Two new sesquiterpenes, godotol A (1) and godotol B (2), were isolated from Pluchea arabica. Thei... more Two new sesquiterpenes, godotol A (1) and godotol B (2), were isolated from Pluchea arabica. Their structures were determined by analysis of NMR data. The absolute configurations of 1 and 2 were established by Mosher ester methodology. The godotols displayed weak activity against bacteria and the brine shrimp larvae. They were also inactive in the DPPH antioxidant assay.
A hydrodistilled oil obtained from the stem bark of Goniothalamus cardiopetalus (Annonaceae) was ... more A hydrodistilled oil obtained from the stem bark of Goniothalamus cardiopetalus (Annonaceae) was analyzed by GC/MS. The oil showed a total of 60 components of which 40 compounds representing 67.1% of the oil were identified. Linalool (11.7%), α-pinene (7.0%), trans-pinocarveol (5.2%), caryophyllene oxide (5.0%) -terpineol (4.9%), guaiol (4.4%) camphor (3.9%) and bornyl acetate (3.9%) were found to be the major
Plectranthus cylindraceus Hoechst. Ex. Benth (syn P. montanus) (Lamiaceae), is one of the lesser-... more Plectranthus cylindraceus Hoechst. Ex. Benth (syn P. montanus) (Lamiaceae), is one of the lesser-known species of the genus Plectranthus that grows naturally in the Dhofar province in the extreme SouthWest of Oman (Miller et al. 1988). It is also found in parts of Saudi Arabia, Soqotra, Yemen, United Arab Emirates and East African countries (Abulfatih 1987; Johns et al. 1990; Alsabahi et al. 1999). In Dhofar, P. cylindraceus is known as 'Zefubrek' in Jabhali. It grows in dry areas particularly after the first rains of the monsoon season to about 60 cm in height with semi-succulent leaves that are opposite and an inflorescence consisting of cylindrical spike of flowers. The plant has a pleasant aroma similar to the commercial product 'Vicks'. In Oman, the Dhofaris rub the leaves of P. cylindraceus between the hands and over the body as a disinfectant and a deodorant (Miller et al. 1988). Plectranthus is a genus of about 300 species (Miller et al. 1988; Abdel-Mogib et al. 2002; Lukhoba et al. 2006) that are traditionally used to treat skin, digestive and respiratory diseases (Alsabahi et al. 1999; Lukhoba et al. 2006). Few studies have been conducted on the chemotype and activity of the essential oils from different species of Plectranthus. The oil of Plectranthus barbatus is antiallergic (Gupta et al. 1993); whereas, the oil of
Frankincense (Luban in Arabian) is an oleo-gum-resin obtained from the evergreen tree of Boswelli... more Frankincense (Luban in Arabian) is an oleo-gum-resin obtained from the evergreen tree of Boswellia sacra (Family Burseraceae) that grows in the arid zone behind the Monsoon Mountains in Dhofar, south of Sultanate of Oman [1]. This oleo-gum-resin can also be produced by other Boswellia species such as B. serrata in India [2], B. frereana and B. carteri in Somalia [3], B. dalzielii in Nigeria [4] and B. socotrana in Yemen [5]. Frankincense has been used for centuries as fragrance material as well as traditional medicine to cure different kind of diseases. In Oman, crushed frankincense of B. sacra was used as a plaster to treat skin lesions and for healing bone fractures.The gum also made up into pills and taken to treat abdominal and chest pain [6]. In Yemen, the oleo-gum-resin of B. socotrana is used traditionally by the native inhabitants for relieving the pain in cavities and sweetening the breath [7]. The gum resin of B. dalzielii is used along with other medicines for the treatment of venereal diseases in Nigeria [8]. Frankincense extracted from the bark of B. serrata is still used in the traditional ayurvedic medicine in India [9]. Investigations of pharmacological activities of essential oil extracted from different type of frankincense reveal wideranging medicinal applications such as antibacterial, antifungal, anticancer, antiinflammatory and asthma medication [10-14]. In this regard, essential oil of B. sacra exhibits inhibition
The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essent... more The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essential oil (5.5%); and its chemical constituents were determined. The GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was characterized by the high content of the monoterpenes (34) which constituted 97.3% in which E-β-ocimene and limonene were the major constituents. The remaining 2.7% was accounted for the sesquiterpenes (16) in which the E-caryophyllene was the major constituent. The analysis proved the complete absence of the diterpenes.
The essential oil of Teucrium stocksianum Boiss. subsp. stocksianum leaf grown in Oman was analyz... more The essential oil of Teucrium stocksianum Boiss. subsp. stocksianum leaf grown in Oman was analyzed by GC-MS. Forty seven components amounting to 76.1% of the total oil were identified. The major constituents were α-cadinol (7.6%), β-selinene (6.4%), trans-verbenol (5.9%), caryophyllene oxide (5.7%), α-phellandren-8-ol (5.0%), verbenone (5.0%) and δ-cadinene (5.1%). The antimicrobial activity of the oil was tested against a panel of seventeen bacterial and six fungal strains by the disc diffusion method. The oil inhibited the growth of all test organisms at various levels; however, it showed significant inhibitory activity against Staphylococcus and Streptococcus species, as well as yeasts. The minimal inhibitory concentrations (MIC) were also determined.
Sultan Qaboos University Journal for Science [SQUJS]
The leaves and flowers of Lavandula dhofarensis were collected from the Dhofar region of Oman and... more The leaves and flowers of Lavandula dhofarensis were collected from the Dhofar region of Oman and hydro-distilled to give low boiling volatiles, which did not condense at 10 oC. The dichloromethane extract of the hydrosol was analyzed by GC/FID and GC/MS. Sixty four compounds were identified in the volatiles of the leaves, accounting for 78.7% of the total. The major components were caryophyllene oxide (8.0%), germacrene (7.9%), spathulenol (7.8%), and b-caryophyllene (6.6%). Eighty six compounds were also identified in the volatiles of the leaves plus flowers, comprising 94.5% of the total. The major compounds were camphor (12.9%), viridiflorol (10.5%), a-terpinyl acetate (7.5%), valerenal (7.2%), a-gurjunene (5.6%), and spathulenol (5.5%). Compounds such as linalool, linalyl acetate, 1,8-cineole, and b-ocimene, which are usually found as the major components of lavender oils, were either absent or detected at low levels (<0.1%) in the hydrosol of L. dhofarensis. This investi...
Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure)... more Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure) have both been used to extract the buds of cloves (Syzygium aromaticum). The yields of eugenol and eugenyl acetate obtained by these methods and also by steam distillation and liquid solvent (Soxhlet) extraction are similar, but the yields of caryophyllene were lower for the methods using water.
The essential oil compositions of four botanically certified and commercially available samples o... more The essential oil compositions of four botanically certified and commercially available samples of Omani lubans (oleo-gum resins of Boswellia sacra Flueck.), locally known as Hoojri, Najdi, Shathari, and Shaabi in Jibali Arabic, obtained from plants growing in four different geographic locations of the Dhofar region of Oman, were analyzed by GC-FID, GC/MS, and (13) C-NMR spectroscopy. The market price of these four grades of lubans differed considerably, according to their color, clump size, and texture. However, this study revealed that Hoojri, the first grade luban, and Shaabi, the fourth grade luban, which greatly differed in their price, closely resembled each other in their essential oil composition, yield, and physicochemical characteristics, except the color and texture. The composition, yield, and specific rotation of the oils of Najdi and Shathari, the second and the third grade lubans, respectively, were different from those of Hoojri and Shaabi, but they both had high lim...
The essential oil compositions of the rhizomes of Cyperus conglomeratus (Cyperaceae) collected fr... more The essential oil compositions of the rhizomes of Cyperus conglomeratus (Cyperaceae) collected from Oman and the leaves of two Annonaceae plants, Desmos chinensis var. lawii and Cyathocalyx zeylanicus collected from India were studied by GC, GC-MS and 13C NMR spectroscopy. Twenty-six compounds, representing 84.4% of the oil were identified in C. conglomeratus, where eugenol (31.3%), alpha-cyperone (10.5%) and cyperotundone (8.4%) were the major compounds. Twelve compounds, constituting 100%, were identified in D. lawii oil, of which benzyl benzoate (58.7%), beta-caryophyllene (23.2%), limonene (4.9%) and alpha-humulene (4.0%) were the major constituents. Thirty-two compounds, comprising 98.0%, were identified in C. zeylanicus oil, of which beta-caryophyllene (21.6%), alpha-pinene (20.4%) and E-beta-ocimene (11.8%) were the major components. The antibacterial and antifungal activities of the oils were tested against a panel of five bacterial and two fungal strains. The oils showed mo...
The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essent... more The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essential oil (5.5%); and its chemical constituents were determined. The GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was characterized by the high content of the monoterpenes (34) which constituted 97.3% in which E-β-ocimene and limonene were the major constituents. The remaining 2.7% was accounted for the sesquiterpenes (16) in which the E-caryophyllene was the major constituent. The analysis proved the complete absence of the diterpenes.
This article serves as an overview, introducing the currently popular area of supercritical fluid... more This article serves as an overview, introducing the currently popular area of supercritical fluids (SFs) and their uses in biotechnology and related areas. It covers the fundamentals of supercritical science and moves on to the biotechnological and associated applications of these fluids. Subject areas covered include pure substances as supercritical fluids, the properties of supercritical fluids, organic cosolvents, solubility, and the following applications: extraction, chromatography, reactions, particle production, deposition, and the drying of biological specimens. Within each application, and where possible, the basic principles of the technique are given, as well as a description of the history, instrumentation, methodology, uses, problems encountered, and advantages over the traditional, nonsupercritical methods. Index Entries: Supercritical fluids; supercritical fluid extraction; supercritical fluid chromatography; rapid expansion of supercritical solutions; supercritical antisolvent; particles from gas-saturated solution; solution enhanced dispersion by supercritical fluids; critical point drying.
Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure)... more Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure) have both been used to extract the buds of cloves (Syzygium aromaticum). The yields of eugenol and eugenyl acetate obtained by these methods and also by steam distillation and liquid solvent (Soxhlet) extraction are similar, but the yields of caryophyllene were lower for the methods using water.
The present study determines the source of dust particles and investigates their impact on the ch... more The present study determines the source of dust particles and investigates their impact on the chemical compositions of plants and soils around a cement factory in Oman within a radius of 10 km of this disturbed ecosystem. A total number of nine samples of the species of ...
Two new sesquiterpenes, godotol A (1) and godotol B (2), were isolated from Pluchea arabica. Thei... more Two new sesquiterpenes, godotol A (1) and godotol B (2), were isolated from Pluchea arabica. Their structures were determined by analysis of NMR data. The absolute configurations of 1 and 2 were established by Mosher ester methodology. The godotols displayed weak activity against bacteria and the brine shrimp larvae. They were also inactive in the DPPH antioxidant assay.
A hydrodistilled oil obtained from the stem bark of Goniothalamus cardiopetalus (Annonaceae) was ... more A hydrodistilled oil obtained from the stem bark of Goniothalamus cardiopetalus (Annonaceae) was analyzed by GC/MS. The oil showed a total of 60 components of which 40 compounds representing 67.1% of the oil were identified. Linalool (11.7%), α-pinene (7.0%), trans-pinocarveol (5.2%), caryophyllene oxide (5.0%) -terpineol (4.9%), guaiol (4.4%) camphor (3.9%) and bornyl acetate (3.9%) were found to be the major
Plectranthus cylindraceus Hoechst. Ex. Benth (syn P. montanus) (Lamiaceae), is one of the lesser-... more Plectranthus cylindraceus Hoechst. Ex. Benth (syn P. montanus) (Lamiaceae), is one of the lesser-known species of the genus Plectranthus that grows naturally in the Dhofar province in the extreme SouthWest of Oman (Miller et al. 1988). It is also found in parts of Saudi Arabia, Soqotra, Yemen, United Arab Emirates and East African countries (Abulfatih 1987; Johns et al. 1990; Alsabahi et al. 1999). In Dhofar, P. cylindraceus is known as 'Zefubrek' in Jabhali. It grows in dry areas particularly after the first rains of the monsoon season to about 60 cm in height with semi-succulent leaves that are opposite and an inflorescence consisting of cylindrical spike of flowers. The plant has a pleasant aroma similar to the commercial product 'Vicks'. In Oman, the Dhofaris rub the leaves of P. cylindraceus between the hands and over the body as a disinfectant and a deodorant (Miller et al. 1988). Plectranthus is a genus of about 300 species (Miller et al. 1988; Abdel-Mogib et al. 2002; Lukhoba et al. 2006) that are traditionally used to treat skin, digestive and respiratory diseases (Alsabahi et al. 1999; Lukhoba et al. 2006). Few studies have been conducted on the chemotype and activity of the essential oils from different species of Plectranthus. The oil of Plectranthus barbatus is antiallergic (Gupta et al. 1993); whereas, the oil of
Frankincense (Luban in Arabian) is an oleo-gum-resin obtained from the evergreen tree of Boswelli... more Frankincense (Luban in Arabian) is an oleo-gum-resin obtained from the evergreen tree of Boswellia sacra (Family Burseraceae) that grows in the arid zone behind the Monsoon Mountains in Dhofar, south of Sultanate of Oman [1]. This oleo-gum-resin can also be produced by other Boswellia species such as B. serrata in India [2], B. frereana and B. carteri in Somalia [3], B. dalzielii in Nigeria [4] and B. socotrana in Yemen [5]. Frankincense has been used for centuries as fragrance material as well as traditional medicine to cure different kind of diseases. In Oman, crushed frankincense of B. sacra was used as a plaster to treat skin lesions and for healing bone fractures.The gum also made up into pills and taken to treat abdominal and chest pain [6]. In Yemen, the oleo-gum-resin of B. socotrana is used traditionally by the native inhabitants for relieving the pain in cavities and sweetening the breath [7]. The gum resin of B. dalzielii is used along with other medicines for the treatment of venereal diseases in Nigeria [8]. Frankincense extracted from the bark of B. serrata is still used in the traditional ayurvedic medicine in India [9]. Investigations of pharmacological activities of essential oil extracted from different type of frankincense reveal wideranging medicinal applications such as antibacterial, antifungal, anticancer, antiinflammatory and asthma medication [10-14]. In this regard, essential oil of B. sacra exhibits inhibition
The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essent... more The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essential oil (5.5%); and its chemical constituents were determined. The GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was characterized by the high content of the monoterpenes (34) which constituted 97.3% in which E-β-ocimene and limonene were the major constituents. The remaining 2.7% was accounted for the sesquiterpenes (16) in which the E-caryophyllene was the major constituent. The analysis proved the complete absence of the diterpenes.
The essential oil of Teucrium stocksianum Boiss. subsp. stocksianum leaf grown in Oman was analyz... more The essential oil of Teucrium stocksianum Boiss. subsp. stocksianum leaf grown in Oman was analyzed by GC-MS. Forty seven components amounting to 76.1% of the total oil were identified. The major constituents were α-cadinol (7.6%), β-selinene (6.4%), trans-verbenol (5.9%), caryophyllene oxide (5.7%), α-phellandren-8-ol (5.0%), verbenone (5.0%) and δ-cadinene (5.1%). The antimicrobial activity of the oil was tested against a panel of seventeen bacterial and six fungal strains by the disc diffusion method. The oil inhibited the growth of all test organisms at various levels; however, it showed significant inhibitory activity against Staphylococcus and Streptococcus species, as well as yeasts. The minimal inhibitory concentrations (MIC) were also determined.
Sultan Qaboos University Journal for Science [SQUJS]
The leaves and flowers of Lavandula dhofarensis were collected from the Dhofar region of Oman and... more The leaves and flowers of Lavandula dhofarensis were collected from the Dhofar region of Oman and hydro-distilled to give low boiling volatiles, which did not condense at 10 oC. The dichloromethane extract of the hydrosol was analyzed by GC/FID and GC/MS. Sixty four compounds were identified in the volatiles of the leaves, accounting for 78.7% of the total. The major components were caryophyllene oxide (8.0%), germacrene (7.9%), spathulenol (7.8%), and b-caryophyllene (6.6%). Eighty six compounds were also identified in the volatiles of the leaves plus flowers, comprising 94.5% of the total. The major compounds were camphor (12.9%), viridiflorol (10.5%), a-terpinyl acetate (7.5%), valerenal (7.2%), a-gurjunene (5.6%), and spathulenol (5.5%). Compounds such as linalool, linalyl acetate, 1,8-cineole, and b-ocimene, which are usually found as the major components of lavender oils, were either absent or detected at low levels (<0.1%) in the hydrosol of L. dhofarensis. This investi...
Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure)... more Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure) have both been used to extract the buds of cloves (Syzygium aromaticum). The yields of eugenol and eugenyl acetate obtained by these methods and also by steam distillation and liquid solvent (Soxhlet) extraction are similar, but the yields of caryophyllene were lower for the methods using water.
The essential oil compositions of four botanically certified and commercially available samples o... more The essential oil compositions of four botanically certified and commercially available samples of Omani lubans (oleo-gum resins of Boswellia sacra Flueck.), locally known as Hoojri, Najdi, Shathari, and Shaabi in Jibali Arabic, obtained from plants growing in four different geographic locations of the Dhofar region of Oman, were analyzed by GC-FID, GC/MS, and (13) C-NMR spectroscopy. The market price of these four grades of lubans differed considerably, according to their color, clump size, and texture. However, this study revealed that Hoojri, the first grade luban, and Shaabi, the fourth grade luban, which greatly differed in their price, closely resembled each other in their essential oil composition, yield, and physicochemical characteristics, except the color and texture. The composition, yield, and specific rotation of the oils of Najdi and Shathari, the second and the third grade lubans, respectively, were different from those of Hoojri and Shaabi, but they both had high lim...
The essential oil compositions of the rhizomes of Cyperus conglomeratus (Cyperaceae) collected fr... more The essential oil compositions of the rhizomes of Cyperus conglomeratus (Cyperaceae) collected from Oman and the leaves of two Annonaceae plants, Desmos chinensis var. lawii and Cyathocalyx zeylanicus collected from India were studied by GC, GC-MS and 13C NMR spectroscopy. Twenty-six compounds, representing 84.4% of the oil were identified in C. conglomeratus, where eugenol (31.3%), alpha-cyperone (10.5%) and cyperotundone (8.4%) were the major compounds. Twelve compounds, constituting 100%, were identified in D. lawii oil, of which benzyl benzoate (58.7%), beta-caryophyllene (23.2%), limonene (4.9%) and alpha-humulene (4.0%) were the major constituents. Thirty-two compounds, comprising 98.0%, were identified in C. zeylanicus oil, of which beta-caryophyllene (21.6%), alpha-pinene (20.4%) and E-beta-ocimene (11.8%) were the major components. The antibacterial and antifungal activities of the oils were tested against a panel of five bacterial and two fungal strains. The oils showed mo...
The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essent... more The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essential oil (5.5%); and its chemical constituents were determined. The GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was characterized by the high content of the monoterpenes (34) which constituted 97.3% in which E-β-ocimene and limonene were the major constituents. The remaining 2.7% was accounted for the sesquiterpenes (16) in which the E-caryophyllene was the major constituent. The analysis proved the complete absence of the diterpenes.
This article serves as an overview, introducing the currently popular area of supercritical fluid... more This article serves as an overview, introducing the currently popular area of supercritical fluids (SFs) and their uses in biotechnology and related areas. It covers the fundamentals of supercritical science and moves on to the biotechnological and associated applications of these fluids. Subject areas covered include pure substances as supercritical fluids, the properties of supercritical fluids, organic cosolvents, solubility, and the following applications: extraction, chromatography, reactions, particle production, deposition, and the drying of biological specimens. Within each application, and where possible, the basic principles of the technique are given, as well as a description of the history, instrumentation, methodology, uses, problems encountered, and advantages over the traditional, nonsupercritical methods. Index Entries: Supercritical fluids; supercritical fluid extraction; supercritical fluid chromatography; rapid expansion of supercritical solutions; supercritical antisolvent; particles from gas-saturated solution; solution enhanced dispersion by supercritical fluids; critical point drying.
Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure)... more Supercritical carbon dioxide and superheated water (subcritical water above 100°C under pressure) have both been used to extract the buds of cloves (Syzygium aromaticum). The yields of eugenol and eugenyl acetate obtained by these methods and also by steam distillation and liquid solvent (Soxhlet) extraction are similar, but the yields of caryophyllene were lower for the methods using water.
The present study determines the source of dust particles and investigates their impact on the ch... more The present study determines the source of dust particles and investigates their impact on the chemical compositions of plants and soils around a cement factory in Oman within a radius of 10 km of this disturbed ecosystem. A total number of nine samples of the species of ...
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