Design, synthesis and in vitro evaluation on HRPE cells of ascorbic and 6-bromoascorbic acid conjugates with neuroactive molecules.
Preliminary investigations allowed us to anticipate that conjugation of nipecotic acid with L-ascorbate (AA) gave a prodrug endowed with anticonvulsant activity in mice. In view of these results, and in order to get deepen insight into the molecular aspects at the base of the transport mechanism, a second generation of compounds, based on 6-bromo-6-deoxy-L-ascorbic acid (BrAA) as the carrier molecule was designed and synthesized. Effects of the chirality of the transported drug was also investigated on R- and S-nipecotic acid. Interaction and uptake modalities were evaluated in our in vitro model based on human retinal pigment epithelium cells (HRPE), which expresses the membrane L-ascorbic acid (AA) SVCT2 transporters. A remarkable increase on SVCT2 affinity was found going from AA to BrAA conjugates, that is, 11 (Ki=1187+/-78 microM) versus 19 (Ki=193+/-14 microM) and 12 (Ki=39.8+/-3.2 microM) versus 20, (Ki=7.4+/-0.8 microM). Taken together, these data are in agreement with our initial hypothesis on the possibility to achieve better affinities by conjugation with AA analogs, and also consent to hypothesize the presence of accessory interactions that may improve transporters recognition.
Manfredini
Stefano
S
Department of Pharmaceutical Sciences, via Fossato di Mortara 17-19, I-44100 Ferrara, Italy. mv9@dns.unife.it
Vertuani
Silvia
S
Pavan
Barbara
B
Vitali
Federica
F
Scaglianti
Martina
M
Bortolotti
Fabrizio
F
Biondi
Carla
C
Scatturin
Angelo
A
Prasad
Puttur
P
Dalpiaz
Alessandro
A
D000818:Animals; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002491:Central Nervous System Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007736:Kynurenic Acid / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D009557:Nipecotic Acids / Q000378:metabolism / Q000494:pharmacology; D029363:Organic Anion Transporters, Sodium-Dependent / Q000037:antagonists & inhibitors / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000378:metabolism; D011355:Prodrugs / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D060347:Sodium-Coupled Vitamin C Transporters; D027981:Symporters / Q000037:antagonists & inhibitors / Q000378:metabolism
D002491:Central Nervous System Agents; D009557:Nipecotic Acids; D029363:Organic Anion Transporters, Sodium-Dependent; D011355:Prodrugs; C555163:SLC23A2 protein, human; C555165:Slc23a2 protein, mouse; D060347:Sodium-Coupled Vitamin C Transporters; D027981:Symporters; C068572:6-deoxy-6-bromoascorbic acid; D007736:Kynurenic Acid; D001205:Ascorbic Acid