Biomedical subjects

V Sultana

Publications and source records attributed to V Sultana.

6 recordsLinked to original sources

PubMed2000

Caulerpin.

The crystal structure of caulerpin (dimethyl 6,13-dihydrodibenzo[b,i]phenazine-5,12-dicarboxylate, C(24)H(18)N(2)O(4)), an indole alkaloid, reported in space group Cc with an acute beta angle, has been redetermined in the correct space group, C2/c. The molecule has twofold crystallographic symmetry and is composed of two essentially planar indole groups fused to an eight-membered cyclooctatetraene ring which adopts a boat conformation. The molecular dimensions are normal. The structure is stabilized by intermolecular and intramolecular interactions involving the indole N-H atom and carbonyl O atom [N.O 3.211 (4) and 2.836 (4) A].

Journal Article↗

PubMed1999

Cytotoxic activity of marine macro-algae on Artemia salina (brine shrimp).

A total of 22 ethanol extracts of seaweed species (13 brown, 6 green and 3 red) collected from the Karachi coast were investigated for brine shrimp cytotoxicity. Of all the species, only six namely Stoechospermum marginatum, Sargassum swartzii, S. binderi, Spatoglossum asperum, Stokeyia indica (brown) and Caulerpa racemosa (green) showed significant activity. n-Hexane-soluble fractions of the ethanol extract of S. marginatum and S. swartzii were found to be responsible for the activity, whereas the methanol-soluble fractions of S. asperum and S. binderi were most active. The water extract of S. indica and C. racemosa exhibited the most prominent activity (LC50 value below 70 micrograms/mL) when compared with the ethanol extracts and their fractions. Cytotoxic activity may be due to the compounds differing in polarity.

Animals↗

PubMed1995

Pharmacokinetics and bioavailability of a sustained-release diltiazem formulation (Mono-Tildiem LP 300 MG) after repeated administration in healthy volunteers.

The usual dosage regimen of diltiazem (Tildiem) is 60 mg 3-4 times a day. A sustained-release formulation has been developed (Mono-Tildiem LP 300 mg) in order to allow a single daily administration. Two repeated dosing studies were performed in healthy volunteers. The absolute bioavailability of sustained-release diltiazem LP 300 mg was investigated using concomitant i.v. administration of 13C-labelled drug: absolute bioavailability of the "once a day" formulation was 35%. The second study compared sustained-release diltiazem LP 300 mg with the standard formulation of diltiazem. The results showed that the diltiazem plasma concentrations obtained after the LP formulation remained stable between 2 and 14 h after administration and were compatible with a once a day administration. Relative bioavailability of sustained-release diltiazem LP 300 mg was 79.3% compared with diltiazem. Therefore, a unitary dose of sustained-release diltiazem LP 300 mg was chosen as the dose equivalent to the daily dose administered with the standard diltiazem formulation.

Administration, Oral↗

PubMed1992

Socially available heroin powders--their chemical compositions and reproductive and behavioural effects on female rats.

Morphine is one of such substances which produce very intense euphoria and a prolonged period of relaxation and sedation. These opioids are known to cause modifications in neuroendocrine system during different stages of life, ranging from fetal through postnatal to adult. Heroin, an opioid, is a derivative of morphine and its long-term use, both in males and females, is associated with alterations in sexual behaviour and changes in endocrine functions. In females, hormonal imbalance thus resulted, can lead to amenorrhea and in some cases infertility. In Pakistan, heroin is available mixed with different additives in a variety of forms. Two varieties (S1 and S2) procured from patients visiting Drug Rehabilitating Clinic in the Civil Hospital, Karachi, were analysed for their qualitative and quantitative properties.

Journal Article↗

PubMed1990

Triterpenoid Saponins from Primula denticulata.

Two triterpene glycosides denticin ( 1) and denticulatin ( 2) have been isolated from the whole plant of PRIMULA DENTICULATA Sm. and their structures were established by spectral and chemical studies as 3beta-{ O-beta- D-glucopyranosyl-(1-->4)-[ O-beta- D-xylopyranosyl-(1-->2)]- O-(beta- D-glucopyranosyl-(1-->4)-[ O-beta- D-glucopyranosyl-(1-->2)]-alpha- L-arabinopyranosyloxy}-16alpha-hydroxy-13beta, 28-epoxyolean-30-al and 3beta-{ O-beta- D-glucopyranosyl-(1-->2)- O-beta- D-glucopyranosyl-(1-->4)-[ O-beta- D-xylopyranosyl-(1-->2)]- O-beta- D-glucopyranosyl-(1-->4)-[ O-beta- D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyloxy}-16alpha-hydroxy-13beta,28-epoxyolean-30-al, respectively.

Journal Article↗

PubMedDate not supplied

Spermine alkaloids from Schweinfurthia papilionacea.

Two new macrocylic alkaloids, 11-epi-ephedradine A (11-epi-orantine) [1] and schweinine [2], were isolated from the whole plant of Schweinfurthia papilionacea, in addition to (-)-ephedradine A (orantine) [3]. Their structures were determined by spectroscopic means, and the stereochemistry has been assigned on the basis of 2D nmr techniques.

Alkaloids↗