A new bioactive proline-rich cyclohexapeptide - diandrine C (6), previously isolated from whole plant of Drymaria diandra (Caryophyllaceae), was synthesized through coupling reactions of tetrapeptide unit Boc-Gly-l-Pro-l-Tyr-l-Trp-OH with dipeptide unit l-Pro-Gly-OMe using N,N-diisopropylcarbodiimide (DIPC) as the coupling agent, followed by cyclization of l...

2 S. Ochoa and L. A. Heppel, in The Chemical Basis of Heredity, ed. W. McElroy and B. Glass (Baltimore, 1957), p. 615. 3A. Rich and D. R. Davies, J. Am. Chem. Soc., 78, 3548, 1956. 4G. Felsenfeld, D. R. Davies, and A. Rich, J. Am. Chem. Soc., 79, 2023, 1957. 6 A. Rich, Nature, 181, 521, 1958. 6 J. J. Fox, N. Yung, J. Davoll, and G. B. Brown, J. Am. Chem. Soc., 78, 2117, 1956. 7B. E. Griffin and...

The use of small angle neutron scattering, SANS, neutron reflectivity, NR, and surface tension to study the mixing properties of the biosurfactant rhamnolipid with a conventional anionic surfactant, sodium dodecyl 6-benzene sulfonate, LAS, is reported. The monorhamnose rhamnolipid, R1, mixes close to ideally with LAS at the air-water interface, whereas for mixtures of LAS with the dirhamnose rh...

Obesity is a major global health issue. High-protein diets have been shown to be associated with weight loss and satiety. The precise mechanism by which protein-rich diets promote weight loss remains unclear. Evidence suggests amino acids, formed as a consequence of protein digestion, are sensed by specific receptors on L-cells in the gastrointestinal (GI) tract. These L-cells respond by secret...

Clinical trials in patients with Parkinson’s disease have shown that transplants of fetal mesencephalic dopamine neurons can form a new functional innervation of the host striatum, but the clinical benefits have been highly variable: some patients have shown substantial recovery in motor function, whereas others have shown no improvement and even a worsening in the 3,4-dihydroxyphenyl-L-alanine...