Mohammad Amzad Hossain

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.

Total phenols, total flavonoids contents and free radical scavenging activity of seeds crude extracts of pigeon pea traditionally used in Oman for the treatment of several chronic diseases

Abstract Objective To investigate total phenols, flavonoids content of methanol crude extract of pigeon pea seeds powder and its different polarities soluble fractions and evaluate their free radical scavenging activity. Methods The powder seeds samples were used for extraction with methanol. Methanol crude extract from the seeds was defatted by water and fractioned by different polarities of solvents. The investigation of total phenols and flavonoids contents of total six crude extracts of pigeon pea were determined by Folin-Ciocalteu reagent and aluminum chloride calorimetric methods. Antioxidant activity of six crude extracts from the seeds of pigeon pea was determined through α,α-diphenyl-β-picrylhydrazyl method. Results Significant amount of total phenols content was presented in hexane crude extract among the six crude extracts of pigeon pea and the order was hexane>chloroform> methanol>ethyl acetate>butanal>water. Similarly, significant amount of total flavonoids content was presented in chloroform crude extract and the order was chloroform>methanol>ethyl acetate>butanol>water>hexane. The crude extracts displayed significant α,α-diphenyl-β-picrylhydrazyl free radical scavenging activity with highest value in hexane extract followed by butanol, methanol, ethyl acetate, chloroform and water crude extracts having value of 95.50%, 83.30%, 64.60%, 64.20%, 60.60% and 52.60%, respectively. Conclusions The crude extracts from seeds of pigeon pea have high contents of total phenols, flavonoids and antioxidant activity. In this regards, it could be used as a medicine for the treatment of different chronic 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.

Phytochemical screening and comparative antimicrobial potential of different extracts of Stevia rebaudiana Bertoni leaves

Abstract Objective To evaluate in vitro antimicrobial potential and phytochemical screening of the crude extracts of leaves of Stevia rebaudiana Bertoni. Methods The essential oil and crude extracts were prepared by using different usual method. Antimicrobial and antifungal activities were measured by the well established methods. Results Highest antifungal index [(12.13±0.08) mm)] and lowest antifungal index [(9.13±0.04) mm] as well as highest antibacterial index [(11.89±0.07) mm] and lowest antibacterial index [(7.24±0.03) mm] were obtained for extracts B, H, A and F, respectively. Invariably extract C, E, I, J and H did not show antimicrobial activity. The extract F showed all antifungal and antibacterial activity except Bacillus cereus and Bacillus megaterium . Conclusions The above findings support the idea that plant extracts of Stevia rebaudiana Bertoni leaves may have a role to be used as pharmaceuticals or preservatives.

Effect of different polarities leaves crude extracts of Omani juniperus excels on antioxidant, antimicrobial and cytotoxic activities and their biochemical screening

Objective To prepare different polarities leave crude extracts of Juniperus excels (J. excels) and to determine their phytochemical screening, antioxidant, antimicrobial and cytotoxic activities.

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.

Evaluation of antioxidant and antimicrobial potential of different leaves crude extracts of Omani Ficus carica against food borne pathogenic bacteria

Abstract Objective To prepare different polarities crude extract from the leaves of Ficus carica and to evaluate their antioxidant and antimicrobial potential against food borne pathogenic bacterial strains. Methods The dried leaves were macerated in absolute ethanol for one week. The ethanol was evaporated and the crude extract was defatted with ethanol-water. The defatted hydro alcoholic crude extract was successively extracted with hexane, chloroform and ethyl acetate. The antioxidant potential was determined against 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Evaluation of antimicrobial potential of different crude extracts against selected Gram positive and Gram negative bacteria by agar disc diffusion method. Results The total extraction yield was 2.2%. The highest extraction yield was in chloroform and the lowest in hexane. The antioxidant results were found in the order of hydro alcoholic>ethyl acetate>hexane>chloroform. Hydro alcoholic crude extract and its derived fractions display moderate antimicrobial potential against the selected bacterial strains such as Staphylococcus aureus, Escheichia coli and Pseudomonas, in the range of 0%–13%. Conclusions It is concluded that the hydro alcoholic and ethyl acetate crude extracts of Ficus carica possess very good antioxidant and antimicrobial potential.