Phytochemistry of Aptenia The purpose of this citizen science was to further explore some of the Mesembryanthemums known synonymously as Aptenias at a more detailed phtochemical level via literature review and TLC, including Mesembryanthemum cordifolium , a common variety - probably Mesembryanthemum lancifolium - and the uncharacterised Mesembryanthemum haeckelianum 'Yellow Aptenia' Mesembryanthemum cordifolium 'True form' syn. Aptenia cordifolia Mesembryanthemum lancifolium syn Aptenia lancifolia Mesembryanthemum cordifolium x haeckelianum 'Red Apple' Mesembryanthemum haeckelianum 'Yellow Aptenia' [Note: sample was sold as Aptenia cordifolia 'Yellow' but M. haeckelianum seems to be a 1 more accurate botanical name] " A. cordifolia has cordate or heart-shaped leaves, while the leaves of A. lancifolia are lance- shaped, tapering gradually towards their bases. Leaf shape is used as a rather tenuous character in distinguishing A. cordifolia from its nearest relative, A. lancifolia ." The phytochemical screening of the ethanolic extract of the leaves of Mesembryanthemum cordifolium , which was a strong antiinflammatory and revealed the presence of alkaloids, flavanoids, tannins, phenols, saponins and steroids , When studied by Gaffney (2006), A. cordifolia and A. lancifolia revealed the presence of the mesembrine-type of mesembrane alkaloids namely 4,5-dihydro-4’-O-methylsceletenone and 4’-O-methylsceletenone, as well as the non-mesembrane alkaloid hordenine. Alkaloids detected by Gaffney (2006) In a further analysis by Said and Ali et al (2021) several more alkaloids were detected in the root. 2 Alkaloids detected in roots of M. cordifolium by Said and Ali et al. 1. 4,5-dihydro-4'-O-methylsceletenone 2. 4'-O-methylsceletenone 3. Sceletenone 4. Mesembrane 5. Dihydrojoubertiamine 6. O-methyljoubertiamine 7. O-methyl-dihydro-joubertiamine 8. Tortuosamine Earlier phytochemical studies noted unidentified indole alkaloids, ferulic acid, 3,4- dimethoxy-dihydrocinnamic acid, as well as the corresponding methyl and ethyl esters. Also identified were pinoresinol and syringaresinol. Oxyneolignans such as apteniol G were discovered. Other constituents Gaffney found some phytochemical diversity through the Aptenias (below) and varying levels of alkaloids, where lower numbers indicate main constituents, throughout different plant parts: 3 Gaffney also found various yields of alkaloids from different plant parts: The above two papers prepared an alkaloid fraction by the following: "...M. cordifolium (A. cordifolia) (250 g) were extracted using 95% ethyl alcohol, then the dried ethanol extract (21.5 g) was further suspended in the least amount of distilled water, transferred to separating funnels, then defatted with light petroleum ether. The remaining aqueous solution was then acidified and extracted with ethyl acetate to give acidic ethyl acetate fraction (2.8 g) (non-alkaloidal fraction). The mother liquor was then completely basified and extracted again with ethyl acetate to give basic ethyl acetate fraction (1.8 g) (alkaloidal fraction)" In this paper, a crude extract was prepared. Plant material was dried at 70 deg. C, crushed and soaked on basified isopropanol (aq. ammonia). After several hrs, the solution was 4 decanted/filtered and concentrated to a small sample. The Mesembryanthemum cordifolium extract was obtained from the following plant: Initial attempts at TLC of a Mesembryanthemum cordifolium leaf/stem basified isopropanol (aq. ammonia) extract (silica, 0.2mm, glass backed, acetone elution) gave poor resolution of the major constituents forming indistinct trailing with Rf values of 0.11, 0.27, 0.45, 0.89 so attempts were made to improve the solvent system to provide better separation of the constituents. Acetone:white spirits:1:1 gave improved results with separation of pigments and a lower Rf band. Rf values of 0.19, 0.24, 0.29, 0.71, 0.83 and 0.93 were obtained, I 2 visualisation not being required but highlighting the constituents more. In the low Rf band there were at least three distinct constituents. The Mesembryanthemum haeckelianum 'Yellow Aptenia' sample was obtained from the following plant TLC with mixed solvent (silica, 0.2mm, acetone:white spirits 1:1, prior to I 2 visualisation) 5 gave the following: There was significantly less visible low Rf constituents in the yellow Aptenia than M. cordifolium . That said, I 2 visualisation gave a band Rf = 0.28 quite intensely The following plant was tentatively identified as Aptenia lancifolia The basified isopropanol (aq. ammonia) extract gave the following TLC (silica, 0.2mm, glass backed, acetone:white spirits 1:1) with Rf values of 0.19, 0.39, 0.81, 0.86 and 0.95. The upper 3 Rf values were strongly pigmented compounds, while the lower Rf band was still visible without I 2 visualisation but enhanced by such. Note that the major low Rf constituent was at a slightly higher Rf than for the M. cordifolium suggesting there may be some phytochemical differences. 6 References Wilson Rwai Waweru, Francis Karomo Wambugu and Rose Mbabazi (2017) Evaluation of anti-inflammatory activity of Aptenia cordifolia leaves extract in wistar albino rats Journal of Pharmacognosy and Phytochemistry 6(1): 238-24 https://www.phytojournal.com/archives/2017/vol6issue1/PartD/6-1-27-713.pdf A study of Mesembryanthemaceae alkaloids (2006) Candice Delphine Gaffney https://def-sa.com/wp-content/uploads/2020/08/Gaffney_Candice_D_2006_0.pdf Asmaa Abo Elgoud Said, Taha F. S. Ali, Eman Zekry Attia, Al-Shaimaa F. Ahmed, Alaa H. Shehata, Usama Ramadan Abdelmohsen & Mostafa Ahmed Fouad (2021) Antidepressant potential of Mesembryanthemum cordifolium roots assisted by metabolomic analysis and virtual screening, Natural Product Research, 35:23, 5493-5497, https://doi.org/10.1080/14786419.2020.1788019 7