Envenomations due to snake bites are commonly treated by parenteral administration of horse or sheep-derived polyclonal antivenoms aimed at the neutralization of toxins. However, despite the widespread success of this therapy, it is still important to search for different venom inhibitors, either synthetic or natural, that could complement or substitute for the action of antivenoms. Several plants have been utilized in folk medicine as antiophidian. However, only a few species have been scientifically investigated and still less had their active components isolated and characterized both structurally and functionally. This article presents a review of plants showing neutralizing properties against snake venoms which were assayed in research laboratories, correlating them with ethnopharmacological studies, as (i) the part of the plant used as antidote, (ii) its respective genus and family and (iii) inhibition of the main pharmacological, toxic and enzymatic activities of snake venoms and isolated toxins. Protective activity of many of these plants against the lethal action of snake venoms has been confirmed by biological assays. Compounds in all of them belong to chemical classes capable of interacting with macromolecular targets (enzymes or receptors). Popular culture can often help to guide scientific studies. In addition, biotechnological application of these inhibitors, as helpful alternative or supplemental treatments to serum therapy, and also as important models for synthesis of new drugs of medical interest, needs to be better oriented and scientifically explored.

Crude extracts and fractions from aerial parts of Physalis angulata have been bioassayed for antimycobacterial activity. Fraction A1-29-12 containing physalins B, F and D exhibited a minimum inhibitory concentration value (MIC) against Mycobacterium tuberculosis H(37)Rv strain of 32 microg/mL. Purified physalin B and physalin D were also tested showing MIC values against Mycobacterium tuberculosis H(37)Rv strain of > 128 microg/mL and 32 microg/mL respectively, suggesting that physalin D plays a relevant role in the antimycobacterial activity displayed. Structural elucidation of both physalins D and B was based on detailed (13)C and (1)H NMR spectral analysis with the aid of 2D-correlation spectroscopy ((1)H-(1)H, COSY, HSQC and HMBC). The assignment of the (13)C chemical shift for physalin D is reported here for the first time.

No abstract

This review discusses the isolation, structural elucidation, and biological activities of halogenated indole alkaloids obtained from marine invertebrates. Meridianins and related compounds (variolins, psammopemmins, and aplicyanins), as well as aplysinopsins and leptoclinidamines, are focused on. A compilation of the 13C-NMR spectral data of these selected natural indole alkaloids is also provided.

The results suggest that the analgesic effects of the acetyl derivative of RA operate via a peripheral-mediated mechanism. The acetyl ester derivative of RA is potentially applicable as a new lead compound for the management of pain and inflammation.