Page 235 - Demo

SECTION I: MOLECULAR GENETIC ENGINEERING AND BIOCHEMICAL TECHNOLOGY 239from the HSQC spectrum. Additionally, the HMBC spectrum shows long-range interactions between C and H, allowing for the assembly of structural fragments and confirming the constructed structure. The interaction between the anomeric H (4.36 ppm) and C-9 (77.33 ppm) confirms that the sugar is attached to the aglycone framework at position C-9. The positions of the four methyl groups are also further validated by the long-range interactions between the protons of the methyl groups and other carbon atoms. A comparison with the spectral data of (6S,9R)-roseoside from the literature [12] shows complete agreement. Therefore, compound 4 was identified as (6S,9R)-roseoside. (6S,9R)-roseoside has been reported to possess antioxidant activity, anti-inflammatory effects, and cytotoxic activity against cancer cells [12].Compound 5 was obtained as a colorless, amorphous solid. The 1H-NMR spectrum of compound 5 shows signals for 4 aromatic protons at dH 6.72 (1H, d, J = 1.5, H-2); 6.67 (1H, d, J = 8.0, H-5); 6.59 (1H, s, H-2%u2019); and 6.50 (1H, dd, J = 8.0; 2.0, H-6) and three methoxy groups at dH 3.87 (3H, s, 3%u2019-OMe); 3.78 (3H, s, 3-OMe) and 3.37 (3H, s, 5%u2019-OMe). The remaining signals belong to 3 -CH groups and 3 -CH2 groups (confirmed by two-dimensional HSQC). The 13C-NMR spectrum of compound 5 shows signals for 21 carbon atoms, including 12 aromatic carbons with chemical shifts dC from 107.83 to 148.66 ppm, suggesting the presence of 2 aromatic rings. Additionally, 3 -CH groups at dC 49.51 (C-8); 42.04 (C-7) and 40.93 (C-8%u2019), along with 3 -CH2 groups at dC 66.82 (C9%u2019); 64.13 (C-9) and 33.64 (C-7%u2019), indicate the presence of a lignan structure in the molecule. The positions of the 3 methoxy groups were determined based on long-range H-C interactions observed in the two-dimensional HMBC spectrum. The interactions between OMe (dH 3.87) / C3%u2019 (dC 148.59); OMe (dH 3.78) / C3 (dC148.66); OMe (dH 3.37) / C5%u2019 (dC 147.62) confirm that the 3 methoxy