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PSE 406 Lecture 13 1
Wood Chemistry
Wood Chemistry
PSE 406/Chem E 470
Lecture 13
Diterpenes and Triterpenes
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PSE 406 Lecture 13 2
Wood Chemistry Pitch Chemicals
When you grab a softwood tree
and your hand sticks to the tree,
you have discovered pitch.
Pitch consists of about 5!5terpenes and resin acids. "esin
acids are g#assy #ike che$ica#s
a#so $ade of isoprene units.
The %hrist$as tree &'$ ho#ding
didn't have any pitch #eft.
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PSE 406 Lecture 13 3
Wood Chemistry Pitch as a Bandage
When a softwood tree
is wounded, it re#eases
pitch to (sea#) the
wound.* Terpenes serve as the
antiseptic and then
evaporate.
* "esin acids serve as thebandage +and a#so as an
antiseptic.
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PSE 406 Lecture 13 4
Wood Chemistry Rosin
The ter$ rosin refers to a $i-ture of resin acids
produced through the disti##ation of pitch.
u$ rosin/ disti##ation of gu$ resins +wound resin
* 0 12 $etric tons +1224 Ta## oi# rosin/ fro$ the wedish word ta##oa which
$eans pine oi#. Produced during the kraft pu#ping
process.
* 0 67, $etric tons +1224 Wood rosin/ Disti##ation of o#d stu$ps.
* 0 3, $etric tons +1224
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PSE 406 Lecture 13 5
Wood Chemistry Diterpenes: Strctre
7 isoprene units #inked head to tai#
8eutra#s/* 9ydrocarbons, pheno#ics, a#coho#s, ketones and a#dehydes
:cids/ Typica##y referred to as resin acids :cid content $uch higher in heartwood than sapwood
COOH
Abietic Acid
CH2OH
Pimarinol Pimaradiene
CHO
Levopimaral
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PSE 406 Lecture 13 6
Wood Chemistry Diterpenes: Strctre
"ing structures
*:cyc#ic, $ono, di, tri and tetracyc#ic
* ;acrocy#cic +1
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PSE 406 Lecture 13 $
Wood Chemistry Diterpenes: !ocation in "ree
%o$position is very species dependent
;ain#y found in conifers +.6#eoresin/ ?= resin acids +tricyc#ic!%>>9
* 9eartwood/ Large a$ount of neutra# diterpenoids
that have been $odified through various reactions/@:ro$atiAation, hydro-y#ation, o-idation, B rearrange$ents
+often #osing % ato$
Tropica# 9ardwoods/* anda#wood/ 16
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PSE 406 Lecture 13 %
Wood Chemistry
DiterpenesPhysical Properties
"osin +$i-ture of diterpenoids is g#ass #ike/ it s#ow#y
softens when heated @ does not have a $e#ting point
Pure resin acids are crysta##ine
* Pi$aric acid $p C 61
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PSE 406 Lecture 13 &
Wood Chemistry
Diterpenes
Plp and Paper Pro#lems
To-icity
* Diterpenoids are pri$ary po##utants in pu#p $i##
eff#uents* Fery to-ic to fish
* Difficu#t to re$ove in treat$ent syste$s
* LD5not particu#ar#y high +abietic 14$g!kg
* &nha#ation prob#e$s in saw $i##s
tickies
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PSE 406 Lecture 13 10
Wood Chemistry $ses o% Diterpenes
"osin/ ;i-ture of
resin acids
* u$ "osin* Ta## >i# "osin
0ses of "osin
* Printing &nks, Paper
iAe, "ubber,
:dhesives,
;isce##aneous
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PSE 406 Lecture 13 11
Wood Chemistry
"riterpenes & SterolsChemical Composition
G isoprene units #inked headto tai#
;any are c#assified assteroids +sterane structure* Triterpenoids and stero#s have
sa$e synthetic pathway sothey shou#d not be separated
* Hoth start fro$ sEua#ene and
then branch off
riterpene' 6 ( 5C
S)ualene
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PSE 406 Lecture 13 12
Wood Chemistry
"riterpenes & SterolsChemical Composition
HO
*Sito'terol
OH
HO
Serratenediol
HO
C+ole'terol
,not in tree'-
S)ualeneHO
*Sito'terol
HO
CH3
Campe'terol
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PSE 406 Lecture 13 13
Wood Chemistry
"riterpenes & SterolsChemical Composition
Triterpenoids e-ist in three for$s* Iree for$
* Jsters of fatty acids
* #ycosides
%an contain a #arge variety of functiona# groups* %arbo-y#
* Jthers
* :cety#* :#coho#s
* Ketones
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PSE 406 Lecture 13 14
Wood Chemistry
"riterpenes& SterolsPhysical Properties
-sitosterol
%rysta##ine
* $p 17% o#ubi#ity
* >rganic so#vents/ ether, a#coho#s, etc
Hoi#ing Point* ;erck inde-/ no boi#ing point #isted. Iound in
ta## oi# pitch < does not disti##
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PSE 406 Lecture 13 15
Wood Chemistry
"riterpenes & SterolsRole in 'atre
tero#s are found in p#ants as both free stero#s, as
stero# esters +of fatty acids and as stero# g#ycosides
erve as co$ponents of $e$branes
* Work with phospo#ipids to create $e$branes which are
on#y per$eab#e to certain che$ica#s
tero# esters
* He#ieved to serve as transport agent to get stero#s fro$
site of biosynthesis to $e$brane
tero# g#ycosides
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PSE 406 Lecture 13 16
Wood Chemistry Sterol le(els in plants
Leve#s of stero#s variab#e depending on p#ant.* Hrocco#i/ 3.7g!kg
* Hanana/ .5g!kg
*:#fa#fa 6.1 g!kg
*:spen +wood/ 5 g!kg
Iree stero#s are found in vegetab#e oi#s.
* Peanut oi#/ 1
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PSE 406 Lecture 13 1$
Wood Chemistry
"riterpenes & Sterols"ree )n%ormation
Iound in both hardwoods and softwoods
* 8ot a very #arge co$ponent in softwoods
*
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PSE 406 Lecture 13 1%
Wood Chemistry
"riterpenes & SterolsPlp and Paper Pro#lems
tero# esters are difficu#t to saponify/ known as
nonsaponifiab#es
* o$e che$ica# conversions during pu#ping but $ost#y
stab#e.
* Large nu$ber of reactions during b#eaching
@ saponification
9ydrophobic nature of stero# esters cause the$ to be
a $aor pitch prob#e$ in paper$aking* ;aor co$ponents of pitch deposits
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PSE 406 Lecture 13 1&
Wood Chemistry
Sterols %rom "reesBenecol *+,
Heneco#/ cho#estero# reducing product.* Known since 125s that vegetab#e stero#s can
reduce b#ood cho#estero#.@ 9igh #eve#s of stero#s can cause other prob#e$s
* 12s shown that p#ant stano#s were effective at#owering cho#estero# without negative effects.@ tano#s not fat so#ub#e so difficu#t to use.
@ Iinnish co$pany +"asio deve#oped a procedure in #ate124s ear#y 122s to produce stab#e fat so#ub#e stano#esters fro$ p#ant derived stero#s.
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PSE 406 Lecture 13 20
Wood Chemistry
Sterols %rom "rees:Benecol *-,
itostano#* i$i#ar structure to
sitostero#
* aturated stero#
* Iound in 8ordic Pine
&n Heneco# the
sitostano# is in the for$
of a fatty acid ester.
HO
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