Epacris crassifolia R. Br. (Epacridaceae) - A Reappraisal

Epacris crassifolia R. Br.s. lat.,as represented in collectionsat G, BM, HO, NSW, MEL, CBG and CAN, has been redefined as threeseparate species. The common lax, prostrate form includes twosubspecies,E. crassifoliassp.crassifoliaR. Br.stat. nov. andE.crassifoliassp.macrofloraCrowden et Menaduessp. nov.separatedon floral morphology.E. pinoideaCrowden et Menaduesp. nov.andE.lithophilaCrowden et Menaduesp. nov.are erect and woody, beingdistinguished on leaf and floral characters. Epacridaceae; Epacris crassifolia ; Epacris lithophila; Epacris pinoidea; new species     

Identification of psiB genes of plasmids F and R6-5. Molecular basis for psiB enhanced expression in plasmid R6-5.

PsiB protein of plasmid R6-5 inhibits the induction of the SOS pathway. The F sex factor also carries a psiB gene homologous to that of R6-5. Yet, it fails to inhibit SOS induction. In order to solve this difference, we characterized the psiB genes of R6-5 and F. We found that (i) the sequences of the two psiB genes share extensive homology the predicted amino acid sequences of the two proteins differing by 5 residues, (ii) the expression of R6-5 psiB is 4 times higher than F psiB gene, (iii) in plasmid R6-5, a Tn10 transposon upstream from the psiB gene enhances psiB expression. Hence, the F sex factor may be unable to prevent SOS induction for two non-exclusive reasons: (i) F PsiB protein, being slightly different from R6-5, may be less active, (ii) the level of synthesis of F PsiB protein may be insufficient to prevent SOS induction.     

Muscarinic M(3) receptor antagonists with (2R)-2-[(1R)-3,3-difluorocyclopentyl]-2-hydroxyphenylacetamide Structures. Part 2

Optimization of the amine part of our original muscarinic M(3) receptor antagonist 1 was performed to identify M(3) receptor antagonists that are superior to 1. Compounds carrying a variety of diamine moieties without hydrophobic substituent on the nitrogen atom were screened against the binding affinity for the M(3) receptor and the selectivity for M(3) over the M(1) and M(2) receptors. This process led to a 4-aminopiperidinamide (2l) with a K(i) value of 5.1 nM and with a selectivity of the M(3) receptor that was 46-fold greater than that of the M(2) receptor. Further derivatization of 2l by inserting a spacer group or by incorporating alkyl group(s) into the amine part resulted in the identification of an 4-(aminoethyl)piperidinamide 2l-b with a K(i) value of 3.7 nM for the M(3) receptor and a selectivity for the M(3) receptor that was 170-fold greater than that of the M(2) receptor.