Antitumor, antibiotic and antileishmanial properties of the Pyranonaphthoquinone Psychorubrin from Mitracarpus frigidus

Abstract

The bioactivity guided fractionation of the dichloromethane extract of Mitracarpus frigidus afforded the pyranonaphthoquinone psychorubrin. This compound, hitherto unknown in the genus Mitracarpus, had its biological activity evaluated against one panel of bacteria and two fungi, three tumor cell lines (HL60, Jurkat and MCF-7) and four Leishmania species. Its identity was confirmed unambiguously by 1 H, 13 C, 1 H-COSY, IR and UV-Vis spectroscopy and mass spectrometry. Psychorubrin displayed a very promising antitumor with IC 50 of 4.5, 5.6 and 1.1 µM for HL60, Jurkat and MCF-7 cell lines, respectively. Antimicrobial activity, mainly against Cryptococcus neoformans (MIC of 87.3 µM) was observed. A pronounced antileishmanial potential was also verified with IC 50 varying from 1.7 to 2.7 µM for the Leishmania species tested. This is the first report of the presence of pyranonapthoquinones in the Mitracarpus genus, which may serve as a chemotaxonomical marker.

Anti-inflammatory and antioxidative effects of the methanolic extract of the aerial parts of Mitracarpus frigidus in established animal models

“…Detection was performed simultaneously at 210, 230, 254 and 280 nm. Four pure standards kaempferol, kaempferol‐ O ‐rutenoside, rutin and ursolic acid, previously identified in Mitracarpus genus[4,9] were used in this experiment as markers, and psychorubrin isolated from this species was also added [8]. For all experiments, MFM and the standards were dissolved in methanol.…”

“…[6,7] Recently, the pyranonaphthoquinone psychorubrin was first isolated from this extract. [8] Moreover, MFM revealed no toxicity signs in rat models. [7] Based on these considerations, the present study was undertaken to evaluate the anti-inflammatory and antioxidative effects of the methanolic extract obtained from the aerial parts of M. frigidus in well-established animal models, and to identify some of its major compounds.…”

“…Previous studies showed that the methanolic extract obtained from this plant (MFM) revealed the presence of flavonoids, tannins, alkaloids, terpenes and quinones, and presented antimicrobial, leishmanicidal, cytotoxic and laxative activities [6,7]. Recently, the pyranonaphthoquinone psychorubrin was first isolated from this extract [8]. Moreover, MFM revealed no toxicity signs in rat models [7]…”

Bioactive Naphthoquinones from Higher Plants

“…rosea HW Lapachol, dehydro-a-lapachone, dehydro-iso-a-lapachone [232] Tecomella (1) undulata R Lapachol, dehydro-a-lapachone [233] Acanthaceae (225) Avicennia ( orders is presented in Fig. 1.…”

Antibacterial and Antibiofilm Activities of Psychorubrin, a Pyranonaphthoquinone Isolated From Mitracarpus frigidus (Rubiaceae)

“…Because antimicrobial resistance and biofilm formation are a global public health challenge, there is a striking need of development of new biologically active molecules against multidrug-resistant bacteria and the adoption of medicinal crude extracts of plants to treat infectious diseases ( Subramani et al, 2017 ). In this context, our group has been studying different potential bioactive antibacterial compounds ( Pinto et al, 2017a , b ), including a natural product termed psychorubrin, a napthoquinone commonly found in a variety of plants ( Fabri et al, 2009 , 2012 ).…”