OdVP3

O-Desmethylvenlafaxine (desvenlafaxine, ODV) is the active metabolite of venlafaxine, with similar activity and less risk for pharmacokinetic drug interactions compared to its parent compound venlafaxine. The purpose of this study was to design a series of esters of ODV and assess their potential as ODV prodrugs with improved bioavailability and brain uptake. Seven esters were synthesized and pharmacokinetic screening was performed in rats. The monoester formed on the phenolic hydroxyl of ODV (ODVP-1, ODVP-2, ODVP-3 and ODVP-5) could be degraded to ODV in rat plasma. These four compounds confirmed as possible prodrugs were then studied to evaluated the relative bioavailability of ODV they produced in beagle dogs. ODVP-1, ODVP-2 and ODVP-3 demonstrated higher relative bioavailability of ODV. Finally, ODVP-1, ODVP-2 and ODVP-3 were studied to evaluate their brain uptake in rats. The concentration of ODV in the rat plasma, brain and hypothalamus after administration of ODVP-1, ODVP-2 or ODVP-3 was higher compared with that of ODV. The higher bioavailability, improved pharmacokineics properties and more rapid penetration and translation of ODV suggest that ODVP-1, ODVP-2 or ODVP-3 may warrant further development and application as ODV prodrugs.

Three venom peptides (OdVP1, OdVP2 and OdVP3) were isolated from the venom of the solitary wasp Orancistrocerus drewseni (Hymenoptera: Eumenidae). The mature venom peptide sequences were determined via ESI-Q-TOF MS/MS and by searching the O. drewseni venom gland/sac-specific EST library. All of the OdVPs shared the typical characteristics of amidated C-termini proteins and contained a high content of hydrophobic and positively charged amino acids, suggesting that they adopt an amphipathic alpha-helical secondary structure, as is the case for mastoparan from Vespula lewisii. The cDNA sequence of the OdVP1 precursor was obtained by 5'- and 3'-rapid amplification of cDNA ends (RACE), and the OdVP2 and OdVP3 precursor transcripts were identified from the venom gland/sac-specific EST library. While the mature peptide sequences were distinct from one another, the overall transcript structure of the OdVPs showed a high homology to that of mastoparan-B from Vespa basalis in that they contained a signal sequence, a prosequence, a mature peptide and a C-terminal glycine. The OdVPs, particularly OdVP2 and OdVP2L (an analog of OdVP2), exhibited strong antifungal activities, but poor antibacterial activities. OdVP2L, which possessed additional Glu-Pro residues, did not have antimicrobial activity against bacteria or Gram-positive yeast but retained activity against Botrytis cinerea.