Biflorin: an o-naphthoquinone of clinical significance

Naphthoquinones biflorin and bis-biflorin (Capraria biflora) as possible inhibitors of the fungus Candida auris polymerase: molecular docking, molecular dynamics, MM/GBSA calculations and in silico drug-likeness study

A new worldwide concern has emerged with the recent emergence of infections caused by Candida auris. This reflects its comparative ease of transmission, substantial mortality, and the increasing level of resistance seen in the three major classes of antifungal drugs. Efforts to create a better design for structure-based drugs that described numerous modifications and the search for secondary metabolic structures derived from plant species are likely to reduce the virulence of several fungal pathogens. In this context, the present work aimed to evaluate in silico two naphthoquinones isolated from the roots of Capraria biflora, biflorin, and its dimmer, bis-biflorin, as potential inhibitors of Candida auris polymerase. Based on the simulation performed with the two naphthoquinones, biflorin and bis-biflorin, it can be stated that bis-biflorin showed the best interactions with Candida auris polymerase. Still, biflorin also demonstrated favorable coupling energy. Predictive pharmacokinetic assays suggest that biflorin has high oral bioavailability and more excellent metabolic stability compared to the bis-biflorin analogue. constituting a promising pharmacological tool.Communicated by Ramaswamy H. Sarma.

4,5-Seco-5,10-friedo-abietane-type diterpenoids with anticancer activity from Salvia atropatana Bunge

The purpose of this study is cytotoxicity-guided isolation of the petroleum ether fraction from the roots of Salvia atropatana for the first time, which has shown to growth inhibition and apoptosis induction in MCF-7 and PC3 cells. Bioassay-guided isolation method was conducted for finding compounds with highest cytotoxicity. Different extracts were prepared from the roots of Salvia atropatana. All extracts were tested for their cytotoxic activity against three cancer cell lines (PC3, MCF-7, and MDA-MB-231). The most cytotoxic extract was chosen for further isolation by column chromatography and HPLC. The chemical structures were determined by spectroscopic methods including 1D and 2D NMR. From the petroleum ether extract, four abietane-type diterpenoids, including a new abietane-type diterpenoid, named atropatanene (1), together with three known diterpenoids, 7α-acetoxyroyleanone (2), and a mixture of two isomers, saprorthoquinone and aethiopinone (3+4), were isolated. The latter exhibited substantial cytotoxicity with IC₅₀ value of 8.73 μg/ml against PC3 cells and led to an increasing number of cells in the subG1 region and an increase in the amount of Bax and cleavage of PARP protein, indicating apoptotic cell death. Owing to its numerous biological activities, Salvia species could be represented as a natural potential source against several cancer cell lines.

Biflorin Ameliorates Memory Impairments Induced by Cholinergic Blockade in Mice

To examine the effect of biflorin, a component of Syzygium aromaticum, on memory deficit, we introduced a scopolamine-induced cognitive deficit mouse model. A single administration of biflorin increased latency time in the passive avoidance task, ameliorated alternation behavior in the Y-maze, and increased exploration time in the Morris water maze task, indicating the improvement of cognitive behaviors against cholinergic dysfunction. The biflorin-induced reverse of latency in the scopolamine-treated group was attenuated by MK-801, an NMDA receptor antagonist. Biflorin also enhanced cognitive function in a naïve mouse model. To understand the mechanism of biflorin for memory amelioration, we performed Western blot. Biflorin increased the activation of protein kinase C-ζ and its downstream signaling molecules in the hippocampus. These results suggest that biflorin ameliorates drug-induced memory impairment by modulation of protein kinase C-ζ signaling in mice, implying that biflorin could function as a possible therapeutic agent for the treatment of cognitive problems.

Allyl and prenyl ethers of mansonone G, new potential semisynthetic antibacterial agents

Four natural 1,2-naphthoquinones: mansonones C, E, G, and H were isolated from the dichloromethane extract of Mansonia gagei Drumm. heartwoods. Mansonone G was further converted to eight ether and four ester analogues. The structures of mansonones and the analogues were well-confirmed by spectroscopic techniques. All compounds were evaluated for their antibacterial activity against Gram-positive and negative bacteria. Further modification of mansonone G furnished certain analogues displaying better activity than natural mansonones. Particularly, allyl and prenyl ethers of mansonone G exhibited better activity against Staphylococcus aureus with MIC sixty-four times better than their natural compound.