Validamycin A (Jinggangmycin A)   中文名称: 井岗霉素

Trehalase, tyrosinase. Validamycin A inhibits trehalase from Rhizoctonia solani with an IC₅₀ of 7.2 × 10⁻⁵ M (72 μM), and its aglycone validoxylamine A inhibits trehalase competitively with a Kᵢ of 1.9 × 10⁻⁹ M (1.9 nM). It inhibits mushroom tyrosinase with an IC₅₀ of 19.23 ± 0.26 mM, and a mixed-type inhibition constant Kᵢ of 5.893 ± 0.038 mM. [1,2,3]
Antibiotic[1], IC50: 72 μM (trehalase)[2], Ki: 5.893 mM (tyrosinase)[3]

对立枯丝核菌海藻糖酶的抑制：Validamycin A对立枯丝核菌海藻糖酶表现出强效抑制活性，IC₅₀为7.2 × 10⁻⁵ M。其苷元validoxylamine A的抑制活性更强，Kᵢ为1.9 × 10⁻⁹ M。Validamycin A对来自立枯丝核菌的纤维素酶、果胶酶、几丁质酶、α-淀粉酶、α-葡萄糖苷酶和β-葡萄糖苷酶均无显著抑制作用。[2]
对酪氨酸酶的抑制：Validamycin A以剂量依赖性、可逆的方式抑制蘑菇酪氨酸酶，IC₅₀为19.23 ± 0.26 mM。抑制类型为混合型抑制，Kᵢ为5.893 ± 0.038 mM，α值为2.096 ± 0.546。失活动力学符合一级反应动力学，分为快相和慢相两个阶段，快相速率常数范围为1.54 × 10⁻³至3.60 × 10⁻³ s⁻¹，慢相速率常数范围为0.45 × 10⁻³至1.45 × 10⁻³ s⁻¹。[3]
对真菌生长和形态的影响：在“树枝状试验法”中，Validamycin A在低至0.01 μg/mL的浓度下即可引起立枯丝核菌菌丝异常分支。在富营养培养基上不显著抑制生长，但在水琼脂上特异性诱导菌丝异常分支并停止菌落发育。[2]
对黄曲霉的影响：Validamycin A在1 μg/mL浓度下显著增加黄曲霉分生孢子中海藻糖水平，延迟分生孢子萌发（特别是在10和12小时），并降低真菌黏附性。Validamycin A对黄曲霉ATCC204304的最低抑菌浓度(MIC)为1 μg/mL。[1]
与两性霉素B的联合作用：在棋盘格实验中，validamycin A与两性霉素B对黄曲霉ATCC204304表现出相加效应（FICI = 0.625）。在两性霉素B耐药（MIC > 4 μg/mL）的黄曲霉临床分离株中，两者联合表现出协同效应，FICI值为0.25–0.28，对应的validamycin A和两性霉素B浓度分别为0.125 μg/mL和2 μg/mL。[1]
对立枯丝核菌海藻糖代谢的影响：Validamycin A在0.1 μg/mL浓度下显著抑制立枯丝核菌菌丝内海藻糖的降解，表明其在体内抑制海藻糖酶活性。[2]
立枯丝核菌细胞摄取与代谢：Validamycin A可被立枯丝核菌菌丝摄取，并在细胞内被β-葡萄糖苷酶水解为具有更高抑制活性的validoxylamine A。Validamycin A（β-D-葡萄糖苷）比其苷元（validoxylamine A）或α-D-葡萄糖苷（validamycin D）更容易被摄取。[2]
井冈霉素 A（0.5–1 μg/mL；18 小时）可阻止 A 生长。分生孢子萌发并抑制黄霉菌[1]。对于人支气管上皮细胞，井冈霉素A没有细胞毒性[1]。 HIS85、HIS244、GLU256、HIS259 和 ASN260 属于有效霉素 A 直接结合的酪氨酸酶活性位点中的残基 [1]。

海藻糖酶抑制实验（立枯丝核菌）：通过比色法测定从海藻糖释放的D-葡萄糖来检测海藻糖酶活性。反应混合物包含125 μL酶溶液、50 μL 0.4 M海藻糖、200 μL抑制剂溶液或水，以及125 μL 0.2 M磷酸盐缓冲液（pH 6.0）。在37°C孵育15分钟后，使用葡萄糖氧化酶法测定释放的葡萄糖。[2]
酪氨酸酶抑制实验：通过监测L-DOPA氧化为多巴色素时475 nm处吸光度的增加，用分光光度法测定酪氨酸酶活性。测定混合物包含2 mM L-DOPA、1.0 μg/mL酪氨酸酶和不同浓度的validamycin A，溶于50 mM磷酸钠缓冲液（pH 7.0），在25°C下进行。[3]
抑制动力学分析：使用Lineweaver-Burk双倒数图确定抑制类型。绘制斜率与y截距相对于抑制剂浓度的二级图，通过线性拟合计算混合型抑制的Kᵢ和α值。[3]
失活动力学：通过将酶与不同浓度的validamycin A（3.125–50 mM）共孵育进行酪氨酸酶抑制的时间进程研究。在不同时间间隔收集等分试样，测量残留活性。半对数图显示双相一级失活动力学，从斜率确定速率常数。[3]
荧光光谱分析：在280 nm激发后测量酪氨酸酶的内源色氨酸荧光（发射波长300–400 nm），以监测validamycin A结合引起的三级结构变化。使用ANS结合荧光（激发390 nm，发射400–600 nm）评估表面疏水性的变化。从荧光猝灭数据计算结合常数（K = 0.06 ± 0.012 mM⁻¹）和结合位点数（n = 1.06 ± 0.37）。[3]
计算对接与分子动力学模拟：使用AutoDock Vina进行对接，CHARMM结合CGENFF参数进行分子动力学模拟，研究validamycin A与酪氨酸酶的结合模式。选择最低能量簇、最大簇和活性位点附近的簇进行10 ns模拟。鉴定出五个残基（HIS85、HIS244、GLU256、HIS259和ASN260）与validamycin A相互作用，距离小于4 Å。[3]

黄曲霉活力测定（XTT）：将黄曲霉分生孢子（10³个）接种于含或不含validamycin A的不同培养基的96孔板中，在37°C孵育18小时。加入XTT溶液（0.5 mg/mL溶于PBS），孵育15分钟，离心后测定上清液在490 nm的吸光度，评估真菌活力。[1]
真菌黏附性测定（结晶紫）：将黄曲霉分生孢子（10⁵个/mL）接种于含或不含validamycin A（1 μg/mL）的沙氏葡萄糖肉汤的96孔板中，在37°C孵育24小时。轻轻洗涤后，用0.1%结晶紫染色，乙醇脱色，测定600 nm吸光度。[1]
黄曲霉分生孢子海藻糖测定：在含或不含validamycin A（1 μg/mL）的SDA上培养5天后收集黄曲霉分生孢子（2 × 10⁸个）。煮沸分生孢子，离心，使用葡萄糖氧化酶法测定上清液中的海藻糖含量。[1]
萌发实验：将黄曲霉分生孢子（1 × 10⁸个）接种于含或不含validamycin A（1 μg/mL）的沙氏葡萄糖肉汤中，在37°C下振荡培养（200 rpm）。在不同时间点，显微镜下计数100个分生孢子，计算萌发百分比。[1]
细胞毒性实验（LDH）：将BEAS-2B人支气管上皮细胞（1 × 10⁴个）与不同浓度的validamycin A（1 μg/mL至1 mg/mL）共孵育24小时。在450 nm处测定LDH释放，计算相对于高对照和低对照的细胞毒性百分比。在高达1 mg/mL的浓度下未观察到显著细胞毒性。[1]
细胞增殖测定[1]
细胞类型： 黄曲霉 ATCC204304
测试浓度： 0.5 μg/mL、1 μg/mL
孵化时间：18小时
实验结果：抑制黄曲霉的生长。

Cellular uptake and metabolism in R. solani: Validamycin A was taken up by R. solani mycelia, and validoxylamine A (the active metabolite) was detected intracellularly within 2 hours, indicating hydrolysis by β-glucosidase. Validamycin A (β-D-glucoside) was more efficiently taken up than validoxylamine A (aglycone) or validamycin D (α-D-glucoside). [2]

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Metabolism / Metabolites
In animals, cleavage to glucose and an amine residue.

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Biological Half-Life
Less than or equal to 5 hr

Cytotoxicity to human bronchial epithelial cells: In BEAS-2B cells, validamycin A at concentrations ranging from 1 μg/mL to 1 mg/mL showed no significant cytotoxicity (LDH release) compared to controls. [1]
Insecticidal activity via tyrosinase inhibition: Validamycin A was proposed as a potential insect growth regulator due to its tyrosinase inhibitory activity, which could interfere with melanization and cuticle hardening in insects. [3]

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Toxicity Data
LC50 (rat) > 5,000 mg/m3

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Non-Human Toxicity Values
LD50 Rat oral > 20,000 mg/kg
LD50 Mice oral > 20,000 mg/kg
LD50 Rat percutaneous > 5000 mg/kg

[1]. The Inhibitory Effect of Validamycin A on Aspergillus flavus. Int J Microbiol. 2020: 3972415.

[2]. Effect of validamycins on glycohydrolases of Rhizoctonia solani. J Antibiot (Tokyo). 1987 Apr;40(4):526-32.

[3]. The effect of validamycin A on tyrosinase: inhibition kinetics and computational simulation. Int J Biol Macromol. 2013 Apr;55:15-23.

Source and structure: Validamycin A is a pseudo-trisaccharide antibiotic produced by Streptomyces hygroscopicus subsp. limoneus, consisting of a valienamine-validamine disaccharide (validoxylamine A) linked to a D-glucose residue via a β-glycosidic bond. It is widely used as an agricultural antibiotic against rice sheath blight caused by Rhizoctonia solani. [2,3]
Mechanism of action in fungi: Validamycin A acts as a prodrug that is taken up by fungal cells and hydrolyzed to validoxylamine A, a potent competitive inhibitor of trehalase. Trehalase inhibition leads to accumulation of trehalose, disruption of energy metabolism, and abnormal hyphal branching, ultimately inhibiting fungal growth. [2]
Mechanism of tyrosinase inhibition: Validamycin A binds to tyrosinase at the active site, interacting with residues HIS85, HIS244, GLU256, HIS259, and ASN260, which are involved in copper coordination. The mixed-type inhibition suggests binding to both free enzyme and enzyme-substrate complex. [3]
Synergistic antifungal activity: The combination of validamycin A with amphotericin B showed synergistic effects against amphotericin B-resistant clinical isolates of A. flavus, suggesting a potential role as an adjunctive therapy for fungal infections. [1]
Clinical relevance: Validamycin A has low toxicity to humans and is already extensively used in agriculture, making it an attractive candidate for repurposing as an antifungal agent or insect growth regulator. [1,3]
Validamycin A is a member of the class of validamycins that is (1R,2S,3S,4S,6R)-4-amino-6-(hydroxymethyl)cyclohexane-1,2,3-triol in which the hydroxy group at position 1 has been converted to its beta-D-glucoside and in which one of the hydrogens attached to the nitrogen is replaced by a (1R,4R,5R,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl group. It is the major validamycin produced by Streptomyces hygroscopicus. It has a role as an EC 2.4.1.231 [alpha,alpha-trehalose phosphorylase (configuration-retaining)] inhibitor, an EC 2.4.1.64 (alpha,alpha-trehalose phosphorylase) inhibitor, an EC 3.2.1.28 (alpha,alpha-trehalase) inhibitor and an antifungal agrochemical. It is a member of validamycins, a secondary amino compound, a polyol and an antibiotic fungicide. It is a conjugate base of a validamycin A(1+).
Validamycin A has been reported in Streptomyces anthocyanicus, Streptomyces hygroscopicus, and Streptomyces lividans with data available.

C20H35NO13

497.49

497.21

C, 48.29; H, 7.09; N, 2.82; O, 41.81

37248-47-8

443629

White to off-white solid powder

1.7±0.1 g/cm3

813.7±65.0 °C at 760 mmHg

130-135ºC

445.9±34.3 °C

0.0±6.6 mmHg at 25°C

1.689

-5.43

253.02

12

14

7

34

697

14

C1[C@@H]([C@H]([C@@H]([C@H]([C@H]1N[C@H]2C=C([C@H]([C@@H]([C@H]2O)O)O)CO)O)O)O[C@H]3[C@@H]([C@H]([C@@H]([C@H](O3)CO)O)O)O)CO

JARYYMUOCXVXNK-CSLFJTBJSA-N

InChI=1S/C20H35NO13/c22-3-6-1-8(12(26)15(29)11(6)25)21-9-2-7(4-23)19(17(31)13(9)27)34-20-18(32)16(30)14(28)10(5-24)33-20/h1,7-32H,2-5H2/t7-,8+,9+,10-,11-,12+,13+,14-,15+,16+,17-,18-,19-,20+/m1/s1

(2R,3R,4S,5S,6R)-2-[(1R,2R,3S,4S,6R)-2,3-dihydroxy-6-(hydroxymethyl)-4-[[(1S,4R,5S,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl]amino]cyclohexyl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol

Validamycin; jinggangmycin; VALIDAMYCIN A; 37248-47-8; Valimon;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： (1). 本产品在运输和储存过程中需避光。  (2). 请将本产品存放在密封且受保护的环境中（例如氮气保护），避免吸湿/受潮。

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

H2O : 125 mg/mL (251.26 mM)

配方 1 中的溶解度: 100 mg/mL (201.01 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；
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