Phytotoxic Activity of Metabolites Isolated from Rutstroemia sp.n., the Causal Agent of Bleach Blonde Syndrome on Cheatgrass (Bromus tectorum)

A fungal pathogen soon to be described as Rutstroemia capillus-albis (Rutstroemiaceae, Helotiales, Leotiomycetes) has been identified as the causal agent of ‘bleach blonde syndrome’ on the invasive annual grass weed Bromus tectorum (cheatgrass) in western North America. This apparently common but previously undescribed disease causes premature senescence and sterility, but does not affect seed germination or seedling emergence and growth. This study investigated whether the new species produces phytotoxins that could be implicated in pathogenesis. The compounds 9-O-methylfusarubin, 9-O-methylbostrycoidin, 5-O-methylnectriafurone, trans-methyl-p-coumarate and terpestacin were isolated from the solid culture of this fungus. The undescribed absolute stereochemistry at C-3 of 9-O-methylfusarubin and at C-1’ of 5-O-methylnectriafurone were assigned by applying electronic and vibrational circular dichroism (ECD and VCD) combined with computational methods and the advanced Mosher’s method, respectively. The first three listed compounds are naphtoquinone pigments, while terpestacin is a sesterterpene, and trans-methyl-p-coumarate could be the product of an unusual fungal phenylpropanoid biosynthesis pathway. In a juvenile plant immersion bioassay, both 9-O-methylfusarubin and terpestacin proved to be highly toxic at 10−4 M, causing wilting and plant death within 10 days. This finding suggests that these two compounds could play a role in pathogenesis on B. tectorum.

Comparing inhalation and ingestion exposure to chemical contaminants and odorants in mixtures

Chemical spills polluting drinking water are often mixtures with each chemical having unique characteristics for partitioning, toxicity, and odour leading to significant differences in human risk exposures. A 2014 chemical spill of crude (4-methylcyclohexyl)methanol (MCHM) resulted in a $126 million USD fine to the water utility. The spill consisted of at least ten chemicals including 34% cis- and 60% trans-4-MCHM and 0.7% cis- and 0.3% trans-methyl-4-methylcyclohexanecarboxylate (MMCHC). While a very minor component, trans-MMCHC contributed substantially to odour because of its high Henry's Law Constant, 2.23 × 10−2 at 40 °C showering, and low odour threshold concentration (OTC), 0.02 ppb-v, air. Using USEPA risk assessment parameters in a 15-minute shower model with influent concentration of 42 ppb-aq cis- and trans-4-MMCHC, representative of initial spill concentrations in the distribution system, adult ingestion and inhalation for trans-MMCHC were almost equal, 4.00 × 10−4 and 4.26 × 10−4 mg/kg/d, respectively. For children, inhalation doses exceeded ingestion dose: 1.72 × 10−3 mg/kg/d versus 0.93 × 10−3 mg/kg/day trans-MMCHC. This exposure assessment with varying OTC for crude MCHM chemicals reinforces considering chemical, physical, and biological properties of all chemicals in the spill. Consumers aware of their exposure to chemicals in drinking water lost consumer confidence; the water utility was required to compensate individuals and businesses for financial losses.

Analysis of Bioactive Chemical Compounds of Trogoderma granarium (Insecta: Coleoptera: Dermestidae) Using Gas Chromatography – Mass Spectrometry

Methanolic extract of bioactive compounds of Trogoderma granarium was assayed. GC-MS analysis of Trogoderma granarium revealed the existence of the Pentanoic acid , 1,1-dimethylpropyl ester , (1H)-Pyrimidinone , 5-chloro-4,6- diphenyl, Cyclobutanemethanol , α-methyl- , Nitro-2-methyl-1,3-propanediol , Hydroxylamine ,O-(2-methylpropyl)- , Uridine , 2',3'-O-(phenylmethylene)- ,Acetic acid ,2-benzoylthio-,2-oxo-2-phenylethyl ester , methylpropyl)- , Uridine , 2',3'-O-(phenylmethylene)- , 5'-(4-methylbenzenesulfo , Indolinol , 1-benzoyl-, Benzeneethanol , β-methyl-,(s)- , Acetic acid ,2-benzoylthio-,2-oxo-2-phenylethyl ester , Phenacyl thiocyanate , Deoxy-L-ribose-2,5-dibenzoate , Methenamine , Alanine , N-methyl-n-propargyloxycarbonyl-, decyl ester , Benzoyl chloride , Thiophene-2-ol , benzoate , Ethanone , -(5- nitrotetrazol-2-yl)-1-phenyl- , 2,5-Dimethylhexane-2,5-dihydroperoxide , Benzamide , N-(3-benzylthio-1,2,4-thiadiazol- 5-yl)- , Methyl p-(2-phenyl-1-benzimidazolyl)benzoate , Methyl-2-phenoxyethylamine , Pentaborane(11) , cis-Methoxy- 5-trans-methyl-1R-cyclohexanol , Nitro-1-phenyl-3-(tetrahydropyran-2-yloxy)propan-1-one , cis-Methoxy-5-transmethyl-1R-cyclohexanol. Trogoderma granarium produce many important secondary metabolites with high biological activities.

Insights into the Essential Oil Compositions of Brazilian Red and Taiwanese Green Propolis

The objective of the present study was to characterize chemically the essential oils of two distinct propolis types: Brazilian red and Taiwanese green. Unlike the non-volatile chemical composition of these types of propolis, which has been extensively studied, the knowledge of the essential oils is scarce or even not investigated. The essential oils were obtained by hydrodistillation of raw propolis samples using a Likens-Nickerson type apparatus and then analyzed by GC/MS. The main volatile components of Brazilian red propolis were the phenylpropanoids: elemicin (26.1–27.5%), methyl eugenol (16.3–23.8%), trans-methyl isoeugenol (9.2–11.6%), isoelemicin (6.1–7.1%) and trans-anethole (4.4–7.1%), while the major constituents of Taiwanese green propolis essential oil were: β-eudesmol (13.9%), 6-methyl-3,5-heptadiene-2-one (12.2%), γ-eudesmol (4.4%), geranial (4.1%) and 6-methyl-5-heptene-2-one (3.7%).

THE ESSENTIAL OIL CONTENTS OF JERINGAU (Acorus calamus L.) RHIZOMES AND THEIR ANTIFUNGAL ACTIVITY AGAINST Candida albicans

Acorus calamus L. rhizome was trusted having antibacterial activity. This study aimed to identify the compounds in the Acorus Calamus L. rhizomes essential oils and to recognize the antifungal activity of the oils against Candida albicans. The extraction of essential oils from rhizome was carried out by steam distillation technique. Identification of compounds in the oils was conducted by Gas Chromatography- Mass Spectroscopy (GCMS), while the antifungal test against Candida albicans was done by well diffusion method. Extraction of 10 kg of rhizomes produced 16.53 mL essential oil with a yield of 0.1653% (? = 1.066), the oil was brownish yellow and very flavorful. GC-MS analysis showed that the essential oil contained 11 compounds, they are (E)-3,7 dimethyl-1,3,6-Octatriene (trans-?-Ocimene) (3,73%), linalool (1,07%), ?-elemene (1,15%), trans methyl isoeugenol (7,68%), shyobunon (15,74%), bicyclogermakren (0,93%), dehidroxy-isocalamendiol (2,61%), ?-calacorene (3,34%), euasarone (26,84), cis-asarone (18,62%); dan trans- asarone (18,29%). Antifungal activity test showed that the growth and biomass inhibition of C. albicans increased with the increase of the oil concentration. Minimum Inhibitory Concentration (MIC) of essential oil toward C. albicans was 1% with the inhibition of 7.83 mm.

Comparative Study of the Volatile Components of Fresh and Fermented Flowers of Alnus sieboldiana (Betulaceae)

Analysis of the volatile components present in the fresh male and female flowers and young leaves shows that 2-phenylethanol is the major component in all these three organs, which play a significant role in the strong resinous aromatic odor. The male flowers contained styrene as a second major compound. The level of styrene does not affect the male flowers odor concentration. The level of β-phenylethyl cinnamate and trans-methyl cinnamate in the fermented male flowers decreased as the fermentation time increased. This was due to the Penicillium enzymatic action on the fermented male flowers.

Volatile Components of the Stressed Liverwort Conocephalum Conicum

The Type-II Japanese Conocephalum conicum, which is known to have (+)-bornyl acetate as a marker compound, was put in the stressed condition to start biosynthesis of a phenyl propanoid, trans-methyl cinnamate. Analysis of the HS-SPME GC/MS of stressed C. conicum showed trans-methyl cinnamate as a major component. This phenomenon results in some confusion from the chemotype perspective since trans-methyl cinnamate is only present in type-III Japanese C. conicum.