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1.
Tree Physiol ; 34(4): 334-42, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24591287

RESUMO

Uptake of nitrogen (N) by sequential root regions in six tree species was measured in roots of 16- to 26-month-old seedlings at 50 and 1500 µM NH4NO3 concentration, at the cell level using oscillating microelectrodes and at the root region level using enriched (15)N application. Our objective was to determine the root regions making the greatest contribution to total N uptake in each species as measured by the two contrasting techniques. White and condensed tannin zones were the regions with the smallest surface area in all species, but these zones often had the highest net flux of NH4(+) and NO3(-). For most species, little variation was found among root regions in N flux calculated using a (15)N mass balance approach, but where significant differences existed, high N flux was observed in white, cork or woody zones. When N fluxes measured by each of the two methods were multiplied by the estimated surface area or biomass of each root region, the effect of root region size had the greatest influence on regional N uptake. Root regions of greatest overall N uptake were the cork and woody zones, on average. Total N uptake may thus be greatest in older regions of tree seedling roots, despite low rates of uptake per unit area.


Assuntos
Acer/metabolismo , Nitrogênio/metabolismo , Pinaceae/metabolismo , Thuja/metabolismo , Transporte Biológico , Biomassa , Nitratos/metabolismo , Isótopos de Nitrogênio/análise , Raízes de Plantas/metabolismo , Compostos de Amônio Quaternário/metabolismo , Plântula/metabolismo , Especificidade da Espécie , Árvores
2.
J Chromatogr Sci ; 50(8): 666-72, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22595260

RESUMO

This paper describes the determination of fatty acid composition of coffee, citrus and rum distillery wastes using reversed-phase high-performance liquid chromatography (RP-HPLC). Lipid extracts of the waste samples are derivatized with phenacyl bromide and their phenacyl esters are separated on a C8 reversed-phase column by using continuous gradient elution with water and acetonitrile. The presence of saturated and unsaturated fatty acids in quantifiable amounts in the examined wastes, as well as the high percentage recoveries, are clear indications that these wastes have potential value as inexpensive sources of lipids. The HPLC procedures described here could be adopted for further analysis of materials of this nature.


Assuntos
Acetofenonas/química , Agricultura , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Ácidos Graxos/análise , Resíduos Industriais/análise , Bebidas Alcoólicas , Citrus , Café , Jamaica
3.
West Indian Med J ; 59(3): 249-52, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21291101

RESUMO

OBJECTIVE: The sesquiterpene, mikanolide, was found to possess antibacterial activity. As a result, a structure-activity relationship study was carried out on mikanolide and eleven of its derivatives. METHODS: Mikanolide and two of its derivatives were isolated from organic extract of Mikania micrantha using chromatographic methods. Nine additional derivatives were synthesized and all were investigated for their antibacterial activity against the Gram positive pathogen Staphylococcus aureus and beta haemolytic Streptococcus group A (BHSA) as well as the Gram negative Escherichia coli using the disk diffusion assay. RESULTS: The investigation revealed that only four of the derivatives displayed antibacterial activity and only pathogens Staphylococcus aureus and beta haemolytic Streptococcus group A were susceptible at a concentration of 100 microg per disk. However there was an increase in activity for three of the derivatives in comparison to mikanolide. CONCLUSION: This study underscores the potential for phytochemicals from locally available plants to be further investigated and developed as antibacterial agents.


Assuntos
Lactonas/farmacologia , Sesquiterpenos de Germacrano/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Humanos , Staphylococcus aureus/efeitos dos fármacos , Streptococcus pyogenes/efeitos dos fármacos , Relação Estrutura-Atividade
4.
J Chromatogr Sci ; 47(8): 674-80, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19772744

RESUMO

Jamaican agro-industries generate large quantities of wastes, which are either discarded or under-utilized. In order to evaluate the possible utilization of these wastes, it is necessary that the profiles of the major biochemical groups be developed. This paper describes the determination of the amino acid composition of coffee, citrus, and rum distillery wastes using a reversed-phase high-performance liquid chromatography method. Acid hydrolysates of the wastes are derivatized with phenylisothiocyanate. They are analyzed as their phenylthiocarbamyl derivatives and determined quantitatively using norleucine as the internal standard. The presence of all the 17 amino acids investigated, nine of which include those essential for animal nutrition, are observed in the samples investigated, suggesting a high quality of protein with implications in the formulation of animal feeds.


Assuntos
Agricultura , Aminoácidos/análise , Aminoácidos/química , Cromatografia Líquida de Alta Pressão/métodos , Resíduos Industriais/análise , Isotiocianatos/química , Jamaica
5.
West Indian Med J ; 56(1): 5-10, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17621837

RESUMO

Epingaione (4-Methyl-1-(5-methyl-2, 3,4,5-tetrahydro-[2,3']bifuranyl-5-yl)-pentan-2-one) was isolated as one of the major lipophilic secondary metabolites from the leaves and stems of Bontia daphnoides L. The compound gave 79.24% and 50.83% anti-proliferation/cytotoxic activity on the human SH-SY5Y neuroblastoma and TE-671 sarcoma cells in vitro at 50 pg/mL, respectively. Epingaione was transformed into eleven derivatives under laboratory conditions using ethanol, some gave greater anti-proliferation/cytotoxic activity on the cancer cell lines tested. One of the derivatives (compound 2) with enhanced cytotoxic activity was elucidated as 5'-Ethoxy-5-methyl-5-(4-methyl-2-oxo-pentyl)-2,3,4,5-tetrahydro-5'H-[2,3']bifuranyl-2'-one. Both epingaione and compound 2 caused an accumulation of arrested or dead SH-SY5Y neuroblastoma in the m-phase of the cell cycle as revealed by the m-phase specific marker KE 67.


Assuntos
Furanos/farmacologia , Myoporaceae , Neuroblastoma/tratamento farmacológico , Pentanonas/farmacologia , Fitoterapia , Sarcoma/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Ensaios de Seleção de Medicamentos Antitumorais , Furanos/química , Humanos , Pentanonas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta , Caules de Planta
6.
West Indian Med J ; 56(1): 22-5, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17621840

RESUMO

OBJECTIVE: Bacterial infection with organisms resistant to antibiotics have increased during the last few decades worldwide. Because of this increase, the authors decided to subject the essential oils from the stem, leaves and fruits of the four native Jamaica species of Bursera to microbial studies. METHODS: Steam distillate extracts from different parts of four native Jamaican spp of Bursera simaruba (Red Birch), Bursera lunanii (Black Birch), Bursera hollickii and Bursera aromatica (Siboney) were tested for their antibacterial activity against six common pathogens: Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylocococcus aureus, methicillin resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A (BHSA) using a disk diffusion assay. RESULTS: The investigation revealed that extracts from two of the four plants tested were active against all the pathogens. These were extracts from the fruits and stems of B. simaruba and those from the fruit of B. lunanii. CONCLUSION: This study gives credence to the ongoing search for locally available plants whose extracts possess significant antimicrobial activity. This may be useful in the development of naturally derived pharmaceuticals.


Assuntos
Infecções Bacterianas/tratamento farmacológico , Bursera , Fitoterapia , Extratos Vegetais , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Frutas , Humanos , Caules de Planta
7.
West Indian med. j ; 56(1): 22-25, Jan. 2007.
Artigo em Inglês | LILACS | ID: lil-471842

RESUMO

OBJECTIVE: Bacterial infection with organisms resistant to antibiotics have increased during the last few decades worldwide. Because of this increase, the authors decided to subject the essential oils from the stem, leaves and fruits of the four native Jamaica species of Bursera to microbial studies. METHODS: Steam distillate extracts from different parts of four native Jamaican spp of Bursera simaruba (Red Birch), Bursera lunanii (Black Birch), Bursera hollickii and Bursera aromatica (Siboney) were tested for their antibacterial activity against six common pathogens: Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylocococcus aureus, methicillin resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A (BHSA) using a disk diffusion assay. RESULTS: The investigation revealed that extracts from two of the four plants tested were active against all the pathogens. These were extracts from the fruits and stems of B. simaruba and those from the fruit of B. lunanii. CONCLUSION: This study gives credence to the ongoing search for locally available plants whose extracts possess significant antimicrobial activity. This may be useful in the development of naturally derived pharmaceuticals.


Assuntos
Humanos , Bursera , Infecções Bacterianas/tratamento farmacológico , Fitoterapia , Extratos Vegetais , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Frutas , Caules de Planta
8.
West Indian med. j ; 56(1): 5-10, Jan. 2007.
Artigo em Inglês | LILACS | ID: lil-471845

RESUMO

Epingaione (4-Methyl-1-(5-methyl-2, 3,4,5-tetrahydro-[2,3']bifuranyl-5-yl)-pentan-2-one) was isolated as one of the major lipophilic secondary metabolites from the leaves and stems of Bontia daphnoides L. The compound gave 79.24and 50.83anti-proliferation/cytotoxic activity on the human SH-SY5Y neuroblastoma and TE-671 sarcoma cells in vitro at 50 pg/mL, respectively. Epingaione was transformed into eleven derivatives under laboratory conditions using ethanol, some gave greater anti-proliferation/cytotoxic activity on the cancer cell lines tested. One of the derivatives (compound 2) with enhanced cytotoxic activity was elucidated as 5'-Ethoxy-5-methyl-5-(4-methyl-2-oxo-pentyl)-2,3,4,5-tetrahydro-5'H-[2,3']bifuranyl-2'-one. Both epingaione and compound 2 caused an accumulation of arrested or dead SH-SY5Y neuroblastoma in the m-phase of the cell cycle as revealed by the m-phase specific marker KE 67.


Assuntos
Humanos , Furanos/farmacologia , Myoporaceae , Neuroblastoma/tratamento farmacológico , Fitoterapia , Pentanonas/farmacologia , Sarcoma/tratamento farmacológico , Linhagem Celular Tumoral , Sobrevivência Celular , Ensaios de Seleção de Medicamentos Antitumorais , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Furanos/química , Folhas de Planta , Caules de Planta , Pentanonas/química , Proliferação de Células/efeitos dos fármacos
9.
Steroids ; 64(11): 770-9, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10577834

RESUMO

The fungi Exophiala jeanselmei var. lecanii-corni [IMI (International Mycological Institute) 312989, UAMH (University of Alberta Microfungus Collection and Herbarium) 8783] and Ceratocystis paradoxa (IMI 374529, UAMH 8784) have been examined for their potential in steroid biotransformation. The study has determined that E. jeanselmei var. lecanii-corni effected overall anti-Markovnikov hydration on dehydroisoandrosterone, and side-chain degradation on a variety of pregnanes. Both ascomycetes were found to carry out redox reactions of alcohols and ketones as well as 1,4 reduction of alpha,beta-unsaturated carbonyl systems.


Assuntos
Ascomicetos/metabolismo , Exophiala/metabolismo , Esteroides/metabolismo , Biotransformação , Análise Espectral , Esteroides/química
10.
J Pharm Pharmacol ; 51(12): 1455-60, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10678503

RESUMO

We have started a systematic scientific study of folklore medicinal plants currently used as alternative medicine in Jamaican society. In this initial study, extracts of plants widely used by the islanders are studied for antibacterial activity against five common pathogens; Streptococcus group A, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa and Escherichia coli. These studies revealed that 25% (approx.) of the plant extracts had antimicrobial activity against at least one of the microbes used. Subsequent to these observations, extracts from Mikania micrantha were examined in detail. This led to the isolation of two sesquiterpenoids, mikanolide and dihydromikanolide, with activity against S. aureus and C. albicans. The results suggest that traditional folk medicine could be used as a guide in our continuing search for new natural products with potential medicinal properties.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Antibacterianos/química , Bactérias/isolamento & purificação , Jamaica , Medicina Tradicional , Extratos Vegetais/química
11.
Community Eye Health ; 11(27): 44-5, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-17492041
12.
Phytochemistry ; 40(3): 735-8, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7576456

RESUMO

The novel assignment of 13C and 1H NMR data for cadina-4,10(15)-dien-3-one obtained from Hyptis verticillata is presented. The study revealed that cadina-4,10(15)-dien-3-one possesses chemosterilant activities against the economically important cattle tick, Boophilus microplus, and toxic action against adult Cylas formicarius the most destructive pest of sweet potato (I pomoea sp.).


Assuntos
Besouros , Inseticidas , Naftalenos/química , Carrapatos , Animais , Isótopos de Carbono , Bovinos , Feminino , Hidrogênio , Espectroscopia de Ressonância Magnética , Masculino , Estrutura Molecular , Naftalenos/isolamento & purificação , Naftalenos/toxicidade , Verduras
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