Extractives in wood Extractives in wood Monoterpenes Resin canals Terpenoids Diterpenoids (resin acids) and their behaviour in Other terpenoids Stilbenes Lignans pulping Heartwood and bark Phenolic substances Hydrolyzable tannins Flavonoids Condenced tannins
Extractives in wood - location and major compounds
fats Ascending water, Sap Inorganics fatty acids Parenchyma cells steryl esters glycosides sterols sugars Cambium and growing zone starch proteins
Terpenoids, terpenes and Extractives sterols
Terpenoids, terpenes and steroids Inorganics | Exist mainly in resin canals of conifers | Terpenoid is a general name for Extractives terpenoids and terpenes, more strictly terpenoid is a terpene with a hydroxyl,
Fats, waxes and their components carbonyl or carboxyl function Phenolic substances
terpene=terpeeni, terpenoid=terpenoidi, steroid=steroidi, phenolic substance=fenolinen resin canal=pihkatiehyt, conifer=havupuu yhdiste
1 General classification of Monoterpenes terpenoids Hemiterpenoid Monoterpenoid Sesquiterpenoid Diterpenoid (1 isoprene unit) (2 isoprene units) (3 isoprene untis) (4 isoprene units) | Consist of two isoprene units | Exist mainly in softwood canal resin
isoprene Triterpenoid | Relatively volatile compounds (6 isoprene units) Sesterterpenoid limonene -codinene (5 isoprene units) abietadiene
O O H Terpenoids O
HO -amyrin OH Tetraterpenoid obhiobolin Polyterpenoid (8 isoprene units) ( >8 isoprene units) Limonene α-pinene β-pinene ∆3-carene n -carotene rubber and gutta-percha
Diterpenes and diterpenoids Diterpenoids from softwood
PIMARANE TYPE 15 12 11 | Consist of 4 isoprene units 13
9 14 | Diterpenoids, mainly resin acids, 8 7 constitute a major part of softwood COOH COOH COOH Pimaric acid Sandropimaric acid Isopimaric acid canal resin, i.e. oleoresin ABIETENE TYPE | In softwood main types are pimarane or abietane types of tricyclic diterpenoids.
COOH COOH COOH COOH COOH Abietic acid Levopimaric acid Palustric acid Neoabietic acid Dehydroabietic acid resin acid=hartsihappo, oleoresin=pihka
2 Triterpenoids and steroids Triterpenoids and steroids
STEROIDS 29 28 | 21 22 25 Both consist of 6 isoprene units 20 26 18 24 23 11 17 | Structures are closely related 12 27 1 19 13 16 2 9 14 | 10 8 15 Steroids in wood, for example: 3 HO 5 7 HO z β-sitosterol 4 6 Sitosterol Sitostanol z sitostanol TRITERPENOIDS | Triterpenoids in wood, for example: OH
z betulinol, found in birch bark CH OH 2 z serratenediol, found in pine bark HO HO
Betulinol Serratenediol
Fats, waxes and their Extractives components
Fatty acids: Terpenoids, terpenes and steroids COOH palmitic acid C16 Inorganics COOH oleic acid C18 COOH linoleic acid C18 Extractives COOH linolenic acid C18 COOH pinolenic acid C18 Fats, waxes and their components Triglycerides: H2 Phenolic substances CO O C CO O CH trilinolein CO O CH2
3 Fats, waxes and their Fats and fatty acids components
| In wood fats occur Fatty acid esters: mainly as O triglycerides waxes R1 O C CH3 n=19-23 H n 2 | Free fatty acids O steryl esters (FA) are present R2 O sterol only in heartwood O R2 O triterpenyl alcohol triterpenyl esters z The amount of free FAs R1= fatty acid chain, R2 = chains of saturated and unsaturated decreases when Composition and amount of lipophilic C14-C20 fatty acids logs are stored extractives of fresh and water-stored logs of Norway spruce.
Extractives Phenolic substances
Terpenoids, terpenes and steroids | Many structures derive from Inorganics phenylpropanol structures | Main groups are stilbenes, lignans, Extractives flavonoids and tannins | to some extent these structures are Fats, waxes and their components hydrophilic Phenolic substances | Are usually also chromophores
stilbene=stilbeeni, lignan=lignaani, flavonoid=flavonoidi, tannin=tanniini, chromophore=kromofori
4 Phenolic substances Extractives
Tannins Stilbene O HO O OH HO HO COOH Terpenoids, terpenes and steroids HO OH
HO Inorganics HO O HO pinosylvin gallic acid O ellagic acid Flavonoids Extractives Lignans OMe OH O HO O OMe H
H O H HO Fats, waxes and their components OH O H O OH O chrysin OH Phenolic substances H OMe HO O OH
HO OMe OH conidendrin OH pinoresinol O taxifolin
Inorganic compounds Properties of extractives
Terpenoids, terpenes and steroids | Wood contains also some metals Inorganics | Main compounds are: z Calcium (Ca), potassium (K), and Extractives magnesium (Mg) | Also some heavy metals are present: Fats, waxes and their components z Iron (Fe), cobalt (Co), and manganese Phenolic substances (Mn)
Hydrophilic to some Lipophilic extent
5 Reactions of extractives in Wood resin and pitch pulping – volatile fraction
| Wood resin = lipophilic, i.e. water insoluble, wood extractive: z Fatty acids | During the initial delignification low z Glycerides molar mass terpenes (monoterpenes, z Resin acids z Sterol and triterpenyl alcohols (i.e. sesquiterpenes) are distilled out of triterpenoids) and wood chips z Their fatty acid esters z Variety of other compounds (i.e., volatile | The volatile fraction, turpentine, is resin components like monoterpenes) recovered from digester relief | Wood pitch = deposit that is rich with wood resin components
Reactions of extractives in Reactions of extractives in pulping – non-volatile fraction: pulping – non-volatile fraction: saponifiable compounds saponification | A part of wood resin is saponifiable I ) Free (fatty and resin) acids → Sodium | Consequently saponification of these soaps saponifiable compounds occurs in alkaline media. II ) Fats (mainly triglycerides) → Sodium | Saponification is actually an alkaline soaps and glycerol (soluble in water) hydrolysis of esters. | The reaction products are soaps which may function as surface active agents III ) Steryl esters → Sodium soaps and | After cooking the soap is removed sterols (insoluble in water) z Tall oil soap saponification=saponifikaatio, saippuoituminen;saponifiable=saippuoituva; tall oil=mäntyöljy; surface active agent=pinta-aktiivinen aine
6 Reactions of extractives in Effects of extractives in pulping – nonvolatile fraction: unsaponifiable compounds pulping and papermaking Major responsible component | Part of the wood resin is Effect groups unsaponifiable Process disturbances z Neutral components : hydrocarbons, Foaming Resin and fatty acid soaps fatty acids, sterols, triterpenyl alcohols Ca soaps of fatty acids, steryl | These compounds may cause Deposits in kraft mills esters, hydrocarbons problems in pulping and bleaching Deposits from All resin groups, but especially mechanical pulps triglycerides and fatty acids z e.g. deposit build-up tendency Wet-end chemistry Colloidal pitch droplets, mainly composed disturbance of triglycerides, fatty acids z Means of deresination are needed Resin acids, diterpene aldehydes deresination=pihkanpoisto Effluent toxicity and alcohols, sterols
Effects of extractives in Some means of deresination pulping and papermaking
| Use of surfactants (e.g. soaps) Major responsible component Effect groups z If concentration of surfactants is Product quality impairment sufficiently high, micelles are formed Lower sheet strength Triglycerides, fatty acids z Micelles can dissolve water insoluble Lower water absorbance All hydrophobic components neutral components Lower friction Fatty acids, triglycerides | Use of talc Unsaturated fatty acids (after Taste and odor oxidation) Allergic reactions Oxidized resin acid products
surfactant=pinta-aktiivinen aine; micelle=miselli; talc=talkki
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