Synthesis of 3-(4-Bromobenzyl)-5-(aryl methylene)-5H-furan-2-ones and their activity as inhibitors of the photosynthetic electron transport chain

A series of 12 3-(4-bromobenzyl)-5-(arylmethylene)-5 H-furan-2-one lactones, designed using the naturally occurring toxin nostoclides as a lead structure, were synthesized and screened as potential inhibitors of photosynthetic electron transport. The structures were confirmed by (1)H and (13)C NMR, MS, and IR analyses. Their biological activity was evaluated both in vitro, as the ability to interfere with light-driven reduction of ferricyanide by isolated spinach chloroplasts, and in vivo, as the capability to inhibite the oxygen production by intact Chlorella cells. Some of the compounds exhibited inhibitory properties in the micromolar range against basal and phosphorylating electron flow from water to K 3[Fe(CN) 6], with no effect on uncoupled electron flow. Thus, they seem to behave as energy-transfer inhibitors. Although poor solubility in water may limit their effectiveness, the active derivatives could present structures to be exploited for the design of new substances endowed with herbicidal activity.     

Anthocyanins present in selected tropical fruits: acerola, jambolão, jussara, and guajiru

Many tropical fruits are rich in anthocyanins, though limited information is available about the characterization and quantification of these anthocyanins. The identification and quantification of anthocyanin pigments in four tropical fruits were determined by HPLC-MS/MS. Fruits studied included acerola (Malphigia emarginata), jussara (Euterpe edulis), jambol?o (Syzygium cumini), and guajiru (Chrysobalanus icaco). All four fruits were found to contain anthocyanin pigments. Anthocyanidin backbones included cyanidin, delphinidin, peonidin, pelargonidin, petunidin, and malvidin. Guajiru contained several acylated forms, while acerola, jussara, and jambol?o contained only nonacylated glycosides. These results demonstrate that these tropical fruits are rich in anthocyanins and that the anthocyanins are widely ranging in anthocyanidin backbone, glycosylation, and acylation.     

Mini‐cutting technique application in Corymbia and Eucalyptus: effects of mini‐tunnel use across seasons of the year

New Forests - The forestry sector has been able to sustainably satisfy the increasing global demand for forest products, thereby positively impacting the economy, while mitigating climate change....     

Less is more: Little seed processing required for direct seeding in seasonal tropics

Seed processing and dormancy break treatments are recommended for rendering seeds restoration-ready. Conversely, fruit structures and seed coats may protect seeds from environmental harm in the field. We evaluated the effects of seed processing (by either keeping fruit structures or extracting seeds) and/or scarification (of physically dormant seeds) on the seedling emergence and establishment of 10 legume tree species from tropical forests and savannas of Central Brazil. We sowed seeds in a greenhouse for reference and in a field experiment conducted in tilled ready-to-seed sites. We monitored seedling emergence and survival for a year. We calculated the costs of harvesting, processing, and pretreating seeds, and considered the final cost of a 1-year-old seedling. Seed extraction resulted in lower emergence for most species in the greenhouse and in the field. It also accelerated emergence of three and four species in the greenhouse and the field, respectively. Scarification resulted in lower seedling emergence in the field for half of the species, while it increased emergence of three species in the greenhouse. Most species presented accelerated emergence both in the greenhouse and the field. The seedling cost was 1.6 to 74.6 times higher when seeds were processed, and 1.3 to 6.0 times when seeds were scarified, except for one species. Keeping fruit structures and seed coats reduced the costs of seeds and increased the success of direct seeding.

     

Changes in soil carbon and nitrogen stocks after conversion of subtropical natural forest to loblolly pine plantations

Pinus plantations have increased in Brazil, and native forest areas have been converted for timber production. The clearing and the long-term loblolly pine (Pinus taeda L.) land-use effects on soil carbon and nitrogen stocks were evaluated in a natural broadleaved forest and in loblolly pine sites cultivated for 29, 35, 38 and 49 years, as well the soil contribution as ecosystem carbon pool. According to the exponential-decay model fitted to changes in carbon stock, the initial soil carbon stock of 200 Mg ha^?1 to a depth of 100 cm in the natural forest decreased by 36% over 49 years of pine cultivation (around 72.4 Mg ha^?1 of C). Around two-thirds of this decrease occurred in the top 30 cm of the soil and intensively in the first 12 years of cultivation, but slowly faded as carbon stock tended to reach a new steady state after approximately 49 years of cultivation. The soil nitrogen stock in the natural forest was 14.2 Mg ha^?1 to a depth of 100 cm and decreased by 36% over the 49 years. This decrease was linear according to the fitted model, especially in the top 30 cm where nitrogen decline was 83% and was proportionally more intense than the carbon decline. Despite the soil carbon decrease, soil remained the largest carbon reservoir in the ecosystem for the growing rotation time of loblolly pine in this region.

     

Litter production and nutrient deposition from native woody species in the Brazilian semi-arid region

Agroforestry Systems - The use of native trees in agroecosystems is a promising way to increase litter deposition and nutrient cycling and foster the recovery of degraded areas, especially in...     

Vegetation restoration is associated with increasing forest width

New Forests - Monitoring and assessment reveal important information about restoration areas and can also be useful for understanding ecological processes such as succession and species-area...     

Implications of landscape configuration on understory forage productivity: a remote sensing assessment of native forests openings

Agroforestry Systems - Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage...     

Variable-rate seeding in soybean according to soil attributes related to grain yield

Precision Agriculture - Defining the ideal soybean stand is essential for obtaining maximum grain yield. As a hypothesis of the work, it was questioned whether it is possible to vary seeding...     

Role of probiotics on the immunity of Nile tilapia Oreochromis niloticus: a review

The development and intensification of Nile tilapia farming systems has happened together with ever increased use of antibiotics and therapeutants. Research on the use of probiotics has come along as alternative to routine use of antibiotics in fish diets. The manipulation of the gut microbiota through dietary probiotic inclusion targeting improved growth rate and disease resistance has been investigated in many farmed fish species. However, mechanisms underlying modulation of fish immune response remains unclear. This review summarizes and discuss recent findings in the role of probiotics on the immunity of Nile tilapia Oreochromis niloticus addressing available information regarding immunological parameters such as phagocytic activity, lysozyme, respiratory burst activity, antioxidant enzymes, complement system as well as immune-related gene expression, in the aim to foster research efforts on effective strategies for the successful use of probiotics in the tilapia farming industry.