Search

Your search keyword '"Orjala J"' showing total 135 results
Start Over Author "Orjala J"
135 results on '"Orjala J"'

2. Short peptide induces an 'uncultivable' microorganism to grow in vitro

Author

Nichols, D., Orjala, J., Mo, S., Lewis, K., Ortenberg, R., O'Connor, P., Zhao, C., Vouros, P., Kaeberlein, T., and Epstein, S.S.

Subjects
Amines -- Chemical properties, Peptides -- Chemical properties, Biological sciences
Abstract

A 24-amino-acid peptide from helper-conditioned medium capable of MSC33 growth induction in agar was isolated to study the interactions between Psychrobacter sp. strain MSC33 and its helper species as models to describe the nature of uncultivability. The findings from the resolution of the phenomenon and domestication of uncultivated species offer insight into the signaling compounds regulating microbial growth and their addition to standard medium formulations.

Published
2008

31. Carmabins A and B, New Lipopeptides from the Caribbean Cyanobacterium Lyngbya majuscula

Author

Hooper, G. J., Orjala, J., Schatzman, R. C., and Gerwick, W. H.

Abstract

Carmabins A and B have been isolated as linear lipotetrapeptides from the BuOH extract of the marine cyanobacterium Lyngbya majuscula. The planar structures were elucidated by extensive 2D NMR analysis, including 1H−15N HMBC and HMQC−TOCSY experiments, together with MS measurements.

Published
1998

36. Acylated Flavonol Glycosides from Leaves of Stenochlaena palustris

Author

Liu, H., Orjala, J., Sticher, O., and Rali, T.

Abstract

From the leaves of Stenochlaena palustris five new O-acylated flavonol glycosides, stenopalustrosides A−E (1−5), have been isolated along with five known compounds, kaempferol 3-O-(3‘ ‘-O-E-p-coumaroyl)−(6‘ ‘-O-E-feruloyl)-β-d-glucopyranoside (6), kaempferol 3-O-(3‘ ‘,6‘ ‘-di-O-E-p-coumaroyl)-β-d-glucopyranoside (7), kaempferol 3-O-(3‘ ‘-O-E-p-coumaroyl)-β-d-glucopyranoside (8), kaempferol 3-O-(6‘ ‘-O-E-p-coumaroyl)-β-d-glucopyranoside (9); and kaempferol 3-O-β-d-glucopyranoside (10). The structures of the isolates were elucidated by spectroscopic methods, mainly 1D and 2D NMR. Compounds 1−4 showed significant antibacterial activities against Gram-positive strains. The structural difference between the isolated antibacterial and nonantibacterial compounds is discussed.

Published
1999

37. Barbamide, a Chlorinated Metabolite with Molluscicidal Activity from the Caribbean Cyanobacterium Lyngbya majuscula

Author

Orjala, J. and Gerwick, W. H.

Abstract

The lipid extract from a Curaçao collection of the marine cyanobacterium Lyngbya majuscula was toxic to the mollusc Biomphalaria glabrata. Subsequent bioassay-guided fractionation of this extract yielded a novel lipopeptide, barbamide, as the active compound (LC100 = 10 μg/mL). The structure of barbamide was determined by spectroscopic methods and was found to contain several unique structural features, including a trichloromethyl group and the methyl enol ether of a β-keto amide.

Published
1996

41. Gibbilimbols A−D, Cytotoxic and Antibacterial Alkenylphenols from Piper gibbilimbum

Author

Orjala, J., Mian, P., Rali, T., and Sticher, O.

Abstract

Fractionation of the petroleum ether extract from the leaves of Piper gibbilimbum collected in Papua New Guinea afforded four new alkenylphenols, gibbilimbols A−D (1−4). The structures of the isolates were elucidated by spectroscopic methods, mainly 1D- and 2D-NMR spectroscopy. Gibbilimbols A−D were found to be toxic to brine shrimp with an LC50 of approximately 5 μg/mL. Gibbilimbols A−D were further found to be cytotoxic toward KB nasopharyngal carcinoma cells (ED50 7.8−2.1 μg/mL). All isolates also showed antibacterial activity toward Staphylococcus epidermidis and Bacillus cereus.

Published
1998

42. Dammarane Triterpenes from the Leaves of Securinega melanthesoides

Author

Schutz, B., Orjala, J., Sticher, O., and Rali, T.

Abstract

Two new dammarane triterpenoids, trans-securinegin [(20S)-24-methylidenedammarane-3α-yl(2E)-3-(4-hydroxyphenyl)-2-propenate (1)] and cis-securinegin [(20S)-24-methylidenedammarane-3α-yl(2Z)-3-(4-hydroxyphenyl)-2-propenate (2)], were isolated from the leaves of Securinega melanthesoides, along with the known compound bergenin. The structures of 1 and 2 were elucidated using spectroscopic methods, mainly 2D NMR techniques.

Published
1998

43. A Novel Extracellular Diterpenoid with Antibacterial Activity from the Cyanobacterium Nostoc commune

Author

Jaki, B., Orjala, J., and Sticher, O.

Abstract

A novel extracellular metabolite with an unprecedented diterpenoid skeleton, 8-[(5-carboxy-2-hydroxy)benzyl]-2-hydroxy-1,1,4a,7,8-pentamethyl-1,2,3,4,4a,6,7,8,8a,9,10,10a-dodecahydrophenanthrene, has been isolated from the culture medium of the terrestrial cyanobacterium Nostoc commune Vaucher (EAWAG 122b) by means of bioguided isolation. The molecule was designated as noscomin. The structure was determined by spectroscopic methods, mainly NMR and mass spectrometry. Noscomin exhibited antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Escherichia coli.

Published
1999

47. Biological Screening of Cyanobacteria for Antimicrobial and MolluscicidalActivity, Brine Shrimp Lethality, and Cytotoxicity.

Author

Jaki, B., Orjala, J., Burgi, H.R., and Sticher, O.

Subjects
*CYANOBACTERIA, *ANTI-infective agents, *MOLLUSCICIDES, *SHRIMPS
Abstract

A total of 86 lipophilic and hydrophilic extracts obtained from 43samples of cultured and field collected freshwater and terrestrial cyanobacteriahave been screened for their biological activities. Anti-microbial evaluationdemonstrated 16.3% to be active against Gram-positive and 5.8% against Gram-negativebacteria, while 10.5% possessed antifungal activity. A lethal effect (>=60%) against brine shrimp ( Artemia salina Leach) was exhibited by8.1% of all extracts at 500 ppm. Cytotoxic activity against KB cells was shownby 1.2%, and 8.1% were active against Caco-2 cells at 50 ppm. A molluscicidaleffect against Biomphalaria glabrata was found for 5.8% of the extracts(LC[sub 100] <100 ppm). [ABSTRACT FROM AUTHOR]

Published
1999
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results