Dryocrassin ABBA   中文名称: 绵马贯众素ABBA

Staphylococcus aureus Sortase A (SrtA) (IC50 = 24.17 µM)[4]。

天然产物 Dryocrasin ABBA 被鉴定为金黄色葡萄球菌分选酶A (SrtA) 的有效抑制剂。在荧光共振能量转移 (FRET) 实验中，Dryocrasin ABBA 能显著降低由SrtA切割模型底物肽 (Dabcyl-QALPETGEE-Edans) 所产生的荧光信号，表明其抑制了SrtA的催化活性。其半数抑制浓度 (IC50) 测定为24.17 µM[4]。
分子动力学模拟和突变实验揭示了其抑制的分子机制。Dryocrasin ABBA 直接结合在SrtA的活性位点，主要与氨基酸残基Ala104、Glu105、Val166、Gly167、Val168、Ile182和Trp194相互作用。关键结合作用包括与Val166和Val168的范德华力，以及与Gly167的强氢键。野生型SrtA与Dryocrasin ABBA 复合物的结合自由能 (ΔGbind) 计算为-25.8 ± 2.8 kcal/mol[4]。
为验证结合位点，构建了点突变体V166A-SrtA和V168A-SrtA。在FRET实验中，Dryocrasin ABBA (40 µM) 对这些突变体的抑制效果相较于野生型SrtA显著减弱。突变体的结合自由能也更弱：V166A为-19.2 ± 3.1 kcal/mol，V168A为-15.3 ± 1.9 kcal/mol，这证实了Val166和Val168是Dryocrasin ABBA 结合并抑制其活性的关键残基[4]。

在感染了金刚烷胺耐药的高致病性禽流感H5N1毒株（A/Chicken/Hebei/706/2005）的小鼠模型中，口服给予 Dryocrassin ABBA 能以剂量依赖性的方式显著提高存活率。感染后第14天，33、18和12.5 mg/kg/天治疗组的存活率分别为87%、80%和60%，而金刚烷胺（20 mg/kg/天）组为53%，未治疗的病毒对照组为20%。[1] Dryocrassin ABBA 治疗（33和18 mg/kg/天）与金刚烷胺治疗组和未治疗组相比，显著增加了感染小鼠的体重。[1] 感染后第7天，与未治疗组相比，33和18 mg/kg/天的 Dryocrassin ABBA 治疗显著降低了肺病毒载量（P < 0.01），且降低程度与金刚烷胺治疗组无显著差异。[1] 感染后第7天，所有病毒感染组的肺指数（干肺重与体重之比）与未感染对照组相比均显著增加，但 Dryocrassin ABBA 治疗组与金刚烷胺治疗组之间无显著差异。[1] 感染后第7天，Dryocrassin ABBA 治疗（33和18 mg/kg/天）显著调节了支气管肺泡灌洗液（BALF）中的细胞因子水平。与金刚烷胺治疗组和未治疗对照组相比，它显著降低了促炎细胞因子（IL-6、TNF-α、IFN-γ、IL-12），并显著增加了抗炎细胞因子（IL-10、MCP-1）（P < 0.01）。对于IL-6、IL-10、MCP-1和IFN-γ，这些效应显示出剂量依赖性模式。[1] 在感染金刚烷胺耐药 H5N1 禽流感病毒（A/Chicken/Hebei/706/2005）的小鼠模型中，口服给予 Dryocassin ABBA（剂量为 33、18 和 12.5 mg/kg）的存活率分别为 87%、80% 和 60%，而金刚烷胺治疗组为 53%，未治疗组为 20%[2]。
与未治疗组相比，Dryocassin ABBA 治疗组小鼠体重显著增加[2]。
感染后第 7 天，33 和 18 mg/kg Dryocassin ABBA 治疗组的肺病毒载量显著低于未治疗组[2]。
感染后第 7 天，33 和 18 mg/kg Dryocassin ABBA 治疗组支气管肺泡灌洗液中促炎细胞因子（IL-6、TNF-α、IFN-γ、IL-12）显著降低，抗炎细胞因子（IL-10、MCP-1）显著升高，与金刚烷胺组和未治疗组相比均有显著差异[2]。
Dryocassin ABBA 治疗组肺指数较未治疗组降低，但与金刚烷胺组相比无显著差异[2]。

采用荧光共振能量转移 (FRET) 实验测定 Dryocrasin ABBA 对金黄色葡萄球菌分选酶A (SrtA) 的抑制活性。将重组SrtA蛋白（野生型或突变型）与不同浓度的Dryocrasin ABBA 或对照溶剂在反应缓冲液 (50 mM Tris-HCl, 5 mM CaCl2, 150 mM NaCl, pH 7.5) 中于37°C预孵育30分钟。随后，向96孔板的每个孔中加入荧光肽底物 (Dabcyl-QALPETGEE-Edans) 以启动酶促反应。混合物在37°C下继续孵育1小时。SrtA切割底物会解除荧光淬灭，导致荧光强度增加。使用酶标仪在激发波长350 nm、发射波长520 nm下测量荧光信号。与对照组相比，Dryocrasin ABBA 存在时荧光信号的降低表明其对SrtA活性的抑制[4]。
同时，采用荧光淬灭法测定了Dryocrasin ABBA 与SrtA的结合亲和力（结合常数，K_A）。在Dryocrasin ABBA 浓度递增的条件下，记录SrtA在激发波长280 nm（带宽5 nm）、发射波长345 nm（带宽10 nm）下的荧光发射光谱。根据淬灭数据计算结合常数[4]。

Mouse Efficacy Study against H5N1: Specific pathogen-free (SPF) female BALB/c mice (n=20 per group) were infected intranasally with 10^4.5 ELD50 of the amantadine-resistant H5N1 virus (A/Chicken/Hebei/706/2005) in 100 µl saline. Starting from day 2 post-infection, mice received Dryocrassin ABBA via oral gavage once daily for 7 consecutive days (days 2 to 8). Three dose groups were used: 12.5, 18.0, and 33 mg/kg body weight per day. The positive control group received amantadine hydrochloride at 20 mg/kg/day via the same route and schedule. The untreated virus control and normal control groups received equivalent volumes of physiological saline. Mice were monitored daily for 14 days for body weight, activity, and mortality. On days 7 and 14 post-infection, subsets of mice were euthanized to collect lungs for lung index calculation and virus titration. [1]
Cytokine Analysis: On day 7 post-infection, mice were euthanized, and lungs were lavaged with sterile saline to obtain bronchoalveolar lavage fluid (BALF). The BALF supernatant was collected after centrifugation. Cytokine concentrations (IL-12, IL-6, IL-10, INF-γ, MCP-1, TNF-α) were measured using a commercial cytokine bead array kit and flow cytometry. [1]
SPF BALB/C female mice were inoculated intranasally with 10^4.5 ELD50 of H5N1 virus in 100 µL saline[2]。
Starting from day 2 post-infection, mice were orally administered Dryocassin ABBA at doses of 12.5, 18, and 33 mg/kg body weight, or amantadine hydrochloride at 20 mg/kg body weight, once daily for 7 days[2]。
Control groups received equivalent volumes of physiological saline[2]。
Body weight, activity, mortality, and survival time were monitored daily for 14 days[2]。
On days 7 and 14, mice were euthanized to collect lungs for lung index calculation and virus load determination[2]。
Bronchoalveolar lavage fluid was collected on day 7 for cytokine analysis using a flow cytometry-based cytokine kit[2]。

This article cites a previous study that indicated that the maximum toxic dose (MTD) of Dryocrassin ABBA in Sprague-Dawley rats was up to 2000 mg/kg body weight and that it was considered a non-toxic substance according to the European Pharmacopoeia 7.0. [1] In this mouse study, no significant adverse reactions or toxicities were reported after administration of Dryocrassin ABBA at the test dose (up to 33 mg/kg/day). [1] It has been reported that the maximum toxic dose of Dryocrassin ABBA in Sprague-Dawley rats was 2000 mg/kg body weight and that it was considered a non-toxic substance according to the European Pharmacopoeia 7.0 (cited in another study, not this article) [2].

[1]. Dryocrassin ABBA, a novel active substance for use against amantadine-resistant H5N1 avian influenza virus. Front Microbiol. 2015 Jun 16;6:592.

[2]. Dryocrassin ABBA, a novel active substance for use against amantadine-resistant H5N1 avian influenza virus. Front Microbiol. 2015 Jun 16;6:592.

[3]. Dryocrassin ABBA Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells Through a Caspase-Dependent Mitochondrial Pathway. Asian Pac J Cancer Prev. 2016;17(4):1823-8.

[4]. Molecular Mechanism of the Flavonoid Natural Product Dryocrassin ABBA against Staphylococcus aureus Sortase A. Molecules. 2016 Oct 26;21(11).

[5]. An Inhibitory Effect of Dryocrassin ABBA on Staphylococcus aureus vWbp That Protects Mice From Pneumonia. Front Microbiol. 2019 Jan 23;10:7.

[6]. Dryocrassin suppresses immunostimulatory function of dendritic cells and prolongs skin allograft survival. Cell Transplant. 2014;23(4-5):641-56.

Dryocrassin ABBA is a phloroglucinol compound and the main active ingredient isolated from the traditional Chinese medicine Rhizoma Dryopteridis Crassirhizomatis (RDC). [1] Rhizoma Dryopteridis Crassirhizomatis is traditionally used to treat inflammatory and infectious diseases. [1] Dryocrassin ABBA has shown protective effects against lethal infection with amantadine-resistant H5N1 avian influenza virus in mouse models. [1] Its mechanism of action is believed to be immunomodulation rather than direct viral inhibition. This protective effect is associated with the reduction of lung lesions, the decrease in viral load, and the shift of the cytokine spectrum from pro-inflammatory to anti-inflammatory (decreased levels of IL-6, TNF-α, IFN-γ, and IL-12; increased levels of IL-10 and MCP-1). [1] Dryocrasin ABBA is considered a potential novel lead compound for the development of therapies against amantadine-resistant avian influenza virus. [1]
Dryocrasin ABBA is a phloroglucinol compound isolated from Rhizoma Dryopteridis Crassirhizomatis (RDC)[2].
In a mouse model, it exhibited antiviral activity against amantadine-resistant H5N1 avian influenza virus, possibly through modulation of inflammatory cytokine responses[2].
This compound is considered a potential lead compound for the treatment of drug-resistant avian influenza infections[2].
Dryocrasin ABBA is a flavonoid natural product. This study found that Dryocrasin ABBA is a novel inhibitor of Staphylococcus aureus sorting enzyme A (SrtA). SrtA is a key virulence factor enzyme that anchors surface proteins to the bacterial cell wall. Inhibiting SrtA is an antiviral strategy that could potentially inactivate the bacteria without killing them, thereby reducing the selective pressure of antibiotic resistance. The results suggest that Dryocrasin ABBA is a promising candidate drug for the treatment of Staphylococcus aureus infection[4].

C43H48O16

820.8316

820.294

12777-70-7

3082025

Light yellow to green yellow solid powder

1.5±0.1 g/cm3

1089.0±65.0 °C at 760 mmHg

626.1±30.8 °C

0.0±0.3 mmHg at 25°C

1.673

8.08

304.72

10

16

14

59

1760

0

PRVKSKWNDSLRBY-UHFFFAOYSA-N

InChI=1S/C43H48O16/c1-9-11-24(46)28-32(50)18(30(48)20(34(28)52)14-22-36(54)26(16(3)44)40(58)42(5,6)38(22)56)13-19-31(49)21(35(53)29(33(19)51)25(47)12-10-2)15-23-37(55)27(17(4)45)41(59)43(7,8)39(23)57/h48-57H,9-15H2,1-8H3

2-acetyl-4-[[3-[[3-[(5-acetyl-2,6-dihydroxy-3,3-dimethyl-4-oxocyclohexa-1,5-dien-1-yl)methyl]-5-butanoyl-2,4,6-trihydroxyphenyl]methyl]-5-butanoyl-2,4,6-trihydroxyphenyl]methyl]-3,5-dihydroxy-6,6-dimethylcyclohexa-2,4-dien-1-one

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

注意: 如下所列的是一些常用的体内动物实验溶解配方，主要用于溶解难溶或不溶于水的产品（水溶度<1 mg/mL）。 建议您先取少量样品进行尝试，如该配方可行，再根据实验需求增加样品量。

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注射用配方1: DMSO : Tween 80： Saline = 10 : 5 : 85 (如： 100 μL DMSO → 50 μL Tween 80 → 850 μL Saline)
*生理盐水/Saline的制备：将0.9g氯化钠/NaCl溶解在100 mL ddH ₂ O中，得到澄清溶液。
注射用配方 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL DMSO → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)
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示例: 以注射用配方 3 (DMSO : Corn oil = 10 : 90) 为例说明, 如果要配制 1 mL 2.5 mg/mL的工作液, 您可以取 100 μL 25 mg/mL 澄清的 DMSO 储备液，加到 900 μL Corn oil/玉米油中, 混合均匀。

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注射用配方 4: DMSO : 20% SBE-β-CD in Saline = 10 : 90 [如：100 μL DMSO → 900 μL (20% SBE-β-CD in Saline)]
*20% SBE-β-CD in Saline的制备（4°C，储存1周）：将2g SBE-β-CD (磺丁基-β-环糊精) 溶解于10mL生理盐水中，得到澄清溶液。
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注射用配方 8: 溶解于Cremophor/Ethanol (50 : 50), 然后用生理盐水稀释。
注射用配方 9: EtOH : Corn oil = 10 : 90 (如： 100 μL EtOH → 900 μL Corn oil)
注射用配方 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL EtOH → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)

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口服配方 1: 悬浮于0.5% CMC Na (羧甲基纤维素钠)
口服配方 2: 悬浮于0.5% Carboxymethyl cellulose (羧甲基纤维素)
示例: 以口服配方 1 (悬浮于 0.5% CMC Na)为例说明, 如果要配制 100 mL 2.5 mg/mL 的工作液, 您可以先取0.5g CMC Na并将其溶解于100mL ddH2O中，得到0.5%CMC-Na澄清溶液；然后将250 mg待测化合物加到100 mL前述 0.5%CMC Na溶液中，得到悬浮液。

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口服配方 3: 溶解于 PEG400 (聚乙二醇400)
口服配方 4: 悬浮于0.2% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 5: 溶解于0.25% Tween 80 and 0.5% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 6: 做成粉末与食物混合

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注意: 以上为较为常见方法，仅供参考， InvivoChem并未独立验证这些配方的准确性。具体溶剂的选择首先应参照文献已报道溶解方法、配方或剂型，对于某些尚未有文献报道溶解方法的化合物，需通过前期实验来确定（建议先取少量样品进行尝试），包括产品的溶解情况、梯度设置、动物的耐受性等。

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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：
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10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
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