**2.16.** *Smilax trinervula*

acetyl groups confer a minor polarity to the compounds with the most activity and are key to

The roots of *S. scobinicaulis*, also called "Hei Ci Ba Quia" in Chinese, are used in traditional Chinese medicine for the treatment of arthritis, gout and inflammatory diseases [10]. Zhang *et al*. studied the chemical composition of *S*. *scobinicaulis*. These researchers first obtained a 95% aqueous ethanol extract from *S*. *scobinicaulis* roots and rhizomes. The extract was concentrated, suspended in water and partitioned with petroleum ether, ethyl acetate and butanol, successively. The ethyl acetate fraction was subjected to column chromatography. The purification was done to isolate and characterize two new flavones (7,3′,5′trihydroxy5,6,4′ trimethoxyflavone (**82**) and 7hydroxy5,6,3′,5′pentamethoxyflavone (**83**), **Figure 18**). The new flavones were evaluated for cell proliferation and viability assay against human breast adenocarcinoma (MCF-7) and human lung carcinoma (H520). The results showed a weak

activity for **82**, but 7hydroxy5,6,3′,5′pentamethoxyflavone, **83** was inactive [10].

**Figure 18.** Flavones from 95% ethanol extract of *S*. *scobinicaulis* roots.

*S. sebeana* is used in traditional Japanese and Chinese medicine to treat syphilis, arthritis and gout [11]. Ao *et al*. evaluated antioxidant activity in isolated phenolic compounds from methanol extracts of *S*. *sebeana* rhizomes and roots [11]. The methanol extract was obtained from maceration of fresh rhizomes and roots with methanol at room temperature. The methanol extract was concentrated, suspended in water and partitioned with hexane, ethyl acetate and butanol, successively. The ethyl acetate fraction was purified in two steps. First, it was subjected to column chromatography packed with sephadex LH20. Some of the fractions collected were selected to evaluate by HPLC to evaluate their components. Finally, the fractions with similar composition were pooled and purified by preparative HPLC. Also, the total phenol content and antioxidant activity expressed by DPPH radical scavenging were evaluated for methanol, ethyl acetate and butanol fractions. The major content of total phenols was

inducing antitumoral activity [55].

252 Phenolic Compounds - Natural Sources, Importance and Applications

**2.14.** *Smilax scobinicaulis*

**2.15.** *Smilax sebeana*

*S*. *trinervula* is a plant used in traditional Chinese medicine. The rhizomes and roots are sources of the Chinese drug "BaQuia" used as a diuretic and to treat pelvic inflammation [56]. Shu *et al*. carried out the first chemical designed to isolate phenolic compounds from rhizomes of *S*. *trinervula*. These researchers obtained a 70% aqueous ethanol extract and removed the solvent [56]. The extract was partitioned with ethyl acetate and butanol. The butanol fraction was subjected to macroporous resin column chromatography. The fractions obtained from this separation were subjected to repeated silica gel and sephadex LH20 column chromatography. Finally, the fractions were subjected to semipreparative HPLC. From this separation process were isolated eight phenolic compounds, three phenylpropanoids and five neolignans. These

**Figure 19.** Phenolic compounds from methanol extract of *S. sebeana* rhizomes and roots.

**Figure 20.** Two neolignans (**87** and **88**) with colon anticancer activity isolated of 70% ethanol extract from *S*. *trinervula* rhizomes.

compounds were evaluated against five human cell lines (SHSY5Y, SGC7901, HCT116, Lovo and Vero) using the MTT method. The anticancer evaluation showed (7*S*,8*R*)4,7,9,9′ tetrahydroxy3,3′dimethoxy8*O*4′neolignan (**87**) and (7*R*,8*R*)4,7,9,9′tetrahydroxy3,3′ dimethoxy-8-*O*4′neolignan (**88**) (**Figure 20**) had cytotoxic activity against Lovo [56].

### **3. Conclusions**

The polar extracts of *Smilax* species have high concentrations of phenolic compounds with high antioxidant activity. The main investigations of *Smilax* species are oriented to evaluate cytotoxicity against human cancer of cervical, lung, breast adenocarcinoma, liver and colon. The results of this review chapter showed flavonol, astilbin and phenylpropanoids binding to the sucrose nucleus (three moieties of ferulic acids and acetyl group to maximize activity) have a high potential as anticancer compounds. The anticancer activity with high concentrations of phenol compounds is attributed to antioxidant activity that induces cell apoptosis. The flavonols and phenylpropanoids can be isolated from ethyl acetate fractions obtained from a 95% aqueous ethanol extract of rhizomes and roots. Also, areal parts of *Smilax* plants contain phenolic compounds, for example, leaves and fruits. **Table 1** shows a resume of total phenols content and DPPH• radical scavenging activity of extracts and fractions obtained from five *Smilax* species. The leaves and fruits of *Smilax* plants contain phenolic compounds. The fruits are also a source of anthocyanins. The chemical studies based on isolation and evaluation of phenolic compounds are few and do not cover more than 10% of the total *Smilax* species. Most studies have been carried out on species that grow in Asia. Hence, it is necessary continue studying the phenolic compound content of *Smilax* species, as well as evaluating their antioxidant, antidiabetic and anticancer properties.


GAE mg: milligrams of gallic acid equivalent, dm: dry matter, IC50: extract concentration necessary to decrease 50% the initial concentration of DPPH•. The fractions were obtained from a partition of corresponding extract.This fraction was obtained from water extract.

**Table 1.** Total phenols, antioxidant activity expressed as DPPH radical scavenging activity of *Smilax* genus species.
