7 research outputs found
Synthesis And Characterization And Performance Evaluation Of Poly (Ester Amide) Urethane Derived From Thevetia Nerrifolia Seed Oil From Nigeria
Thevetia nerrifolia seed oil was extracted from the seed-bearing oil using hot extraction method involving the use of Soxhlet apparatus. The oil was characterized for physicochemical properties which include; specific gravity, refractive index, acid value, iodine value, and saponification value respectively. N, N-bis (2-hydroxyl ethyl) Fatty amide was obtained from the oil by reacting the oil with diethanolamine at 120oC, which was then reacted with phthalic anhydride at 140-150oC to give poly (ester amide). The poly (ester amide) was modified by reacting with 2, 4-diisocyanate under N2 atmosphere at 120oC to give poly (ester amide) urethane. Physicochemical characterization was carried out on both fatty amides, the unmodified and modified poly (ester amide). The film properties and chemical resistance were carried out on both the unmodified and urethane modified poly (ester amide). FTIR and TGA analysis were also carried out on the unmodified and the modified poly (ester amide). Findings revealed that the oil is semi-drying; suitable for surface coatings and that the performances of the poly (ester amide) were enhanced in terms of chemical resistance, film properties and thermal stability upon modification with a diisocyanate
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Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid Loci
The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses