Phenylpropanoid-rich Essential Oils of Piper Species from the Amazon and their Antifungal and Anti-cholinesterase Activities.

The essential oils (EOs) from aerial parts of Piper aduncum, P. callosuin and P. marginatum, collected from the Amazon region of Brazil, were analyzed by GC-MS and then evaluated for their antifungal and anticholinesterase activities. The essential oils were dominated by phenylpropanoids, such as dillapiole (73.0%) in P. aduncum, safrole (66.0%) in P. callosum and 3,4-methylenedioxypropiophenone (21.8%) in P. inarginatum. The analyzed oils showed low to moderate antifungal activity; with detection limits (DL) from 10 to 100 pg against Cladosporium cladosporioides and C. sphareospermum. In the anticholinesterase (AChE) evaluation, the oils of P. callosum (DL = 0.01 ng) and P. marginatum (DL = 0.01 ng) were one hundred times more potent than the standard physostigmine (DL = 1.0 ng). Molecular docking analysis showed that phenylpropanoids docked reasonably well with acetyleholinesterase and may be responsible for the anti-AChE activities of the Piper EOs. This is the first presentation about acetylcholinesterase inhibition by methylenedioxyphenyl-propanoids.

Chemical profile and biological potential of non-polar fractions from Centroceras clavulatum (C. Agardh) Montagne (Ceramiales, Rhodophyta).

The present study reports the Gas Chromatography-Mass Spectrometry (GC-MS) evaluation of the hexanes and dichloromethane fractions from extracts of the red alga Centroceras clavulatum (C. Agardh) Montagne. Twenty three compounds were identified, totaling ca. 42% of both fractions (0.18 g mass extract). The main constituents of the fractions were hexadecanoic acid (17.6%) and pentadecanoic acid (15.9%). Several secondary metabolites with interesting biological activity, such as (-)-loliolide, neophytadiene, phytol were identified. In addition, several classes of secondary metabolites, including phenolic compounds (e.g., phenylacetic acid), terpene derivatives, fatty acids, halogenated compound (e.g., 2-chlorocyclohexenol), lignoids, steroids, esters, amides (e.g., hexadecanamide), ketones, carboxylic acids, aldehydes and alcohols were observed. The occurrence of several of these structural classes is described for the first time in this species. The same fractions analyzed by GC-MS, and a separate set of polar fractions, were evaluated against two life cycle stages (epimastigote and trypomastigote forms) of the protozoan Trypanosoma cruzi and against phytopatogenic fungi Cladosporium cladosporiodes and C. sphaerospermum. The dichloromethane fraction was active against both T. cruzi forms (epimastigote IC(50) = 19.1 µg.mL-1 and trypomastigote IC(50) = 76.2 µg.mL-1). The hexanes and ethyl acetate fractions also displayed activity against both fungi species (200 µg) by TLC-bioautography.

Intracellular sequestration of manganese and phosphorus in a metal-resistant fungus Cladosporium cladosporioides from deep-sea sediment.

A heavy metal resistant fungus was isolated from the sediment of Pacific Ocean, and identified to be Cladosporium cladosporioides. It grew normally in a medium containing 60 mM Mn(2+) and could endure 1,200 mM as the highest concentration tested. Quantification analysis confirmed a high accumulation of Mn which was 58 mg/g in dried biomass. Under transmission electron microscope, many intracellular crystals were observed in the cytoplasm of the hypha cells grown in a Mn-rich medium, and varied from a few nanometers to 200 nm in length. Energy dispersive X-ray (EDX) analysis showed that the crystals were composed of manganese and phosphorus in atomic ratio of 1.6:1 (Mn/P). Further, factors which might influence the resistance of this fungus were investigated. As a result, its high resistance to Mn(2+) was found dependent on the presence of Mg(2+), and could be further enhanced by phosphate. However, the effect of phosphate was not observed without the presence of Mg(2+). In addition, the resistance was also influenced by pH of the medium, which was lost above pH 8. This is the first report on a fungus which showed a hyper resistance to manganese by forming a large quantity of intracellular Mn/P crystals.

The accumulation of phytoalexin in cucumber plant after stress.

During the course of pathogens penetrating the plant cell, besides of chemical secretion, the pathogens may cause mechanical signal by the physical pressure on the plant cell. In the current study, we use the pressure as the stress signal to study the induction in plant resistance and the effect of accumulation of phytoalexin. We found that stress can induce the resistance in cucumber seeding significantly. Peptides contained RGD motif can specific block the adhesion between plant cell wall and plasma membrane. When breaking the plant cell wall and plasma membrane by using RGD peptides, the stress induction effect is almost absolutely eliminated. The results of assay with TLC and HPLC showed that stress stimulation could increase the accumulation of cucumber seeding phytoalexin. So, we can conclude that the accumulation of phytoalexin is one possible reason of improve the stress induced resistance. When block the adhesion between plant cell wall and plasma membrane by RGD, there are only part of accumulation of phytoalexin. The results suggest that stress induced resistance and accumulation of phytoalexin of plant is required for the adhesion of plant cell wall-plasma membrane.

Species-specific selection on soil fungal population after olive mill waste-water treatment.

Soil was treated with olive mill waste water (OMW) in order to study the effect of this agriculture waste on soil fungal population. Changes in fungal composition were observed after soil pollution. In order to test OMW selective pressure, growth kinetics of Penicillium cyclopium, Scopulariopsis brevicaulis and Cladosporium cladosporioides were studied on solid media supplemented with different OMW concentrations. S. brevicaulis and C. cladosporioides did not grow at OMW concentration higher than 50%, while at concentrations lower than 50% a growth decrease was observed. Instead, P. cyclopium was able to actively grow at all concentrations of OMW tested. Therefore the OMW can influence and modify the soil fungal homeostasis.

Unusual antimicrobial compounds from Aeollanthus buchnerianus.

Using bioassay guided isolation, three novel 12 carbon polyoxygenated fatty acids and a novel abietane diterpene have been isolated from the chloroform extract of aerial parts of Aeollanthus buchnerianus (Lamiaceae). Rigorous spectroscopic methods were used for compound identification. (Z,Z)-8zeta-acetoxy-5zeta-hydroxydodeca-2,6-dienoic acid and (Z,Z)-5zeta, 8zeta-dihydroxydodeca-2,6-dienoic acid inhibited the spore germination of Cladosporium cucumerinum (both with Minimum Inhibitory Dose (MID) values of 1 microgram) and Aspergillus niger (MID 5 and 25 microgram respectively). Further, they also reduced the hyphal growth of Pythium ultimum. (Z)-5zeta-hydroxy-6zeta,7zeta,8zeta-triacetox ydodeca-2-dienoic acid exhibited short term inhibition of the growth of Cladosporium cucumerinum. The novel abietane diterpenoid, (rel)-14alpha-acetoxyabiet-7-en-18-oic acid inhibited the growth of the gram positive bacteria Bacillus subtilis, Staphylococcus aureus and Streptomyces scabies (MIC values 80, 20 and 20 micrograms ml(-1) respectively).

Secoiridoids and antifungal aromatic acids from Gentiana algida.

Fractionation of an aqueous acetone extract of the whole herb of Gentiana algida gave one new [2'-(o,m-dihydroxybenzyl)sweroside] and five known secoiridoids, together with anofinic acid, fomannoxin acid, sitosterol, daucosterol, stigmasterol, oleanolic acid, orientin and gentianose. The structures were determined by spectral methods and a few chemical transformations. Anofinic acid and fomannoxin acid were found to be active against Cladosporium cucumerinum, a plant pathogenic fungus. Preliminary structure-activity studies indicated that the presence of carboxylic moieties in these acids was presumably a precondition for activity, whereas their methyl esters, inactive to the fungus, were active against the human pathogenic yeast Candida albicans. The chemotaxonomic significance of the isolates is discussed briefly.

Microbial utilization of Pinus radiata bark.

A screening program using suspensions of ground bark in mineral salts media, or extracts prepared from ground bark by treating with hot water, sulfuric acid, ammonium hydroxide, or sodium hydroxide, yielded more than 200 pure cultures of fungi, yeasts, and bacteria. Only 38 of these have good growth on liquid bark media. All were filamentous fungi, although many bacteria and yeasts were among the cultures that failed to give appreciable growth. Species of Penicillium, Scopulariopsis, Aspergillus, Trichoderma, Cladosporium, and Fusarium were among the most actively growing cultures. Cell biomass yields, as measured by cell nitrogen determination, were too low for economic production of single cell protein.