Diverse chemical modifications of the chlorogenic acid composition of Viscum combreticola Engl.: A premise for the state of readiness against excessive sunlight exposure

Rationalising the retro‐Diels‐Alder fragmentation pattern of viscutins using electrospray interface‐tandem mass spectrometry coupled to theoretical modelling

“…Chromatographic separation using a liquid chromatography‐quadrupole‐time‐of‐flight tandem mass spectrometer (LC‐MS‐9030 q‐TOF, Shimadzu Corporation, Kyoto, Japan) for sample analysis was performed based on our previous study 3 . The viscutins and other secondary metabolites were separated using a Shim‐pack Velox C 18 column (100 × 2.1 mm, 2.7 μm) (Shimadzu Corporation) maintained at 55°C.…”

“…The collected samples were air dried to complete dryness, ground and extracted based on our recent study. 3 Briefly, 2 g of the samples was weighed and extracted in 20 ml of 80% methanol overnight by shaking on a digital rotisserie tube rotator (Dlab Scientific, Beijing, China) at 70 rpm. The crude extracts were then centrifuged on a swinging bucket centrifuge (Thermo Fisher, Johannesburg, South Africa) at 2739g for 10 min.…”

“…Combretum erythrophyllum , Acacia karroo , Pseudolachnostylis maprouneifolia Pax and Sclerocarya birrea 1,3 are some of the common host plants of V. combreticola Engl. The phytochemistry of different species of Viscum is complex, consisting of various classes of secondary metabolites such as viscotoxins, lectins, flavonoids, hydroxycinnamic acid derivatives, terpenoids, coumarins, lignans, alkaloids, carbohydrates, sterols and amino acids, that have been reported widely in literature 3–6 . Flavonoids, a significant class of phenolic natural products, are widely distributed in these plants either as free aglycones or as glycosides 7,8 .…”

“…(Santalacaeae), a perennial and evergreen leafless semi‐parasitic plant, is native to southern and tropical Africa 1,2 . Combretum erythrophyllum , Acacia karroo , Pseudolachnostylis maprouneifolia Pax and Sclerocarya birrea 1,3 are some of the common host plants of V. combreticola Engl. The phytochemistry of different species of Viscum is complex, consisting of various classes of secondary metabolites such as viscotoxins, lectins, flavonoids, hydroxycinnamic acid derivatives, terpenoids, coumarins, lignans, alkaloids, carbohydrates, sterols and amino acids, that have been reported widely in literature 3–6 .…”

“…alkaloids, carbohydrates, sterols and amino acids, that have been reported widely in literature. [3][4][5][6] Flavonoids, a significant class of phenolic natural products, are widely distributed in these plants either as free aglycones or as glycosides. 7,8 Viscutins are flavan glycosides that were identified in Viscum tuberculatum by Kubo et al, 9 and they are not as ubiquitous in the plant kingdom as other flavonoid subclasses.…”