Francis Prima, Chakraborty Kajal
Marine Bioprospecting Section of Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.
Marine Bioprospecting Section of Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.
Steroids. 2021 Aug;172:108858. doi: 10.1016/j.steroids.2021.108858. Epub 2021 May 7.
Two pregnane-type of steroid derivatives characterized as 5α-pregna-3β-methyl pent-3-enoate-12β, 16β diol-20-one (clathroid A) and 12β,15β- dihydroxypregna-4,6-diene-3,20-dione (clathroid B) were purified from the crude extract of the marine sponge, Clathria (Thalysias) vulpina (family Microcionidae) by extensive chromatographic fractionation. Spectroscopic methods including nuclear magnetic resonance spectroscopy were employed to characterize the purified clathroids A-B. The studied compounds exhibited duel inhibitory potentials against pro-inflammatory cyclooxygenase-2 and 5-lipoxygenase (median inhibitory concentration, IC < 1 mM), whereas the attenuation property of clathroid A against 5-lipoxygenase (IC 0.85 mM) was greater than the standard anti-inflammatory ibuprofen (IC 4.51 mM, p < 0.05). Greater selectivity index (anti cyclooxygense-2/anti cyclooxygense-1) of the studied clathroids (>1) than ibuprofen (0.43) attributed the greater selective attenuation properties towards pro-inflammatory inducible cyclooxygenase-2 than its constitutive isoenzyme cyclooxygenase-1. The antioxidant potentials of clathroid A against 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (IC 0.80 mM) and diphenyl-1-picrylhydrazyl (IC 0.83 mM) free radicals were greater than those of clathroid B (IC 0.86-0.96 mM). Structure-activity analyses showed that the bioactivities of the clathroids were directly related to their electronic parameters coupled with permissible hydrophobic properties. Clathroid A exhibited grater electronic parameter (topological polar surface area tPSA, 83.83) than clathroid B (74.60) and ibuprofen (37.30), which were found to be in agreement with the prospective anti-inflammatory profile of clathroid A. Clathroid A exhibited higher number of hydrogen bonding interactions with 5-lipoxygenase active site and lesser docking values, such as docking score (DS -12.90 kcal mol) and inhibition constant (Ki 1.11 nM) than those recorded by clathroid B (DS -10.49 kcal mol; Ki 13.88 nM). The molecular binding properties of clathroid A with 5-lipoxidase inferred that its docking score/ binding energy were positively correlated with their in vitro bioactivie potentilas. A putative biosynthetic pathway of the studied clathroids was proposed from a pregnenolone precursor. The present study recognized the potential of clathroid A isolated from C. (Thalysias) vulpina as prospective anti-inflammatory lead that could find its use in medicinal applications.
从海洋海绵Clathria (Thalysias) vulpina（微海绵科）的粗提物中，通过广泛的色谱分离，纯化出了两种孕烷类甾体衍生物，分别为5α-孕烷-3β-甲基戊-3-烯酸酯-12β,16β-二醇-20-酮（克拉索醇A）和12β,15β-二羟基孕烷-4,6-二烯-3,20-二酮（克拉索醇B）。采用包括核磁共振光谱在内的光谱方法对纯化后的克拉索醇A - B进行了表征。所研究的化合物对促炎环氧化酶-2和5-脂氧合酶均表现出双重抑制潜力（半数抑制浓度，IC < 1 mM），而克拉索醇A对5-脂氧合酶的抑制特性（IC 0.85 mM）强于标准抗炎药布洛芬（IC 4.51 mM，p < 0.05）。所研究的克拉索醇类化合物（>1）比布洛芬（0.43）具有更高的选择性指数（抗环氧化酶-2/抗环氧化酶-1），这归因于其对促炎诱导型环氧化酶-2比对其组成型同工酶环氧化酶-1具有更强的选择性抑制特性。克拉索醇A对2,2'-联氮-双(3-乙基苯并噻唑啉-6-磺酸)（IC 0.80 mM）和二苯基-1-苦基肼（IC 0.83 mM）自由基的抗氧化潜力大于克拉索醇B（IC 0.86 - 0.96 mM）。构效关系分析表明，克拉索醇类化合物的生物活性与其电子参数以及适当的疏水性质直接相关。克拉索醇A表现出比克拉索醇B（74.60）和布洛芬（37.30）更高的电子参数（拓扑极性表面积tPSA，83.83），这与克拉索醇A预期的抗炎特性相符。与克拉索醇B（对接分数DS -10.49 kcal mol；抑制常数Ki 13.88 nM）相比，克拉索醇A与5-脂氧合酶活性位点的氢键相互作用数量更多，对接值更小，如对接分数（DS -12.90 kcal mol）和抑制常数（Ki 1.11 nM）。克拉索醇A与5-脂氧化酶的分子结合特性表明，其对接分数/结合能与其体外生物活性潜力呈正相关。从孕烯醇酮前体出发，提出了所研究的克拉索醇类化合物的一种推测生物合成途径。本研究认识到从Clathria (Thalysias) vulpina中分离出的克拉索醇A作为潜在抗炎先导物在医药应用中的潜力。
