3-Oxo-4-ene Sterols. The main constituents were a-humulene (16.9%), pentadecane (10.2%) and a-cubebene (9.7%). It is concluded that the photo-dissociation mechanism of the substituted PAH cations studied here is site selective in the substituted subunit. Polyketides rich fractions exhibited significant plant growth promotion of Brassica seedlings. The possible mechanisms for EI ionization spectra of hexane. Upon ongoing irradiation, these species further fragment. Alkenylcarbocations are found at m/z values of 55, 41 and 27. Similar trend to fragmentation pattern was observed in chaetoviridin B and E. Similarly [M] + peak at m/z 284.2967 was fragmented to daughter ions at m/z 162 and 121, originated due to breaking of methylene bond. Fragmentation pattern of amides by EI and HRESI: ... the hexanes-ethyl acetate (typically 10 –30%) as eluent yielding the desired amides.15 Compounds 1b, 2e and 5d were synthesized by the slow addi-tion of n-butyl lithium (1.3 equivalent), at 78 C under nitrogen atmosphere, to a solution of 2-pyrrolidinone (1.2 equiv.) Download : Download high-res image (228KB)Download : Download full-size image. For example, hexane fragmentation patterns. Published by Elsevier Ltd. All rights reserved. A systematic study, using ion trap time-of-flight mass spectrometry, is presented for the photo-fragmentation of methyl- and methoxy-substituted derivatives of HBC cations, (OCH3)6HBC+ and (CH3)4(OCH3)2HBC+.
The molecular ion (m/ z = 86) is not abundant, and the base peak is at m/ z = 57. In this study, this was achieved by an Excel template and the Solver function of Excel (Add-in function under Data/Analysis; see supplementary material). UPLC-QTOF-MS/MS analysis revealed characterization of twenty-six metabolites. UPLC-QTOF-MS/MS analysis of ethyl acetate and methanolic fractions resulted tentative characterization of fifteen and eleven metabolites, respectively. Both substituted HBC cations fragment through sequential loss of CH3CO units upon laser (595nm) irradiation, resulting in a PAH-like derivative C36H12+ and a methyl-substituted PAH derivative C44H24+, respectively. Copyright © 2020 Elsevier B.V. or its licensors or contributors. This work also shows experimental evidence that photo-fragmentation of substituted PAHs may contribute to the formation in space of smaller species that are normally considered to form by merging atoms and molecules.
Results and discussion: The hexane extract was analyzed by GC-MS technique which allowed the identifi-cation of 32 compounds. Most potential Chaetomium globosum 5157 has been selected based on antagonistic potential. Alkanones and polyketides dominated fraction have found highly effective against S. sclerotiorum.
However, distinct research gaps are visible regarding detail characterization of bioactive metabolites. © 2020 British Mycological Society. © 2016 Elsevier B.V. All rights reserved.
C36H12+ follows largely this latter fragmentation scheme upon irradiation. They tend to fragment at the branched point. GC–MS analysis of hexane fraction revealed twenty-six volatile organic compounds, representing 65.5% of total components in which 3-octanone (21.4%) was found to be most abundant. Cholesterol oxidase converts 3β-hydroxy-5-ene sterols to their 3-oxo-4-ene analogues.
In summary, using the theoretical fragmentation patterns of pure TAG, one can search for their combination that will match the experimentally obtained fragmentation pattern. https://doi.org/10.1016/j.molap.2016.08.001. Thus the current study has been planned to characterize volatile and nonvolatile compounds of most potential strain of C. globosum 5157. The likely explanation for this observation is that geometry 2c not only comprises a carbon skeleton with pure aromatic properties, but in addition contains four reactive CH 3 units. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Chemo-profiling of bioactive metabolites from.
Comparative assessment of C. globosum 5157 vis a vis Trichoderma harzianum A28 revealed promising effect of C. globosum 5157 with respect to antifungal properties and plant growth promotion of Brassica seedlings. Antifungal potential of hexane fraction exhibited high inhibitory action against Sclerotium rolfsii (139.2 μg mL−1) whereas ethyl acetate fraction was highly effective against Sclerotinia sclerotiorum (112.1 μg mL−1). Elution with diethyl ether-hexane 6:4 (v/v) afforded the title compound (316 mg; yield, 79%).
Fragmentation resulted peaks at 296 due to loss of Cl and side chain of α-hydroxy-pentone moiety (136 amu). Mass Spectrum of Hexane Mass Spectrum of Hexane Since all C-C bonds are similar in hexane, all bonds to break equally. For lower laser energy C44H24+ dehydrogenates and photo-fragments through CH3 and CHCH2 unit losses; for higher laser energy isomerization takes place, yielding a regular PAH-like configuration, and both stepwise dehydrogenation and C2/C2H2 loss pathways are found. Twenty-six volatile organic compounds have been identified in GC–MS.