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1

Biological activities and chemical composition of solvent extracts of Stoechospermum marginatum (C.Agardh)

100%
Esmaeili A., Khakpoor M.
Acta Biochimica Polonica
|
2012
|
tom 59
|
nr 4
 The objective of this study was to evaluate the chemical composition CH3OH-CH2Cl2 (1:1) extract and biological activities of various extracts derived from the aerial parts of the brown marine alga Stoechospermum marginatum (C. Agardh). Gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS) were used to analyze the composition of the essential oil. Total phenolics assay demonstrated a high value in hexane extract (HE), with a lower value for chloroform extract (CE), and the lowest value for methanol extract (ME). DPPH (2,2-diphenyl-1-picrylhydrazyl) assay showed that extracts of S. marginatum possess radical scavenging activity (RSA). Tests of the antioxidant property of the extracts revealed both electron and hydrogen transfer mechanisms. The antibacterial activity of the ME, CE, and HE as well as an ethanol extract was estimated against seven Gram-positive and Gram-negative bacteria. The ethanol extract showed the highest antibacterial activity, and the HE showed the lowest.
2

Microbial transformation of citral by Penicillium sp.

100%
Esmaeili A., Tavassoli A.
Acta Biochimica Polonica
|
2010
|
tom 57
|
nr 3
 Thymol is present in the essential oils from herbs and spices, such as thyme. It is produced by these plant species as a chemical defense against phytopathogenic microorganisms. Therefore, this compound has attracted great attention in food industry, i.e., it has been used as a natural preservative in foods such as cheese to prevent fungal growth. Previous studies concerning the biotransformation of nerol by Penicillium sp. and microbial transformation of citral by sporulated surface cultures method (SSCM) of Penicillium digitatum have been reported. The objective of this research was to study the pathway involved during biotransformation of citral by Penicillium sp. using two methods. The culture preparation was done using different microbial methods and incubation periods to obtain Penicillium for citral biotransformation. The biotransformation products were identified by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). A comparison of the two methods showed that SSCM was more effective, its major products were thymol (21.5 %), geranial (18.6 %) and nerol (13.7 %). LM produced only one compound - thymol - with a low efficiency.
3
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Microbial transformation of alpha-naphthol by Aspergillus niger -PTCC 5011

81%
Esmaeili A., Fazeli S., Moazami N.
Herba Polonica
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2012
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tom 58
|
nr 2
The metabolism of α-naphthol by Aspergillus niger PTCC 5011, a fungi isolated in Ardebil, Iran, from industrial wastewater, was studied. A. niger metabolized approximately 80% of α-naphthol within 5 days. The identification and quantification of degradation products using GC-MS demonstrated that approximately 41% of the parent compound was converted into 1-ethyl-2-methyl benzene, 7.43% was converted into acetonaphthone, 5.55% was transformed into 4-hydroxy-1-naphthyl sulfate, 3% into 1,4-naphthoquinone, and about 6.68% into 2-phenyl-1,2,3-tetrahydro-1-naphthol. These results support a role for A. niger in affecting the environmental fat of pollutants in ecosystems.
4

Biotransformation of [-]-menthol by spores of Mucor ramannianus and study of the pathways involved

81%
Esmaeili A., Saad N., Safaiyan S., Rustaiyan A.
Herba Polonica
|
2009
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tom 55
|
nr 2
51-58
The biotransformation of (–)–menthol by Mucor ramannianus was studied. It was carried out with sporulated surface cultures of Mucor ramannianus. The main bioconversion products obtained from (–)–menthol were trans-p-menthan-8-ol, trans-menth-2-en-1-ol, sabinane, pmenthane- 3,8-diol, isomenthol, and 1,8-cineole, also resulting in higher yields. Biotransformation with sporulated surface cultures was also monitored in Petri dishes and the same solid medium, Sabouraud Dextrose Agar (SD A), was used. In the solid agar medium inoculated with spores of Mucor ramannianus, first germination of the spores and then mycelial growth took place. After 1 week, the surfaces of Petri dishes were covered with spores and biotransformation reaction had started. However, there is no report on the biotransformation of (-)-menthol using Mucor ramannianus. Six isolates (93.6%) found Mucor ramannianus as a biocatalyst and biotransformation of (–)–menthol was investigated. The pathways involved in the biotransformation of (–)–menthol by two main products are also discussed.
5
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Biotransformation of myrcene by Pseudomonas putida PTCC 1694

81%
Esmaeili A., Hashemi E., Safaiyan S., Rustaiyan A.
Herba Polonica
|
2011
|
tom 57
|
nr 1
Terpineol and linalool are sources of fragrances providing an unique volatile terpenoid alcohol of low toxicity, and thus are widely used in the perfumery industry. They are also being applied in folk medicine and in aromatherapy, as well as important chemical constituents of the essential oil of many plants. Previous studies have implicated the biotransformation of limonene by Pseudomonas putida. The objective of this research was to study the pathways involved in biotransformation of myrcene by Pseudomonas putida. The culture preparation was done by using such variables as different microbial methods and incubation periods to obtain maximum cells of P. putida for myrcene biotransformation. It was found that myrcene was converted to dihydrolinalool, cis-β-dihydroterpineol, linalool and cis-ocimene-8-oxo in high percentages. The biotransformation products were identified by theoretical study (TS), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet visible (UV), gas chromatography (GC), nuclear magnetic resonance (NMR) and gas chromatography/ mass spectroscopy (GC-MS). Comparison of different incubation times showed that 120 h which was more effective, the major products were dihydrolinalool (4.1%), cis- β-dihydroterpineol (67.6%) and linalool (25.8%). The main compounds comprised 97.5%. The incubation period of 72 h yielded dihydrolinalool (16.7%), cis-ocimene-8-oxo (61.6%), Biotransformation of Myrcene by Pseudomonas putida PTCC 1694 trans-β-dihydroterpineol (8.4%) and β-cadinene (3.5%), with main compounds comprising 86.7%. Incubation for 30 h yielded dihydrolinalool (59.5%), cis-β-dihydroterpineol (25.0%), hexadecanoic acid (12.5%), and the main compounds comprising 97.0%.
6

Biotransformation of menthol by sporulated surface cultures of Penicillium sp. and study of the pathways involved

71%
Esmaeili A., Hoseiny Zarea A., Sharafian S., Safaiyan S., Rustaiyan A.
Herba Polonica
|
2009
|
tom 55
|
nr 1
78-83
A simple and efficient method of carrying out biotransformation reactions on terpenoid compounds was developed. For these experiments, a sporulated surface culture of Penicillium sp. was inoculated on solid media in conical flasks. After a short incubation the spores germinated and a mycelia culture was formed. After a week the cultures had completely sporulated and a bioconversion reaction started. For this purpose, a known volume of menthol was added onto the sporulated surface of culture. After 7 days, a period during which transformation took place, menthol was extracted with Et2O three times. After evaporation the recognition by GC and GC/MS was followed. The main bioconverted products obtained from menthol by surface Penicillium sp. with the use of sporulated surface culture were α-pinene (18.0%), sabinene (11.6%), trans-p-menthan-1-ol (10.6%), p-menth-1-ene (5.8%), 1,8-cineole (6.4%) and limonene (3.2%). The pathways of biotransformation of menthol by Penicillium sp. to main products are also discussed.
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