The genus Artocarpus (Moraceae) consists of approximately 50 species and is widely distributed throughout Indonesia   . Some members of this genus have been used medicinally to treat various diseases    . Different compounds isolated from some species of Artocarpus have been shown to exhibit interesting biological properties    . Artocarpus odoratissimus, otherwise known as Terep (Sasak), grow in tropical and sub-tropical region. The medicinal values of A. odoratissimus have been used as an antimalarial. Based on chemotaxonomy, Artocarpus plants contain flavonoid. Isolation of flavonoid from Artocarpus plants can be useful for undergraduate students  -  . Students were exposed to skills as extraction, fractionation, and purification of flavonoid. Major coumpound in Artocarpus plants is flavonoid as shown in Figure 1.
2. Experimental Overview
This experiment is suited to upper-level undergraduate students who have a
Figure 1. Major compound in Artocarpus.
concrete understanding of chromatograhy techniques employed in purification of organic compounds. The isolation step is straightforward and has also been completed with consistent reproducibility by upper-level undergraduate students. The experiment can be completed in two three-week laboratory sessions. This experiment allows the student to design their own activities in order to isolate flavonoid from A. odoratissimus. The whole procedure of flavonoid isolation from A. odoratissimus is discussed. The A. odoratissimus plant material was collected from Narmada (Lombok), Indonesia. During the laboratory sessions, the student practices a variety of techniques such as extraction of natural products, thin-layer chromatography (TLC), and gravitational column chromatography (GCC). The students identify flavonoid through the interpretation of a wide variety of spectroscopic data.
3. Experimental Details
TLC analysis was performed using precoated Si gel plates (Merck Kieselgel 60 F254, 0.25 mm). Gravitational column chromatography (GCC) was carried out using Merck Si gel 60 GF254. Plant materials of A. odoratissimus were collected in Narmada (Lombok), Indonesia and identified at the biology department of Mataram University, Indonesia in April 2015 (Table 1).
The dried of A. odoratissimus (460 g) was extracted with methanol. Methanol extract was evaporated to yield 27.19 g crude extract. GCC of 1 g crude extract over Si gel, using a n-hexane and chloroform (7:3) as eluent, afforded 6
Table 1. Procedures to isolate flavonoid from Artocarpus odoratissimus.
fractions. Recrystallization method was used for purification fraction I to yield 106 mg coumpound 1. Fraction 3 was GCC on Si gel (n-hexane and chloroform (6:4)) to yield 31 mg coumpound 2.
The experiment involves the use of some potentially hazardous reagents. Laboratory coats and eye protection must be worn while performing this experiment. Chloroform is toxic if inhaled, swallowed, or absorbed through the skin. Protective gloves must be worn when handling Gravitational column chromatography. The n-hexane system used as a mobile phase is extremely flammable and is toxic to the eyes, skin, and respiratory system. Avoid inhaling vapor and use in a fume hood. Ultraviolet (UV) radiation can cause severe damage to the eyes. Do not look directly into the light source.
We wish to thank Jono Irawan from Study Program of Chemistry Education, Faculty of Teacher Training and education, University of Mataram, Indonesia, for his contribution as laboratory assistant in this research.