Seven conjugates composed of well-known fluoroquinolone antibacterial agents, ciprofloxacin (CIP) or levofloxacin (LVX), and a cell-penetrating peptide transportan 10 (TP10-NH2) were synthesised. The drugs were covalently bound to the peptide via an amide bond, methylenecarbonyl moiety, or a disulfide bridge. Conjugation of fluoroquinolones to TP10-NH2 resulted in congeners demonstrating antifungal in vitro activity against human pathogenic yeasts of the Candida genus (MICs in the 6.25–100 µM range), whereas the components were poorly active. The antibacterial in vitro activity of most of the conjugates was lower than the activity of CIP or LVX, but the antibacterial effect of CIP-S-S-TP10-NH2 was similar to the mother fluoroquinolone. Additionally, for two representative CIP and LVX conjugates, a rapid bactericidal effect was shown. Compared to fluoroquinolones, TP10-NH2 and the majority of its conjugates generated a relatively low level of reactive oxygen species (ROS) in human embryonic kidney cells (HEK293) and human myeloid leukemia cells (HL-60). The conjugates exhibited cytotoxicity against three cell lines, HEK293, HepG2 (human liver cancer cell line), and LLC-PK1 (old male pig kidney cells), with IC50 values in the 10–100 µM range and hemolytic activity. The mammalian toxicity was due to the intrinsic cytoplasmic membrane disruption activity of TP10-NH2 since fluoroquinolones themselves were not cytotoxic. Nevertheless, the selectivity index values of the conjugates, both for the bacteria and human pathogenic yeasts, remained favourable.
七种由知名的
氟喹诺
酮类抗菌药物
环丙沙星(
CIP)或
左氧氟沙星(LVX)与细胞穿透肽运输素10(TP10-NH2)组成的共轭物被合成。这些药物通过酰胺键、亚甲基羰基或二
硫桥与肽共价结合。将
氟喹诺酮类药物与TP10-NH2结合导致所得的同系物在体外显示出对人类致病酵母假丝酵母属(Candida属)的抗真菌活性(最小抑菌浓度在6.25-100 µM范围内),而其组分的活性较差。大多数共轭物的体外抗菌活性低于
CIP或LVX的活性,但
CIP-S-S-TP10-NH2的抗菌效果与母体
氟喹诺
酮类相似。此外,对于两种代表性的
CIP和LVX共轭物,显示出了快速的杀菌效果。与
氟喹诺
酮类相比,TP10-NH2及其大多数共轭物在人类胚胎肾细胞(HEK293)和人骨髓白血病细胞(HL-60)中产生的活性氧自由基(ROS)
水平相对较低。这些共轭物对三种
细胞系(HEK293、HepG2(人肝癌
细胞系)和LLC-PK1(老年公猪肾细胞))表现出细胞毒性,IC50值在10-100 µM范围内,并具有溶血活性。哺乳动物毒性是由于TP10-NH2的固有胞质膜破坏活性,因为
氟喹诺酮类药物本身并不具有细胞毒性。然而,这些共轭物对细菌和人类致病酵母的选择性指数值仍然有利。