Ent-trachyloban-19-oic acid isolated from Iostephane heterophylla as a promising antibacterial agent against Streptococcus mutans biofilms

From the roots of Iostephane heterophylla, six known compounds, namely, ent-trachyloban-19-oic acid (1), the mixture of ent-kaur-16-en-19-oic acid (2) and ent-beyer-15-en-19-oic acid (3), xanthorrhizol (4), 16α-hydroxy-ent-kaurane (5) and 16α-hydroxy-ent-kaur-11-en-19-oic acid (6) were isolated using a bioassay-guided fractionation method. The known compounds (1-6) were identified by comparison of their spectroscopic data with reported values in the literature. In an attempt to increase the resultant antimicrobial activity of 1 and 4, a series of reactions was performed on ent-trachyloban-19-oic acid (1) and xanthorrhizol (4), to obtain derivatives 1a, 1b, and 4a-4d. All the isolated compounds (1-6) and the derivatives 1a, 1b, and 4a-4d were evaluated for their antimicrobial activity against two oral pathogens, Streptococcus mutans and Porphyromonas gingivalis associated with caries and periodontal disease, respectively. Compounds 1, 1b, 2+3, 4 and 4d inhibited the growth of S. mutans with concentrations ranging from 4.1 μg/mL to 70.5 μg/mL. No significant activity was found on P. gingivalis except for 4 with an MIC of 6.8 μg/mL. The ability of 1, 1b, 2+3, 4 and 4d to inhibit biofilm formation by S. mutans was evaluated. It was found that 1, 1b, 4 and 4d interfered with the establishment of S. mutans biofilms, inhibiting their development at 32.5, 125.0, 14.1 and 24.4 μg/mL, respectively.     

Pharmacokinetics of albendazole sulfoxide enantiomers administered in racemic form and separately in rats

The pharmacokinetic behaviour of albendazole sulfoxide (ABZSO) enantiomers was studied in rats after the oral administration of 10 mg/kg of rac-ABZSO, 5 mg/kg of (-)-ABZSO or 5 mg/kg of (+)-ABZSO. The disposition profiles of ABZSO enantiomers were similar in all treatments, but the calculated area under the curve for the (-)-ABZSO was higher in all cases compared with (+)-ABZSO. The results suggest that there is no chiral inversion of ABZSO enantiomers. After the administration of rac-ABZSO, 17.2% of the total dose was recovered in urine as albendazole ABZ (0.1%), albendazole sulfone ABZSO(2) (0.3%), albendazole 2-aminosulfone (ABZ-SO(2)NH(2)) (3.1%) and ABZSO (13.7%). The ratio (+) to (-) was similar in urine (1.6) and blood (1.7).     

Analysis of highbush blueberry (Vaccinium corymbosum L.) fruit growth with exponential mixed models

Blueberry fruit growth commonly exhibits a double-sigmoid pattern. The goal of this work was to characterize and compare fruit growth of cultivars differing in ripening time using exponential non-linear mixed models. Mixed-effects five-parameter exponential (Gompertz I and II; logistic; monomolecular) models were fitted to fruit diameter data from 2 years and three cultivars grown in the field in a cool temperate environment. Gompertz II mixed model provided the best fit to fruit growth data and was used for further analysis. In later ripening cultivars ‘Cape Fear’ and ‘Herbert’, clear-cut double-sigmoid patterns were observed, absolute growth rate models exhibited two marked peaks, and relative growth rate showed an initial decreasing trend, and a subsequent peak. The earlier cv. ‘O’Neal’ did not exhibit a defined double-sigmoid pattern. The time between relative extremes of absolute growth acceleration is proposed as an objective criterion for fixing stage boundaries within growth curves. Exponential mixed models accurately fitted blueberry growth patterns. These equations highlighted differences in fruit growth patterns between early and late ripening highbush blueberry cultivars.     

Foregut fermentation in the hoatzin, a neotropical leaf-eating bird

The only known case of an avian digestive system with active foregut fermentation is reported for the hoatzin (Opisthocomus hoazin), one of the world's few obligate folivorous (leaf-eating) birds. Hoatzins are one of the smallest endotherms with this form of digestion. Foregut fermentation in a flying bird may be explained by increased digestive efficiency by selection of highly fermentable and extremely patchy resources, coupled with microbial nutritional products and secondary compound detoxification. This unexpected digestive system gives a new perspective to the understanding of size limitations of vertebrate herbivores and to the evolution of foregut fermentation.     

Evaluation of Potential Feed Ingredients for the Juvenile Four‐sided Sea Cucumber,Isostichopus badionotus

The objective of this study was to evaluate two seaweed species, Solieria filiformis and Macrocytis piryfera, both as dry‐meal powder and predigested meal, to be used as ingredients in artificial diets for the juvenile four‐sided sea cucumber, Isostichopus badionotus. Four diets were tested in triplicate: S. filiformis dry‐meal powder and predigested meal and M. piryfera dry‐meal powder and predigested meal, mixed with 70% of beach sand. Survival exceeded 90% in all the treatments, and there were no differences in the growth of juveniles using dry‐meal powder or predigested meal. Weight gain was calculated for all the diets, and the highest values were obtained by animals fed S. filiformis. No differences between using dry‐meal powder and predigested meal were found, so these diets were excluded from the second trial. The ingestion rate was the same with both algae, but the feed conversion ratio was twice as high for M. piryfera. Solieria filiformis exhibited a number of differences in fatty acid and amino acid profiles, including higher proline, arginine, and saturated fatty acid levels. The results indicate that S. filiformis has better nutritional characteristics to be an ingredient for an artificial I. badionotus juvenile diet.     

Pastamaking and breadmaking quality of soft-textured durum wheat lines

The effects of grain texture on pastamaking and breadmaking quality were studied in three F₈ soft-textured durum wheat lines (SDLs) containing wild-type alleles Pina-D1a and Pinb-D1a as compared with their hard durum sister lines (HDLs). SDLs homozygous for a small 5DS segment, less than 14.4 cM in size, accumulated puroindolines A (Pin-A) and B (Pin-B) and showed SKCS values (19.9-23.6) significantly lower than those (72.6-76.8) of their hard-textured counterparts lacking Pin-A and Pin-B. In addition, SDLs exhibited approximately 24% higher flour extraction rates compared with HDLs. Reducing the kernel hardness decreased farinograph water absorption, dough tenacity (P) and, accordingly, alveograph P/L ratio, but increased farinograph stability, mixing tolerance and dough extensibility (L). Spaghetti cooking quality, as determined by the sensory judgment of firmness, stickiness and bulkiness, was unaffected by the kernel hardness, whereas the loaf volume exhibited a 10% increase associated with kernel softening. Flour and semolina, but not spaghetti, from SDLs showed a substantial reduction in yellowness (b^*) and brownness (100 − L^*) likely due to their finer particle size compared with HDLs. Alleles Pina-D1a and Pinb-D1a may offer new perspectives for breeding dual purpose (pasta and bread) durum wheat varieties.     

Chemical Composition and Nutritional Value of Unripe Banana Flour (<Emphasis Type="Italic">Musa acuminata</Emphasis>, var. Nanicão)

Banana flour obtained from unripe banana (Musa acuminata, var. Nanicão) under specific drying conditions was evaluated regarding its chemical composition and nutritional value. Results are expressed in dry weight (dw). The unripe banana flour (UBF) presented a high amount of total dietary fiber (DF) (56.24 g/100 g), which consisted of resistant starch (RS) (48.99 g/100 g), fructans (0.05 g/100 g) and DF without RS or fructans (7.2 g/100 g). The contents of available starch (AS) (27.78 g/100 g) and soluble sugars (1.81 g/100 g) were low. The main phytosterols found were campesterol (4.1 mg/100 g), stigmasterol (2.5 mg/100 g) and β-sitosterol (6.2 mg/100 g). The total polyphenol content was 50.65 mg GAE/100 g. Antioxidant activity, by the FRAP and ORAC methods, was moderated, being 358.67 and 261.00 μmol of Trolox equivalent/100 g, respectively. The content of Zn, Ca and Fe and mineral dialyzability were low. The procedure used to obtain UBF resulted in the recovery of undamaged starch granules and in a low-energy product (597 kJ/100 g).     

Effect of soil bacteria on the ability of polycyclic aromatic hydrocarbons (PAHs) removal by Trametes versicolor and Irpex lacteus from contaminated soil

The effect of bacteria represented by indigenous soil microflora or a mixture of soil bacteria Pseudomonas aeruginosa and Rhodococcus erythropolis on fungal growth, extracellular enzyme production and polycyclic aromatic hydrocarbons (PAHs) biodegradation efficiency in soil of white-rot fungi Trametes versicolor and Irpex lacteus was investigated. Both fungi were able to colonize soil. The growth yields measured by ergosterol were about two-fold in I. lacteus after 10 weeks. Laccase was produced in T. versicolor cultures in the presence or absence of bacteria but live bacteria reduced the laccase levels in soil about 5 times. Manganese-dependent peroxidase (MnP) was not detected in T. versicolor cultures. The amounts of MnP and laccase in I. lacteus cultures were not affected by the presence of bacteria. T. versicolor was more efficient in PAH removal for all PAHs tested although its capacity to colonize soil was lower. The removal rates of PAHs by T. versicolor in sterile soil were 1.5-fold, 5.8-fold and 1.8-fold for 2-3-ring, 4-ring and 5-6-ring PAHs, compared to I. lacteus, respectively. I. lacteus showed a low efficiency of removal of pyrene, benzo[a]anthracene and benzo[k]fluoranthene, compared to T. versicolor, whereas chrysene and benzo[b]fluoranthene were degraded by neither fungus. The main effect of the presence of the indigenous microflora or R. erythropolis and P. aeruginosa was a significant decrease of degradation of total PAHs by both T. versicolor and I. lacteus. Weak fungal/bacterial synergistic effects were observed in the case of removal of acenapthylene, benzo[a]pyrene, dibenzo[a,h]anthracene and benzo[g,h,i]perylene by I. lacteus and acenapthylene by T. versicolor. However, the bacterial effects were different in the two fungi. PAH abiotic losses represented 15 and 21% of the total PAHs after 5 and 10 weeks, respectively; naphthalene and acenaphthene were removed from the soil due to volatilization.     

Do Collembola affect the competitive relationships among soil-borne plant pathogenic fungi?

The feeding preference of the collembolan Protaphorura armata in the presence of Fusarium culmorum and Gaeumannomyces graminis var. tritici, two soil-borne fungi pathogenic for winter cereals, was studied in a simplified experimental system including wheat seedlings. Analysis of gut content of all animals from microcosms containing inoculum of both fungi showed that F. culmorum was clearly preferred but that G. graminis var. tritici was also fed. At microscopic examination the majority of F. culmorum conidia present in the gut lacked cytoplasmic content, and only few conidial cells were intact. The feeding preference of P. armata favoured G. graminis var. tritici over F. culmorum in the competition for infection sites on wheat plants; in fact, the former resulted the prevalent cause of plant disease.

The viability of fungal propagules after passage through the gut of P. armata was also studied. No colonies of G. graminis var. tritici and only a few colonies of F. culmorum developed from faecal pellets set on agar medium. Fungal propagules dispersed by springtails were not sufficient to induce disease, as demonstrated by introducing animals, previously fed on fungal cultures separately, into microcosms containing a sterile substrate where wheat kernels were seeded.