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Terpenoids Against Infectious Diseases
Published in Dijendra Nath Roy, Terpenoids Against Human Diseases, 2019
Sanhita Ghosh, Kamalika Roy, Chiranjib Pal
Abietane acids are a group of phenanthrene diterpenoids. In an assay, pisiferic acid (Table 8.1) was found to have serious activity against Proteus vulgaris, Staphylococcus aureus and Bacillus subtilis. However, it is wise to note that methylation of the acid or phenol group abolished pisiferic acid’s activity against Proteus vulgaris. In addition, it was interesting to find that methylation of both the acid or phenol groups simultaneously abolished almost all of its antimicrobial activity (Kobayashi and Nishino 1986). A structural activity relationship study revealed that the carboxy group at the C-10 position was important for activity against Gram-negative bacteria and that the hydroxy group at position 12 was found to be important for activity against Gram-positive bacteria (Kobayashi and Nishino 1986). A study comparing the actions of pisiferic, dehydroabietic and podocarpic acids and ferruginol found that the aromatic ring C and the isopropyl group are necessary for Gram-positive antibacterial action. In addition, the hydroxy group ortho to the isopropyl group enhances the antimicrobial property of the compounds, whereas a change of the carboxy group to position 4 decreases the effects (San Feliciano et al. 1993). As already postulated for Abietic acids, the lipophilicity of pisiferic acid has a major role in its action against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), while a lower degree of lipophilicity elicits an increase in activity against Proteus vulgaris (San Feliciano et al. 1993).
Column chromatography and HPLC analysis of phenolic compounds in the fractions of Salvinia molesta mitchell
Published in Egyptian Journal of Basic and Applied Sciences, 2018
A major study conducted in S. molesta by Li et al. [23] using bioactivity guided fractionation of ethanol extract yielded 50 compounds, including 17 abietane diterpenes (1, 17–22), nine phenolics (2–4, 29–32, 49 and 50), five fatty acids (24–28), five triterpenes (35–39), four apocarotenoids (42–45), two acyclic sesquiterpenoids (6 and 23), two monoterpenes (5 and 46), two jasmonates (33 and 34), two steroids (40 and 41) and two coumarins (47 and 48). All the abietane diterpenes were isolated from S. molesta for the first time, and out of the 6 compounds, (1–6), salviniol (1) was a rare abietane diterpene with new ferruginol-menthol coupled skeleton and both salviniside I (2) and salviniside II (3) were novel benzofuran glucose conjugates with unique 10-membered macrodiolide structures. Another study has shown that naringinin was the major phenolic compound present in acetone: methanol (1:1) extract of S. molesta which was identified and quantified by HPLC followed by myricetin along with rutin, epicatechin, catechin, quercetin, kaempferol and vanillin. These compounds were also found to have free radical scavenging potential [24].
Effect of Calcium on the Phase Distribution of Resin and Fatty Acids in Pitch Emulsions
Published in Journal of Dispersion Science and Technology, 2011
Donald MacNeil, Anna Sundberg, Lari Vähäsalo, Bjarne Holmbom
The phase distribution of dehydroabietic acid was not much affected by the addition of calcium (Figure 5), whereas the other resin acids were strongly affected (Figures 3 and 4, Table 1). Dehydroabietic was still practically entirely soluble in the pH range tested even at 10 mM Ca2+. However, less than 50% of the other resin acids, both pimarane-type and abietane-type acids, were found in the water phase even at pH 10–12. Due to the higher solubility, dehydroabietic acid is by far the most common main resin acid in deinking lines, in contrast to process water in TMP lines, as seen in previous unpublished deinking studies. The low effect of calcium on the solubility of dehydroabietic acid is expected due to its structure. While resin acids and especially fatty acids obtain most of the hydrophilic nature from their carboxyl group, dehydroabietic acid also obtains it from its aromatic ring. When a calcium ion attaches to (for example) a pair of fatty acids, the hydrophilic nature of the carboxyl group is secluded and the dimer or agglomerate of fatty acids is rendered hydrophobic. For hydroabietic acid, however, even the seclusion of the carboxyl group is not sufficient for rendering the entire molecule hydrophobic due to its still exposed aromatic ring.