This study,ANALYSIS OF ISOPIMARIC ACID IN TIMBER WOOD USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) AND GAS CHROMATOGRAPHY-MASS SPECTROSCOPY(GC-MS) contains concise information that will serve as a framework or guide for your project work. The project study is well-researched for academic purposes and are usually provided in complete chapters with adequate References.
Keywords:ANALYSIS OF ISOPIMARIC ACID IN TIMBER WOOD USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) AND GAS CHROMATOGRAPHY-MASS SPECTROSCOPY(GC-MS)
1.0 INTRODUCTION AND LITERATURE REVIEW
Wood dust is known to be a human carcinogen, based on sufficient evidence of carcinogenicity from studies in humans. It has been demonstrated through human epidemiologic studies that exposure to wood dust increases the occurrence of cancer of the nose (nasal cavities and par nasal sinuses).
Tannins, terpenes and other compounds are the fillers in woody tissue making it a complex substance (Rogge et al., 1998). Many softwood species (gymnosperms) are prolific resin producers. The softwood genera, including pines (Pinus), spruces (Picea), larches (Larix), and firs (Pseudotsuga), have well-established systems of horizontal and vertical ducts filled with resin (Parham and Gray, 1984).
The moisture content of wood varies considerably and the optimal content in terms of minimizing particulate emissions during wood combustion is between 20% and 30% (Core et al., 1982). If the moisture content is too high, an appreciable amount of energy is necessary to vaporize the water, reducing the heating value of the wood as well as decreasing combustion efficiency, which in turn increases smoke formation (Core et al., 1982).
Resin acids and lignans are therefore of interest due to their biological activity (Core et al., 1982). Their composition, distribution and roles were discussed quite early . Lignans (0.4-3 % w/w) have been reported in pine knots, while no detectable amounts were found in the stemwood. As for resin acids, the knots contained large amounts (4.5-30 % w/w) and the stemwood minor amounts.
Lignans are found in large amounts (6-24% w/w), in Finnish spruce knots; with hydroxymatairesinol (HMR, Scheme 1) comprising 65-85% of these lignans. HMR has three chiral centers and occurs as two natural diastereomers. The major diasteromer has been proven to be the 7S,8R,8’R isomer, while the minor isomer, allo-hydroxymatairesinol, has the 7R,8R,8’R configuration. In recent years hydroxymatairesinol has been used as a chiral source in the synthesis of derivatives with bioactive effects. Sapwood tissue contains negligible amount of lignans. In general, only minor amounts of resin acids (< 2/< 0.5 % w/w in stemwood/knots) have been detected in spruce samples (Craedy, 2007). No lignans have been found in Salic caprea (Krat, 2004) and minor amounts of lignan glycosides have been isolated from the inner bark of Betula pendula (Bresy, 2005). A lignan has been isolated from Juniperus communis berries. However, the wood has not been analysed.
Based on the accumulated knowledge, mainly from trees sampled in Nigeria, and due to potential differences caused by geographical location, this study undertakes a screening analysis of isopimaric acid as a resin acid in different Nigerian timber woods.
The main aim of this study is to characterize the presence and concentration of isopimaric acid in different timber woods using HPLC/GC-MS analytical methods. Other objectives of this study are: To provide a review on the isopimaric acid and its derivatives.
To review previous work on the synthesis of isopimaric acid.
To theoretically review woods and their properties.
To make recommendations suggestions for further research work.
1.2 LITERATURE REVIEW
1.2.1 Isopimaric acid (IPA) is a toxin which acts as a large conductance Ca2+-activated K+ channel (BK channel) opener. IPA originates from many sorts of trees, especially conifers. IPA is one of the members of the resin acid group which is a tricyclic diterpene. It has a condensed three-ring structure, one carboxyl-group and a (conjugated) double bond. IPA acts on the large-conductance calcium activated K+ channels (BK channels).
BK channels are formed by α subunits and accessory β subunits arranged in tetramers. The α subunit forms the ion conduction pore and the β subunit contributes to channel gating. IPA interaction with the BK channel enhances Ca2+ and / or voltage sensitivity of the α subunit of BK channels without affecting the channel conductance. In this state BK channels can still be inhibited by one of their inhibitors, like charybdotoxin (CTX). Opening of the BK channel leads to an increased K+-efflux which hyperpolarizes the resting membrane potential, reducing the excitability of the cell in which the BK-channel is expressed.
Figure1 Ring structure of Isopimaric Acid
IUPAC name (1R,4aR,4bS,7R,10aR)-7-Ethenyl-1,4a,7-trimethyl-3,4,4b,5,6,9,10, 10a-octahydro-2H-phenanthrene-1-carboxylic acid
In 1948, Harris and Sanderson suggested structures for two diterpenoid constituents of pine oleoresin, pimaric and isopimaric acids . Extensive chemical work appeared to confirm their assignments. In combination with arguments based on optical rotation and optical rotatory dispersion, this led to general acceptance of the structure and stereochemistry shown in 1 for pimaric acid and in I1 for isopimaric acid. Another isomer, sandaracopimaric acid, was assigned configuration I11 (Sanderson et al, 1948). The elegant total synthesis by Ireland and Schiess of dl-pimaradiene and dl-sandaracopimaradiene confirmed the structure of the corresponding acids (Ireland and Schiess, 1995). With reasonable assumptions regarding the steric course of the reactions, supplemented by evidence from ultraviolet absorption spectra and relative adsorption, this work provided strong support for the stereocheinistry shown in I and 111. Further confirmation of the structure and absolute configuration was given by Milne and Smith (1960), who transformed a steroid degradation product into pimar-8-ene (ll). Finally, transformation of testosterone into sandaracopimaradiene by Bose and Harrison (1992) and of 3ß-hydroxyandrost-5-ene-17-one into the same diene by Fetizon and Golfier (2000) established beyond question the configuration at C-13 for all three acids. Thus, primaric and sandaracopimaric acids are correctly represented in every detail by I and 111.
The chemistry and optical rotatory dispersion of isopimaric acid seemed perfectly consistent with the structure and stereochemistry denoted by II. However, Church and Ireland synthesized the corresponding pimaradiene and found it similar to 1,7-dimethyl-9-phenanthrol, but identity could not be rigorously established.
1.2.2 HAZARD EFFECT OF ISOPIMARIC ACIDS ON ANIMAL AND AQUATIC LIVES
Studies on rainbow trout hepatocytes have shown that IPA increases intracellular calcium release, leading to a disturbance in the calcium homeostasis. This could be important in the possible toxicity of the toxin.
This toxin may be of value in the treatment of urinary bladder overactivity, stroke treatment and in problems with the hyperactivity of (vascular) smooth muscle cells. (Kaczorowski, 1996).
Resin acids refers to mixtures primarily. Abietic acid is the main component but several related carboxylic acids. Nearly all resin acids have the same basic skeleton: three fused ring fused with the empirical formula C19H29COOH. These materials occur in rosin but also occur in fossilcoal or copal resins, in old pine tree stumps, etc. Resin acids are tacky, yellowish gums that are water-insoluble. They are used to produce soaps for diverse applications, but their use is being displaced increasingly by synthetic acids such as 2-ethylhexanoic acid or petroleum-derived naphthenic acids.
Resin acids are protectants and wood preservatives that are produced by parenchymatousepithelial cells that surround the resin ducts in trees from temperate coniferous forests. The resin acids are formed when two- and three-carbon molecules couple with isoprene building units to form mono- (volatile), sesqui- (volatile), and diterpene(nonvolatile) structures. Resin acids have two functional groups, carboxyl group and double bonds.
Pines contain numerous vertical and radial resin ducts scattered throughout the entire wood. The accumulation of resin in the heartwood and resin ducts causes a maximum concentration in the base of the older trees. Resin in the sapwood, however, is less at the base of the tree and increases with height.
In 2005, as an infestation of the Mountain pine beetle (Dendroctonus ponderosae), devastated the Lodgepole Pine forests of northern interior British Columbia, Canada, resin acid levels three to four times greater than normal were detected in infected trees, prior to death. These increased levels show that a tree uses the resins as a defense. Resins are both toxic to the beetle and the fungus and also can entomb the beetle in diterpene remains from secretions. Increasing resin production has been proposed as a way to slow the spread of the beetle in the “Red Zone” or the wildlife urban interface.
1.2.4 Number of Chemical components found in wood
Figure 2Ring Structure of Abietic Acid
- abietic acid
- abieta-7,13-dien-18-oic acid
- 13-isopropylpodocarpa -7,13-dien-15-oic acid
- neoabietic acid
- dehydroabietic acid
- palustric acid
- levopimaric acid
- simplified formula C20H30O2, or C19H29COOH
- represents the majority 85-90% of typical tall oil.
- structurally shown as (CH3)4C15H17COOH
- molecular weight 302
Figure 3 Ring Structure Of Pimaric Acid
- pimaric acid
- pimara-8(14),15-dien-18-oic acid
- isopimaric acids
- simplified formula C20H30O2 or C19H29COOH
- structurally represented as (CH3)3(CH2)C15H18COOH
- molecular weight 302
Resin acids, because of the same protectant nature they provide in the trees where they originate, also impose toxic implications on the effluent treatment facilities in pulp manufacturing plants. Furthermore, any residual resin acids that pass the treatment facilities add toxicity to the stream discharged to the receiving waters.
1.2.5The Chemistry of Wood
A native forest typically consists of many different botanical species, and forests like the Boreal forest comprises both softwood (conifers, such as spruce, tamarack) and hardwood (aspen, birch, poplar) trees. When processed for lumber this produces wood (for pulp and paper, or timber for construction and furniture purposes, or for energy through burning) and waste residues (bark and branches, leaves) that can also be used as an energy source, or to extract valuable compounds such as essential oils or bioactive chemicals.
The forest, and plant biomass in general, consists of what is commonly referred to as lignocellulose. Lignocellulosic materials comprise 3 main chemical components: cellulose (a carbohydrate biopolymer made up of repeating residues of glucose, and makes up ~50 % of the total weight of plant biomass), the hemicelluloses (an ambiguously defined group of carbohydrate biopolymers that exist in close association with cellulose in the plant cell wall and makes up between 20-30 % depending upon the plant species. There are 2 predominant types of hemicellulose polysaccharides; the xylans, chiefly found in hardwoods and to a minor extent in softwoods, and the galactoglucomannans of softwoods.), and lignin (a natural aromatic (85 %) and phenolic (15 %) polymer found in both the primary and secondary cell wall layers, and is present to the extent of 20-30 % and is species dependent. Lignin shields the carbohydrate polymers from microbial and enzymatic attack, and also confers mechanical strength and conduit of water in the tree).
The chemistry with respect to the hemicelluloses and lignins differs greatly between softwood & hardwood tree species. Other polysaccharides, usually of mixed constitution, are also present but in lesser amounts. Trees also produce a host of other compounds of varying chemical nature in minor and trace amounts, and some of high-value finds commercial applications. For example, wood bark, which comprises about 13 to 21 % of wood on a dry weight basis, contains a variety of chemicals some being of economic importance when extracted, and esp., as pharmaceuticals. Well-known examples of bark extractives include taxol (paclitaxel, for cancer chemotherapy) from Pacific yew tree, quinine (antimalarial agent from the Cinchona tree), aspirin (analgesic from willow tree), and curare (anaesthetic from Strychnus toxifera). Conifer leaves contain essential oils, and this too is a valued product. A host of many other natural products (phytochemicals) are used in pharmaceuticals, or as the basis of organic synthesis to produce more efficacious medicines.
Wood is a complex polymeric structure consisting of lignin (qv) and carbohydrates (qv) [cellulose (qv) and hemicelluloses], which form the visible lignocelIulosic structure of wood. Also present, but not contributing to wood structure, are minor amounts of other organic chemicals and minerals. The organic chemicals are diverse and can be removed from the wood with various solvents. The minerals constitute the ash residue remaining after ignition at a high temperature.
Wood species cannot readily be determined by chemical analysis because composition is affected by many variables, including geographical location, soil and weather conditions, and location of the wood within a given tree. Some generalizations are possible to distinguish hardwood and softwood composition, eg, the average lignin content of softwood is slightly higher than that of hardwood. If the minerals and small amounts of nitrogen and sulfur (0,1 -0.2%) are ignored, the elementary composition of dry wood averages 50% carbon, 6% hydrogen, and 44% oxygen.
Lignin is an amorphous, insoluble organic polymer and is very difficult if not impossible to isolate in a natural state. Molecular weights of isolated lignins range from the low thousands to as high as 50,000. The basic chemical structural unit is a methoxy-substituted propylphenol moiety, bonded in an irregular pattern of ether and carbon-carbon linkages. Lignin comprises 18-30% by weight of the dry wood, most of it concentrated in the compound middle lamella and the layered cell wall. It imparts a woody, rigid structure to the cell walls and distinguishes wood from other fibrous plant materials of lesser lignin content. Quantitative analysis usually involves removing the carbohydrate material by acid hydrolysis and filtering and weighing the insoluble residue (referred to as Klason lignin).
1.2.8 AIMS/OBJECTIVES OF THE STUDY
The main aim of this study is to characterize the presence and concentration of isopimaric acid in different timber woods using HPLC/GC-MS analytical methods. Other objectives of this study are:
- To provide a review on the isopimaric acid and its derivatives.
- To review previous work on the synthesis of isopimaric acid.
- To theoretically review woods and their properties.
- To make recommendations suggestions for further research work.
Keywords: ANALYSIS OF ISOPIMARIC ACID IN TIMBER WOOD USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) AND GAS CHROMATOGRAPHY-MASS SPECTROSCOPY(GC-MS)
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