• YAKHAK HOEJI
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• v.39 no.5
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• pp.565-568
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• 1995

A new antiplatelett agent, aspalatone ([3-(2-methyl-4-pyronyl)]-2-acetyloxybenzoate) was demonstrated to inhibit MDA generation from arachidonic acid catalyzed by partially purified bovine seminal vesicle cyclooxygenase. This inhibition was also observed with acetylsalicylic acid. The results suggest that the mechanism for the antiplatelet effect of aspalatone is, like acetylsalicylic acid, due to its inhibition of cyclooxygenase.

• Archives of Pharmacal Research
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• v.17 no.3
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• pp.166-169
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• 1994

The anti-inflammatory activity of acetylsalicylic acid maltol ester (aspalatone), a potential anti-thombotic agent, was studied using the several experimental animal models of inflammation. By oral administration, aspalatone was found to possess the weak anti-inflammatory activity in models of an acute inflammation, in which aspalatone showed approximately one-third to one-fourth of the anti-inflammatory activity of aspirin. Aspalatone (200 mg/kg/day) and aspirin (50 mg/kg/day), however, did not show the inhibitory activity against granuloma fomation and adjuvant-induced arthritis.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.348-352
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• 1996

The antioxidant efficacy of aspalatone, a new antithrombotic agent, has been recognized in the neurotoxic model and in the cardiotoxic model in proliminary studies. We examined the specific activity of antiosidnat enzyme in the rat blood following administrations of aspirin, maltol, aspirin together with maltol, salicylmaltol (major metabolite of aspalatone) and aspalatone, respectively. Our assessment showed that salicylmaltol, maltol, aspalatone enhanced antiperoxidative activity. In addition, neither aspirin nor combination of aspirin and maltol, showed any significant effect on the activity of antioxidant enzyme. Because $H_{2}$$O_{2}$ accumulation may stimulate the thrombogenesis in blood, the result suggests that the induction of blood antiperoxidative activity produced by aspalatone may have beneficial effects on the thrombogenesis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.236-236
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• 1994

Acetylsalicylic acid (ASA)와 고려홍삼의 항산화 성분인 maltol을 축합하여 신물질 aspalatone을 합성하고, 흰쥐에서의 지혈시간 연장 효과, 항혈소판 응집 억제 (in Vitro, ex ViVO) 효과 및 생쥐의 혈전 모델을 이용한 항혈전 (in vivo) 효과를 연구하였다. SD계 웅성 흰쥐에 15 mg/kg의 낮은 용량으로 경구투여 할 경우, aspalatone과 ASA는 각각 최소한 8일 연속투여후 지혈시간을 유의적으로 연장시켰으며 같은 용량으로 10일 간 경구투여. 하였을 때, aspalatone 투여군은 대조군에 비하여 지혈시간이 57% (p<0.005) 연장된 반면, ASA 투여군은 44% 연장되었다. 반면, aspalatone의 아세칠 기를 갖지 않는 salicylic acid maltnl ester는 같은 용량에서 지혈시간을 유의적으로 연장시키지 않았다. Aspalatone은 in vitro에서 collagen에 의해 유도된 흰쥐 혈소판 응집을 강력하게 억제하였으나 (IS$_{50}$ = 0.18 mM), ASA와 마찬가지로 ADP에 의한 응집은 억제하지 않았다. Aspalatnne과 다른 대조약물들의 ex vivo에서의 혈소판 응집 억제능은 ASA>dipyridamdle(equation omitted)aspalatone>ticlopidine의 순이었다. 1회 경구투여로 aspalatone은 생쥐의 collagen에 의한 혈전에 기인하는 치사율을 억제하였다 (ED$_{50}$ = 32mg/kg). Aspalatone을 10일 간 투여하면 유효용량이 현저히 감소하여 20 mg/kg에서 치사율을 90% (p<0.001) 억제하였으며, 이러한 항혈전 효과는 투여중단 4일 후에도 지속되었다. 또한, 경구투여시 위궤양을 유발하는 ASA (ulcer index : 29 mm 200 mg/kg p.o.)와는 다르게 aspalatone은 위궤양을 유발하지 않는다는 장점을 갖는다 (0.71 mm, 800 mg/kg p.o.). In vitro에서 malondialdehyde 생성 억제를 지표로 한 aspalatone의 항산화 활성 ($IC_{50}$/ = 0.11 mM)은 maltol ($IC_{50}$/ = 0.084 mM)과 유산하다. 이러한 실험결과를 토대로 하여 aspalatone을 위궤양을 유발하지 않는 항혈전 신약으로 개발하기 위한 연구가 진행 중이다.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.332-337
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• 2000

Physicochemical properties of aspalatone (acetylsalicylic acid maltol ester, AM), which has been recently found to have an antithrombotic effect, were studied in terms of solubility, dissolution, partition coefficient (Pc) and stability. The solubility of AM at 37$^{\circ}C$ was about 1.2 mg/ml and the P$_{c}$ value for n-octanol/water and chloroform/water was 11.4 and 382.6, respectively. Dissolution rates of AM at pH 1.2 and 6.8 were more than 80% within 30 min. The degradation of AM followed apparent first-order kinetics, and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be at around 4.0. Half-lives at pH 1.2 and 6.8 were 33.5 and 44.4 hr, respectively. The degradation rate of AM at pH 1.2 was somewhat faster than that of aspirin, but at pH 7.0, the degradation rate of AM was slower than that of aspirin.n.

• Journal of Pharmaceutical Investigation
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• v.30 no.4
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• pp.267-271
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• 2000

The effect of cyclodextrins on the solubility and stability of aspalatone (acetylsalicylic acid maltol ester, AM, CAS 147249-33-0), which has been recently found to have an antithrombotic effect, was investigated. The addition of ${\beta}-cyclodextrin\;({\beta}-CD),\;dimethyl-{\beta}-cyclodextrin\;(DMCD)\;or\;2-hydroxypropyl-{\beta}-cyclodextrin\;(HPCD)$ to the aqueous solution increased the solubility of AM concentration-dependently. From the phase solubility diagram, stability constants for $AM-{\beta}-CD$, -DMCD or -HPCD complexes were calculated to be 43.1, 78.3 and $53.0\;M^{-1}$. The addition of ${\beta}-CD$, DMCD or HPCD to AM solution retarded the degradation rate of AM in the acidic region. However, ${\beta}-CD$ and HPCD rather acted as an accelerator of degradation in the neutral and alkaline regions. DMCD had a stabilizing effect at all pHs studied.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.572-577
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• 2001

The feasibility of skin penetration was studied for aspalatone (AM, acetylsalicylic acid maltol ester), a novel antithrombotic agent. In this studys hairless mouse dorsal skins were used as a model to select composition of vehicle and AM. Based on measurements of solubility and partition coefficient, the concentration of PC that showed the highest flux for AM across the hairless mouse skin was found to be 40%. The cumulative amount permeated at 48 h, however, appear inadequate, even when the PC concentration was employed. To identify a suitable absorption enhancer and its optimal concentration for AM, a number of absorption enhancers and a variety of concentration were screened for the increase in transdermal flux of AM. Amongst these, linoleic acid (LOA) at the concentration of 5% was found to have the largest enhancement factor (i.e., 132). However, a further increase in AM flux was not found in the fatty acid concentration greater than 5%, indicating the enhancement effect is in a bell-shaped currie. In a study of the effect of AM concentration on the permeation, there was no difference in the permeation rate between 0.5 and 1% for AM, below its saturated concentration. At the donor concentration of 2%, over the saturated condition, the flux of AM was markedly increased. A considerable degradation of AM was found during permeation studies, and the extent was correlated with protein concentrations in the epidermal and serosal extracts, and skin homogenates. In rat dorsal skins, the protein concentration decreased in the rank order of skin homogenate > serosal extract > epidermal extract. Estimated first order degradation rate constants were $6.15{\pm}0.14,{\;}0.57{\pm}0.02{\;}and{\;}0.011{\pm}{\;}0.004{\;}h^{-1}$ for skin homogenate, serosal extract and epidermal extract, respectively. Therefore, it appeared that AM was hydrolyzed to some extent into salicylmaltol by esterases in the dermal and subcutaneous tissues of skin. taken together, our data indicated that transdermal delivery of AM is feasible when the combination of PC and LOA is used as a vehicle. However, since AM is not metabolically stable, acceptable degradation inhibitors may be nervessary to fully realize the transdermal delivery of the drug.

• Journal of Pharmaceutical Investigation
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• v.31 no.1
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• pp.27-35
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• 2001

To evaluate the site-specific permeation of aspalatone (acetylsalicylic acid maltol ester, AM) through gastrointestinal tract, the enzymatic degradation and permeation studies were carried out using gastric, duodenal and jejunal mucosae of rabbits. It was found that $15.2{\pm}11.4%$, $11.6{\pm}5.2$ and $0.8{\pm}0.6%$ of the donor dose of AM, salicylmaltol (SM) and aspirin (ASA) permeated through the upper gastric mucosa after 8 hr of permeation, respectively. After 8 hr of AM permeation, SM and ASA were measured to be $15.0{\pm}1.7$ and $2.6{\pm}0.8%$ of the dose in the donor solutions, respectively, and salicylic acid (SA) was not detected even after 6 hr, suggesting a very low gastric damage. For the gastric mucosa, the increase of donor dose from 100 to $1,000\;{\mu}g/ml$ increased the permeation flux dose-dependently (r=0.9905). For the duodenal and jejunal mucosae, however, AM was fully degraded into SM and SA due to the esterase activities within 30 min. AM and ASA were not detected in the receptor solution. This result indicates that AM is not a prodrug of ASA. Addition of potassium fluoride (0.5%) into the donor solution delayed the degradation of AM, but did not allow the permeation through duodenal mucosa even by the inhibition of esterase activity. The addition of $dimethyl-{\beta}-cyclodextrin$ and $2-hydroxypropyl-{\beta}-cyclodextrin$ (5%) into the donor solutions also did not show favorable effects on the permeation of AM through various mucosae. In comparison of permeation rates of AM and ASA through the upper gastric mucosa, the flux of ASA was 4.2 times faster than AM based on the molar concentration. ASA also was fully degraded in the donor solutions faced with duodenal and jejunal mucosae within 2 hr, and was not detected in the receptor solution, suggesting a slower metabolism compared with AM.