3209-13-0Relevant articles and documents
Total Synthesis of Anti-MRSA Active Diorcinols and Analogues
Boehlich, G. Jacob,de Vries, Jessica,Geismar, Olivia,Gudzuhn, Mirja,Streit, Wolfgang R.,Wicha, Sebastian G.,Schützenmeister, Nina
, p. 9846 - 9850 (2020)
Diorcinols and related prenylated diaryl ethers were reported to exhibit activity against methicillin-resistant clinical isolates of Staphylococcus aureus (MRSA). Within these lines, we report the first total synthesis of diorcinol D, I, J, the proposed structure of verticilatin and recently isolated antibacterial diaryl ether by using an efficient and highly divergent synthetic strategy. These total syntheses furnish the diaryl ethers in only five to seven steps employing a Pd-catalyzed diaryl ether coupling as the key step. The total synthesis led to the structural revision of the natural product verticilatin, which has been isolated from a plant pathogenic fungus. Furthermore, these structures were tested in order to determine their antibacterial activities against different MRSA strains as well as further Gram-positive and -negative bacteria.
Progress towards the total synthesis of hamigerans C and D: A direct approach to an elaborated 6-7-5 carbocyclic core
Duquette, Douglas Charles,Jensen, Thomas,Stoltz, Brian Mark
, p. 263 - 267 (2018/02/16)
The hamigeran family of natural products has been the target of numerous synthetic efforts because of its biological activity and interesting structural properties. Herein, we disclose our efforts toward the synthesis of hamigerans C and D, unique among the initially isolated members because of their 6-7-5 carbocyclic core. Our approach directly targets this tricyclic motif by sequential Negishi and Heck coupling reactions, yielding an advanced intermediate with all necessary carbons and sufficient functionality poised for completion of the synthesis of these two natural products.
Correlating lignin structural features to phase partitioning behavior in a novel aqueous fractionation of softwood Kraft black liquor
Stoklosa, Ryan J.,Velez, Julian,Kelkar, Shantanu,Saffron, Christopher M.,Thies, Mark C.,Hodge, David B.
supporting information, p. 2904 - 2912 (2013/10/08)
In this work, a set of softwood lignins were recovered from a Kraft black liquor using a novel pH-based fractionation process involving sequential CO 2 acidification and separation of the solvated aqueous lignin fraction. These recovered lignin fractions were characterized with respect to properties that may be responsible for their phase partitioning behavior as well as properties that may render the lignins more suitable for materials applications. Lignin fractions were recovered between a pH range of 12.8 and 9.5 with the bulk of the lignin (90%) recovered between a pH of 11.1 and 10.0. While all the fractions were found to consist primarily of lignin as validated by sample methoxyl content, the first fractions to phase separated were found to be especially enriched in aliphatic extractives and polysaccharides. From the bulk of the lignin that was recovered between a pH of 11.1 and 10.0 a number of noteworthy trends were discernible from the data. Specifically, the phenolic hydroxyl content was found to exhibit a strong negative correlation to the fractionation pH and exhibited a nearly 50% increase with recovery at decreasing pH, while the GPC-estimated molecular weights and 13C NMR-estimated β-O-4 content showed strong positive correlations to the pH at recovery. The aliphatic hydroxyl content exhibited minimal differences between recovery conditions. Overall, these results suggest that this fractionation approach can generate lignin fractions enriched in select physical or structural properties that may be important for their application as feedstocks for renewable chemicals or materials.
