Secondary metabolites from Penicillium sp. 8PKH isolated from deteriorated rice straws

In the search for bioactive secondary metabolites from terrestrial fungi, four compounds, namely, 3-methyl-3H-quinazolin-4-one (1), aurantiomide C (2), 3-O-methylviridicatin (3), and dehydrocyclopeptine (4), were isolated from Penicillium sp. 8PKH, fungal strain, isolated from deteriorated rice straws. The structures of the isolated compounds were identified by extensive NMR and mass analyses and comparison with literature data. This is the first report of the structure of 3-methyl-3H-quinazolin-4-one (1) with full NMR spectral data having been previously identified by GC-MS from Piper beetle. Analysis of the non-polar fractions of the strain extract by GC-MS revealed the presence of additional eight compounds: methyl-hexadecanoate, methyl linoleate, methyl-9 (Z)-octadecenoate, methyl-octadecanoate, cis-9-oxabicyclo (6.1.0) nonane, 9,12-octadecadienal (9E,12E), ethyl-(E)-9-octadecenoate, and 3-buten-2-ol. The isolated compounds were evaluated for their antimicrobial and cytotoxic activities and exhibited little or no inhibitory activities against the test strains. The taxonomical characterisation and fermentation of the fungal strain were reported as well.

Altitude Variation in the Composition of Essential Oils, Fatty Acid Methyl Esters, and Antimicrobial Activities of Two Subspecies of Primula vulgaris Grown in Turkey

In this study, the changes caused by variation of altitude to the essential oils (EOs), fatty acid methyl esters (FAMEs), and antimicrobial activities of Primula vulgaris Huds. subsp. vulgaris ( Pvv) and P. vulgaris Huds. subsp. sibthorpii (Hoffmanns) W.W. Sm. & Forrest ( Pvs)) grown in Turkey were investigated. Major fluctuations in the composition of Pvv and Pvs oils included methyl-4-methoxy salicylate (4.5–35.3%; Pvv and 3.2–37.2%; Pvs), ( Z,Z,Z)-7,10,13-hexadecatrienal (5.1–21.8%; Pvv and 4.4–15.2%; Pvs) and flavone (5.5–14.9%; Pvv and 1.6–18.0%; Pvs). Fatty acid profile (C6:0–C26:0) changes were noted in Pvv and Pvs. Methyl hexadecanoate (2.4–9.3%) and methyl octadecanoate (1.0–4.7%) were present in all the FAME samples of the plants. The antimicrobial activity of the EOs of Pvv and Pvs were tested against nine bacterial species, which showed activity against Mycobacterium smegmatis with minimum inhibitory concentrations (MIC) varying from 8.5 to 59.2 μg/mL in all samples, respectively, depending on the altitude at which the oils were obtained.

Deuterium isotope effects and assignment of 13C chemical shifts in spectra of methyl octadecanoate and the sixteen isomeric oxooctadecanoates

13C nmr spectra of the 16 isomeric gem-dideuterooctadecanoates were measured and second and third atom deuterium isotope effects calculated for most of the affected carbons of 12 of the isomers. The average value for the second atom effect was −0.20 ppm and for the third atom effect was −0.05 ppm. From these effects and the changes in spectra caused by introduction of two deuterons at positions along the fatty acid chain, chemical shifts were determined for all carbons of methyl octadecanoate. Spectra of seven dideuterooxooctadecanoates, with both deuterons attached to a carbon γ to the oxo group, were measured, and using isotope effects, unambiguous assignments of chemical shift were made. Chemical shifts were thus assigned to all carbons in the 16 isomeric oxooctadecanoates and these show the effect of the carbonyl group at different positions in the chain. The results indicate that, in addition to large effects on carbons α and β to the oxo group, the γ to θ carbons are all shielded with displacements: γ −0.46, δ −0.30, ε −0.27, ζ −0.13, η −0.09, and θ −0.06 ppm. The effects of the oxo and ester carbonyls extend over seven methylene groups, but shielding due to ester carbonyl is a little smaller. Spectra of 2- to 9-oxo esters showed that interaction between the two carbonyl groups causes relatively greater shielding of carbons situated between the groups.

Some Aliphatic Methyl Esters from Aralia elata Seemann (Araliaceae)

The dried bark of Aralia elata Seemann was extracted with n-hexane. Methyl pentadecanoate, methyl hexadecanoate, methyl octadecanoate, methyl eicosanoate, methyl docosanoate, methyl tetracosanoate, methyl hexacosanoate, and 1-hexacosene were identified from the extract by means of GC-Mass spectrometer.