# Natural Compounds: A Dynamic Field of Applications
## 2 Contributions
In addition to an application as antimicrobials, natural compounds, in pure form or as a mixture like essential oils, are also investigated as therapeutic agents with a potential application on other health problems like aging-associated diseases, cancer, diabetes or wounds. _Portulaca olercea_ is used to alleviate a wide range of illnesses [54] and the extracts of this plant are known to possess a strong in vivo antioxidant capacity [55; 56]. Based on the potent antioxidant activity of natural compounds olercones isolated from this plant, [PERSON] et al. [57] carried out the synthesis of olercones D-F and evaluated their lifespan extension properties using the nematode _Caenorhabditis elegans_ as the experimental aging model. The olercone E was the most active to extend the lifespan of nematodes. Therefore, this compound should be considered in the development of anti-aging formulations. Another study where the antioxidant activity of natural compounds was assessed is proposed by [PERSON] et al. [58]. They optimize and validate a new green and fast microextraction procedure to obtain a phenolic acids-rich fraction from almond (_Prunus dulcis_) cold-pressed oil residue. The authors identified and quantified some of the most abundant constituents, protocatechuic, _p_-hydroxybenzoic, chlorogenic and _p_-coumaric acids and evaluated the antioxidant activity of this fraction. They suggest it as a source of antioxidant natural compounds with applications in food preservation, as medicine and in cosmetic preparations. Thus, it is given a contribution to value a very abundant by-product of the almond oil industry. _Salvia miltiorrhizae_ is one of the well-known traditional herbal medicines that has increased its scientific interest for its remarkable bioactivity against cardiovascular disease, renal damage, tumor angiogenesis and tumor cell invasion [59; 60]. [PERSON] et al. [61] evaluate a series of compounds isolated from _S. miltiorrhizae_ Radix such as tanshinone IIA, rosmarinic acid, salvianic acid A, salvianic acid B and caffe acid for their cytotoxic activity and mode of action against the HCT-116 cell line (human colorectal cancer, one of the most commonly diagnosed malignant diseases [62]). Only a terpenoid, tanshinone IIA, shows an inhibitory effect on cell survival (IC\({}_{50}\) 61.6 \(\mu\)g/mL). Morphological changes observed by Hoechst staining, an increase in cleaved caspase-7 and -8 and Bax expression as well as a decrease in Bcl-2 show this compound as an inducer of apoptosis which may be a useful chemotherapy strategy for patients with colorectal cancer. The flavonoid-type compounds named chalcones and flavanones are natural isomeric compounds which exhibit a broad range of patented therapeutic applications [63]. Since they are chemically very labile, chalcones and flavanones are also excellent scaffolds to medicinal chemistry and development of new drugs [64; 65; 66]. In this context, the optimization of the aldol condensation synthesis route by using unexplored bases to prepare hydroxylated and methoxylated chalcones and flavanones proposed by [PERSON] et al. [67] is well come. The application of the synthesized compounds as cytotoxic, antioxidant, antibacterial and anticholinesterase agents were evaluated, and SAR are discussed. The SAR study showed the same substituent group can cause an opposite effect on the level of different biological activities, given as a significant contribution to better understand the medicinal chemistry of these compounds. Plants are also considered to be sources of natural compounds with antidiabetic activity, as shown by [PERSON] et al. [68]. They studied the chemical composition of essential oils from _Prangos pubularia_ roots and describe it as a potent protein tyrosine phosphatase 1B (PTP-1B) inhibitor.