Farmer et al., "Dissociation of antimicrobial and hemolytic activities in cyclic peptide diastereomers
by systematic alterations in amphipathicity," Journal of Biological Chemistry, vol.
Knaus, "Syntheses, calcium channel agonist-antagonist modulation activities, and nitric oxide release studies of nitrooxyalkyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(2,1,3-benzoxadiazol-4-yl) pyridine-5-carboxylate racemates, enantiomers, and diastereomers
," Journal of Medicinal Chemistry, vol.
Some of these molecules, including silybin and isosilybin, are naturally present as diastereomers
(A and B), but silychristin may also exist in the diastereomeric form (Lee et al.
GreenSep Nitro separates geometrical isomers as well as diastereomers
. It is suited for separating compounds that contain aromatic group, polarizable electrons and conjugate systems.
Determination of flame retardant hexabromocyclododecane diastereomers
Each regioisomer can form 8 racemic diastereomers
leading to 64 theoretically possible different [F.sub.2]-IsoPs (4).
Unfortunately, the difference between the retention times was too small to resolve the diastereomers
Thus, in theory, it is possible to synthesize 511 incorrect diastereomers
based on this one hydrocarbon skeleton.
The four stereoisomers can be grouped into two pairs of enantiomers, resulting in two diastereomers
(RR + SS and RS + SR).
Incubation with a cell free preparation obtained from midguts of silkworm larvae revealed that (24R,28R)-fucosterol epoxide and (24R,28S)-isofucosterol ([[DELTA].sup.24(28)]-Z isomer of 6) epoxide, out of the four diastereomers
at the C-24 and C-28 positions, were converted into desmosterol by the lyase.
The residue was purified by preparative HPLC eluting with a mixture of n-hexane and 2-propanol (95:5) to give 8 (0.2096 g, 0.98 mmol, 83%) as a 1:1 mixture of diastereomers
(3R)-8a (white cristalline solid, mp 52-53 [degrees]C) and (3S)-8b (colorless oil).
The resulting diastereomers
were subjected to capillary electrophoresis (buffer: 50 mM [Na.sub.2][B.sub.4][O.sub.7] in 23% aqueous MeCN, pH 10.3, injection: 3 psi s, voltage: 30 kV, detection: 200nm, temperature: 27 [degrees]C).