Further phytochemical investigation of the aerial parts of Cyperus rotundus L. afforded a new steroid glycoside named sitosteryl (6′-hentriacontanoyl)-β-D-galactopyranoside (4) in addition to three furochromones, khellin (2), visnagin (3) and ammiol (9). Furthermore, benzo-α-pyrone (coumarin) (1), salicylic acid (5), caffeic acid (6), protocatechuic acid (7), p-coumaric acid (8), tricin (10) and isorhamnetin (11) were isolated. The structures of these compounds were established by spectroscopic methods. The isolated furochromones were tested for insect antifeedant activity against larvae Spodoptera littoralis when incorporated in artificial diet and offered to larvae in a chronic feeding bioassay. Also, visnagin, khellin and sitosteryl (6′-hentriacontanoyl)-β-D-galactopyranoside showed strong cytotoxic activity against L5178y mouse lymphoma cells and were also active in the brine shrimp lethality test.

Further phytochemical study on the aerial parts of Cyperus rotundus L. led to the isolation of a fructose-amino acid conjugate, N-(1-deoxy-α-D-fructos-1-yl)-L-tryptophan (16) and its tautomers, in addition to n-butyl-β-D-fructopyranoside (1), ethyl-α-D-glucopyranoside (2), adenosine (3), (−)-(E)-caffeoylmalic acid (4), vitexin (5), isovitexin (6), orientin (7), epiorientin (8), myricetin 3-O-β-D-galactopyranoside (9), luteolin 7-O-β-D-glucuronopyranoside-6″-methyl ester (10), chlorogenic acid (11), luteolin 4′-O-β-D-glucuronopyranoside (12), luteolin 7-O-β-D-glucuronopyranoside (13), uridine (14) and ellagic acid (15). Their structures were elucidated on the basis of spectroscopic methods. Additionally, antioxidant and α-amylase inhibitory activities of some of the isolated phenolic compounds were carried out.

Potential of coumarins against Covid-19.

A new pentacyclic triterpenoid, 3β,25-epoxy-3α,22β,23α-trihydroxy-olean-12-en-28-oic acid (1), together with seven known compounds, including five triterpenoids, β-amyrin (2), lantadene B (3), lantanilic acid (4), lantanolic acid (5) and ursolic acid (6) in addition to β-sitosterol (7) and benzoic acid (8) has been isolated from the leaves of Lantana montevidensis. Their chemical structures were elucidated by spectroscopic analysis and by comparison with the literature data and/or authentic samples. Compound 1 showed moderate to weak antibacterial activity against Staphylococcus aureus and Escherichia coli.