No abstract

No abstract

Growth inhibitory activities and nutritional indices of catalpol (1), 8-O-acetylharpagide (2), and harpagide (3) were determinated in larvae and adults of Tribolium castaneum, respectively. Compound 1 produced a series of allelochemical effects probably related with the DNA synthesis. This iridoid possessed the highest inhibitory activity against DNA polymerase. Molecular orbital calculations suggest that a pi-pi charge transfer recognition model could explain the action of iridioids toward nucleic acid synthesis.

No abstract

No abstract

Foodborne diseases have become a health issue worldwide, mainly due to the consumption of contaminated foods that are either raw, improperly heat treated or cross‐contaminated after adequate heat treatment foods. A group of alkaloids extracted from plants were tested to evaluate their antimicrobial effect against different strains of Yersinia enterocolitica and other foodborne bacteria. The results obtained reveal that oliveridine and pachypodanthine inhibited Y. enterocolitica growth, with MIC values of 25 μmol l−1 and 100 μmol l−1 respectively. The results indicated that both alkaloids are good growth inhibitors, but oliveridine showed greater inhibitory effect with lower MIC values. Inhibitory alkaloids can be developed as potential antimicrobials in food system to prevent or treat foodborne diseases, thus contributing to solve the global issue of contaminated food consumption. Significance and Impact of the Study Alkaloids are abundant secondary metabolites in plants and represent one of the most widespread class of compounds endowed with multiple and varied pharmacological properties. In this work, we propose two aporphinoid alkaloids extracted from plants as new antimicrobial agents. Oliveridine and pachypodanthine inhibited Yersinia enterocolitica growth for up to 96 h of culture. This is the first reported study of the activity of these alkaloids as antimicrobial compounds.

No abstract

Human Immunodeficiency Virus (HIV) is the viral agent of Acquired Immunodeficiency Syndrome (AIDS), and at present, there is no effective vaccine against HIV. Reverse Transcriptase (RT) is an essential enzyme for retroviral replication, such as HIV as well as for other RNA infectious viruses like Human T lymphocyte virus. Polymerases act in DNA metabolism, modulating different processes like mitosis, damage repair, transcription and replication. It has been widely documented that DNA Polymerases and Reverse Transcriptases serve as molecular targets for antiviral and antitumoral chemotherapy. Coumarins are oxygen heterocycles that are widely distributed throughout the plant kingdom. Natural coumarins have attraction due to their bioactive properties such as tumor promotion inhibitory effects, and anti-HIV activity. Coumarins and derivates exhibit potent inhibitory effects on HIV-1 replication in lymphocytes and compounds isolated from Calophyllum inophyllum or DCK derivates showed inhibitory activity against human RT. Furthermore, natural isocoumarins isolated from cultures of fungi or hydroxycoumarins were able to inhibit human DNA polymerase. In view of their importance as drugs and biologically active natural products, and their medicinally useful properties, extensive studies have been carried out on the synthesis of coumarin compounds in recent years. Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs), a class of antiretroviral chemotherapeutic agents, act by binding to an allosteric pocket showing, generally, low toxicity. This work tries to summarize the investigation about natural and synthetic coumarins with the ability to inhibit key enzymes that play a crucial role in DNA metabolism and their possible application as antiretroviral and antitumoral agents.