RA-dimer A, a novel dimeric antitumor bicyclic hexapeptide from Rubia cordifolia L.

RA-dimer A, a novel dimeric antitumor bicyclic hexapeptide from Rubia cordifolia L. Two antitumour bicyclic hexapeptides from Rubia cordifolia Studies on antitumor cyclic hexapeptides RA obtained from Rubiae Radix, Rubiaceae. VI Minor antitumor constituents. New antitumor bicyclic hexapeptides, RA-XI, -XII, -XIII and -XIV from Rubia cordifolia. Isolation, structural elucidation, and synthesis of RA-XVII, a novel bicyclic hexapeptide from Rubia cordifolia, and the effect of side chain at residue 1 upon the conformation and cytotoxic activity A novel bicyclic hexapeptide, RA-XVIII, from Rubia cordifolia: Structure, semi-synthesis, and cytotoxicity A novel bicyclic hexapeptide, RA-XVIII, from Rubia cordifolia: Structure, semi-synthesis, and cytotoxicity New Cytotoxic Bicyclic Hexapeptides, RA-XXIII and RA-XXIV, from Rubia cordifolia L. Structures of cytotoxic bicyclic hexapeptides, RA-XIX, -XX, -XXI, and -XXII, from Rubia cordifolia L. Isolation and antitumor activity of cyclic hexapeptides isolated from Rubiae radix.