wood bark as valuable raw material for compounds with biological activity
TRANSCRIPT
Wood bark as valuable raw material for compounds with biological activity
Valentin I.PopaGheorghe Asachi Technical University of Iasi
Faculty of Chemical Engineering and Environmental Protection
Blvd. Mangeron No.71, Iasi, 700050, Romaniae-mail [email protected]; [email protected]
Structure of the bark• Bark is a highly
heterogeneous and chemically complex section of woody biomass. It is usually divided into the living inner bark and dead outer bark, representing 10-15 % of the total weight of the tree.
Component Softwoods HardwoodsWood Bark Wood Bark
Lignin 25-30 40-55 18-25 40-50Polysaccharides 66-72 30-48 74-80 32-45Extractives 2-9 2.-25 2-5 5-10Ash 0.2-0.6 Up to 20 0.2-0.6 Up to 20
Composition by mass of lignin, polysaccharide, extractive and ash in woods and barks. The non-extractive components are based on extractive-free material. Taken from (USDA, 1971)
• Bark contains useful products waiting for the right economic conditions or the development of satisfactory commercial processes
Solvent Typical substances removed in whole or part
Petroleum etherether, benzene,
chloroform
Alcohol, acetone, aqueous alcohol, aqueous acetone
Hot or cold water
Aqueous alkali
Acid hydrolysis
Terpenes and their derivatives, fats, waxes, free and wax acids and alcohols, sterols, resins.
Simple polyphenols and their glycosides, tannins, mono- and disaccharides (sugars).
Disaccharides, starch, gums, pectins, tannins, mucilages.
Phlobaphenes, phenolic acids, some bark lignin and hemicelluloses, suberin fragments.
Simple sugars and uronic acids derived from holocellulose, leaves residue of “lignin.”
Fractionation of bark
Chemical composition of barkChemical compounds,%
Softwood bark
Hardwood bark
Alcohol-benzene extractCold water extract
Hot water extractExtract with NaOH,1 %CelluloseLigninPentosansTannin
4.45-7.503.20-5.10
6.00-7.7031.40-50.0030.60-35.0032.70-39.7011.30-12.70
1.90-3.00
2.70-5.506.30-7.40
16.00-16.5028.40-29.0031.60-41.7019.00-30.0021.00-24.500 -
• C.I.Simionescu, V.I.Popa et al., Holzforschung und Holzverwertung,40(6), 136 (1988)
biochemicaldegradation
burningadditives
compost fodderlignocelluloses
SEPARATION
BARK
EXTRACTION OF SECONDARY COMPOUNDS
Rough mixture ofhemicelluloses + polyphenols
Hcell-OH
PF-OHHcell-OH
softwoods24-26%hardwoods15-20%
-furfural- galacotse- glucose- arabinose- xylose
PF-OH
phenolsubstitute(adhesives)
softwoods10-12%
hardwoods4-6%
- C6 phenols- C6-C1 phenolic acids- C6-C2 acetophenone- C6-C3 coumarone- C6-C1-C6 xanthone- C6-C3-C6 stilbens-(C6-C3)2 lignans
PF O CH2 CHO
CH2OH PF OH+
PF O CH2 CHO
CH2OH PF OH+
O CH2PF CH CH2 O
OH
PF OH prepolymer crosslinking
Obtaining phenolformaldehyderesins with vegetal alkaline extracts
Compound, g R1 R2 R3 R4 R5PhenolExtract from:hardwood barksoftwood barkFormaldehyde, 37 %ParaformaldehydeSodium hydroxide solution, 40 %
150
55
200 9
17
150
60
180 8
17
150
40
181 6
17
150
65207 12
16
150
70215 10
17
Shear strength of plywood glued (N/mm2) withmodified phenolformaldehyde resins
Plywood made of:
Fenoplac R1 R2 R3 R4 R5
3 veneerminimummaximum5 veneerminimummaximum
1.5 -
2.1-
1.82.6
2.73.0
1.82.4
2.22.8
1.62.6
--
2.42.8
2.73.0
2.42.6
2.52.8
Influence of addition of the alkaline extract from beech bark on the properties of wood fiber boards (Transversal, L-longitudinal)
Degree of resin substitution, %
Strength, kg/cm2
Density, Kg/cm3
Water absorption, %
Swelling, %
0
10
20
30
40
T 340L 340T 665L 568T 350L424T 430L 386T 505L 446
1000
1150
1100
1090
1090
30.00
13.70
23.30
23.68
23.90
17.5
12.5
12.8
11.5
15.2
Physico-mechanical properties of wood fiber board obtained at industrial level (compared
with standard level)Characteristics First quality Second
qualityExperimental values
Apparent density,kg/m3
Water absorption (after 24 h immersion), %Thickness swelling (after 24 h immersion), %Static bending strength, daN/cm2Internal transversal cohesion, daN/cm2
1000(+10%,-5 %)
30
18
400
8.38
1000(+10%,-5 %)
40
25
300
8.38
991-1021
12.55-17.29
13.80-15.60
327-424
8.63-12.80
Bark
Extraction (II)
ResinsExtraction
(I)
Polyphenols
Fractionation(I) Hemicelluloses
Fractionation(II) Cellulose
CompostingBioremediation
Lignin
Acid hydrolysis/ enzymatic
Nano- and micro cellulose
NaOH solution
Polyphenols• Secondary metabolites (more than 8000
compounds) Properties: antioxidants; prooxidants; anticancer
agents; apoptosis-inducing; antibacterial, antiparasite; anti-HIV activities; amelioration of cardiovascular diseases; improvement of endothelial function; modulation of gamma-glutamylcysteine synthase expression; improvement of health and survival on high –fat diet; colouring agents; chelating agents
15
Polyphenols were tested in:• Seed germination• Plant cultivation• Bioremediation• Plant grafting• Tissue plant culture• Microorganism cultivation (carotenes
pigments obtaining, mutagenesis)• Modulation of sugars metabolism
(diabete and alcoholic fermentation) O.C. Bujor, I. A. Talmaciu, I. Volf, and V. I. Popa Biorefining to recover aromatic compounds with biological
properties, Tappi J.,14 (3) 187-193 (2015)
17
POLYPHENOLS ENCAPSULATION BY ELECTROSPINNING TO OBTAIN SUBSTRATES
WITH BIOLOGICAL ACTIVITY
Polyphenols (gallic, vanillic, syringic acids, catechine, spruce bark extract) were encapsulated in nanofibrous membranes, using biocompatible polymers: [poly (2-hydroxyethyl methacrylate (pHEMA), poly [(lactic acid)-co-(glycolic acid)] (PLGA)]
Roxana-Elena Ghitescu, Ana-Maria Popa, Valentin I. Popa, Rene M. Rossi, Giuseppino Fortunato
Encapsulation of polyphenols into pHEMA e-spun fibers and determination of their antioxidant activities
International Journal of Pharmaceutics, 494, 278–287(2015)
• The immobilized polyphenols were tested with very good results to inhibit the reactive oxygen species produced by carbon nanotubes in the cells A549 originated from an explant culture of lung carcinomatous tissue from a 58-year-old Caucasian male.
19
DCF 60 minutes
0100200300400500600700800
20µg/mlMWCNT
100 50 25 12.5 6.25 3.12 1.5 0.78
Concentration of catechin (%)
Fluo
resc
ence
48
5nm
[MW
- bl
anks
]
no catechin 0.25% catechin in PLGA fibers 0.5% catechin in PLGA fibers
DCF 120 minutes
0100200300400500600700800
20µg/mlMWCNT
100 50 25 12.5 6.25 3.12 1.5 0.78
Concentration of catechin (%)
Fluo
resc
ence
485
nm
[MW
-bla
nks]
no catechin 0.25% catechin in PLGA fibers 0.5% catechin in PLGA fibers
Hemicelluloses based products
21
• Valentin I.Popa -Hemicelluloses in pharmacy and medicine in Polysaccharides in medicinal and pharmaceutical application, Edited by Valentin I.Popa, Smithers, Rapra, 2011
Filtratediscarded
sodium chlorite oxidation
Residue (Holocellulose)
Extractive-free wood bark
Filtrate
(Pectic substancesand water-soluble
polysaccharides)* Yield – 12. 5 % Filtrate
(Mixture of pectic substances and acidic xylan)
Residue
Filtrate (Xylan, “glucan” and water-soluble galacto-glucomann)
Residue
Residue
Filtrate(Mainly glucomannan)
Yield – 2.5%
Residue (pure cellulose)
Yield – 30.3%
Three successive preparations with aqueous barium hydroxidePure glucomannan (alkali-soluble)Yield – 2.0%; Percent composition:Galactose -4; Glucose – 25; Mannose – 71.
*All yields reported in this scheme are based on dry extractive- free bark
Hot ammonium oxalate solution
10% (w/w) sodium carbonate solution
24% (w/w) Potassium hydroxide
Yield – 4.3%
Yield – 8.5%
17% (w/w)sodium hydroxide + 4% boric acid
Fig.1 Fractionation scheme for Extraction of Hemicelluloses from Bark of Engelmann Spruce
24% Potassium hydroxide Extract Uronic acid – 7.3; Galactose – 8.8; Glucose – 29.4;Mannose – 3.3; Arabinose – 8.8; Xylose – 42.5
Composition:(relative percent)
Precipitate Yield – 2.2 %
Filtrate (see fig. 3)
Uronic acid – 3.3; Galactose – 11.4; Glucose – 6.64;Mannose – 10.8; Arabinose – Trace; Xylose – 27.9
Composition:(relative percent)
Insoluble Portion Yield – 0.3%
Soluble Portion Yield – 1.8%
Uronic acid – 2; Galactose – 10; Glucose –38;Mannose – 40; Arabinose – Trace; Xylose – 10
Composition:(relative percent)
Uronic acid – 2; Galactose – 11; Glucose – 57;Mannose – 2; Arabinose – Trace; Xylose – 28
Composition:(relative percent)
Three successivePrecipitations with Fehling’s solution
Aqueous Barium hydroxide (5%)
(This fraction consist mainly of the water-soluble galactoglucomannan ) (This fraction consist mainly of the heteropolymeric “glucan”)
Fig.2 Fractionation scheme for Extraction of Hemicelluloses from Bark of Engelmann Spruce: Resolution of 24% Potassium hydroxide Extract
Filtrate remaining after addition of Fehling’s Solution to Potassium hydroxide extract (See fig. 2)Yield – 6.0%
Uronic acid – 7.9; Galactose – 9.1; Glucose – 25.1; Mannose – Nil; Arabinose – 14.3; Xylose – 43.6
Composition:(relative percent)
Insoluble PortionYield – 0.5%
Soluble PortionYield – 4.8%
Uronic acid – 10; Galactose – 12; Glucose – 15; Mannose – Nil; Arabinose – 33; Xylose – 30
Composition:(relative percent)
Uronic acid – 7; Galactose – 20; Glucose – 25.1; Mannose – Nil; Arabinose – 10; Xylose -56
Composition:(relative percent)
Soluble PortionYield – 4.5%
Small precipitate(Discarded)
Uronic acid – 7; Galactose –6; Glucose – 12; Mannose – Nil; Arabinose – 10; Xylose – 65
Composition:(relative percent)
Aqueous barium hydroxide
CTA-OH + aqueous Sodium hydroxide
(This fraction consist mainly of the acidic arabinoxylan)
Fig.3 Fractionation scheme for Extraction of Hemicelluloses from Bark of Engelmann Spruce: Resolution of 24% Potassium hydroxide Extract (continued)
Reactions:• Acid hydrolysis• Enzymatic hydrolysis• Esterification• Etherification• Enzymatic modification (treatment
with laccase of hemicelluloses from annual plants allow obtaining gels)
Directions to use hemicelluloses: • ethanol-fermentation C6• polyols-2,3 butylene glycol-aerobic
fermentation• lactic, acetic, butyric acids-fermentation• fodder yeast (50 % proteins; 2-7 % fats-
vitamins) Candida utilis• xylitol- xylose reducing- sweetener• furfural-furfurilic alcohol,furan resins,
poly(amide) -4,6
Derivatives of de xylan:-acetates; -butyrates;-benzoates- extrusion agents for fatty acids -carboxymethylxylan- (surfactants, flocculants,
adhesives for paper coating);-eating packages;-xylan sulfate- (antiHIV, antitumor, antioxidant,
anticoagulant, antimicrobial, decrease of cholesterol);
-biofilms (xyloglucan/chitosan) –immobilisation of streptomicyn, antioxidants, antifungal and, antimicrobials agents, dyes, nutrients, packagings).
-arabinoxylans- emulsifying agents; thickening, food stabilisers, immunotherapy agents;
-4-O-methylglucuronoxylan-antitumor.
Advantages to use hemicelluloses in pharmacy, cosmetics and medicine:
- are accessible-are not toxic-can be chemically and enzymatically modified-are biodegradable-are biocompatible
Health benefic effects:-they improve lipids and minerals
metabolism;-they improve the function of colon and
assure protection against cancer;-they reduce the risk of heart diseases Examples:-regeneration of tissues-support for controlled delivery of drugs--gels for cells immobilisation
Cellulose based products
Nanocellulose-supermaterial• Eco-friendly• Lightweight• Ductile• Stronger than steel and Kevlar• The super-material is theoretically derived from plant
matter that has been reduced to small bit and pieces, and then purified by a homogenizer to remove non-cellulose components like lignin. The remaining cellulose fibers are finally separated and processed into a thick substrate that boasts of long polymers or crystallized structures. This ultimately results in what is termed as nanocrystalline cellulose or nanocellulose ‘paste’, an incredible material with flexibility, malleability, super-strength as well as low-impact credentials.
Uses of nanocellulose• Composites• Paper and boards• Food• Hygiene and absorbent products• Emulsion and dispersion• Oil recovery• Medical , cosmetic and phramaceutical
• V.I.PopaNanotechnology and nanocelluloseCeluloză şi Hârtie, 63 (4), 14-23 (2014)• V.I.PopaObtaining of nanocellulose (I)Celuloză şi Hârtie, 64 (1), 3-10 (2015)• V.I.Popa Obtaining nanocellulose (II)Celuloză şi Hârtie, in press
Nanofibrile
Schematic representation of (a) the homogenizer and (b) the
microfluidizer
Procedure for individualizing cellulose nanofibers by ultrasonication
Nanocellulose
1) High-strength yet lightweight body armor -
2) Low-impact (fuel efficient) yet super-durable vehicles
3) Medical usages
4) Bendable battery systems
5) Flexible electronic displays • -
6) Bio-fuel can be a by-product when ‘growing’ nanocellulose
• Sugars resulted in the hydrolysis pretreatments colud be used by fermentation to obtain biofuels or other valuable bioproducts, thus contributing to the efficiency of the porocess of nanocellulose fabrication.
Lignina
Lignin based products
Biological properties of lignin
1. Lignins as antibacterials2. Lignins as antioxidants and
photoprotectors 3. Lignins in reduction of
carcinogenesis4. Anti-HIV properties of lignins5. Lignin as spermicide
48
• Valentin I.Popa, Lignin in biological systems
in Polymeric Biomaterials, 2 vol, Founding Editor: Severian Dumitriu, Editor: Valentin I.Popa, 2013, CRC Press
Conversion of native lignin into lignophenol derivatives and control of their functionality
Lignins as antibacterials/Escherichia coli
Influence of different lignin samples on pathogenic bacteria sorption (Curan-commercial kraft lignin-
Borregaard Ltd)
The influence of lignin on phytopatogenic microorganisms
Lignins as antioxidants and photoprotectors • Inhibitory effect of
different lignin solutions on haemolysis induced by AAPH. [2,2’-azobis (2-amidopropane) dihydrochloride] a peroxyl radical initiator. LG-lignosulfonates, BG –lignin from bagasse, SE lignin from steam explosion and CU- Curan a commercial lignin.
Haemolysis and photohaemolysis of CPZ (chlorpromazine a photohaemolytic compound) in the
presence and absence of different lignins
Relative ABTS-radical scavenging activity of lignin samples
• The ABTS+* [ABTS - 2,2’-azino-bis(3-ethylbenzo-thiazoline-6-sulphonate)] cation radicals were generated by an enzymatic system consisting of peroxidase and hydrogen peroxide.
• He-hemp, Si-sisal, Ab-abaca, Ju-jute, Fl-1-flax, SW-Ls-1- lignosulfonate from softwood (Boresperse 3A),SW-Kr-1- kraft from softwood (Indulin AT), SW-Ls-2- lignosulfonate from softwood (Wafex P), Fl-2- soda flax (Bioplast), Fl-ox-soda flax oxidised, SW-Kr-2- kraft from softwood (Curan 100), SW-SF-1( soda from softwood (precipitated at high pH), SW-Kr-3-kraft from softwood, HW-organosolv (Alcell) from mixed hardwoods, SW-SF-2- soda softwood (precipitated at low pH), SW-Kr-4-kraft (Curan 2711P
Relative chain-breaking antioxidant effect of lignin in lipid peroxidation
Precipitated lignin 3mg/mL; melatonin 1µM; quercetin 1µM; commercial lignin 3 mg/mL.
SampleSuperoxide aninon Hydroxyl radical
Precipitated lignin 51.44 ±1.29 33.68±0.91
Commercial lignin 47.15±2.04 27.81±1.30
Melatonin 79.06±0.32 53.89±1.07
Quercetin 71.46±0.85 53.07±1.13
Inhibition percentages of superoxide anion and hydroxyl radical generation
Antimutagenic activity of modified kraft spruce lignin against 4-nitroquinoline-N-
oxide
LIGNIN The are specialized phagocytic cells that attack foreign substances, infectious
microbes and cancer cells through destruction and ingestion
CONCLUSION• Wood bark contains useful products
waiting for the right economic conditions or the development of satisfactory commercial processes.
• By applying the biorefining concept wood bark could be used to obtain compounds of high interest in the biological field.
Thank you for your attention!
Questions