[Calcification of the aortic valve and bone metabolism in the elderly].
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Aged↗
Biomedical subjects
M A Rashid
Publications and source records attributed to M A Rashid.
A new structural alternative in benzo[b]furans for antimicrobial activity.
Two series of 2-substituted and three new diacetyl benzofurans were synthesized through palladium-catalyzed reactions and their in vitro antimicrobial spectra were assessed. The compounds demonstrated mild to significant growth inhibition against antibiotic-susceptible standard and clinically isolated strains of Gram-positive and Gram-negative bacteria as well as human fungal pathogens. Ampicillin and kanamycin were used as references for antibacterial screening; nystatin and amphotericin B were used for antifungal screening. Varying substitution at the benzofuran moiety and subsequent antimicrobial screening identified the C-3-acetyl functionality as a new structural alternative for optimal antimicrobial property in the benzofuran class of compounds.
Anti-Bacterial Agents↗
Neolignan and megastigmane glycosides from the leaves of Pterospermum semisagittatum.
Three compounds namely, (7S,8R)-dihydrodehydrodiconiferyl alcohol-9'-O-beta-D-glucopyranoside (1), 10-hydroxy-4,7-megastigmadien-3-one-9-O-beta-D-glucopyranoside (2) and 9-hydroxy-4,7-megastigmadien-3-one-10-O-beta-D-glucopyranoside (3) were isolated from the methanol extract of Pterospermum semisagittatum. The structures of these compounds were elucidated by spectroscopic methods. While glycosides 2 and 3 appear to be new, this is the third report of isolation of compound 1 from any natural source.
Cyclohexanones↗
Analgesic, antiinflammatory and CNS depressant activities of sesquiterpenes and a flavonoid glycoside from Polygonum viscosum.
Analgesic, antiinflammatory and CNS depressant activities of four sesquiterpenes, viscosumic acid, viscozulenic acid, viscoazucine and viscoazulone, and a flavonoid glycoside, quercetin-3-O-(6''-feruloyl)-beta-D-galactopyranoside isolated form the aerial parts of Polygonum viscosum (Polygonaceae) have been assessed. All test compounds exhibited CNS depressant activity in open field test, all but viscoazulone showed analgesic activity in Eddy's hot plate test, all sesquiterpenes inhibited acetic acid induced abdominal writhing in mice, and all but viscoazucine and the flavonoid glycoside exhibited mild to moderate antiinflammatory effect on carrageenan induced rat paw edema.
Acetic Acid↗
Cytotoxicity and antibacterial activity of extractives from Wedelia calendulacea.
The cytotoxicity and antibacterial activity of petroleum ether, chloroform and methanol extracts of Wedelia calendulacea were assayed by brine shrimp lethality bioassay and standardized disk diffusion method against 19 bacterial strains. Three diterpenes isolated from the plant were also evaluated for in vitro antibacterial activities. The LC50 for the crude extracts against the brine shrimp nauplii were found to be 4.59 microg/ml, 7.99 microg/ml and 14.88 microg/ml, respectively, whereas the positive control, vincristine sulfate showed an LC50 of 0.58 microg/ml. Among the crude extracts and pure compounds tested, (-)-kaur-16-en-19-oic acid isolated from the chloroform extract showed the highest inhibitory activity against most of the bacterial strains with mean zone of inhibition of 10-21 mm at 200 microg/disc.
Animals↗
Antibacterial activity and cytotoxicity of extractives from Ravenia spectabilis.
A methanolic extract of Ravenia spectabilis, an isolated alkaloid, arborinine plus a fraction comprising arborinine and gamma-fagarine (VLC), showed mild to significant in vitro antibacterial activity. In a brine shrimp lethality bioassay, the extract and the fraction were found to exhibit moderate cytotoxicity having LC50 of 76.26 microg/ml and 14.98 microg/ml, respectively.
Animals↗
Triterpene constituents from the leaves of Melicope indica.
Phytochemical investigation of a petroleum ether extract of Melicope indica afforded two unusual pentacyclic triterpenes viz. neohop-13(18)-en-3alpha-ol (1) and fern-8(9)-en-3beta-ol (2) and the ubiquitous steroids, stigmasterol and sitosterol. The structures of 1 and 2 were independently elucidated on the basis of 2D NMR data and confirmed by comparison with those of related compounds. While compound 1 is a new natural product, this is the first report of occurrence of fern-8(9)-en-3beta-ol (2) from the genus Melicope.
Magnetic Resonance Spectroscopy↗
Antibacterial activity and cytotoxicity of extractives from Uvaria hamiltonii stem bark.
The extracts as well as piperolactum C, goniopedaline, 6beta-hydroxystigmasta-4,22-dien-3-one and a mixture of cis- and trans-4-hydroxymelleins obtained from Uvaria hamiltonii stem bark exhibited mild to moderate in vitro antibacterial activity. The results obtained were compared with a standard antibiotic, kanamycin. In a brine shrimp lethality bioassay the pet-ether, dichloromethane, methanol extracts and a major alkaloid, piperolactum C were found to exhibit mild to moderate cytotoxicity.
Animals↗
Antimicrobial and cytotoxic constituents of Loranthus globosus.
(+)-Catechin, 3,4-dimethoxycinnamyl alcohol and 3,4,5-trimethoxycinnamyl alcohol were isolated from the barks of Loranthus globosus. All compounds showed significant antimicrobial and cytotoxic activities.
Animals↗
Lunamarin C, a new terpenoid coumarin from Clausena heptaphylla.
The petroleum ether extract of the leaves of Clausena heptaphylla afforded a new coumarin, lunamarin C (1). Its structure was determined by extensive analysis of spectral data, including 2D NMR and by comparison with structurally related compounds, lunamarins A (2) and B (3).
Coumarins↗
Dammarane derivatives from the dried fruits of Forsythia suspensa.
Anti-inflammatory activity guided fractionation of the n-hexane soluble fraction of a 70% aqueous methanolic extract of the dried fruits of Forsythia suspensa afforded two new triterpenes. The structures of these compounds were elucidated as 3beta-acetyl-20,25-epoxydammarane-24alpha-ol (1) and 3beta-acetyl-20,25-epoxydammarane-24beta-ol (2) on the basis of spectral data interpretation as well as by comparison with those of structurally similar compounds.
Fruit↗
Antibacterial activity of Barringtonia racemosa.
The antibacterial activity of the ethanol extract of Barringtonia racemosa roots, its chloroform soluble fraction and, a there from an isolated clerodane diterpenoid is reported.
Anti-Bacterial Agents↗
Antibacterial activity of Clausena heptaphylla.
The antibacterial activity of different crude extracts of Clausena heptaphylla leaves as well as three purified coumarins, obtained from the cold methanol extract, is reported.
Anti-Bacterial Agents↗
Antibacterial activity of Vitex trifolia.
The petroleum ether and ethanol extracts of Vitex trifolia leaves exhibited moderate inhibiting activity against both gram-positive and gram-negative bacteria.
Anti-Bacterial Agents↗
Microspinosamide, a new HIV-inhibitory cyclic depsipeptide from the marine sponge Sidonops microspinosa.
Microspinosamide (1), a new cyclic depsipeptide incorporating 13 amino acid residues, was isolated from extracts of an Indonesian collection of the marine sponge Sidonops microspinosa. Its structure was elucidated by extensive NMR and mass spectral analyses, and by chemical degradation and derivatization studies. The tridecapeptide 1 incorporates numerous uncommon amino acids, and it is the first naturally occurring peptide to contain a beta-hydroxy-p-bromophenylalanine residue. Microspinosamide (1) inhibited the cytopathic effect of HIV-1 infection in an XTT-based in vitro assay with an EC(50) value of approximately 0.2 microg/mL.
Animals↗
Chondropsin D, a new 37-membered-ring macrolide lactam from the marine sponge Chondropsis species.
Chondropsin D (2), a new 37-membered-ring macrolide lactam, was isolated as a minor constituent of an aqueous extract of the marine sponge Chondropsis sp. This sponge sample had previously been the source of chondropsins A (1) and B, two novel polyketide-derived macrolides with potent cytotoxic activity. The structure of 2 was initially deduced from analysis of spectral data. This assignment was supported by the observation that chondropsin A (1), which contains a 35-membered macrocyclic ring, could be converted to chondropsin D (2) by a base-catalyzed intramolecular transesterification reaction. Rearrangement of the methylated derivative of chondropsin A (3) to the corresponding methylated analogue of chondropsin D (4) confirmed the structure of 2.
Animals↗
A new isoquinoline alkaloid from the marine sponge Haliclona species.
Two isoquinoline alkaloids, including the new compound 1, were isolated from the cytotoxic fractions of an aqueous extract of the marine sponge Haliclona sp. The structures of these compounds were established as 1-hydroxymethyl-7-methoxyisoquinolin-6-ol (1) and mimosamycin (2) by conventional spectroscopic methods and by comparison with related compounds. Mimosamycin (2) was the principal cytotoxin with an IC(50) of approximately 10 microg/mL against melanoma and ovarian human tumor cell lines.
Alkaloids↗
New cytotoxic N-methylated beta-carboline alkaloids from the marine ascidian Eudistoma gilboverde.
Bioassay-guided fractionation of an extract of the marine ascidian Eudistoma gilboverde provided three new beta-carboline alkaloids identified as 2-methyleudistomin D (1), 2-methyleudistomin J (2), and 14-methyleudistomidin C (3). Six known metabolites, eudistomins C, D (4), E, J (5), K, and L, were also isolated and characterized. The structures of the new metabolites were elucidated by spectroscopic analyses and by comparison of their spectral data with related literature values. Of the three new compounds, 14-methyleudistomidin C (3) exhibited the most potent cytotoxic activity with IC(50)'s of < 1.0 microg/mL against four different human tumor cell lines.
Alkaloids↗