Isolation, Structure Determination of Sesquiterpenes from Neurolaena lobata and Their Antiproliferative, Cell Cycle Arrest-Inducing and Anti-Invasive Properties against Human Cervical Tumor Cells

Polyphenols in edible plant leaves: an overview of their occurrence and health properties

Edible plant leaves (EPLs) constitute a major renewable functional plant biomass available all year round, providing an essential source of polyphenols in the global diet. Polyphenols form a large family of antioxidant molecules. They protect against the harmful effects of free radicals, strengthen immunity and stimulate the body's natural defenses thanks to their antibacterial and antiviral functions. This study refers to phenolic compounds from 50 edible plant leaves divided into four categories: green leafy vegetables, underutilized leafy vegetables, leafy spices and leafy drinks. It provides data on the identification, occurrence and pharmacological functions of polyphenols contained in EPLs, and provides a better understanding of trends and gaps in their consumption and study. Certain EPLs, such as moringa (Moringa oleifera Lam.), tea (Camellia sinensis L.) and several leafy spices of the Lamiaceae family, reveal important characteristics and therapeutic potential. The polyphenol composition of EPLs makes them functional plants that offer relevant solutions in the fight against obesity, the management of food insecurity and the prevention of chronic diseases.

Isolation and NMR Scaling Factors for the Structure Determination of Lobatolide H, a Flexible Sesquiterpene from Neurolaena lobata

A new flexible germacranolide (1, lobatolide H) was isolated from the aerial parts of Neurolaena lobata. The structure elucidation was performed by classical NMR experiments and DFT NMR calculations. Altogether, 80 theoretical level combinations with existing ¹³C NMR scaling factors were tested, and the best performing ones were applied on 1. ¹H and ¹³C NMR scaling factors were also developed for two combinations utilizing known exomethylene containing derivatives, and the results were complemented by homonuclear coupling constant (J_HH) and TDDFT-ECD calculations to elucidate the stereochemistry of 1. Lobatolide H possessed remarkable antiproliferative activity against human cervical tumor cell lines with different HPV status (SiHa and C33A), induced cell cycle disturbance and exhibited a substantial antimigratory effect in SiHa cells.