Qasim Al-Riyami

Study of total phenol, flavonoids contents and phytochemical screening of various leaves crude extracts of locally grown Thymus vulgaris

OBJECTIVE To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol, flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al Jabal Al Akhdar, Nizwa, Sultanate of Oman. METHODS The leave sample was extracted with methanol and evaporated. Then it was defatted with water and extracted with different polarities organic solvents with increasing polarities. The prepare hexane, chloroform, ethyl acetate, butanol and methanol crude extracts were used for their evaluation of total phenol, flavonoids contents and phytochemical screening study. The established conventional methods were used for quantitative determination of total phenol, flavonoids contents and phytochemical screening. RESULTS Phytochemical screening for various crude extracts were tested and shown positive result for flavonoids, saponins and steroids compounds. The result for total phenol content was the highest in butanol and the lowest in methanol crude extract whereas the total flavonoids contents was the highest in methanol and the lowest hexane crude extract. CONCLUSIONS The crude extracts from locally grown Thymus vulgaris showed high concentration of flavonoids and it could be used as antibiotics for different curable and uncurable diseases.

Identification and characterization of chemical compounds in different crude extracts from leaves of Omani neem

Abstract Azadirachta indica (neem) belonging to Meliaceae family is very important medicinal plant which is traditionally used to treat different diseases. The objective of this study was to evaluate in vitro antioxidant activity and characterize the chemical constituents in different crude extracts of the leaves of Azadirachta indica (neem) by using modern sensitive gas chromatography–mass spectrometry (GC–MS). The evaluation of antioxidant activity of different crude extracts was determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. GC–MS analyses showed that majority of these identified compounds in various crude extracts contain normal hydrocarbons, phenolic compounds, terpeniods, alkaloids and glycosides. The high percentage of compounds that were identified in the crude extracts are chemically and biologically important. The evaluation of antioxidant capacity of different crude extracts was in the order of chloroform > butanol > ethyl acetate extract > hexane extract > methanol extract. The important chemical constituents were present in the leaf crude extracts of neem that can be endorsed to cultivation on a domestic plantation. The appropriate crude extracts for selective bioactive organic compounds can be chosen on the basis of GC–MS analysis. Therefore the identified good number of chemical compounds from various extracts of neem might have some ecological benefit for different aliments. Result from this study suggested that the chloroform crude extracts of neem could be used as a natural antioxidant.

Comparative study of total phenolics, flavonoids contents and evaluation of antioxidant and antimicrobial activities of different polarities fruits crude extracts of Datura metel L.

Abstract Objective To determine the total phenolics and flavonoids and to evaluate antioxidant and antimicrobial activities of different extracts from fruits of Datura metel (D. metel). Methods Different crude extracts from the fruits of D. metel were subjected to determination of total phenolics, flavonoids, antioxidant and antimicrobial activities by established methods. Resutls The total phenolics results showed that ethyl acetate extract was the most efficient (60.26%) compared to hexane, chloroform, butanol and methanol extracts which had phenolic contents of 50.08, 35.50, 52.54 and 26.49%, respectively. Almost similar results were obtained from the fruits crude extracts for total flavonoids and results found that methanol crude extract was the highest (1.71%) compared to other crude extracts. The antioxidant activity results showed that methanol extract acted the highest activity compared to other extracts and in the order of methanol>ethyl acetate>hexane>chloroform>butanol extract. All extracts were displayed moderate antibacterial potential against the tested bacteria such as Staphylococcus aureus, Escherichia coli and Pseudomonus aeruginosa in the range of 0%–10%. Conclusions The results of this present study clearly showed that the crude extracts of D. metel demenstrated antimicrobial and antioxidant activities and it may act as potential antioxidant sources for human biological system.

Chemical composition of essential oils and in vitro antioxidant activity of fresh and dry leaves crude extracts of medicinal plant of Lactuca Sativa L. native to Sultanate of Oman

OBJECTIVE To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L. (L. sativa). METHODS The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L. sativa (lettuce) grown in Sultanate of Oman by hydro distillation method. The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity (DPPH) method. RESULTS About 20 chemical compounds of different concentration representing 83.07% and 79.88% respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves as α-pinene (5.11% and 4.05%), γ-cymene (2.07% and 1.92%), thymol (11.55% and 10.73%), durenol (52.00% and 49.79%), α-terpinene (1.66% and 1.34%), thymol acetate (0.99% and 0.67%), caryophyllene (2.11% and 1.98%), spathulenol (3.09% and 2.98%), camphene (4.11% and 3.65%), limonene (1.28% and 1.11%) representing these major chemical compounds. However, some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including β-pinene, α-terpinolene, linalool, 4-terpineol, α-terpineol, o-methylthymol, L-alloaromadendrene and viridiflorene. CONCLUSIONS The chemical constituents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes, sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons. Therefore, the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant, antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.

Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

OBJECTIVE To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L (T. vulgaris) by gas chromatography-mass spectrometry (GC-MS). METHODS The shade dried leaves powder was extracted with methanol by using Soxhlet extractor. Methanol crude extracts of T. vulgaris and the derived fractions of hexane, chloroform, ethyl acetate and butanol were obtained. RESULTS Qualitative analyses of various organic crude extracts of T. vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds. Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important. Further, the T. vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation. The crude extracts were prepared from the powder leaves of T. vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis. CONCLUSIONS All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T. vulgaris are biologically active molecules. Thus the identification of a good number of compounds in various crude extracts of T. vulgaris might have some ecological role.

Gas chromatography–mass spectrometry analysis and total phenolic contents of various crude extracts from the fruits of Datura metel L.

Abstract Datura metel is considered as medicinal plants worldwide. Locally it is used as a traditional medicine due to its medicinal values. The objective of this present work is to identify the chemical ingredients and evaluation of total phenolics contents of different crude extracts from the locally grown D. metel. In vitro evaluation of total phenolics contents of different crude extracts was measured by established Folin–Ciocalteu reagents method. The identification of chemical ingredients was carried out in various crude extracts of D. metel by using sensitive gas chromatography–mass spectrometry (GC–MS). The results showed from different chromatogram that high percentage ingredients are high molecular weight ingredients such as polyphenolics and their derivatives, flavonoids, triterpeniods, hydrocarbons etc. The identified high percentage chemical ingredients present in the crude extracts are biologically active. The phenolic contents of crude extracts as gallic acid equivalents were found to be highest in chloroform followed by the order methanol > butanol > ethyl acetate > hexane extract. The identification of good number of chemical ingredients by spectrometry method in various crude extracts of D. metel fruits might have some ecological significance. In conclusion, chloroform crude extract contains highest phenolics content could be used as antibiotics.

Constituents of the essential oil from different brands of Syzigium caryophyllatum L by gas chromatography–mass spectrometry

Objective: The aim of this present study was to isolate and analyze the chemical composition of essential oils from two different imported brands of Syzigium caryophyllatum (clove) samples using gas chromatography-mass spectrometry (GC-MS). Methods: The two essential oils were isolated by hydrodistillation from two different brands of Syzigium caryophyllatum (clove) such as Guzal and Shahi clove samples using Clevenger type apparatus. Results: Eleven chemical components were identified in the essential oil isolated from Guzal clove imported from Indonesia. The isolated components representing 99.03% of the Guzal clove oil were identified as eugenol (51.51%), caryophyllene (36.20%), 毩- caryophyllene (4.26%), acetyleugenol (2.64%), carvacrol (2.42%), 毩-cubebene (0.77%) and thymol (0.42%) were the major components with some other minor components isolated from the same. About twenty two components representing 99.73% were identified within the essential oil isolated from the Shahi brand clove which was imported from India with the main components being eugenol (46.53%), caryophyllene (43.03%), 毩-caryophyllene (4.61%), aceteugenol (2.54%), copaene (0.80%), 毩-farnesene (0.72%), germacrene (0.43%) and 毮-cadinene (0.27%). Conclusions: Both the isolated essential oils were found to be rich in eugenol and caryophyllene. The clove essential oil from Guzal and Shahi was found to be comparable in terms of its eugenol and caryophyllene contents. According to the above findings, it is suggested that both brands of clove are of similar quality.

Isolation, fractionation and identification of chemical constituents from the leaves crude extracts of Mentha piperita L grown in Sultanate of Oman.

OBJECTIVE To analyze and identify the chemical compositions of different organic plants crude extracts of Mentha piperita (M. piperita) grown in Sultanate of Oman by gas chromatography-mass spectrometry (GC-MS). METHODS The powder sample was extracted with methanol by using Soxhlet extractor. Methanol crude extracts of M. piperita and its derived fractions of hexane, chloroform, ethyl acetate and butanol were prepared. RESULTS Qualitative analyses of various organic plant crude extracts of M. piperita by using GC-MS showed that majority of these compounds are bioactive. CONCLUSIONS According to the results of the present study, the plant crude extracts could be used as medicine for the treatment of different diseases. The analysis and identification of the chemical compounds in the plant crude extracts by using GC-MS was the first time.

Composition of Essential Oil of Thymus vulgaris grown in Oman

Abstract Thymus vulgaris L. belongs to the Lamiaceae family and has a pleasant smell. It is native to the Westren Mediterranean region and southern Italy. The fresh plant material was collected in the month of April from Al Jabal Al Abyadh in Sharqiya region of Oman. The aerial parts of T. vulgaris were separated from fresh plant material and essential oil was isolated by steam distillation method using Clevengers apparatus. The oil was analyzed by GC-MS. A total of eighteen constituents were identified, the major constituent was durenol (56.2 %). Other main constituents were thymol (15.04 %), p-cymene (8.69 %), δ-terpinene (5.24 %), and α-pinene (2.65 %).

Re: Health Professions Education in Oman: A contemporary perspective.

Sir, I read with interest the article by Dr. Ritu Lakhtakia,1 which appeared in your November 2012 issue. I would like to draw the attention of the author and other readers to a very important omission—the training in Oman of pharmacists and clinical pharmacists. The first Bachelor of Pharmacy (BPharm) programme was started in the fall of 2003 by the Oman Medical College, a private college in Bausher, Muscat. This is a four-and-a-half-year programme, and its first graduates received their degrees in December 2007. The second educational institution to offer a BPharm degree was the School of Pharmacy in the College of Pharmacy & Nursing of the University of Nizwa, a private non-profit institution. This is a five-year programme; the first students were admitted in the fall of 2004 and graduated in March 2010. The fourth class of graduating students are due to collect their degree certificates in March 2013. In the fall of 2003, the College of Medicine & Health Sciences in Sultan Qaboos University, which is a government institution, started a two-year graduate programme leading to a Master of Science degree (MSc) in Biomedical Sciences, with a major in Clinical Pharmacy. I present these programmes to complete the information related to the education of healthcare professionals in Oman. I would like to acknowledge that I have been involved in, or taught at, all three of these institutions during the course of my career.