Impact of copper-based fungicides on the antioxidant quality of ethanolic hop extracts.

Hops contain a variety of compounds possessing antioxidant capacity including phenolic and polyphenolic compounds as well as α- and ß- acids. These compounds may contribute to the oxidative stability of beer during brewing and storage. Hop plants may be treated with copper-based fungicides (CBFs) which have been shown to increase the total copper content of harvested hop cones; however, copper ions are well known to catalyze the generation of reactive oxygen species production in beer and may negatively impact its oxidative stability. Increased copper content in CBF-treated hops has been previously shown to have deleterious effects on the aroma quality of hops and beer. The impact of CBFs on the antioxidant content and quality of hops has not been previously investigated. In this study, ethanolic extracts of CBF-treated hops are evaluated for their metal content and antioxidant quality in order to determine whether excess copper from CBF treatment negatively impacts their antioxidant capacity.

Antisoiling Performance of Lotus Leaf and Other Leaves after Prolonged Outdoor Exposure.

Recently, the antisoiling performances of superhydrophobic (SH) surfaces have received much attention due to their potential applications in self-cleaning photovoltaic glass and other surfaces without the need to be rinsed with water. In this work, we systematically compared the antisoiling performances of lotus leaf and other plant leaves by first drying them in the shade and then placing them outdoors in a slight breeze for 1-2 months. The results show that after being dried in the shade, the lotus leaf and the canna leaf retain their SH properties, comparable with their fresh states. The firmiana leaf is still hydrophilic. However, when the leaves are exposed to rain, no rain drops adhere to the surface of the lotus leaf but many droplets adhere to the canna leaf. Furthermore, after being incubated outdoors in the absence of rain for 1 month, the lotus leaf retained its SH properties, the canna leaf was no longer SH, and the firmiana leaf became more hydrophilic. SEM imaging with EDS and elemental mapping all confirmed that after outdoor exposure for 1-2 months, only a small amount of dust was found on the lotus leaf but a significant amount of dust was present on the canna leaf, with even more on the firmiana leaf. These results confirm that the lotus leaf has excellent antisoiling performance. The low interactions between the lotus leaf surface and the dust particles are most likely responsible for this unique property. On the contrary, the canna leaf, and especially the firmiana leaf, do not possess this property because neither their surface microstructures nor their surface free energies are favorable to reduce interactions between the leaf surface and dust particles. This study will be helpful in designing and preparing a surface with antisoiling performance.

Expanding the laticifer knowledge in Cannabaceae: distribution, morphology, origin, and latex composition.

Cannabaceae is a known family because of the production of cannabinoids in laticifers and glandular trichomes of Cannabis sativa. Laticifers are latex-secreting structures, which in Cannabaceae were identified only in C. sativa and Humulus lupulus. This study aimed to expand the knowledge of laticifers in Cannabaceae by checking their structural type and distribution, and the main classes of substances in the latex of Celtis pubescens, Pteroceltis tatarinowii, and Trema micrantha. Such information is also updated for C. sativa. Samples of shoot apices, stems, leaves, and flowers were processed for anatomical, histochemical, ultrastructural, and cytochemical analyses. Laticifers are articulated unbranched in all species instead of non-articulated as previously described for the family. They occur in all sampled organs. They are thick-walled, multinucleate, with a large vacuole and a peripheral cytoplasm. The cytoplasm is rich in mitochondria, endoplasmic reticulum, dictyosomes, ribosomes, and plastids containing starch grains and oil drops. Pectinase and cellulase activities were detected in the laticifer wall and vacuole, confirming its articulated origin, described by first time in the family. These enzymes promote the complete dissolution of the laticifer terminal walls. The latex contains proteins, lipids, and polysaccharides in addition to phenolics (C. sativa) and terpenes (C. pubescens, T. micrantha). The presence of laticifers with similar distribution and morphology supports the recent insertion of Celtis, Pteroceltis, and Trema in Cannabaceae. The articulated type of laticifer found in Cannabaceae, Moraceae, and Urticaceae indicates that the separation of these families by having distinct laticifer types should be reviewed.

Assessment of antimutagenic action of Celtis glabrata Steven ex Planch. (Cannabaceae) extracts against base pair exchange and frame shift mutations on Salmonella typhimurium TA98 and TA100 strains by Ames test.

CONTEXT: Celtis glabrata is used in Turkey for the treatment of various health disorders. OBJECTIVE: The acetone, chloroform, ethanol, and methanol extracts of C. glabrata leaf, fruit, and seed were investigated to evaluate their antimutagenic activities. MATERIAL AND METHODS: The antimutagenicity of these extracts was determined by Ames test against mutagens (4-nitro-O-phenylenediamine, 2-aminofluorene (2-AF), and sodium azide (SA)). The extracts were used at concentrations between 5 and 0.005 mg/plate. RESULTS: The ethanol extracts of leaves exhibited strong antimutagenicity (70%) against 2-AF with S9 at 5 mg/plate on TA98. But methanol (61%, 53%) and acetone (53%, 52%) also revealed strong inhibition rates at concentrations of ≥ 0.5 mg/plate. Among the extracts, the highest activity (96%) was obtained from acetone extract against SA without S9, followed by chloroform extract (91%) at a dose of 5 mg/plate on TA100 with S9. Ethanol (without S9) and chloroform (with S9) extracts showed strong antimutagenicity at all doses. Exception of chloroform and acetone (without S9), all fruit extracts (with/without S9) manifested strong antimutagenicity at doses of ≥ 0.5 mg/plate on TA98 strain. Ethanol extracts revealed 68% inhibition against 2-AF on TA98. Acetone and ethanol extracts manifested 84% and 82% inhibition against SA on TA100, respectively. All the extracts of seeds revealed strong inhibition against 2-AF at ≥ 0.5 mg/plate doses on TA98, but acetone extract showed excellent antimutagenicity (94%). Moreover, the chloroform (74, 73, 63, 54%), acetone (74, 72, 70, 65%) and methanol (74, 67, 63, 61%) extracts of seeds revealed strong antimutagenic activity on TA100 against SA with S9. DISCUSSION AND CONCLUSION: This plant may be natural source of antimutagenic agents.

Friedel-crafts alkylation of acylphloroglucinols catalyzed by a fungal indole prenyltransferase.

Naturally occurring prenylated acylphloroglucinol derivatives are plant metabolites with diverse biological and pharmacological activities. Prenylation of acylphloroglucinols plays an important role in the formation of these intriguing natural products and is catalyzed in plants by membrane-bound enzymes. In this study, we demonstrate the prenylation of such compounds by a soluble fungal prenyltransferase AnaPT involved in the biosynthesis of prenylated indole alkaloids. The observed activities of AnaPT toward these substrates are much higher than that of a microsomal fraction containing an overproduced prenyltransferase from the plant hop.

Anatomical and physical changes in leaves during the production of tamales.

PREMISE OF THE STUDY: Tamale preparation has a long tradition in Mexico. To understand which material properties have been considered important for this purpose throughout the years, a study was conducted of the anatomical, chemical, and mechanical properties of the leaves of four plant species used in tamale preparation in Veracruz, Mexico: Calathea misantlensis, Canna indica, Musa paradisiaca, and Oreopanax capitatus. METHODS: Four cooking treatments were considered: fresh (F), roasted (soasado, R), steamed (S), and roasted plus steamed (R/S). Chemical, anatomical, and mechanical analyses were conducted before and after each treatment. Leaf samples were tested for tensile strength at both parallel and perpendicular orientation relative to the fibers. KEY RESULTS: Musa paradisiaca had the highest proportion of cellulose, while the remaining species shared similar lower proportions. Leaves were stronger and stiffer in the longitudinal direction of the fibers. Musa paradisiaca leaves had higher values of mechanical strength than the other species. The cooking process that most affected the mechanical properties was steaming. CONCLUSIONS: The chemical constituents of the leaves are closely correlated with their physical properties. The treatment that caused the greatest decrease in leaf physical integrity was steaming, while the combination of roasting and steaming showed similar results to those of steaming alone. No evident anatomical changes are produced by any of the treatments. This is one of the few studies comparing physical, chemical, and anatomical characteristics of leaves used for human consumption, before and after cooking.

Bioactive phenolic amides from Celtis africana.

Nine compounds have been isolated for the first time from Celtis africana, namely trans-N-coumaroyltyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), lauric acid (4), oleic acid (5), palmitic acid (6), lupeol (7), ß-sitosterol (8) and oleanolic acid (9), respectively. Their structures have been elucidated by different spectroscopic techniques. The isolated compounds were screened for their antioxidant, anti-inflammatory and acetylcholinestrease enzyme inhibitory activities. Compounds 1-3 showed significant antioxidant and anti-inflammatory activities and weak to moderate acetylcholinestrease enzyme inhibition activity.