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1.

Background

Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC50 values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereomers complexed with South African HIV protease (C-SA) was performed. This will enable us to rationalize the considerable difference between inhibitory concentration (IC50) of PCU-lactam-NH-EAIS and PCU-lactone-CO-EAIS peptides.

Results

The PCU-lactam model exhibited more negative calculated binding free energies of solvation than the PCU-lactone model. The same trend was observed for the PCU-peptide inhibitors, which correspond to the experimental activities for the PCU-lactam-NH-EAIS peptide (IC50 = 0.076 μM) and the PCU-lactone-CO-EAIS peptide inhibitors (IC50 = 0.850 μM). Furthermore, a density functional theory (DFT) study on the natural atomic charges of the nitrogen and oxygen atoms of the three PCU-lactam, PCU-lactim and PCU-lactone models were performed using natural bond orbital (NBO) analysis. Electrostatic potential maps were also used to visualize the electron density around electron-rich regions. The asymmetry parameter (η) and quadrupole coupling constant (χ) values of the nitrogen and oxygen nuclei of the model compounds were calculated at the same level of theory. Electronic molecular properties including polarizability and electric dipole moments were also calculated and compared. The Gibbs theoretical free solvation energies of solvation (∆Gsolv) were also considered.

Conclusions

A general trend is observed that the lactam species appears to have a larger negative charge distribution around the heteroatoms, larger quadrupole constant, dipole moment and better solvation energy, in comparison to the PCU-lactone model. It can be argued that these characteristics will ensure better eletronic interaction between the lactam and the receptor, corresponding to the observed HIV protease activities in terms of experimental IC50 data.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0115-5) contains supplementary material, which is available to authorized users.  相似文献   
2.
In this study we report the synthesis and activity against bovine viral diarrhea virus (BVDV) of a novel series of bicycle δ-sultones containing γ-lactones. BVDV is responsible for major losses in cattle. Some of the synthesized δ-sultones showed pronounced anti-BVDV activity with EC50 values of 0.12–1.0 μM and no significant cytotoxicity. Among them, the ortho bromosubstituted derivative 4f (EC50 = 0.12 μM) showed better antiviral activity than other derivatives and was 10 fold more that of than positive control ribavirin (EC50 = 1.3 μM). BVDV is also considered to be a valuable surrogate for the hepatitis C virus (HCV) in antiviral drug studies. The above results provided a novel candidate for the development of anti-HCV agents.  相似文献   
3.
D-Saccharic acid 1,4-lactone (DSL) is a derivative of D-glucaric acid. It is a beta-glucuronidase inhibitor and possesses anticarcinogenic, detoxifying, and antioxidant properties. In the present study, the protective effects of DSL were investigated against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity and cell death in vitro using murine hepatocytes. Exposure of TBHP caused a reduction in cell viability, enhanced the membrane leakage, and disturbed the intracellular antioxidant machineries in murine hepatocytes. Investigating the signaling mechanism of TBHP-induced cellular pathophysiology and protective action of DSL, we found that TBHP exposure disrupted mitochondrial membrane potential, facilitated cytochrome c release in the cytosol, and led to apoptotic cell death via mitochondria-dependent pathways. DSL counteracted these changes and maintained normalcy in hepatocytes. Combining, results suggest that DSL possesses the ability to ameliorate TBHP-induced oxidative insult, cytotoxicity, and apoptotic cell death probably due to its antioxidant activity and functioning via mitochondria-dependent pathways.  相似文献   
4.
Kim MR  Jung HJ  Min BS  Oh SR  Kim CS  Ahn KS  Kang WS  Lee HK 《Phytochemistry》2002,59(8):861-865
Two C(16)-lactonic compounds, actinolides A-B (1-2), were isolated from the stems of Actinodaphne lancifolia, together with five known lactones (3-7) and three known lignans (8-10). Their structures were determined spectroscopically, which included 2D NMR spectroscopic analysis.  相似文献   
5.
Bioguided-fractionation of a CH(2)Cl(2) extract of the stems of Uvaria klaineana (Annonaceae) led to isolation of klaivanolide, a novel bisunsaturated 7-membered lactone (5-acetoxy-7-benzoyloxymethyl-7H-oxepin-2-one), together with benzyl benzoate. Klaivanolide showed potent in vitro antileishmanial activity against both sensitive and amphotericin B-resistant promastigote forms of Leishmania donovani with IC(50) values of 1.75 and 3.12 microM, respectively. The compound also showed in vitro trypanocidal activity against trypomastigote forms of Trypanosoma brucei brucei GVR 35. Its structure was established by 1D and 2D NMR and other spectroscopic techniques.  相似文献   
6.
《Process Biochemistry》2014,49(10):1637-1646
One-pot conversion with whole cells of bacteria was performed for biooxidation of meso monocyclic (3a–b) and bicyclic diols (3c–e) into corresponding chiral lactones of bicyclo[4.3.0]nonane structure (2a–b) as well as exo- and endo-bridged lactones with the structure of [2.2.1] (3c–d) and [2.2.2] (3e). Micrococcus sp. DSM 30771 was selected as biocatalyst with significant alcohol dehydrogenase activity. Among tested strains, microbial oxidation of meso diols 3a–e catalyzed by Micrococcus sp. afforded enantiomerically pure ((+)-(2S,3R)-2c (ee = 99%), (+)-(2S,3R)-2e (ee = 99%)) or enriched ((+)-(1S,5R)-2a (ee = 90%), (−)-(1S,5R)-2b (ee = 86%), (+)-(2S,3R)-2d (ee = 80%)) lactone moieties. Comparative study with respect to microbial cultivation as well as biooxidation was undertaken to verify agreement of secondary metabolite biosynthesis in different scales: from MTP (4 mL), across shake flask (100 mL) till bioreactor (4 L). The results from biotransformations showed quite similar dependence in oxidation of all substrates 3a–e in MTP and flasks as well, thereby confirmed the validity and reasonable approach of using MTP for preliminary studies.  相似文献   
7.
毛茛属刺果毛茛化学成分研究   总被引:1,自引:0,他引:1  
从刺果毛茛Ranunculus muricatus Linn.全草乙醇提取物分离得到17个化合物,通过MS、NMR等方法鉴定为:小毛茛内酯(1)、阿魏酸(2)、对羟基香豆酸(3)、原儿茶酸(4)、咖啡酰基(5)、丹参素(6)、丹参素甲酯(7)、山萘酚-3-O-β-D-槐糖-7-O-β-D-葡萄糖苷(8)、槲皮素-3-O-(2’’’-E-咖啡酰基)-α-L-阿拉伯糖-(1→2)-β-D-葡萄糖-7-O-β-D-葡萄糖苷(9)、山萘酚-3-O-β-D-葡萄糖-7-O-β-D-葡萄糖苷(10)、槲皮素-7-O-β-D-葡萄糖苷(11)、槲皮素-3-O-(2’’’-E-咖啡酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(12)、山萘酚-3-O-(2’’’-E-咖啡酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(13)、槲皮素-3-O-(2’’’-E-阿魏酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(14)、山萘酚-3-O-(2’’’-E-对羟基香豆酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(15)、芹菜素-8-C-α-L-阿拉伯糖-6-C-β-D-葡萄糖苷(16)、芹菜素-6-C-β-D-葡萄糖-8-C-β-D-葡萄糖苷(17)。除化合物4外,其他化合物均为首次从刺果毛茛中分离得到。  相似文献   
8.
Lactone compounds are widely distributed in nature and play important roles in organisms. These compounds are synthesized and metabolized enzymatically in vivo; however, detailed investigation of these enzymes lags behind that of other common enzymes. In this paper, recent work on the enzymes involved in the metabolism of lactone compounds will be reviewed. In particular, fundamental and application studies on lactonases and Baeyer-Villiger monooxgenases of microbial origin are described.  相似文献   
9.
Five new lactones, litsenolide F1 (1), lisealactone H1 (10), lisealactone H2 (11), akolactone D (13), and akolactone E (14), along with thirteen known compounds were isolated from the pericarps of Litsea japonica (Thunb.) Jussieu. Their chemical structures were elucidated by extensive spectroscopic analyses, including 1D and 2D NMR, HRMS, and chemical methods. The isolated compounds were evaluated for their inhibitory effects on NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Among them, 2-alkylidene-3-hydroxy-4-methylbutanolide derivatives (compounds 19) exhibited the most potent activity, with IC50 values in the range of 2.9–12.8?μM. In additon, compounds 1, 3, 4, and 6 showed inhibition of iNOS and COX-2 expression in concentration-dependent manner. Compound 3 suppresses mRNA expression of iNOS, COX-2, IL-6, and TNF-α in LPS-stimulated RAW264.7 cells. Based on these evidence, the isolated lactones from L. japonica could be promissing candidates for the development of new anti-inflammatory agents.  相似文献   
10.
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