Limonoids from the fruits of Swietenia macrophylla with inhibitory activity against H 2 O 2 -induced apoptosis in HUVECs

Swieteliacates S-U, phragmalin limonoids, from the leaves of Swietenia macrophylla

Three novel phragmalin-type limonoids, swieteliacates S-U (1-3), were isolated from Swietenia macrophylla leaves, alongside four previously identified limonoids (4-7). The structures, encompassing absolute configurations, were delineated through 1D and 2D NMR analyses, high-resolution mass spectrometry (HR-MS), and NMR and ECD calculations. Swieteliacate S (1) is a distinctive cryptate comprising a tricyclo[4.2.110,30.11,4]decane fragment and an additional five-membered oxygen ring. Compounds 3 and 5 exhibited inhibition rates of 26.08 ± 2.26% and 15.42 ± 3.66%, respectively, on triglyceride (TG) production in Hep G2 cells at 40 μM.

Putative Identification of New Phragmaline-Type Limonoids from the Leaves of Swietenia macrophylla King: A Case Study Using Mass Spectrometry-Based Molecular Networking

Swietenia macrophylla King is a plant commonly known as Brazilian mahogany. The wood from its stem is highly prized for its exceptional quality, while its leaves are valued for their high content of phragmalin-type limonoids, a subclass of compounds known for their significant biological activities, including antimalarial, antitumor, antiviral, and anti-inflammatory properties. In this context, twelve isolated limonoids from S. macrophylla leaves were employed as standards in mass spectrometry-based molecular networking to unveil new potential mass spectrometry signatures for phragmalin-type limonoids. Consequently, ultra-performance liquid chromatography coupled with high-resolution mass spectrometry was utilized for data acquisition. Subsequently, the obtained data were analyzed using the Global Natural Products Social Molecular Networking platform based on spectral similarity. In summary, this study identified 24 new putative phragmalin-type limonoids for the first time in S. macrophylla. These compounds may prove valuable in guiding future drug development efforts, leveraging the already established biological activities associated with limonoids.

Research progress of meliaceous limonoids from 2011 to 2021

Covering: July 2010 to December 2021Limonoids, a kind of natural tetranortriterpenoids with diverse skeletons and valuable insecticidal and medicinal bioactivities, are the characteristic metabolites of most plants of the Meliaceae family. The chemistry and bioactivities of meliaceous limonoids are a continuing hot area of natural products research; to date, about 2700 meliaceous limonoids have been identified. In particular, more than 1600, including thirty kinds of novel rearranged skeletons, have been isolated and identified in the past decade due to their wide distribution and abundant content in Meliaceae plants and active biosynthetic pathways. In addition to the discovery of new structures, many positive medicinal bioactivities of meliaceous limonoids have been investigated, and extensive achievements regarding the chemical and biological synthesis have been made. This review summarizes the recent research progress in the discovery of new structures, medicinal and agricultural bioactivities, and chem/biosynthesis of limonoids from the plants of the Meliaceae family during the past decade, with an emphasis on the discovery of limonoids with novel skeletons, the medicinal bioactivities and mechanisms, and chemical synthesis. The structures, origins, and bioactivities of other new limonoids were provided as ESI. Studies published from July 2010 to December 2021 are reviewed, and 482 references are cited.

Limonoids from Swietenia macrophylla and their antitumor activities in A375 human malignant melanoma cells

Swietelinins A - C (1-3) and swieteliacates F - R (4-16), sixteen new limonoids and 18 known limonoids (17-34) were isolated from Swietenia macrophylla. The absolute configurations of these compounds were defined by using a combination of electronic circular dichroism data analysis and single-crystal X-ray diffraction data. Swieteliacate J (10) is the first limonoid possessing an unusual 8β, 9β-epoxy ring system. All of the compounds were tested for cytotoxicity against four human tumor cell lines (SMMC-7721, SW620, A549, and A375). Compounds 10, 11, and 19 exhibited selectively moderate cytotoxicity against four tumor cell lines, especially 19 exhibited significant cytotoxic effects against A375 with IC₅₀ an value of 9.8 μM and was more active than the positive control, dacarbazine with an IC₅₀ value of 22.4 μM. Compound 19 effectively induced apoptosis of A375, which was associated with G2/M-phase cell cycle arrest. Flow cytometric analysis showed that the treatment by 19 significantly induced A375 cell apoptosis in a dose-dependent manner.

Thermal Niche for Seed Germination and Species Distribution Modelling of Swietenia macrophylla King (Mahogany) under Climate Change Scenarios

Swietenia macrophylla is an economically important tree species propagated by seeds that lose their viability in a short time, making seed germination a key stage for the species recruitment. The objective of this study was to determine the cardinal temperatures and thermal time for seed germination of S. macrophylla; and its potential distribution under different climate change scenarios. Seeds were placed in germination chambers at constant temperatures from 5 to 45 °C and their thermal responses modelled using a thermal time approach. In addition, the potential biogeographic distribution was projected according to the Community Climate System Model version 4 (CCSM4). Germination rate reached its maximum at 37.3 ± 1.3 °C (To); seed germination decreased to near zero at 52.7 ± 2.2 °C (ceiling temperature, Tc) and at 12.8 ± 2.4 °C (base temperature, Tb). The suboptimal thermal time θ150 needed for 50% germination was ca. 190 °Cd, which in the current scenario is accumulated in 20 days. The CCSM4 model estimates an increase of the potential distribution of the species of 12.3 to 18.3% compared to the current scenario. The temperature had an important effect on the physiological processes of the seeds. With the increase in temperature, the thermal needs for germination are completed in less time, so the species will not be affected in its distribution. Although the distribution of the species may not be affected, it is crucial to generate sustainable management strategies to ensure its long-term conservation.

Diverse lignans with anti-inflammatory activity from Urceola rosea

Seventeen structurally diverse lignans, comprising six new compounds, ecdysanols A (1), B (11), C - E (13-15), and F (17), were isolated from the caulis of Urceola rosea. The structures and absolute configurations of these new compounds were elucidated by means of extensive analysis of mass and NMR data, as well as chiroptical properties. A bioassay in vitro showed that all lignans possessed anti-inflammatory effects by inhibiting the production of TNF-α, NO and/or IL-6 in LPS-stimulated RAW264.7 cells. Ecdysanol F (17) showed the most strongly effect against NO and IL-6 levels.

Anti-inflammatory constituents from Perilla frutescens on lipopolysaccharide-stimulated RAW264.7 cells

Perilla frutescens (L.) Britt. (Lamiaceae) is a traditionally medicinal herb in East Asian countries to treat various diseases. In present study, the low-polarity constituents of the aerial parts of P. frutescens were investigated and their anti-inflammatory effect on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were assayed. Three new furanoid monoterpenoids, named as frutescenones A - C (1-3), together with thirteen known compounds (4-16) were isolated and identified on the basis of extensive spectroscopic analysis and a single-crystal X-ray diffraction study. Among these components, 1 is an unusual monoterpenoid with 2,3'-bifuran skeleton, and 3 is a rare perillaketone-adenine hybrid heterodimer, while the revised NMR arrangements of 4 were reported at the first time. Furthermore, monoterpenoid 4 and alkaloid 15 showed remarkably inhibitory effect on the production of inflammatory mediator (NO) and pro-inflammatory cytokines (TNF-α and/or IL-6) in LPS-stimulated RAW264.7 cells.