol that lead, respecti5el8, to guaiac8l )U, s8ring8l)S and p-h8dro98phen8l propane )p-G-t8pe units

1110

Cro2atic %-G

defor2ation in thes8ring8lring

11+0.(6

11++.*(

1+;'.0

111

Cro2atic%-G inplanedefor2ingin

guaiac8lring

110'.1(

1101.(

1101.'6

11*(.0

11*(.'

The strong band at 1'01 c2V1 is attributed to the %/G as822etric5ibrations )as822etric in 2eth8l, 2eth8lene, and 2etho98l

groups ) ahan et al., *++.The band at

110.10 11'.*

11.('

11'.*

111.'0

1;1.

+

1;'.+

1

10*(.1

1;(.+

010+( *romatic s"eletal

vibration R =C?

stretching

Cro2atics@eleton 5ibrations in the lignin preparations areassigned at 10++, 1+;, and 1'** c2 =1.

*ntio1idant property

*ntio1idant activity is "nown as the capacity of the compound, which inhibit the o1idation

degradation of pero1idation of any compound li"e a lipid (ogins"y V., and +issi, /. *.,

2%. The scavenging and reducing properties of the e1tracted paddy lignin were evaluated

through J))0, *OT6, F*) and 02?2 assays. Table $, indicating that most e1tracts display

significant antio1idant properties by four methods tested. It must also be noted that the

antio1idant activities assessed are in direct relation with the polyphenolic content of the

e1tract, as in result T)=.

There were various types of assessment of antio1idant activities. The ma1imum assay based

on the electron transfer and hydrogen atom donation reactions. The electron transfer mostly

attributed to J))0S, as can say that the Euenching of J))0S radical to form J))0-0 is also

possible. 6ome others methods also based on the electron transfer such as T)= assay using

Folin-=iocalteu reagent, *OT6SR decolouri5ation, 02?2 reducing power and ferric ionreducing antio1idant power (F*). Following above mentioned methods were applied for


9/10

the assessments of scavenging and reducing power of e1tracted paddy straw lignin in our

present study

Radical scaveDPPH•+ scavenging activity

J))0 assay is mainly attributed to the electron transfer assays,however the Euenching of

J))0 radical to form J))0-0 is also possible There are 2an8 assa8s for the assess2ent of antio9idant properties,the 2aorit8 of the2 are based on electron transfer and h8drogenato2 donation reactions. Cfter co2prehensi5e criticalassess2ent of the 2ost freBuentl8 used 2ethods, Guang, ?u, andPrior )*++ concluded that ?$C%, TP% 2easured ith Folin/%iocalteureagent and one of the electronEh8drogen transfer assa8s shouldbe reco22ended for representati5e e5aluation of antio9idant properties.PPG = assa8 is 2ainl8 attributed to the electron transfer assa8s,hoe5er the Buenching of PPG = radical to for2 PPG-G isalso possible. ?ther electron transfer based 2ethods include the TP% assa8 using Folin/%iocalteu reagent, CWTS =X decolourisation assa8and ferric ion reducing antio9idant poer )F$CP. Folloing theabo5e 2entioned reco22endation, all these 2ethods ere appliedfor the assess2ent of 4. opulus antio9idant potential in our stud8

The antio9idant properties of the ste2 e9tracts ere e5aluatedthrough PPG= and F$CP assa8s. The results =and their respecti5e TP% 5alues= are included in Table (, indicating that 2ost e9tracts

displa8 signi7cant antio9idant properties b8 both 2ethods tested. These results are in agree2ent ith literature reports on theantio9idant acti5ities of grape ste2 e9tracts )Ma@ris et al., *++aSpigno Y e Fa5eri, *++. &t 2ust also be noted that the antio9idantacti5ities assessed are in direct relation ith the pol8phenoliccontent of the e9tract, as is delineated in Fig. * )CYW. Finall8, a goodcorrelation coef7cient as found beteen the F$CP assa8 andPPG radical sca5enging assa8 )$ Z +.6'0, Fig. *%.

Urape ste2 e9tracts: Pol8phenolic content and assess2ent oftheir in 5itroantio9idant propertiesMaria Cnastasiadi a, Garris Pratsinis b, i2itris [letsas b, Cle9ios-Leandros S@altsounis

c,Ser@os C. Garoutounian LAT - Food Science and Technolog8 '6 )*+1* (10e(**

*ntio1idant activity is defined as the ability of a compound to

inhibit o1idative degradation li"e lipid pero1idation (ogins"y

and +issi, 2%. The ferric thiocyanate method measures the

amount of pero1ide produced during the initial stages of o1idation

which are the primary products of o1idation. +*/) e1hibited

effective antio1idant activity in the linoleic acid emulsion system.

The effect of $ lgm+ +*/) on lipid pero1idation of a linoleic

acid emulsion is shown in Table $ and Fig. $, and was

found to be 9$.2L. ?n the other hand, O0*, O0T, a-tocopherol

and trolo1 e1hibited &$.$L, &2.#L, B&.#L and .$L pero1idationof linoleic acid emulsion at the same concentration, respectively.


10/10

)ero1idation of linoleic acid emulsion without +*/) or standard

compounds was accompanied by a rapid increase in pero1ides.

=onseEuently, these results clearly indicate that +*/) had effective

and potent antio1idant activity in the ferric thiocyanate

assays.

Furthermore, +*/) had effective reducing power determined byusing the potassium ferricyanide reduction and cupric ions (=u2R

reducing methods when compared to the standards. To measure

the reductive ability of +*/), Fe$R7Fe2R transformation was investigated

in the presence of +*/) using the method of ?yai5u

(#9&B. *s can be seen in Table $, +*/) (r2 .9#& demonstrated

powerful Fe$R reducing ability with statistically significant differences

(p .#. The reducing power of +*/), O0*, O0T, a-tocopherol

and trolo1 increased steadily with increasing concentration of

samples. The reducing power of +*/) and the standard compounds

were as follows O0* W O0T a-tocopherol W trolo1 W +*/). The

results demonstrated that +*/) had mar"ed ferric ions (Fe$Rreducing ability and electron donor properties for neutrali5ing free

radicals by forming stable products. 0owever, this reducing power

was lower than that of the standard antio1idants used. The outcome

of the reducing reaction is to terminate the radical chain

reactions that may otherwise be very damaging

Documents

UV and FTIR Interpretation