**1. Introduction**

Aging is a complicated biological process that is controlled by a large number of genetic and environmental factors [1–4]. Many theories have been proposed to account for the aging process, but none of them offers a fully acceptable explanation. Among all the theories, the free radical theory of aging, proposed by professor Harman in 1956 [5], has been extensively investigated. This theory continues to be revised and remains a strong theory for the aging process until now. Free radical theory explains that aging is caused by cumulative oxidative stress from free radicals, resulting in cell death and, eventually, death of the organism [6]. Hence, this theory suggests that antioxidants that can sacrificially scavenge ROS (reactive oxygen species) and/or RNS (reactive nitrogen species) are effective for delaying the aging process. Indeed, early studies have indicated that plant-derived polyphenol antioxidants, including curcumin, quercetin, and resveratrol, show therapeutic potential for aging and aging-associated diseases [7,8]. In addition, other synthetic flavonoids have been continuously reported as novel antioxidants exhibiting antiaging properties [9–12].

*Portulaca oleracea* L. is a well-known annual weed, one that is widely distributed in temperate and tropical regions. This plant has been used for a long time, not only as an edible potherb, but also as a traditional medicine in many countries, being used to alleviate a wide range of illnesses [13]. In addition to phytochemical research, many pharmacological studies have been performed using the extracts or single compounds from *Portulaca oleracea* L. to reveal their therapeutic properties. Interestingly, the extracts of this plant are known to possess not only a strong in vivo antioxidant capacity, but also anti-aging activity in a d-galactose-induced mice model [14,15].

Recently, oleracones, a novel series of flavonoids, were isolated from *Portulaca oleracea* L. by Chinese researchers [16,17]. They reported the potent antioxidative potential of oleracones, which allowed us to speculate that oleracones may also possess anti-aging properties [16,17]. The current paper includes the concise sequential synthesis of oleracones and an evaluation of their possible lifespan-extension properties using *Caenorhabditis elegans*, an excellent experimental model to study aging. Among the reported oleracones, we planned to synthesize two homoisoflavones, oleracones D (**1**) and F (**2**), and a dihydrochalcone, olereacone E (**3**), which exhibit potent antioxidative effects (Figure 1).

**Figure 1.** The structures of oleracones D (**1**), F (**2**), and E (**3**).

#### **2. Materials and Methods**
