The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Soek Sin Teh - One of the best experts on this subject based on the ideXlab platform.
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Comparative studies of selected Calophyllum plants for their anti-inflammatory properties
Pharmacognosy Magazine, 2019Co-Authors: Siau Hui Mah, Soek Sin TehAbstract:Background: Calophyllum (Clusiaceae) plants have been used as traditional medicine for rheumatism, vein problems, hemorrhoids, and gastric ulcers. The traditional uses of this genus prompted us to investigate six Malaysian Calophyllum species which are Calophyllum inophyllum, Calophyllum soulattri, Calophyllum lowii, Calophyllum teysmannii, Calophyllum benjaminum and Calophyllum javanicum for their anti-inflammatory properties. Materials and Methods: The stem bark of six plants was extracted with n-hexane (Hex), ethyl acetate (EA), and methanol (MeOH). The activities of the extracts were evaluated by determining the inhibition of nitric oxide (NO) production by lipopolysaccharide-induced RAW 264.7 cells, as well as protein denaturation. Results and Discussion: The C. lowii extracts showed the most significant activities against NO production with IC50values of Abbreviations used: NO: Nitric oxide; spp.: Species; Hex: Hexane; EA: Ethyl acetate; MeOH: Methanol.
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Acetyl-cholinesterase Enzyme Inhibitory Effect of Calophyllum species
Tropical Journal of Pharmaceutical Research, 2015Co-Authors: Soek Sin Teh, Muhamad Syarik Bin Muhamad Sahimi, Siau Hui Mah, Nur Ain Jamaluddin, Zuraini AhmadAbstract:Purpose: To search for new acetylcholinesterase enzyme inhibitors from Calopyllum species. Methods: Six stem bark extracts of Calophyllum inophyllum , C. soulattri , C. teysmannii , C. lowii , C. benjaminum and C. javanicum were subjected to anti-cholinesterase analysis against acetylcholinesterase (AChE) enzyme using Ellman’s method. Results: Most of the extracts showed promising inhibitory activity against AChE at concentrations of 100 μg/mL, with the methanol extract of C. inophyllum demonstrating the strongest inhibitory effect of 81.28 % followed by the methanol extract of C. benjaminum with 74.32 % inhibition. The methanol extracts of Calophyllum inophyllum and Calophyllum bejaminum also showed significant inhibitory activity towards the acetylcholinesterase (AChE) enzyme. Conclusion: Calophyllum species is capable of yielding potential lead compounds for the development for acetyl-cholinesterase enzyme inhibition drugs. Keywords: Calophyllum species, Acetylcholinesterase, Inhibitors
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Chemical Constituents of Calophyllum Benjaminum and Calophyllum Javanicum and their Bioactivities
The Open Conference Proceedings Journal, 2013Co-Authors: Muhamad Syarik Bin Muhamad Sahimi, Soek Sin Teh, Ahmad Azri Fitri Ismail, Mohd Aspollah SukariAbstract:Previous studies on Calopyllum species have resulted in isolation of secondary metabolites such as xanthone and coumarins. However, phytochemistry investigations on Calophyllum benjaminum and Calophyllum javanicum have never been reported. Our recent study on the chemical constituents of the stem bark of both Calophyllum benjaminum and Calophyllum javanicum have yielded three xanthones. These were identified as fuscaxanthone C (1), β-mangostin (2), thwaitesixanthone (3), and dombakinaxanthone (4) together with four triterpenes known as friedelin, β-sitosterol, γ-sitosterol and stigmasterol. The hexane, chloroform, ethyl acetate and methanol extracts of Calophyllum benjaminum were tested for antioxidant properties by DPPH free radical scavenging test. Only the methanol extract shows significant antioxidant activity.
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Chemical Constituents of Calophyllum Teysmannii and Calophyllum Lowiiand their Bioactivities
The Open Conference Proceedings Journal, 2013Co-Authors: Nur Ain Jamaluddin, Soek Sin Teh, Mohd Aspollah SukariAbstract:A number of Calophyllum (Clusiaceae) species have been investigated but only a few have been extensively studied. Phytochemical studies on the Calophyllum species have revealed plants from this genus to be rich in secondary metabolites such as xanthones, coumarins, flavonoids and triterpenoids. The study on chemical constituents of the stem bark of Calophyllum teysmannii and Calophyllum lowii has resulted in the isolation and characterization of four xanthone derivatives, named ananixanthone (1), thwaitesixanthone (2), fuscaxanthone C (3) and caloxanthone L (4). Several triterpenoids and steroids, friedelan-3-one, stigmasterol, sitosterol and glutanone were also successfully isolated from these plants. The structures of these minor components were established by means of spectroscopic analysis including nuclear magnetic resonance (NMR1D, 2D), UV, IR and mass spectrometry. The crude extracts of Calophyllum lowii were tested against DPPH free radical scavenging agent. However only methanol extracts gave strong antioxidant activity.
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Secondary Metabolites from Calophyllum Sclerophyllum and Calophyllum Hoseii
The Open Conference Proceedings Journal, 2013Co-Authors: Shaari Daud, Emilia Abd Malek, Soek Sin TehAbstract:Calophyllum spp have been known for their biological activities. This genus belongs to the Guttifereae family where are rich with secondary metabolites such as xanthones, flavonoids and coumarins. Our recent phytochemical study on the bark of Calophyllum sclerophyllum and Calophyllum hoseii has led to the isolation of six xanthones, one coumarin and one flavanoid. These compounds are macluraxanthone (1), trapezifolixanthone (2), rubraxanthone (3), thwaitesixanthone (4), dombakinaxanthone (5), osajaxanthone (6), calopolyanolide A (7) and catechin (8). We report here the structural elucidations of these compounds based on the basis of detailed 1D-NMR (H, C and DEPT) and 2D-NMR (COSY, HMQC and HMBC) spectroscopic analysis.
Lianet Monzote - One of the best experts on this subject based on the ideXlab platform.
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Antimicrobial Assessment of Resins from Calophyllum Antillanum and Calophyllum Inophyllum.
Phytotherapy research : PTR, 2015Co-Authors: Osmany Cuesta-rubio, Ahmad Oubada, Adonis Bello, Louis Maes, Paul Cos, Lianet MonzoteAbstract:The Calophyllum genus is well-known for its antimicrobial and cytotoxic activities, and therefore, we analyzed these biological activities for resins of Calophyllum antillanum and Calophyllum inophyllum growing in Cuba. C. antillanum resins showed a potent activity against Plasmodium falciparum (IC50 = 0.3 ± 0.1 µg/mL), while its cytotoxicity against MRC-5 cells was much lower (IC50 = 21.6 ± 1.1 µg/mL). In contrary, the resin of C. inophyllum showed an unspecific activity. The presence of apetalic acid, isoapetalic acid, calolongic acid, pinetoric acid I, pinetoric acid II, isocalolongic acid, pinetoric acid III, and isopinetoric acid III in C. antillanum resins was also confirmed. These results demonstrated for the first time the potential activity of C. antillanum resins against P. falciparum.
Phila Raharivelomanana - One of the best experts on this subject based on the ideXlab platform.
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the wound healing and antibacterial activity of five ethnomedical Calophyllum inophyllum oils an alternative therapeutic strategy to treat infected wounds
PLOS ONE, 2015Co-Authors: Teddy Leguillier, Marylin Lecsobornet, Christelle Lemus, Delphine Rousseauralliard, Nicolas Lebouvier, Edouard Hnawia, Mohammed Nour, William G L Aalbersberg, Kamelia Ghazi, Phila RaharivelomananaAbstract:Background Calophyllum inophyllum L. (Calophyllaceae) is an evergreen tree ethno-medically used along the seashores and islands of the Indian and Pacific Oceans, especially in Polynesia. Oil extracted from the seeds is traditionally used topically to treat a wide range of skin injuries from burn, scar and infected wounds to skin diseases such as dermatosis, urticaria and eczema. However, very few scientific studies reported and quantified the therapeutic properties of Calophyllum inophyllum oil (CIO). In this work, five CIO from Indonesia (CIO1), Tahiti (CIO2, 3), Fiji islands (CIO4) and New Caledonia (CIO5) were studied and their cytotoxic, wound healing, and antibacterial properties were presented in order to provide a scientific support to their traditional use and verify their safety.
Ricardo Reyes-chilpa - One of the best experts on this subject based on the ideXlab platform.
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Trends in the chemical and pharmacological research on the tropical trees Calophyllum brasiliense and Calophyllum inophyllum, a global context
Scientometrics, 2015Co-Authors: Juan C. Gomez-verjan, Ignacio González-sánchez, Edgar Antonio Estrella-parra, Ricardo Reyes-chilpaAbstract:Tropical trees of Calophyllum genus (Calophyllaceae) have chemical and biological importance as potential source of secondary active metabolites which can lead to the development of new drugs. Research on this species has been rising since 1992 due to the discovering of anti-HIV properties of Calanolide A found in Calophyllum inophyllum leaves. This compound is the most important natural product for potential development of new anti-HIV drugs and phytomedicines. The scientometric analysis (1953---2014) here performed revealed that the most studied species of Calophyllum genus are: C. inophyllum and C. brasiliense, distributed in the Asian, and American continents, respectively. Current research on these species is carried out mainly in India and Brazil, respectively, where these species grow. Research on C. brasiliense is focused mainly on ecological, antiparasitic, cytotoxic properties, and isolation of new compounds. Chemical studies and biodiesel development are the main topics in the case of C. inophyllum. Text mining analysis revealed that coumarins, and xanthones are the main secondary active metabolites responsible for most of the reported pharmacological properties, and are potential compounds for the treatment of leukemia and against intracellular parasites causing American Trypanosomiasis and Leshmaniasis. On the other hand, C. inophyllum represents an important source for the development of 2nd generation biodiesel. Medicinal and industrial applications of these species may impulse sustainable forest plantations. To our knowledge this is the first scientometric and text mining analysis of chemical and biomedical research on Calophyllum genus, C. brasiliense and C. inophyllum.
B Ashok - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive review of Calophyllum inophyllum as a feasible alternate energy for CI engine applications
Renewable and Sustainable Energy Reviews, 2019Co-Authors: V. Vigneshwar, B Ashok, S. Yogesh Krishnan, R. Susanth Kishna, R. Srinath, K NanthagopalAbstract:Abstract Tree seed oils seem to be a transportation fuel for compression ignition engine at the regular usage around the globe. In India, the seven out of eight customers prefer to use diesel vehicles for their regular usage which has depicted a highly crooked situation. In this present report, a comprehensive review of Calophyllum inophyllum biodiesel as alternative energy source for compression ignition engine applications through various categories like properties assessment, utilization in diesel engine etc. This review report summarizes the various novel production technologies for Calophyllum inophyllum biodiesel that have been used in recent times along with their production yield comparative analysis. Many optimized production methodologies of Calophyllum inophyllum biodiesel have been comparatively evaluated with other feedstock based biodiesels. It has been noticed that the raw oil per Calophyllum inophyllum tree would be around 11.7 kg and Calophyllum inophyllum biodiesel yield through supercritical intensification method is closed to 99% which is significantly higher than other biodiesel feedstock. Further, the impacts of Calophyllum inophyllum biodiesel properties on compression ignition engine behaviours were eventually outlined. Inaddtion, the recent research outputs on the effect of various higher alcohols, antioxidants and nanoparticles with Calophyllum inophyllum biodiesel fuel at various concentrations are discussed in a comprehensive manner. The overall influence of changing compression ignition engine operating parameters such as injection timing, injection pressure and compression ratio variations during Calophyllum inophyllum biodiesel fuel operations are critically outlined. Inaddtion, the various properties of Calophyllum inophyllum biodiesel are compared with other feedstock biodiesels and fewer experimental work outputs are highlighted. In the end, the life cycle cost analysis of Calophyllum inophyllum biodiesel has also been presented. Finally, some specific conclusions about Calophyllum inophyllum biodiesel are summarized and few critical problems on the commercial utilization of Calophyllum inophyllum biodiesel are also pointed out.
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influence of injection timing and exhaust gas recirculation of a Calophyllum inophyllum methyl ester fuelled ci engine
Fuel Processing Technology, 2017Co-Authors: B Ashok, Pradeep J Bhasker, K Nanthagopal, Sakthi D VigneshAbstract:Abstract The present work examines the prospect of using 100% Calophyllum inophyllum methyl ester as a promising alternative fuel for future generation. In this research work, a strategy is developed to reduce NO X emissions of Calophyllum inophyllum biodiesel fuelled diesel engine by varying the injection timing between 21°, 23° and 25° bTDC and by admitting exhaust gas recirculation at the rate of 10%, 20% and 30%. The experiments are conducted in a four stroke diesel engine using 100% Calophyllum inophyllum biodiesel and the engine characteristics are compared with neat diesel engine. Certain important parameters like brake specific energy consumption, brake thermal efficiency, heat release rate, in-cylinder pressure, exhaust emissions including NO X and smoke density are evaluated for various injection timing and EGR rates. Retardation of injection timing to 21° bTDC reduces the NO X emissions very marginally with significant loss in engine performance. It is found that 10% exhaust gas recirculation rate could reduce the NO X emissions more effectively which would meet the proposed Euro V standards. Thus it is observed that exhaust gas recirculation is an effective method to control emissions of 100% Calophyllum inophyllum biodiesel without much compromise in engine efficiency when compared to the influence of injection timing.
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An assessment of Calophyllum inophyllum biodiesel fuelled diesel engine characteristics using novel antioxidant additives
Energy Conversion and Management, 2017Co-Authors: B Ashok, Pathikrit Bhowmick, Dhruv Malhotra, A.k. Jeevanantham, K Nanthagopal, Pranjal AgarwalAbstract:Abstract In this present study, the effect of antioxidant additives with pure Calophyllum inophyllum methyl ester on the performance, combustion and emission characteristics has been investigated. New antioxidant additive namely Ethanox was added to the Calophyllum inophyllum biodiesel at concentrations of 200 ppm, 500 ppm and 1000 ppm for oxides of nitrogen reductions and the experimental results were compared to Butylated hydroxytoluene antioxidant at same concentrations. An experimental study was done on a twin cylinder, four stroke diesel engine at a constant speed of 1500 rpm with two different antioxidants, Ethanox and Butylated hydroxytoluene individually mixed with pure Calophyllum inophyllum at concentrations of 200 ppm, 500 ppm and 1000 ppm by weight. The experimental results showed that the addition of antioxidants with Calophyllum inophyllum biodiesel produced higher brake specific fuel consumption and higher brake thermal efficiency compared to pure biodiesel. Significant reductions in oxides of nitrogen emissions were observed with Ethanox and Butylated hydroxytoluene addition with biodiesel at all concentrations compared to neat biodiesel. The reduction oxides of nitrogen emission was 12.6% for Ethanox 1000 ppm and 21% for Butylated hydroxytoluene 500 ppm compared to neat biodiesel. Comparable combustion characteristics were obtained by addition of Ethanox with biodiesel than Butylated hydroxytoluene antioxidant. Moreover, the addition of Ethanox and Butylated hydroxytoluene antioxidants with neat biodiesel increase the carbon monoxide, unburned hydrocarbons and smoke emission at all concentrations than biodiesel. Ethanox addition with biodiesel has shown better results compared to Butylated hydroxytoluene antioxidant.
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influence on the effect of zinc oxide and titanium dioxide nanoparticles as an additive with Calophyllum inophyllum methyl ester in a ci engine
Energy Conversion and Management, 2017Co-Authors: K Nanthagopal, A Tamilarasu, Ajith Johny, B Ashok, Aravind MohanAbstract:Abstract The present experimental work aims at investigating the effect of zinc oxide and titanium dioxide nanoparticles addition in Calophyllum inophyllum biodiesel in twin cylinder water cooled direct injection four stroke diesel engine. The nanofluids have been prepared from 50 ppm and 100 ppm concentrations of titanium dioxide and zinc oxide with distilled water through ulrasonication process. Four different Calophyllum inophyllum nano emulsions have been prepared with the proportions of 93% of Calophyllum inophyllum biodiesel, 5% of nanofluids of zinc oxide and titanium dioxide and 2% of span 80 using mechanical stirrer. The compression ignition engine characteristics were examined with all four Calophyllum inophyllum nano emulsions and the results were compared with conventional diesel and pure Calophyllum inophyllum biodiesel under various engine loads. The diesel engine operation with CIME nano emulsions improves brake thermal efficiency by 5–17% compared to pure CIME fuel at maximum brake power due to large surface to volume ratio of nanoparticles which exhibit rapid evaporation and better atomization. Further, the CO and HC emissions were reduced drastically for CIME nano emulsions compared to pure biodiesel and conventional diesel fuel. The NOx emission was lower than pure Calophyllum inophyllum biodiesel for all CIME nano emulsions but slightly higher than conventional diesel fuel. The smoke emission of diesel engine was reduced drastically for all CIME nano emulsions compared to both pure biodiesel and diesel fuels at all engine loads. Combustion characteristics of in cylinder gas pressure and heat release rate were increased by the addition of nano particles with pure Calophyllum inophyllum at all engine loads. Finally, it can be observed that the doping of nano particles with biodiesel has a very good effect on performance characteristics with notable improvement in performances and minimum emissions.
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Calophyllum inophyllum methyl ester biodiesel blend as an alternate fuel for diesel engine applications
alexandria engineering journal, 2017Co-Authors: B Ashok, K Nanthagopal, Sakthi D VigneshAbstract:Abstract Calophyllum inophyllum oil is non-edible in nature could be used as a source for biodiesel esterification in India and it is also available in abundant quantities in places such as Southern east and East Asia and Australia. The present research work examines the suitability of Calophyllum inophyllum as promising feedstock for biodiesel production and its employability in diesel engine operation. The Calophyllum trees are found in abundance in India and can reduce the dependency of petroleum imports to a certain extent. The biodiesel Calophyllum inophyllum Methyl Ester (CIME100) and its blends CIME30 and CIME60 are used in engine testing. The experimental parameters such as brake thermal efficiency, brake specific energy consumption, unburned hydrocarbon, carbon monoxide, and NOx emissions are evaluated with CIME100 biodiesel and the results are compared with conventional fuel. It is observed that the CIME biodiesel resulted in slight decrease in brake thermal efficiency. The hydrocarbon and carbon monoxide emissions are reduced with the use of biodiesel with significant penalty in oxides of nitrogen emissions. In addition, the combustion parameters such as cylinder gas pressure, ignition delay period, and heat release rate of CIME100 are discussed in detailed and compared to conventional diesel fuel under various loading conditions.
