ACE/angiotensin-converting enzyme

已经证明，在高血压患者中，卡托普利 (SQ 14225) 的发病率和有效性与利尿剂和 β 受体阻滞剂相似。已证明卡托普利可减缓糖尿病肾病的进展，但依那普利和赖诺普利可阻止白蛋白尿正常的糖尿病患者的疾病进展[4]。该溶液含有等摩尔比例的顺式和反式卡托普利，酶专门选择化合物的反式形式。该酶及其底物结合碱基表现出结构和立体电子互补性[5]。

卡托普利是一种ACE抑制剂，可拮抗RAAS的作用。RAAS是一种稳态机制，用于调节血流动力学、水和电解质平衡。在交感神经刺激期间或当肾血压或血流量降低时，肾素从肾脏肾小球旁器的颗粒细胞中释放。在血流中，肾素将循环血管紧张素原切割为ATI，随后通过ACE将其切割为ATII。ATII通过多种机制提高血压。首先，它刺激肾上腺皮质分泌醛固酮。醛固酮进入肾单位的远曲小管（DCT）和集合管，在那里它通过增加细胞膜上钠通道和钠钾ATP酶的数量来增加钠和水的重吸收。其次，ATII刺激垂体后叶分泌加压素（也称为抗利尿激素或ADH）。ADH通过在DCT和集合管细胞的顶端表面插入水通道蛋白2通道，刺激肾脏进一步吸收水分。第三，ATII通过直接动脉血管收缩来提高血压。刺激血管平滑肌细胞上的1型ATII受体会导致一连串的事件，导致肌细胞收缩和血管收缩。除了这些主要作用外，ATII还通过刺激下丘脑神经元来诱导口渴反应。ACE抑制剂抑制ATI向ATII的快速转化，并拮抗RAAS诱导的血压升高。ACE（也称为激肽酶II）也参与血管舒张剂缓激肽的酶促失活。抑制缓激肽的失活会增加缓激肽水平，并可能通过引起血管舒张增加和血压下降来维持其作用。

ACE抑制测定[1]
使用Chang等人描述的以HHL为底物的分光光度法测量不同浓度的EA和CP对ACE活性的抑制作用及其IC50值。简言之，含有0.3M NaCl（pH 8.3）的20mM硼酸钠缓冲液用于制备EA、CP、ACE和底物HHL溶液。ACE催化反应在37°C下在以下组成的试管中进行30分钟：100μL EA或CP、100μL ACE溶液（40mU/mL）和100μL HHL（15mM）溶液（A1）；100μL EA或CP溶液和200μL硼酸盐缓冲液（A2）；100μL硼酸盐缓冲液、100μL ACE溶液和100μL HHL溶液（A3）；和300μL硼酸盐缓冲液（A4）。通过加入3mL OPA溶液的碱性溶液（pH 12.0）来停止酶促反应。在25°C下孵育20分钟后，使用Beckman DU-640在390nm处测量每个反应的吸光度。使用以下方程计算EA或CP对ACE的抑制作用：抑制作用（%）=[1–（A1–A2）/（A3–A4）]×100。ACE活性的IC50值通过方程IC50=（50–b）/m计算，该方程源自ACE活性的线性回归图，其中b是截距，m是方程的斜率。

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ACE抑制动力学参数的测定[1]
根据Michaelis–Menten动力学模型确定Vmax和Km值的动力学参数。通过上述方法测定ACE（40mU/mL）在有EA（0.091μM）或CP（0.00625μM）和没有EA或CP的情况下由HHL形成l-组氨酸-l-亮氨酸的反应速率，得到饱和曲线，然后绘制与HHL浓度（0.94、1.85、3.75、7.50、15mM）的关系图。Lineweaver–Burk图是使用饱和曲线得出的，以确定抑制的类型。使用MS Excel计算动力学参数（Km和Vmax）。

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研究了含巯基的血管紧张素转换酶ACE竞争性抑制剂卡托普利对碳酸酐酶CA酯酶活性的抑制作用。选择这种小分子，以及依那普利，是为了代表硫醇和羧酸盐，作为金属蛋白抑制剂的两个众所周知的金属结合官能团。由于卡托普利也被观察到通过与催化金属离子结合来抑制其他金属酶，如酪氨酸酶和金属β-内酰胺酶，并且将CA视为一种含锌的金属酶，在本研究中，我们开始确定卡托普利/依那普利是否抑制纯化的人CA II的CA酯酶活性？然后，我们揭示了抑制剂的效力（IC50、Ki和Kdiss值）以及抑制模式。我们的结果还表明，依那普利是比卡托普利更有效的CA抑制剂。由于依那普利不代表巯基部分，因此羧酸基团可能在抑制CA酯酶活性中起决定作用，这一结论通过分子对接研究得到了证实。此外，由于卡托普利/依那普利对CA的抑制能力远低于经典磺酰胺类药物，因此当前研究的结果可以解释为什么这些药物在体内达到的浓度下没有表现出有效的CA抑制作用，也可以阐明产生新一类抑制剂的方法，这些抑制剂将区别性地抑制各种CA异构体[2]。

The angiotensin converting enzyme (ACE) inhibitors are widely used in the management of essential hypertension, stable chronic heart failure, myocardial infarction (MI) and diabetic nephropathy. There is an increasing number of new agents to add to the nine ACE inhibitors (benazepril, cilazapril, delapril, fosinopril, lisinopril, pentopril, perindopril, quinapril and ramipril) reviewed in this journal in 1990. The pharmacokinetic properties of five newer ACE inhibitors (trandolapril, moexipril, spirapril, temocapril and imidapril) are reviewed in this update. All of these new agents are characterised by having a carboxyl functional groups and requiring hepatic activation to form pharmacologically active metabolites. They achieve peak plasma concentrations at similar times (t(max)) to those of established agents. Three of these agents (trandolapril, moexipril and imidapril) require dosage reductions in patients with renal impairment. Dosage reductions of moexipril and temocapril are recommended for elderly patients, and dosages of moexipril should be lower in patients who are hepatically impaired. Moexipril should be taken 1 hour before meals, whereas other ACE inhibitors can be taken without regard to meals. The pharmacokinetics of warfarin are not altered by concomitant administration with trandolapril or moexipril. Although imidapril and spirapril have no effect on digoxin pharmacokinetics, the area under the concentration-time curve of imidapril and the peak plasma concentration of the active metabolite imidaprilat are decreased when imidapril is given together with digoxin. Although six ACE inhibitors (captopril, enalapril, fosinopril, lisinopril, quinapril and ramipril) have been approved for use in heart failure by the US Food and Drug Administration, an overview of 32 clinical trials of ACE inhibitors in heart failure showed that no significant heterogeneity in mortality was found among enalapril, ramipril, quinapril, captopril, lisinopril, benazepril, perindopril and cilazapril. Initiation of therapy with captopril, ramipril, and trandolapril at least 3 days after an acute MI resulted in all-cause mortality risk reductions of 18 to 27%. Captopril has been shown to have similar morbidity and mortality benefits to those of diuretics and beta-blockers in hypertensive patients. Captopril has been shown to delay the progression of diabetic nephropathy, and enalapril and lisinopril prevent the development of nephropathy in normoalbuminuric patients with diabetes. ACE inhibitors are generally characterised by flat dose-response curves. Lisinopril is the only ACE inhibitor that exhibits a linear dose-response curve. Despite the fact that most ACE inhibitors are recommended for once-daily administration, only fosinopril, ramipril, and trandolapril have trough-to-peak effect ratios in excess of 50%[5].

Absorption, Distribution and Excretion
60-75% in fasting individuals; food decreases absorption by 25-40% (some evidence indicates that this is not clinically significant)
The drug /captopril/ is metabolized and renally excreted. More than 95% of a dose is excreted renally, both as unchanged (45-50%) drug and as metabolites.
In dogs, approximately 75% of an oral dose is absorbed but food in the GI tract reduces bioavailability by 30-40%. It is distributed to most tissues (not the CNS) and is 40% bound to plasma proteins in dogs.
Approximately 60-75% of an oral dose of captopril is rapidly absorbed from the GI tract in fasting healthy individuals or hypertensive patients. Food may decrease absorption of captopril by up to 25-40%, although there is some evidence that this effect is not clinically important. Following oral administration of a single 100-mg dose of captopril in fasting healthy individuals in one study, average peak blood drug concentrations of 800 ng/mL were attained in 1 hour.
/MILK/ Concentrations of captopril in human milk are approximately one percent of those in maternal blood.
For more Absorption, Distribution and Excretion (Complete) data for Captopril (7 total), please visit the HSDB record page.

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Metabolism / Metabolites
Hepatic. Major metabolites are captopril-cysteine disulfide and the disulfide dimer of captopril. Metabolites may undergo reversible interconversion.
About half the absorbed dose of captopril is rapidly metabolized, mainly to captopril-cysteine disulfide and the disulfide dimer of captopril. In vitro studies suggest that captopril and its metabolites may undergo reversible interconversions. It has been suggested that the drug may be more extensively metabolized in patients with renal impairment than in patients with normal renal function.

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Biological Half-Life
2 hours
A 43 year old patient with mild heart failure attempted suicide by ingesting between 5000 and 7500 mg of captopril. Blood pressure oscillated around 100-120/50-75 mm Hg and pulse rate showed no tendency to accelerate (75-100/min). ... The calculated half-life of captopril was 4.4 hr. ...
The half life of captopril is about 2.8 hours in dogs ... .
The elimination half-life of unchanged captopril appears to be less than 2 hours in patients with normal renal function. The elimination half-life of captopril and its metabolites is correlated with creatinine clearance and increases to about 20-40 hours in patients with creatinine clearances less than 20 mL/minute and as long as 6.5 days in anuric patients.

Hepatotoxicity
Captopril, like other ACE inhibitors, has been associated with a low rate of serum aminotransferase elevations (
Likelihood score: B (likely but rare cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because of the low levels of captopril in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects in breastfed infants.
◉ Effects in Breastfed Infants
In one report of 12 mothers, several continued to breastfeed their infants while taking captopril 100 mg three times daily. No adverse effects were seen in the infants.[1]
A woman was diagnosed with Cushing's disease during pregnancy. Postpartum she took metyrapone 250 mg 3 times daily, bisoprolol 10 mg twice daily, and captopril 12.5 mg twice daily. She breastfed her preterm infant about 50% milk and 50% formula. At 5 weeks postpartum, the infant's pediatric team found his growth and development to be appropriate.[3]
◉ Effects on Lactation and Breastmilk
In a series of controlled studies reported in one paper, captopril had no effect on the circadian rhythm of prolactin, the response to prolactin-stimulating drugs or serum prolactin in patients with prolactin-secreting tumors.[4]
In a study of young hypertensive males, captopril 25 mg orally markedly decreased serum prolactin at 90 minutes after the dose compared to placebo.[5] The maternal prolactin level in a mother with established lactation may not affect her ability to breastfeed.
In one report, 1 woman out of 12 subjects was unable to produce enough milk for the study while taking captopril 100 mg 3 times daily even though she had been successfully breastfeeding for 6 months.[1] It is not known if this decrease was an effect of captopril.

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Protein Binding
25-30% bound to plasma proteins, primarily albumin

[1]. Eritadenine from Edible Mushrooms Inhibits Activity of Angiotensin Converting Enzyme in Vitro. J Agric Food Chem. 2016;64(11):2263-2268.

[2]. Captopril/enalapril inhibit promiscuous esterase activity of carbonic anhydrase at micromolar concentrations: An in vitro study. Chem Biol Interact. 2017;265:24-35.

[3]. Simplified captopril analogues as NDM-1 inhibitors. Bioorg Med Chem Lett. 2014;24(1):386-389.

[4]. The molecular basis for the selection of captopril cis and trans conformations by angiotensin I converting enzyme. Bioorg Med Chem Lett, 2006. 16(19): p. 5084-7.

[5]. Song, J.C. and C.M. White, Clinical pharmacokinetics and selective pharmacodynamics of new angiotensin converting enzyme inhibitors: an update. Clin Pharmacokinet, 2002. 41(3): p. 207-24.

Captopril is a L-proline derivative in which L-proline is substituted on nitrogen with a (2S)-2-methyl-3-sulfanylpropanoyl group. It is used as an anti-hypertensive ACE inhibitor drug. It has a role as an EC 3.4.15.1 (peptidyl-dipeptidase A) inhibitor and an antihypertensive agent. It is a pyrrolidinemonocarboxylic acid, a N-acylpyrrolidine, an alkanethiol and a L-proline derivative.
Captopril is a potent, competitive inhibitor of angiotensin-converting enzyme (ACE), the enzyme responsible for the conversion of angiotensin I (ATI) to angiotensin II (ATII). ATII regulates blood pressure and is a key component of the renin-angiotensin-aldosterone system (RAAS). Captopril may be used in the treatment of hypertension.
Captopril is an Angiotensin Converting Enzyme Inhibitor. The mechanism of action of captopril is as an Angiotensin-converting Enzyme Inhibitor.
Captopril is an angiotensin-converting enzyme (ACE) inhibitor used in the therapy of hypertension and heart failure. Captopril is associated with a low rate of transient serum aminotransferase elevations and has been linked to rare instances of acute liver injury.
Captopril has been reported in Microcystis aeruginosa with data available.
Captopril is a sulfhydryl-containing analog of proline with antihypertensive activity and potential antineoplastic activity. Captopril competitively inhibits angiotensin converting enzyme (ACE), thereby decreasing levels of angiotensin II, increasing plasma renin activity, and decreasing aldosterone secretion. This agent may also inhibit tumor angiogenesis by inhibiting endothelial cell matrix metalloproteinases (MMPs) and endothelial cell migration. Captopril may also exhibit antineoplastic activity independent of effects on tumor angiogenesis. (NCI04)
A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.
See also: Moveltipril (is active moiety of); Captopril; hydrochlorothiazide (component of).

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Drug Indication
For the treatment of essential or renovascular hypertension (usually administered with other drugs, particularly thiazide diuretics). May be used to treat congestive heart failure in combination with other drugs (e.g. cardiac glycosides, diuretics, β-adrenergic blockers). May improve survival in patients with left ventricular dysfunction following myocardial infarction. May be used to treat nephropathy, including diabetic nephropathy.
Treatment of heart failure

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Mechanism of Action
There are two isoforms of ACE: the somatic isoform, which exists as a glycoprotein comprised of a single polypeptide chain of 1277; and the testicular isoform, which has a lower molecular mass and is thought to play a role in sperm maturation and binding of sperm to the oviduct epithelium. Somatic ACE has two functionally active domains, N and C, which arise from tandem gene duplication. Although the two domains have high sequence similarity, they play distinct physiological roles. The C-domain is predominantly involved in blood pressure regulation while the N-domain plays a role in hematopoietic stem cell differentiation and proliferation. ACE inhibitors bind to and inhibit the activity of both domains, but have much greater affinity for and inhibitory activity against the C-domain. Captopril, one of the few ACE inhibitors that is not a prodrug, competes with ATI for binding to ACE and inhibits and enzymatic proteolysis of ATI to ATII. Decreasing ATII levels in the body decreases blood pressure by inhibiting the pressor effects of ATII as described in the Pharmacology section above. Captopril also causes an increase in plasma renin activity likely due to a loss of feedback inhibition mediated by ATII on the release of renin and/or stimulation of reflex mechanisms via baroreceptors. Captopril’s affinity for ACE is approximately 30,000 times greater than that of ATI.
The local role of the renin angiotensin system (RAS) was documented recently beside its conventional systemic functions. Studies showed that the effector angiotensin II (AngII) alters bone health, while inhibition of the angiotensin converting enzyme (ACE-1) preserved these effects. The newly identified Ang1-7 exerts numerous beneficial effects opposing the AngII. Thus, the current study examines the role of Ang1-7 in mediating the osteo-preservative effects of ACEI (captopril) through the G-protein coupled Mas receptor using an ovariectomized (OVX) rat model of osteoporosis. 8 weeks after the surgical procedures, captopril was administered orally (40 mg/kg/day), while the specific Mas receptor blocker (A-779) was delivered at infusion rate of 400 ng/kg/1 min for 6 weeks. Bone metabolic markers were measured in serum and urine. Minerals concentrations were quantified in serum, urine and femoral bones by inductive coupled plasma mass spectroscopy (ICP-MS). Trabecular and cortical morphometry was analyzed in the right distal femurs using micro-CT. Finally, the expressions of RAS peptides, enzymes and receptors along with the receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) were determined femurs heads. OVX animals markedly showed altered bone metabolism and mineralization along with disturbed bone micro-structure. Captopril significantly restored the metabolic bone bio-markers and corrected Ca2+ and P values in urine and bones of estrogen deficient rats. Moreover, the trabecular and cortical morphometric features were repaired by captopril in OVX groups. Captopril also improved the expressions of ACE-2, Ang1-7, Mas and OPG, while abolished OVX-induced up-regulation of ACE-1, AngII, Ang type 1 receptor (AT1R) and RANKL. Inhibition of Ang1-7 cascade by A-779 significantly eradicated captopril protective effects on bone metabolism, mineralization and micro-structure. A-779 also restored OVX effects on RANKL expression and ACE-1/AngII/AT1R cascade and down-regulated OPG expression and ACE-2/Ang1-7/Mas pathway. In line with the clinical observations of the bone-preservative properties following ACE-1 inhibition, local activation of ACE-2/Ang1-7/Mas signaling and suppressed osteoclastogenesis seem responsible for the osteo-preservative effect of captopril, which could offers a potential therapeutic value in treatment of disabling bone and skeletal muscular diseases.

C9H15NO3S

217.29

217.077

C, 49.75; H, 6.96; N, 6.45; O, 22.09; S, 14.76

62571-86-2

Captopril hydrochloride;198342-23-3;Captopril-d3;1356383-38-4

44093

White to off-white, crystalline powder
Crystals from ethyl acetate/hexane

1.3±0.1 g/cm3

427.0±40.0 °C at 760 mmHg

104-108 °C(lit.)

212.1±27.3 °C

0.0±2.2 mmHg at 25°C

1.551

0.27

96.41

2

4

3

14

244

2

S([H])C([H])([H])[C@@]([H])(C([H])([H])[H])C(N1C([H])([H])C([H])([H])C([H])([H])[C@@]1([H])C(=O)O[H])=O

FAKRSMQSSFJEIM-BQBZGAKWSA-N

InChI=1S/C9H15NO3S/c1-6(5-14)8(11)10-4-2-3-7(10)9(12)13/h6-7,14H,2-5H2,1H3,(H,12,13)/t6-,7-/m0/s1

(2S)-1-[(2S)-2-methyl-3-sulfanylpropanoyl]pyrrolidine-2-carboxylic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

配方 1 中的溶解度: ≥ 2.5 mg/mL (11.51 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 25.0 mg/mL澄清DMSO储备液加入到400 μL PEG300中，混匀；然后向上述溶液中加入50 μL Tween-80，混匀；加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: ≥ 2.5 mg/mL (11.51 mM) (饱和度未知) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL澄清DMSO储备液加入900 μL 20% SBE-β-CD生理盐水溶液中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

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配方 3 中的溶解度: ≥ 2.5 mg/mL (11.51 mM) (饱和度未知) in 10% DMSO + 90% Corn Oil (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL 澄清 DMSO 储备液加入到 900 μL 玉米油中并混合均匀。

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配方 4 中的溶解度: 32.5 mg/mL (149.57 mM) in PBS (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶.

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。