A Mangiferin Monomethyl Ether from Mangifera indica L.

Synthesis of Mangiferin, Isomangiferin, and Homomangiferin

“…The 3- O -methyl group was assigned according to the HMBC correlation between the signal of O -CH 3 (3.89 and 3.87 ppm) with that of C-3 (166.2 and 167.2 ppm). The 1 H MNR signal of the 3- O -methyl group in compound 3 (homomangiferin) also appeared as two peaks in pyridine- d 5 at ambient temperature (3.70 and 3.61 ppm), which is in accordance with the literature report for the natural compound (3.77 and 3.68 ppm) …”

Synthesis of Mangiferin, Isomangiferin, and Homomangiferin

“…The 3- O -methyl group was assigned according to the HMBC correlation between the signal of O -CH 3 (3.89 and 3.87 ppm) with that of C-3 (166.2 and 167.2 ppm). The 1 H MNR signal of the 3- O -methyl group in compound 3 (homomangiferin) also appeared as two peaks in pyridine- d 5 at ambient temperature (3.70 and 3.61 ppm), which is in accordance with the literature report for the natural compound (3.77 and 3.68 ppm) …”

Chemical Constituents of Gentianaceae X: Xanthone-O-Glucosides of Swertia Purpurascens Wall

“…Of these, two appeared a t a significantly lower field (6 2.40 and 2.48) than the remaining four (6 1.85, 1.90, 2.02, and 2.08), suggesting their assignments as aromatic acetoxy. The upfield signals of the remaining acetoxy groups are in good agreement with the chemical shifts of the acetylated 8-D-glucopyranoside (21,22). The signals from the aromatic protons at Cz and Cq (6 6.83 and 6.60, respectively) in the hexaacetate were practically the same as those from the corresponding protons of 1,5,8-trjacetoxy-3-methoxyanthone (bellidifolin triacetate) (6 6.84 and 6.58) and swerchirin diacetate (6 6.84 and 6.54) (23).…”

“…While the natural occurrence of xanthone-0-glycosides is restricted so far to the members of the family Gentianaceae (Table I), the related C-glucosides-uiz., mangiferin (IV) and isomangiferin (V), occur widely among angiosperms (3,22,24,25). Mangiferin has also been reported to occur with its 3-methyl ether (homomangiferin) in Liliaceae (25).…”

Naturally Occurring Xanthones: Chemistry and Biology

“…Prox [86] established the fragmentation pattern of mangiferin and related C-glycosides. Aritomi and Kawasaki [27,28] obtained satisfactory results using peracetylated derivatives of the same and analogous compounds. In mass spectrum of O-glycosides, no discernible molecular ion peak can be observed, but an important fragment ion peak due to the aglycone moiety appears, followed by further fragmentation.…”

Synthesis of Mangiferin, Isomangiferin, and Homomangiferin

“…The 3- O -methyl group was assigned according to the HMBC correlation between the signal of O -CH 3 (3.89 and 3.87 ppm) with that of C-3 (166.2 and 167.2 ppm). The 1 H MNR signal of the 3- O -methyl group in compound 3 (homomangiferin) also appeared as two peaks in pyridine- d 5 at ambient temperature (3.70 and 3.61 ppm), which is in accordance with the literature report for the natural compound (3.77 and 3.68 ppm) …”

Chemical Constituents of Gentianaceae X: Xanthone-O-Glucosides of Swertia Purpurascens Wall

“…Of these, two appeared a t a significantly lower field (6 2.40 and 2.48) than the remaining four (6 1.85, 1.90, 2.02, and 2.08), suggesting their assignments as aromatic acetoxy. The upfield signals of the remaining acetoxy groups are in good agreement with the chemical shifts of the acetylated 8-D-glucopyranoside (21,22). The signals from the aromatic protons at Cz and Cq (6 6.83 and 6.60, respectively) in the hexaacetate were practically the same as those from the corresponding protons of 1,5,8-trjacetoxy-3-methoxyanthone (bellidifolin triacetate) (6 6.84 and 6.58) and swerchirin diacetate (6 6.84 and 6.54) (23).…”

“…While the natural occurrence of xanthone-0-glycosides is restricted so far to the members of the family Gentianaceae (Table I), the related C-glucosides-uiz., mangiferin (IV) and isomangiferin (V), occur widely among angiosperms (3,22,24,25). Mangiferin has also been reported to occur with its 3-methyl ether (homomangiferin) in Liliaceae (25).…”

Naturally Occurring Xanthones: Chemistry and Biology

“…Prox [86] established the fragmentation pattern of mangiferin and related C-glycosides. Aritomi and Kawasaki [27,28] obtained satisfactory results using peracetylated derivatives of the same and analogous compounds. In mass spectrum of O-glycosides, no discernible molecular ion peak can be observed, but an important fragment ion peak due to the aglycone moiety appears, followed by further fragmentation.…”

Synthesis of Mangiferin, Isomangiferin, and Homomangiferin

“…The 3- O -methyl group was assigned according to the HMBC correlation between the signal of O -CH 3 (3.89 and 3.87 ppm) with that of C-3 (166.2 and 167.2 ppm). The 1 H MNR signal of the 3- O -methyl group in compound 3 (homomangiferin) also appeared as two peaks in pyridine- d 5 at ambient temperature (3.70 and 3.61 ppm), which is in accordance with the literature report for the natural compound (3.77 and 3.68 ppm) …”

Chemical Constituents of Gentianaceae X: Xanthone-O-Glucosides of Swertia Purpurascens Wall

“…Of these, two appeared a t a significantly lower field (6 2.40 and 2.48) than the remaining four (6 1.85, 1.90, 2.02, and 2.08), suggesting their assignments as aromatic acetoxy. The upfield signals of the remaining acetoxy groups are in good agreement with the chemical shifts of the acetylated 8-D-glucopyranoside (21,22). The signals from the aromatic protons at Cz and Cq (6 6.83 and 6.60, respectively) in the hexaacetate were practically the same as those from the corresponding protons of 1,5,8-trjacetoxy-3-methoxyanthone (bellidifolin triacetate) (6 6.84 and 6.58) and swerchirin diacetate (6 6.84 and 6.54) (23).…”

“…While the natural occurrence of xanthone-0-glycosides is restricted so far to the members of the family Gentianaceae (Table I), the related C-glucosides-uiz., mangiferin (IV) and isomangiferin (V), occur widely among angiosperms (3,22,24,25). Mangiferin has also been reported to occur with its 3-methyl ether (homomangiferin) in Liliaceae (25).…”

Naturally Occurring Xanthones: Chemistry and Biology

“…Prox [86] established the fragmentation pattern of mangiferin and related C-glycosides. Aritomi and Kawasaki [27,28] obtained satisfactory results using peracetylated derivatives of the same and analogous compounds. In mass spectrum of O-glycosides, no discernible molecular ion peak can be observed, but an important fragment ion peak due to the aglycone moiety appears, followed by further fragmentation.…”