# State-of-the-Art and Opportunities for Bioactive Pentacyclic Triterpenes from Native Mexican Plants
## 2 Pentacyclic Triterpenes from Mexican Plants
### Biological Activity Survey of PCTs Found in Mexican Plants
The lowest bacilli load per lung was observed on day 30 (approximately 0.003 \(\times\) 10\({}^{6}\) bacilli/lung with respect to 0.005 \(\times\) 10\({}^{6}\) bacilli/lung in the control population) in the PCTs mixture plus antibiotics. Instead, the lowest lung surface percentage affected by pneumonia occurred on day 60, with an approximate percentage of 13% with respect to 10% of mice treated only with antibiotics. At the transcriptional level, for IFN-\(\upgamma\), TNF-\(\upalpha\), and iNOS, PCTs plus antibiotics induced high expression [33]. PCTs' antimicrobial activity has also been analyzed by [PERSON] et al., who extracted 3\(\upbeta\)-friedinol **(15)** and a mixture of \(\upalpha\)-amyrin **(16)** and \(\upbeta\)-amyrin **(17)** from _Heterotheca inuloides_ (Mexican arnica) and tested them against _Helicobacter_ pylori, employing concentrations ranging from 1.95 to 31.25 \(\upmu\)g/mL [34]. In this study, none of the tested concentrations showed a 100% bacterial inhibition of the bacterial growth and due to this reason, testing of the compounds at concentrations higher than 31.25 \(\upmu\)g/mL is required to identify their respective MIC. Lantanilic acid **(18)**, camaric acid **(19)**, and lantadene B **(20)** from _Lantana camara_ var. _aculeata_ (L.) were isolated and evaluated against _Leishman mexicana_ promastigotes and _L. amazonensis_ amastigotes [35]. It is important to mention, prior to the isolation of the noted compounds, that a series of chromatographic fractions were proven. Both **(18)** and **(19)** acids, together with **(20)**, were part of a chromatographic fraction (mixture) that led to an IC\({}_{50}\) of 7.9 \(\pm\) 0.3 and 11.2 \(\pm\) 2.2 \(\mu\)g/mL against _L. amazonensis_ and _L. mexicana_, respectively. Additionally, **(18)** and **(19)** in another fraction showed an IC\({}_{50}\) of 23.6 \(\pm\) 2.6 and 2.8 \(\pm\) 0.5 \(\mu\)g/mL with the same species. Additionally, **(20)** was identified in a mixture, with an IC\({}_{50}\) of 8 \(\pm\) 1.1 and 22 \(\pm\) 9.3 \(\mu\)g/mL on _L. amazonensis_ and _L. mexicana_, respectively. As control drugs, pentamidine for _L. amazonensis_ and Glucantime(r) (Sanofi-Aventis) for _L. mexicana_ were used. In their isolated form, these PCTs had the following IC\({}_{50}\)s against _L. mexicana_: 9.50 \(\pm\) 0.28 \(\mu\)M for **(18)**, 2.52 \(\pm\) 0.08 \(\mu\)M for **(19)**, and 23.45 \(\pm\) 2.15 \(\mu\)M for **(20)** while the reference drug had an IC\({}_{50}\) of 11,000 \(\pm\) 2.15 \(\mu\)M. In addition, the mixtures of the compounds presented a cytotoxic effect against BALB/c mouse peritoneal macrophages when tested from 12.5 to 200 \(\mu\)g/mL and a half maximal cytotoxic concentration (CC\({}_{50}\)) higher than 100 \(\mu\)g/mL [35]. Recently, a multi-institutional research group reported cytotoxic and antibacterial activity in _Cisus incisa_ leaf extracts due in part to \(\alpha\)-amyrin-3-O-\(\beta\)-D-glucopyranoside **(21)** among other phytocompounds [36]. For the antimicrobial testing, the team employed methicillin-resistant _Staphylococcus aureus_ (MRSA), linezolid-resistant _Staphylococcus epidermis_ (LRSE), vancomycin-resistant _Enterococcus facetum_ (VREF), carbapenemems-resistant _Acinetobacter baumanii_ (CRAB), _Escherichia coli_ producing extended-spectrum \(\beta\)-lactamase (ESBL), _Pseudomonas aeruginosa_ resistant to carbapenems (PARC), carbapenemems-resistant _Klebsiella pneumoniae_ NDM-1 + (New Delhi metallo-\(\beta\)-lactamase) (KPNDM-1+), _Klebsiella pneumoniae_ producer of ESBL (KPPB), and carbapenems-resistant _Klebsiella pneumoniae_ producer of OXA-48 oxacillinase (KPOX). The phytochemicals were applied at 200, 100, 50, 25, 12.5, 6.25, and 3.12 \(\mu\)g/mL, using levofloxacin at the same doses and DMSO as the negative control. This study showed that compound **(21)** had an MIC of 100 \(\mu\)g/mL against PARC; however, all the other tested microorganisms showed an MIC higher than 200 \(\mu\)g/mL [36]. PCTs have also been evaluated as anti-inflammatory agents. [PERSON] et al.