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17 results on '"Gewali, M. B."'

4. An antiproliferative norditerpene dilactone, Nagilactone C, from Podocarpus neriifolius

Author

Shrestha, K, Banskota, A. H., Kodata, S., Shrivastava, G., Strobel, G., and Gewali, M. B.

Subjects
antiproliferative activity for cancer cells, norditerpene dilactone, nagilactone C, Podocarpus neriifolius
Abstract

An ethanolic extract of Podocarpus neriifolius D. Don (Podocarpaceae) showed antiproliferative activity against two major tumor cell lines, viz. human HT-1080 fibrosarcoma and murine color 26-L5 carcinoma. Bioassay guided fractionation showed the highest antiproliferative activity in chloroform–soluble fraction. Nagilactone C, the major constituent of this fraction was isolated and characterized by using NMR, IR and FAB-MS spectroscopic methods. Nagilactone C possessed potent antiproliferative activity against human fibrosarcoma and murine colon carcinoma tumor cell lines exhibiting ED50 values of 2.3 and 1.2 μg/ml, respectively. Hence, nagilactone C could be the active constituent present in this plant.

Published
2001

8. Elemental and Organic Carbon, Ionic and Non ionic components in TSP and PM10 Particulates of Kathmandu Valley, Nepal.

Author

Sharma, R. K., Bhattarai, B. K., Sapkota, B. K., Gewali, M. B., Kjeldstad, B., and Ito, N.

Subjects
ORGANIC compound analysis, IONIC structure, CHEMICAL structure, RADIOACTIVE aerosols, AERODYNAMICS
Abstract

Particulate matters of different aerodynamic diameters; TSP, PM10 for 24 hours were collected on quartz 47mm filter paper using Frm OMNITM Ambient Air Sampler from December 2010 to March 2011 and analyzed. The analysis of these sample collected were carried out by gravimetric, X-ray fluorescent and ion-chromatographic methods. TSP value for the observed period lies between 31.3-84.08 μg/m³ while PM10 ranges from 39.5-104.2 μg/m³. Daily carbonaceous aerosols concentration in TSP varied widely between (5.3-18.2 μg/m³) for Organic carbon (OC) and 5.6-10.2 μg/m³ for Elemental carbon (EC). Similarly in PM10 the range was from 4.8-14.1 and 3.9-10.1 μg/m³ respectively. The OC/EC ratio in the particulate matters ranges from 0.9-1.4. OC/EC ratio within 1.1 infers vehicular emission as a major source of carbonaceous aerosols in the valley. Further, among the nonionic components analyzed (K, Ca, Fe, Ti and Pb) showed highest -andCa2+ are only in few samples. Few samples of soil analyzed shows maximum of 32 elements. Variation in the concentration of ionic nonionic and carbonaceous aerosols is not related with wind pattern and its velocity. [ABSTRACT FROM AUTHOR]

Published
2015

9. BIODIESEL PRODUCTION FROM JATROPHA CURCAS (L.) OIL OF NEPAL BY TRANSESTERIFICATION PROCESS.

Author

Shrestha, K., Ghimire, J. R., and Gewali, M. B.

Subjects
BIODIESEL fuels, OIL & fat extraction, JATROPHA
Abstract

The highest percentage of the oil i.e. 58.3% was found in the seeds (Kernel) collected from Rolpa district. The physico-chemical parameters like moisture content, oil content, specific gravity, density, viscosity, refractive index, iodine value, saponification value and acid value (% Free Fatty Acid), were determined. Then extracted oil was converted into biodiesel by transesterification process with methanol using different concentration of alkali catalyst viz. 0.5%, 1.0% and 1.5% NaOH. The result showed that 1% NaOH catalyst was found to be the most effective concentration producing 87% crude fatty acid methyl esters (FAME) and 10% crude glycerol. Composition of FAME present in the biodiesel was identified by GC-MS method. [ABSTRACT FROM AUTHOR]

Published
2013

10. Eleven Novel Diarylheptanoids and Two Unusual Diarylheptanoid Derivatives from the Seeds of Alpinia blepharocalyx

Author

Tezuka, Y., Gewali, M. B., Ali, M. S., Banskota, A. H., and Kadota, S.

Abstract

An EtOH extract of the seeds of Alpinia blepharocalyx afforded 11 novel diarylheptanoids, named deoxycalyxin A (1), epicalyxin F (2), calyxin K (3), epicalyxin K (4), calyxin I (5), epicalyxin I (6), calyxin J (7), epicalyxin J (8), and calyxin L (9), an epimeric mixture of calyxin M (10) and epicalyxin M (11), and two unusual diarylheptanoid derivatives, named neocalyxins A (12) and B (13), together with four known calyxins, calyxins A (14), F (15), E (16), and G (17). Structures were elucidated by spectroscopic techniques including 2D NMR spectroscopy. All compounds were examined for cytotoxicity toward murine colon 26-L5 carcinoma and human HT-1080 fibrosarcoma cells. Diarylheptanoids 2, 3, and 5 were cytotoxic against both cell lines, while 4 and 6−8 were cytotoxic against human fibrosarcoma cells.

Published
2001

11. Epicalyxin F and Calyxin I:  Two Novel Antiproliferative Diarylheptanoids from the Seeds of Alpinia blepharocalyx

Author

Gewali, M. B., Tezuka, Y., Banskota, A. H., Ali, M. S., Saiki, I., Dong, H., and Kadota, S.

Abstract

Epicalyxin F (1) and calyxin I (2), two novel diarylheptanoids, were isolated from a residual fraction of an EtOH extract of Alpinia blepharocalyx. Calyxin I (2) represented a new carbon skeleton, and epicalyxin F (1) possessed potent antiproliferative activity toward HT-1080 fibrosarcoma and colon 26-L5 carcinoma with ED50 values of 1.71 and 0.89 μM, respectively.

Published
1999

12. Steroidal Alkaloids from the Leaves of Sarcococca coriacea of Nepalese Origin

Author

Kalauni, S. K., Choudhary, M. I., Shaheen, F., Manandhar, M. D., Atta-ur-Rahman, Gewali, M. B., and Khalid, A.

Abstract

Two new steroidal alkaloids, (−)-vaganine D (1) [(20S)-20-(N,N-dimethylamino)-3β-(senecioylamino)-5α-pregn-16-en-4β-yl acetate], and (+)-nepapakistamine A (2) [(20S)-20-(N-methylamino)-3β-(tigloylamino)-5α-pregn-16-en-2β,4β-diacetate], were isolated from the leaves of Sarcococca coriacea. Their structures were elucidated on the basis of their spectral properties. Compounds 1 and 2 were found to be cholinesterase inhibitors.

Published
2001

15. An antiproliferative norditerpene dilactone, Nagilactone C, from Podocarpus neriifolius.

Author

Shrestha K, Banskota AH, Kodata S, Shrivastava SP, Strobel G, and Gewali MB

Subjects
Animals, Antineoplastic Agents, Phytogenic isolation & purification, Cell Division drug effects, Diterpenes chemistry, Diterpenes isolation & purification, Drug Screening Assays, Antitumor, Humans, Mice, Plant Extracts isolation & purification, Plant Extracts pharmacology, Tumor Cells, Cultured drug effects, Antineoplastic Agents, Phytogenic pharmacology, Cycadopsida, Diterpenes pharmacology
Abstract

An ethanolic extract of Podocarpus neriifolius D. Don (Podocarpaceae) showed antiproliferative activity against two major tumor cell lines, viz. human HT-1080 fibrosarcoma and murine color 26-L5 carcinoma. Bioassay guided fractionation showed the highest antiproliferative activity in chloroform-soluble fraction. Nagilactone C, the major constituent of this fraction was isolated and characterized by using NMR, IR and FAB-MS spectroscopic methods. Nagilactone C possessed potent antiproliferative activity against human fibrosarcoma and murine colon carcinoma tumor cell lines exhibiting ED50 values of 2.3 and 1.2 microg/ml, respectively. Hence, nagilactone C could be the active constituent present in this plant.

Published
2001
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16. Evidence for paclitaxel from three new endophytic fungi of Himalayan yew of Nepal.

Author

Shrestha K, Strobel GA, Shrivastava SP, and Gewali MB

Subjects
Antibodies, Monoclonal, Chromatography, High Pressure Liquid, Mass Spectrometry, Molecular Structure, Nepal, Spectrometry, Mass, Electrospray Ionization, Fungi chemistry, Paclitaxel chemistry, Paclitaxel isolation & purification, Plants, Medicinal, Taxus chemistry
Abstract

Taxus wallichiana, collected from the Himalayan region of Nepal, yielded, among others, three different endophytic fungi including Sporormia minima, Trichothecium sp., and an unidentified dimorphic fungus. Each was shown to produce paclitaxel in a culture medium. Each of these fungi represents a new report as a paclitaxel producer. The production of paclitaxel was confirmed by an immunoassay that utilized monoclonal antibodies, TLC chromatography as well as high performance liquid chromatography combined with on-line mass spectrometry.

Published
2001
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17. Analysis of a thread used in the Kshara Sutra treatment in the Ayurvedic medicinal system.

Author

Gewali MB, Pilapitiya U, Hattori M, and Namba T

Subjects
Catechols analysis, Chromatography, Gas, Chromatography, High Pressure Liquid, Diterpenes analysis, Gas Chromatography-Mass Spectrometry, Plant Extracts analysis, Triterpenes analysis, Medicine, Ayurvedic, Plants, Medicinal analysis
Abstract

From a Kshara Sutra thread which is used in the therapy of fistula in the Ayurvedic medicinal system, euphol, 3,12-di-O-acetyl-8-O-benzoylingol, 3,12-di-O-acetyl-8-O-tigloylingol, curcumin, p-coumaroylferuloylmethane and di-p-courmaroylmethane were isolated and characterized. In addition, GLC and GC/MS confirmed the presence of euphol, antiquol B, cycloeucalenol and 24-methylene cycloartanol in the thread.

Published
1990
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