Fatty acid composition of three species of Hypnea (Gigartinales, Rhodophyta) from Karachi coast

Hypnea musciformis (Wulf.) Lamour., H. pannosa J. Ag. and H. valentiae (Turn.) Mont., collected from the northern Arabian Sea coast of Pakistan, have been investigated for their fatty acid compositions through GC-MS. Palmitic acid was present in largest quantity (55-57%) and oleic was the major (7.6-8.4%) unsaturated fatty acid. Pentacosanoic and hexacosenoic acids are being reported for the first time from any species of Hypnea. The three species differed remarkably due to their habitat ecology

Acyclic diterpene alcohols isolated from four algae of Bryopsidophyceae and their toxicity

Three new acylic diterpenoids belonging to the class of phytol series have been isolated. They were obtained from the ethyl acetate soluble fractions of four siphonaceous green seaweeds, Bryopsis pennata Lamour., Caulerpa taxifolia (Vahl) C. Ag., Codium decorticatum (Woodw.) Howe and Valoniopsis pachynema (Mart.) Børg., collected from Karachi coast of Pakistan. Structures of these compounds were elucidated with the help of spectroscopic methods and confirmed by comparison with the known compounds. Even the known compounds are being reported for the first time from a green algal source. All the compounds were found to display a strong toxicity at all the three concentrations tested in the brine shrimp bioassay

Antihypertensive, antidyslipidemic and endothelial modulating activities of Orchis mascula

The objective of this study was to investigate the possible mode(s) of action for the medicinal use of Orchis mascula (OM) (family Orchidaceae) in hypertension and dyslipidemia. In spontaneously hypertensive rats (SHRs), OM significantly (

Kinetics of thermal degradation of betamethasone valerate and betamethasone dipropionate in different media

The effect of pH, media, phosphate concentration and ionic strength on the kinetics of thermal degradation of betamethasone valerate and betamethasone dipropionate has been investigated. A validated HPLC method has been used to determine the parent compounds and their major thermal degradation products identified in the reaction. Betamethasone-17-valerate gave rise to two major products, namely, betamethasone-21-valerate and betamethasone alcohol, and betamethasone dipropionate degraded into three major products, namely, betamethasone-17-propionate, betamethasone-21-propionate and betamethasone alcohol, in different media. Betamethasone valerate showed maximum stability at pH 4-5 while betamethasone dipropionate was maximally stable at pH 3.5-4.5. The degradation of betamethasone valerate and betamethasone dipropionate was found to follow first-order kinetics and the apparent first-order rate constants (kobs ) for thermal degradation in different media range from 0.399-9.07×10 -3 h -1 and 0.239-1.87×10 -3 h -1 , respectively. The values of the rate constants decrease with increasing solvent polarity, phosphate concentration and ionic strength. The second-order rate constants ( k΄) for the phosphate ion inhibited reactions lie in the range of 3.02-1.30×10 -6 M -1 s -1

Pharmacological Basis for the Medicinal Use of Black Pepper and Piperine in Gastrointestinal Disorders

Dried fruits of Piper nigrum (black pepper) are commonly used in gastrointestinal disorders. The aim of this study was to rationalize the medicinal use of pepper and its principal alkaloid, piperine, in constipation and diarrhea using in vitro and in vivo assays. When tested in isolated guinea pig ileum, the crude extract of pepper (Pn.Cr) (1-10 mg/mL) and piperine (3-300 mu M) caused a concentration-dependent and atropine-sensitive stimulant effect. In rabbit jejunum, Pn.Cr (0.01-3.0 mg/mL) and piperine (30-1,000 mu M) relaxed spontaneous contractions, similar to loperamide and nifedipine. The relaxant effect of Pn.Cr and piperine was partially inhibited in the presence of naloxone (1 mu M) similar to that of loperamide, suggesting the naloxone-sensitive effect in addition to the Ca(2+) channel blocking (CCB)-like activity, which was evident by its relaxant effect on K(+) (80mM)-induced contractions. The CCB activity was confirmed when pretreatment of the tissue with Pn.Cr (0.03-0.3 mg/mL) or piperine (10-100 mu M) caused a rightward shift in the concentration-response curves of Ca(2+), similar to loperamide and nifedipine. In mice, Pn.Cr and piperine exhibited a partially atropine-sensitive laxative effect at lower doses, whereas at higher doses it caused antisecretory and antidiarrheal activities that were partially inhibited in mice pretreated with naloxone (1.5 mg/kg), similar to loperamide. This study illustrates the presence of spasmodic (cholinergic) and antispasmodic (opioid agonist and Ca(2+) antagonist) effects, thus providing the possible explanation for the medicinal use of pepper and piperine in gastrointestinal motility disorders