Phytochemicals from the Stem Bark of Calophyllum havilandii P. F. Stevens and their Biological Activities

The genus Calophyllum from the family Calophyllaceae has been extensively investigated in the past due to its rich source of bioactive phenolics such as coumarins, chromanones, and xanthones. In this study, phytochemical investigation on the stem bark of Calophyllum havilandii has afforded a new 4-propyldihydrocoumarin derivative, havilarin (1) together with calolongic acid (2), caloteysmannic acid (3), isocalolongic acid (4), euxanthone (5), and β-sitosterol (6). The chemical structure of compound 1 was elucidated and established based on detailed spectroscopic techniques, including MS, IR, UV, 1D and 2D NMR. The results of anti-bacillus study indicated that the chloroform extract showed promising activities with MIC value ranging between 0.5 to 1 μg/mL on selected bacillus strains. Besides, the plant extracts and compounds 1-4 were assessed for their cytotoxicity potential on HL-7702 cell line. All the tested plant extracts and respective chemical constituents displayed non-cytotoxic activity on HL-7702 cell line.

Design, Synthesis, and Biological Evaluation of Novel Chromanone Derivatives as Multifunctional Agents for the Treatment of Alzheimer's Disease

Based on a multitarget strategy, a series of novel chromanone-1-benzyl-1,2,3,6-tetrahydropyridin hybrids were identified for the potential treatment of Alzheimer's disease (AD). Biological evaluation demonstrated that these hybrids exhibited significant inhibitory activities toward acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B). The optimal compound C10 possessed excellent dual AChE/MAO-B inhibition both in terms of potency and equilibrium (AChE: IC₅₀ = 0.58 ± 0.05 μM; MAO-B: IC₅₀ = 0.41 ± 0.04 μM). Further molecular modeling and kinetic investigations revealed that compound C10 was a dual-binding inhibitor bound to both the catalytic anionic site and peripheral anionic site of AChE. In addition, compound C10 exhibited low neurotoxicity and potently inhibited AChE enzymatic activity. Furthermore, compound C10 more effectively protected against mitochondrial dysfunction and oxidation than donepezil, strongly inhibited AChE-induced amyloid aggregation, and moderately reduced glutaraldehyde-induced phosphorylation of tau protein in SH-SY5Y cells. Moreover, compound C10 displayed largely enhanced improvements in cognitive behaviors and spatial memory in a scopolamine-induced AD mice model with better efficacy than donepezil. Overall, the multifunctional profiles of compound C10 suggest that it deserves further investigation as a promising lead for the prospective treatment of AD.

The relationship between Hirshfeld potential and cytotoxic activity: a study along a series of flavonoid and chromanone derivatives

The present study examines a series of six biologically-active flavonoid and chromanone derivatives by X-ray crystal structure analysis: (E)-3-benzylidene-2-phenylchroman-4-one, C₂₂H₁₆O₂, I, (E)-3-(4-methylbenzylidene)-2-phenylchroman-4-one, C₂₃H₁₈O₂, II, (E)-3-(3-methylbenzylidene)-2-phenylchroman-4-one, C₂₃H₁₈O₂, III, (E)-3-(4-methoxybenzylidene)-2-phenylchroman-4-one, C₂₃H₁₈O₃, IV, (E)-3-benzylidenechroman-4-one, C₁₆H₁₂O₂, V, and (E)-3-(4-methoxybenzylidene)chroman-4-one, C₁₇H₁₄O₃, VI. The cytotoxic activities of the presented crystal structures have been determined, together with their intermolecular interaction preferences and Hirshfeld surface characteristics. An inverse relationship was found between the contribution of C...C close contacts to the Hirshfeld surface and cytotoxic activity against the WM-115 cancer line. Dependence was also observed between the logP value and the percentage contribution of C...H contacts to the Hirshfeld surface.

Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A

The construction of the biologically interesting chromone skeleton was realized by PhIO-mediated dehydrogenation of chromanones under mild conditions. Interestingly, this method also found application in the synthesis of the naturally occurring frutinone A.

Diastereodivergent Synthesis of Hexahydro-6H-benzo[c]chromen-6-one Derivatives Catalyzed by Modularly Designed Organocatalysts

The diastereodivergent synthesis of hexahydro-6H-benzo[c]chromen-6-one derivatives with good to high diastereoselectivities (up to 98:2 d.r.) and enantioselectivities (up to >99 % ee) has been achieved by using a domino Michael/Michael/hemiacetalization reaction between trans-2-hydroxy-β-nitrostyrenes and trans-7-oxo-5-heptenals followed by oxidation. With use of appropriate modularly designed organocatalysts (MDOs) that are self-assembled in situ from amino acid derivatives and cinchona alkaloid derivatives, two different diastereomers of the desired hexahydro-6H-benzo[c]chromen-6-ones are obtained from the same substrates.