Roseiro, Antimicrobial activity of resin acid
To test the toxic effects, stock solutions of [beta]-sitosterol (Calbiocem, 95%), stigmasterol (Sigma, 95%) and resin acid
(Sigma, 99%) were prepared, while samples of effluent and treated effluent (pH= 7.0) were previously filtrated through a 0.45 [micro]m membrane and sterilized by using a filter syringe (0.20 [micro]m).
Decay in roof exposure was best modeled using the initial MC gain/permeability, moisture uptake following rain, extent of checking, and the amount of dehydroabietic resin acid
. Three, or all four, of these factors are related to the MC of wood, a critical factor in fungal decay.
Natural resin acids
present in rosin of Pinus spez., including isopimaric acid (1), mercusis acid (2), neoabietic acid (3), dehydroabietic acid (4), and podocarpic acid (8), as well as resin acid
derivatives [beta], 9 [alpha], 13 [alpha]-H-tetrahydroabietic acid (5), 8 [alpha], 9 [alpha], 13[alpha],-H-terahydroabietic acid (6), 13 [alpha],-H-[delta] (8) -dihydroabietic acid (7), maleopimaric acid (9), and fumaropimaric acid (10), were studied for their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-Ea) activation induced by 12-O-tetradecanoylphorabol-13-acetate (TPA).
To illustrate the value of two-stage, or combination, degradative processes, the kinetics of resin acid
mineralization were assessed using two-stage laboratory scale systems.
All sawdust and pellets samples for fatty and resin acid
analysis were dried at 105[degrees]C for 24 hours before extraction.
The normal products of wood include tannins, resin acids
. stillbenes, and lignin among other compounds.
In addition to lignin, the ethanol used to obtain it is recovered and recycled; furfural, acetic acid, valuable extractives (resin acids
, terpenes, fatty acids, phytosterols) are isolated; and the cellulose and hexose sugars derived from hemicellulose are subjected to enzymatic conversion/fermentation to fuel ethanol.
Examples include carrageenan from kelp, biodiesel from vegetable oils, and resin acids
from the "extractives" of trees.
In alkaline conditions, such as in kraft pulping, the triglycerides are completely saponified, and the free fatty acids and resin acids
are dissolved, but sterols and some steryl esters and waxes do not form soluble soap and tend to deposit and cause pitch problems.
Composed mainly of cellulose, polyoses, and lignin, wood dust may contain a variety of nonpolar organic extractives (fatty acids, resin acids
, waxes, alcohols, terpenes, sterols, steryl esters, and glycerols), polar organic extractives (tannins, flavonoids, quinones, and lignans), and water-soluble extractives (carbohydrates, alkaloids, proteins, and inorganic material) (20).
Many acetone soluble polar components, including oxidized resin acids
, also are important to pulp and papermaking and can be readily assayed using gas chromatography.