Search PubMed⌕ Search

Biomedical subjects

J A Duke

Publications and source records attributed to J A Duke.

14 recordsLinked to original sources
PubMed1992

Common purslane: a source of omega-3 fatty acids and antioxidants.

omega-3 fatty acids, alpha-tocopherol, ascorbic acid, beta-carotene and glutathione determined in leaves of purslane (Portulaca oleracea), grown in both a controlled growth chamber and in the wild, were compared in composition to spinach. Leaves from both samples of purslane contained higher amounts of alpha-linolenic acid (18:3w3) than did leaves of spinach. Chamber-grown purslane contained the highest amount of 18:3w3. Samples from the two kinds of purslane contained higher leaves of alpha-tocopherol, ascorbic acid and glutathione than did spinach. Chamber-grown purslane was richer in all three and the amount of alpha-tocopherol was seven times higher than that found in spinach, whereas spinach was slightly higher in beta-carotene. One hundred grams of fresh purslane leaves (one serving) contain about 300-400 mg of 18:3w3; 12.2 mg of alpha-tocopherol; 26.6 mg of ascorbic acid; 1.9 mg of beta-carotene; and 14.8 mg of glutathione. We confirm that purslane is a nutritious food rich in omega-3 fatty acids and antioxidants.

Antioxidants↗
PubMed1985

Medicinal plants.

Explore the source record for details and available documents.

Medicine, Traditional↗
PubMed1983

The process in which nucleotide is buried into the active site of heavy meromyosin.

The process in which nucleotide is buried into the active site of heavy meromyosin was studied with stopped-flow apparatus by monitoring the time-course of the large fluorescence increase of 1,N6-ethenoadenosine triphosphate (epsilon-ATP) when it binds from acrylamide-containing solutions. We have recently reported that free epsilon-ATP fluorescence is effectively quenched by acrylamide while bound epsilon-ATP is resistant to quenching by acrylamide. In the present study it was found that in the first step the phosphate moiety binds at a high rate, while the adenine moiety is still on the rim of the active site; the adenine moiety is then pulled into a crevice, and finally epsilon-ATP hydrolysis occurs.

Adenosine Triphosphatases↗
PubMedDate not supplied

Antineoplastic agents, 162. Zephyranthes candida.

The Chinese medicinal plant Zephyranthes candida was found to contain a cytostatic constituent. Separation of a n-BuOH extract directed by results of a bioassay employing the P-388 lymphocytic leukemia led to trans-dihydronarciclasine [2] as the principal cytostatic agent with ED50 3.2 X 10(-3) micrograms/ml.

Alkaloids↗
PubMedDate not supplied

Effects of maturity and plant spacing on the morphine content of two varieties of Papaver somniferum L.

Two varieties of opium poppy were grown under irrigation for one season and their capsules analysed for morphine content by gas chromatography. Harvest of the capsules at 29-33 days after flowering (mature seed) gave 6.70 kg/ha morphine as compared to 5.36 kg/ha morphine in capsules harvested at 4-6 days after flowering. With constant row spacing (30 cm between double rows on ridges 102 cm apart), a plant spacing of 6 cm gave 20 per cent more morphine than either 12- or 18-cm spacing. There was no statistical difference in morphine content between a blue- and a white-seeded variety.

Arizona↗