| 1. |
- Mbah, JA, et al.
(författare)
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Two chromones from Peperomia vulcanica
- 2002
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Ingår i: Phytochemistry. - 0031-9422. ; 60:8, s. 799-801
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Tidskriftsartikel (refereegranskat)abstract
- Two chromones: 5-hydroxy-2-(14'-(E)-nonadecenyl) chromone (1) and 5-hydroxy-2-[12'-(3",4"-methylenedioxyphenyl)dodecanyl] chromone (2), together with six known compounds have been isolated from Peperomia vulcanica Baker & C. H. Wright (Piperaceae). Their structures were determined by spectroscopic analysis including 2D NMR techniques.
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| 2. |
- Omolo, JO, et al.
(författare)
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Hericenols A-D and a chromanone from submerged cultures of a Stereum species
- 2002
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Ingår i: Phytochemistry. - 0031-9422. ; 60:4, s. 431-435
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Tidskriftsartikel (refereegranskat)abstract
- Extracts of submerged cultures of a Stereum species afforded four new pentasubstituted phenolic compounds, named hericenols A, B, C, and D (1-4), 6-hydroxymethyl-2,2-dimethylchroman-4-one (5) and the known erinapyrone C. Hericenol A (1) showed weak antimicrobial activity while hericenol C (3) was weakly cytotoxic. The structures of the metabolites were determined by spectroscopic techniques. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 3. |
- Pistelli, L, et al.
(författare)
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Pterocarpans from Bituminaria bituminosa and Bituminaria morisiana.
- 2003
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Ingår i: Phytochemistry. - 0031-9422. ; 64:2, s. 595-598
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Tidskriftsartikel (refereegranskat)abstract
- The aerial parts of Mediterranean papilionaceous plants Bituminaria morisiana and B. bituminosa afforded, along with known phenolics, the prenylated pterocarpans bitucarpin A and B, whose structure was elucidated by spectroscopic techniques. A known isoflavonoid (8-prenyldaidzein) was also obtained for the first time as a genuine plant constituent. The accumulation of pterocarpans at the expense of biogenetically more primitive shikimate metabolites like furanocoumarins or isoflavonoids supports the inclusion of this plant, once part of the genus Psoralea, into the distinct genus Bituminaria.
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| 4. |
- Silberborth, S, et al.
(författare)
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Gerronemins A-F, cytotoxic biscatechols from a Gerronema species
- 2002
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Ingår i: Phytochemistry. - 0031-9422. ; 59:6, s. 643-648
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Tidskriftsartikel (refereegranskat)abstract
- The gerronemins A-F (1-6) were isolated as the cytotoxic components of an extract of a Gerronema species detected in a screening for new cytotoxic metabolites from basidiomycetes. Their structures were elucidated by spectroscopic techniques, and they are composed of a C-12-C-16 alkane or alkene substituted at both ends by 2,3-dihydroxyphenyl groups. The gerronemins blocked the inducible expression of a hCOX-2 and iNOS promoter driven reporter gene with IC50-values of 1-5 mug/ml. In addition, cytotoxic activities were observed which were due the inhibition of cellular macromolecular syntheses.
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| 5. |
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| 6. |
- Broussalis, Adriana M., et al.
(författare)
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First cyclotide from Hybanthus (Violaceae)
- 2001
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Ingår i: Phytochemistry. - : Elsevier. - 0031-9422 .- 1873-3700. ; 58:1, s. 47-51
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Tidskriftsartikel (refereegranskat)abstract
- Hypa A, a novel macrocyclic polypeptide containing 30 amino acid residues, has been isolated from the n-butanol extract of the Argentine plant Hybanthus parviflorus. The sequence, cyclo-(SCVYIPCTITALLGCSCKNKVCYNGIPCAE), was determined by automated Edman degradation, quantitative amino acid analysis and nanospray MS/MS2. Three intramolecular disulfide bridges stabilize the cyclic peptide backbone of hypa A. Using these structural features to classify the peptide as a cyclotide, we extended the distribution of that substance class to a new genus, and now propose a uniform nomenclature for cyclotides.
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| 7. |
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| 8. |
- Svangård, Erika, et al.
(författare)
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Primary and 3-D modelled structures of two cyclotides from Viola odorata
- 2003
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Ingår i: Phytochemistry. - 0031-9422 .- 1873-3700. ; 64:1, s. 135-142
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Tidskriftsartikel (refereegranskat)abstract
- Two polypeptides named vodo M and vodo N, both of 29 amino acids, have been isolated from Viola odorata L. (Violaceae) using ion exchange chromatography and reversed phase HPLC. The sequences were determined by automated Edman degradation, quantitative amino acid analysis, and mass spectrometry (MS). Using MS, it was established that vodo M (cyclo-SWPVCTRNGAPICGESCFTGKCYTVQCSC) and vodo N (cyclo-SWPVCYRNGLPVCGETCTLGKCYTAGCSC) form a head-to-tail cyclic backbone and that six cysteine residues are involved in three disulphide bonds. Their origin, sequences, and cyclic nature suggest that these peptides belong to the family of cyclic plant peptides, called cyclotides. The three-dimensional structures of vodo M and vodo N were modelled by homology, using the experimentally determined structure of the cyclotide kalata B1 as the template. The images of vodo M and vodo N show amphipathic structures with considerable surface hydrophobicity for a protein modelled in a polar environment.
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| 9. |
- Andersson, Derek, et al.
(författare)
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Myrosinases from root and leaves of Arabidopsis thaliana have different catalytic properties
- 2009
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Ingår i: Phytochemistry. - : Elsevier BV. - 0031-9422 .- 1873-3700. ; 70:11-12, s. 1345-1354
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Tidskriftsartikel (refereegranskat)abstract
- Myrosinases (EC 3.2.1.147) are beta-thioglucoside glucosidases present in Brassicaceae plants. These enzymes serve to protect plants against pathogens and insect pests by initiating breakdown of the secondary metabolites glucosinolates into toxic products. Several forms of myrosinases are present in plants but the properties and role of different isoenzymes are not well understood. The dicot plant model organism Arabidopsis thaliana seems to contain six myrosinase genes (TGG1-TGG6). In order to compare the different myrosinases, cDNAs corresponding to TGG1 from leaves and TGG4 and TGG5 from roots were cloned and overexpressed in Pichia pastoris. The His-tagged recombinant proteins were purified using affinity chromatography and the preparations were homogenous according to SDS-PAGE analysis. Myrosinase activity was confirmed for all forms and compared with respect to catalytic activity towards the allyl-glucosinolate sinigrin. There was a 22-fold difference in basal activity among the myrosinases. The enzymes were active in a broad pH range, are rather thermostable and active in a wide range of salt concentrations but sensitive to high salt concentrations. The myrosinases showed different activation-inhibition responses towards ascorbic acid with maximal activity around 0.7-1 mM. No activity was registered towards desulphosinigrin and this compound did not inhibit myrosinase activity towards sinigrin. All myrosinases also displayed O-beta-glucosidase activity, although with lower efficiency compared to the myrosinase activity. The differences in catalytic properties among myrosinase isozymes for function in planta are discussed.
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| 10. |
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