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1.
Planta Med ; 65(3): 250-4, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10232071

ABSTRACT

The activity of an ethanolic extract of Galipea officinalis bark against Mycobacterium tuberculosis was shown to reside mainly in the basic alkaloidal fraction although the major part of the alkaloids present were in the neutral fraction. Six alkaloids were isolated from the bark including two other alkaloids not previously reported from G. officinalis and a new quinoline named allocuspareine, whose structure was determined by spectroscopic methods. 1H- and 13C-NMR spectral data for three of these compounds are reported for the first time. Isolation and testing of fractions and individual alkaloids against ten strains of M. tuberculosis showed that all the alkaloids possessed some activity but that the unidentified most polar basic fraction exhibited the greatest effect.


Subject(s)
Alkaloids/pharmacology , Antitubercular Agents/pharmacology , Mycobacterium tuberculosis/drug effects , Trees/chemistry , Alkaloids/chemistry , Circular Dichroism , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Mycobacterium tuberculosis/growth & development
2.
J Pharm Biomed Anal ; 15(6): 839-43, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9172110

ABSTRACT

High-performance liquid chromatographic (HPLC) and densitometry procedures were developed to determine the principal alkaloids in the roots of C. thalictroides. In both techniques the alkaloids content was assessed using cytisine as an internal standard. The purity and identity of the peaks of the alkaloids was examined by diode array detection and by comparison with the standards. The content of individual alkaloids was found to be in the range 0.02-1.1% w/w.


Subject(s)
Alkaloids/analysis , Apomorphine/analysis , Azocines , Chromatography, High Pressure Liquid , Densitometry , Aporphines/analysis , Chromatography, Thin Layer , Molecular Structure , Pyridines , Quinolizines , Reproducibility of Results , Time Factors
3.
Planta Med ; 61(2): 154-7, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7753923

ABSTRACT

The 13C-NMR spectra of seven chromone alkaloids isolated from Schumanniophyton magnificum have been obtained. Assignment of signals was carried out with the help of heteronuclear coupling experiments and other correlation techniques on the alkaloids and their acyl derivatives. On the basis of the signals observed the structures of the piperidino-alkaloid schumannificine and its N-methyl and anhydro analogues have been revised to that of a piperidone ring linked to the noreugenin via a carbon-carbon bond and a lactol bridge.


Subject(s)
Alkaloids/chemistry , Chromones/chemistry , Piperidines/chemistry , Magnetic Resonance Spectroscopy , Mass Spectrometry/methods , Molecular Structure , Plants/chemistry
4.
Antiviral Res ; 25(3-4): 235-44, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7535992

ABSTRACT

The activity against human immunodeficiency virus (HIV) and herpes simplex virus (HSV), of the non-polar fraction of a methanolic extract of the rootbark of Schumanniophyton magnificum was found to be present in a fraction containing the chromone secondary amine schumannificine 1. Other chromone alkaloids present in the plant were isolated and tested for inhibition of HIV and HSV infections in C8166 and Vero cells, respectively. Acyl and methyl derivatives were prepared and tested. Of all the compounds tested, schumannificine 1 displayed the greatest activity against HIV, whereas potent anti-HSV activity was observed for a number of its derivatives. The presence of a piperidine ring and unsubstituted hydroxy groups on the molecules seems to favour the anti-HIV activity. The anti-HIV activity is considered to be due to irreversible binding to gp120 rather than inhibition of reverse transcriptase or protease.


Subject(s)
Alkaloids/pharmacology , Antiviral Agents/pharmacology , Chromones/pharmacology , Alkaloids/isolation & purification , Animals , Antiviral Agents/isolation & purification , Chlorocebus aethiops , Chromones/chemistry , Chromones/isolation & purification , HIV Envelope Protein gp120 , HIV Protease , HIV Reverse Transcriptase , HIV-1/drug effects , Herpesvirus 1, Human/drug effects , Humans , Plants/chemistry , Pyrones/chemistry , Pyrones/pharmacology , RNA-Directed DNA Polymerase/drug effects , Structure-Activity Relationship , Vero Cells
5.
J Pharm Biomed Anal ; 10(8): 555-60, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1463789

ABSTRACT

The kosins are phloroglucinol derivatives isolated from female flowers of Hagenia abyssinica (Rosaceae) and were tested for possible cytotoxic activity in vitro and in vivo against a panel of three transplantable murine adenocarcinomas of the colon of varying growth characteristics and morphology (MAC system). Significant reductions in colony formation were observed in vitro in MAC 15A tumour following 1, 3, 6 and 24 h exposure to all kosins (alpha-kosin, kosotoxin and protokosin). The kosins (kosotoxin and protokosin) were also found to be cytotoxic against MAC tumour cells in vivo in some cases. Kosotoxin was subjected to preliminary toxicity studies in mice. It showed no observable toxicity up to 200 mg kg-1 orally and was found to be toxic at doses in excess of 50 mg kg-1 (i.p.). A single dose of 100 mg kg-1 (i.p.) was lethal for 100% of the animals.


Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Neoplasms, Experimental/drug therapy , Phloroglucinol/analogs & derivatives , Administration, Oral , Animals , Antineoplastic Agents, Phytogenic/toxicity , Liver/drug effects , Liver/metabolism , Male , Mice , Phloroglucinol/therapeutic use , Phloroglucinol/toxicity , Rats , Tumor Cells, Cultured , Tumor Stem Cell Assay
6.
J Pharm Biomed Anal ; 8(8-12): 859-65, 1990.
Article in English | MEDLINE | ID: mdl-2100633

ABSTRACT

The phenolic constituents of male and female flowers of Hagenia abyssinica were examined using chromatographic and spectroscopic techniques. Chromatographic analysis of kosins (phloroglucinols) was carried out using TLC, reversed-phase LC and glass-capillary GLC. Purification of the crude kosins was effected by silica gel column chromatography and purification of phenolic acids using ion-exchange resins and preparative TLC on silica gel. The kosins were characterized by TLC, LC, UV, IR, MS and H1 NMR spectroscopy while the phenolic acids were characterized by UV-spectroscopy, TLC and LC. The phenolic acids found were protocatechuic acid, p-hydroxybenzoic acid and vanillic acid. The content of the kosins and phenolic acids was established quantitatively for both male and female flowers.


Subject(s)
Plants, Medicinal/analysis , Africa, Eastern , Chromatography, Gas , Chromatography, Ion Exchange , Chromatography, Thin Layer , Indicators and Reagents , Magnetic Resonance Spectroscopy , Phenols/analysis , Phloroglucinol/analogs & derivatives , Phloroglucinol/analysis , Reference Standards , Solvents , Spectrophotometry, Infrared , Spectrophotometry, Ultraviolet
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