Diverse prenylated C6-C3 derivatives from the stems and branches of Illicium ternstroemioides A. C. Smith with anti-inflammatory and antiviral activities

Fifteen unreported prenylated C6-C3 derivatives (1-15) were isolated from the stems and branches of Illicium ternstroemioides A. C. Smith, including one bis-prenylated C6-C3 derivative (1), three prenylated C6-C3 derivative-shikimic acid ester hybrids (2-4) and 11 prenylated C6-C3 monomers (5-15). The structures of compounds 1-15 were elucidated by spectroscopic analysis (UV, IR, 1D and 2D NMR, and HRESIMS). The absolute configurations of the compounds were determined using electronic circular dichroism (ECD), induced circular dichroism (ICD), and the modified Mosher's method. Among the isolates, compounds 11, 12, and 15 exhibited significant anti-inflammatory activities by inhibiting the nitric oxide with IC50 values ranging from 1.89 to 24.83 μM in lipopolysaccharide-stimulated murine RAW 264.7 macrophages and murine BV2 microglial cells; compounds 2, 3, and 7 exhibited antiviral activitives against Coxsackievirus B3 with an IC50 value of 33.3, 25.9, and 27.8 μM, respectively.

Membrane-Targeting Neolignan-Antimicrobial Peptide Mimic Conjugates to Combat Methicillin-Resistant Staphylococcus aureus (MRSA) Infections

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) continue to endanger public health. Here, we report the synthesis of neolignan isomagnolone (I) and its isomer II, and the preparation of a series of novel neolignan-antimicrobial peptide (AMP) mimic conjugates. Notably, conjugates III5 and III15 exhibit potent anti-MRSA activity in vitro and in vivo, comparable to that of vancomycin, a current effective treatment for MRSA. Moreover, III5 and III15 display not only fast-killing kinetics and low resistance frequency but also low toxicity as well as effects on bacterial biofilms. Mechanism studies reveal that III5 and III15 exhibit rapid bactericidal effects through binding to the phosphatidylglycerol (PG) and cardiolipin (CL) of the bacterial membrane, thereby disrupting the cell membranes and allowing increased reactive oxygen species (ROS) as well as protein and DNA leakage. The results indicate that these neolignan-AMP mimic conjugates could be promising antimicrobial candidates for combating MRSA infections.

Asymmetric Hydrogenation of Racemic α-Aryl-β-ethoxycarbonyl Cyclopentanones via Dynamic Kinetic Resolution and Its Application to the Synthesis of (+)-Burmaniol A

An efficient asymmetric hydrogenation of racemic α-aryl-β-ethoxycarbonyl cyclopentanones via dynamic kinetic resolution is reported. Via catalysis by a chiral iridium Ir-SpiroPAP catalyst, a range of racemic α-aryl-β-ethoxycarbonyl cyclopentanones were hydrogenated to the corresponding ester-functionalized chiral 2-arylcyclopentanols with three contiguous stereocenters in high yields with excellent enantio- and diastereoselectivities. This method was successfully applied in the enantioselective synthesis of cyclopentane-based γ-amino ester/alcohol derivatives and phenylpropanoid (+)-burmaniol A.

Monoterpenoid coumarins and monoterpenoid phenylpropanoids from the root bark of Ailanthus altissima

Three new monoterpenoid coumarins, zantholin A (3), altissimacoumarin P-Q (5, 6), two new monoterpenoid phenylpropanoids, altissmaphenylpropanoids A-B (2, 4), along with two known compounds (7, 8), were obtained from aqueous EtOH extracts of the root bark of Ailanthus altissima.