Antimicrobial activity of some N-substituted amides of long-chain fatty acids

Phytochemical analysis, antioxidant capacities, and in vitro biological activities of the extract of seed coat as by-products of pea

Converting seed coat peas (hulls) (SCP) into beneficial products provides a solution for waste treatment. This study aimed to investigate the phytoconstituents and biological activities of SCP extract. Phytochemical screening, total bioactive compounds, and GC-MS analysis were evaluated. Then, the antioxidant, antibacterial, anticancer, and antiviral activities of SCP extract were determined. The results demonstrate that SCP extract has bioactive compounds such as carbohydrates (29.53 ± 4.23 mg/mL), protein (0.24 ± 0.02 mg/mL), phenolics (27.04 ± 0.94 mg GAE/g extract), and flavonoids (17.19 ± 0.48 mg QE/g extract). The existence of more than 16 substances was determined using GC-MS analysis. The extract showed potential antioxidant activities, with the maximum activity seen for extract (IC50 µg/mL) = 79.16 ± 1.77 for DPPH, 67.40 ± 5.20 for ORAC, and 61.22 ± 4.81 for ABTS assays. The SCP extract showed potent antimicrobial activity against four gram-positive bacteria (Bacillus cereus, Streptomyces sp., Staphylococcus aureus, and Salmonella sp.) and two gram-negative bacteria (Escherichia coli and Pseudomonas sp.). SCP extract exhibited potential anticancer activity against lymphoma U937 and leukemic cells (THP1). The extract exhibited potential antiviral activity, with a selectivity index (SI) equal to 11.30 and 18.40 against herpes simplex-II (HSV-2) and adenovirus (Ad7), respectively. The results demonstrate more accurate information about peas by-products' chemical and antioxidant activities in various applications. The chemical components of peas by-products were found to have an in vitro antioxidant, antibacterial, and antiviral activity against leukemia and lymphoma.

Single Cell Oil (SCO)-Based Bioactive Compounds: I-Enzymatic Synthesis of Fatty Acid Amides Using SCOs as Acyl Group Donors and Their Biological Activities

Fatty acid amides (FAAs) are of great interest due to their broad industrial applications. They can be synthesized enzymatically with many advantages over chemical synthesis. In this study, the fatty acid moieties of lipids of Cunninghamella echinulata ATHUM 4411, Umbelopsis isabellina ATHUM 2935, Nannochloropsis gaditana CCAP 849/5, olive oil, and an eicosapentaenoic acid (EPA) concentrate were converted into their fatty acid methyl esters and used in the FAA (i.e., ethylene diamine amides) enzymatic synthesis, using lipases as biocatalysts. The FAA synthesis, monitored using in situ NMR, FT-IR, and thin-layer chromatography, was catalyzed efficiently by the immobilized Candida rugosa lipase. The synthesized FAAs exhibited a significant antimicrobial activity, especially those containing oleic acid in high proportions (i.e., derived from olive oil and U. isabellina oil), against several human pathogenic microorganisms, insecticidal activity against yellow fever mosquito, especially those of C. echinulata containing gamma-linolenic acid, and anticancer properties against SKOV-3 ovarian cancer cell line, especially those containing EPA in their structures (i.e., EPA concentrate and N. gaditana oil). We conclude that FAAs can be efficiently synthesized using microbial oils of different fatty acid composition and used in specific biological applications.

Relationship of chemical structure and antimicrobial activity of alkyl amides and amines

Contrary to the limited effects of alkyl amides and their corresponding N-derivatives, alkyl amines affected both gram-positive and gram-negative organisms. As with other alkyl derivatives the most sensitive gram-negative bacteria were usually more resistant than the most resistant gram-positive bacteria. Compounds with a chain-length of 11 to 15 are most active. Although some of the general properties relating the activity of fatty acids to their antimicrobial action are similar to those of amine compounds, the amines are unique in that monounsaturation does not increase compound activity. The possible modes of action of these compounds are discussed.