Acetophenone derivatives from the roots of Melicope ptelefolia

Natural-derived acetophenones: chemistry and pharmacological activities

Acetophenones are naturally occurring phenolic compounds which have found in over 24 plant families and also fungi strains. They are exist in both free or glycosides form in nature. The biological activities of these compounds have been assayed and reported including cytotoxicity, antimicrobial, antimalarial, antioxidant and antityrosinase activities. Herein, we review the chemistry and biological activity of natural acetophenone derivatives that have been isolated and identified until January 2024. Taken together, it was reported 252 acetophenone derivatives in which the genera Melicope (69) and Acronychia (44) were the principal species as producers of acetophenones.

Status of research on natural protein tyrosine phosphatase 1B inhibitors as potential antidiabetic agents: Update

Protein tyrosine phosphatase 1B (PTP1B) is a crucial therapeutic target for multiple human diseases comprising type 2 diabetes (T2DM) and obesity because it is a seminal part of a negative regulator in both insulin and leptin signaling pathways. PTP1B inhibitors increase insulin receptor sensitivity and have the ability to cure insulin resistance-related diseases. However, the few PTP1B inhibitors that entered the clinic (Ertiprotafib, ISIS-113715, Trodusquemine, and JTT-551) were discontinued due to side effects or low selectivity. Molecules with broad chemical diversity extracted from natural products have been reported to be potent PTP1B inhibitors with few side effects. This article summarizes the recent PTP1B inhibitors extracted from natural products, clarifying the current research progress, and providing new options for designing new and effective PTP1B inhibitors.

Approaches to Decrease Hyperglycemia by Targeting Impaired Hepatic Glucose Homeostasis Using Medicinal Plants

Liver plays a pivotal role in maintaining blood glucose levels through complex processes which involve the disposal, storage, and endogenous production of this carbohydrate. Insulin is the hormone responsible for regulating hepatic glucose production and glucose storage as glycogen, thus abnormalities in its function lead to hyperglycemia in obese or diabetic patients because of higher production rates and lower capacity to store glucose. In this context, two different but complementary therapeutic approaches can be highlighted to avoid the hyperglycemia generated by the hepatic insulin resistance: 1) enhancing insulin function by inhibiting the protein tyrosine phosphatase 1B, one of the main enzymes that disrupt the insulin signal, and 2) direct regulation of key enzymes involved in hepatic glucose production and glycogen synthesis/breakdown. It is recognized that medicinal plants are a valuable source of molecules with special properties and a wide range of scaffolds that can improve hepatic glucose metabolism. Some molecules, especially phenolic compounds and terpenoids, exhibit a powerful inhibitory capacity on protein tyrosine phosphatase 1B and decrease the expression or activity of the key enzymes involved in the gluconeogenic pathway, such as phosphoenolpyruvate carboxykinase or glucose 6-phosphatase. This review shed light on the progress made in the past 7 years in medicinal plants capable of improving hepatic glucose homeostasis through the two proposed approaches. We suggest that Coreopsis tinctoria, Lithocarpus polystachyus, and Panax ginseng can be good candidates for developing herbal medicines or phytomedicines that target inhibition of hepatic glucose output as they can modulate the activity of PTP-1B, the expression of gluconeogenic enzymes, and the glycogen content.

New Acetophenones and Chromenes from the Leaves of Melicope barbigera A. Gray

The dichloromethane extract from leaves of Melicope barbigera (Rutaceae), endemic to the Hawaiian island of Kaua'i, yielded four new and three previously known acetophenones and 2H-chromenes, all found for the first time in M. barbigera. The structures of the new compounds obtained from the dichloromethane extract after purification by chromatographic methods were unambiguously elucidated by spectroscopic analyses including 1D/2D NMR spectroscopy and HRESIMS. The absolute configuration was determined by modified Mosher's method. Compounds 2, 4 and the mixture of 6 and 7 exhibited moderate cytotoxic activities against the human ovarian cancer cell line A2780 with IC₅₀ values of 30.0 and 75.7 µM for 2 and 4, respectively, in a nuclear shrinkage cytotoxicity assay.

(±)-Meliviticines A and B: Rearranged prenylated acetophenone derivatives from Melicope viticina and their antimicrobial activity

Two new prenylated acetophenone derivatives racemates, meliviticines A (1) and B (2) with unprecedented rearranged skeletons, were isolated from Melicope viticina. Subsequent chiral resolution led to the separation of two pairs of enantiomers, (±)-meliviticines A (1a/1b) and (±)-meliviticines B (2a/2b). Their structures including absolute configurations were elucidated by extensive spectroscopic data, electronic circular dichroism analysis, and X-ray crystallography. A plausible biosynthetic pathway of 1 and 2, involving ring cleavage and rearrangement of the prenylated acetophenone backbone was proposed. All the isolates showed moderate antimicrobial activities with MIC values of 25-50 μg/mL against several bacterial and fungal strains.