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Seven previously undescribed preurianin-type limonoids, namely paraxylines A-G, and three known analogs were isolated from stem bark of Dysoxylum parasiticum. The structures, including absolute configurations, were established through spectroscopic analyses, quantum chemical calculations using the density functional theory method, as well as the DP4+ algorithm. Paraxylines A-G were identified as the first preurianin-type with full substitution at C, D-rings, leading to the highly oxygenated seco-limonoids skeleton. The secreted alkaline phosphate assay against an engineered human and murine TLR4 of HEK-Blue cells was performed to evaluate the immune regulating effects. Among them, paraxyline B was found to be a remarkable TLR4 agonist whereas two analogs (toonapubesins A and B) were found to antagonise lipopolysaccharide stimulation of the TLR4 pathway. Paraxylines A and C-E acted either as agonists or antagonists depending on the origin of the TLR4 receptor (human or mouse). The effect of these selected compounds on the expression of pro-inflammatory cytokines TNF-α, IL-1α, IL-1β, and IL-6 of the NF-κB signaling pathway were examined in macrophage cell lines, revealing dose-dependent effects. Additionally, paraxylines A, C, D, and G also presented modest cytotoxic activity against MCF-7 and HeLa cell lines with IC 50 values ranging from 23.1 to 43.5 μM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lansium domesticum Corr. is a member of the Meliaceae family that is widely spread in tropical and subtropical region of Asia and America. Traditionally, the fruit of this plant has been consumed because of its sweet taste. However, the fruit peels and the seeds of this plant have been rarely utilized. The previous chemical investigation of this plant showed the presence of secondary metabolites with many biological activities, including cytotoxic triterpenoid. Triterpenoids is a class of secondary metabolites which contain thirty carbon atoms in the main skeleton. The high modification of this type of compound, including the ring opening, highly oxygenated carbons, and the degradation of its carbon chain to give the nor-triterpenoid structure, is responsible for its cytotoxic activity. In this paper, we isolated and elucidated the chemical structure of two new onoceranoid triterpenes, kokosanolides E ( 1 ) and F ( 2 ), from the fruit peels of L. domesticum Corr., along with a new tetranortriterpenoid, kokosanolide G ( 3 ), from the seeds of L. domesticum Corr. The structural determination of compounds 1-3 was undertaken through FTIR spectroscopic analysis, 1D and 2D NMR, mass spectrometry, as well as through a comparison of the chemical shifts of the partial structures of compounds 1-3 with the literature data. The cytotoxic properties of compounds 1-3 were tested against MCF-7 breast cancer cells using the MTT assay. Moderate activity was shown by compounds 1 and 3 , with IC 50 values of 45.90 and 18.41 μg/mL, respectively, while compound 2 showed no activity (IC 50 168.20 μg/mL). For the onoceranoid-type triterpene, the high symmetrical structure of compound 1 is presumably the reason for its better cytotoxic activity compared with that of compound 2 . Compound 3 showed moderate activity, mainly because of the presence of the furan ring, which, based on the literature, gives better cytotoxic activity in a tetranortriterpenoid-type structure. The findings of three new triterpenoid compounds from L. domesticum indicate the significant value of this plant as a source of new compounds.

Two new azadirone-type limonoids, namely lasiocarpine A ( 1 ) and lasiocarpine B ( 2 ) were isolated from the fruit of Chisocheton lasiocarpus along with three known limonoids ( 3 - 5 ). UV, IR, one- and two- dimensional NMR, and mass spectrometry were used to determine the chemical structure of the isolated compounds. Furthermore, their cytotoxic activity against breast cancer cell line MCF-7 was evaluated using PrestoBlue reagent. From these compounds, lasiocarpine A ( 1 ) showed the strongest activity with an IC 50 value of 43.38 μM.

Guarea is one of the largest genera of the American Meliaceae family, consisting of over 69 species which are widely distributed in Mexico, Argentina, and Africa and are used in traditional medicine for several diseases. Previous studies reported that the Guarea species produce secondary metabolites such as sesquiterpenoid, diterpenoid, triterpenoid, limonoid, steroid, and aromatic compounds. The preliminary chemical investigation commenced by isolating the limonoid compound, dihydrogedunin, in 1962; then, 240 compounds were obtained from the isolation and hydrodistillation process. Meanwhile, sesquiterpenoid is a significant compound with 52% of Guarea species. The extract and compounds were evaluated for their anti-inflammation, antimalarial, antiparasitic, antiprotozoal, antiviral, antimicrobial, insecticidal, antioxidant, phosphorylation inhibitor, and cytotoxic biological activities. The Guarea genus has also been reported as one of the sources of active compounds for medicinal chemistry. This review summarizes some descriptions regarding the types of Guarea species, especially ethnobotany and ethnopharmacology, such as the compounds isolated from the part of this genus, various isolation methods, and their bioactivities. The information can be used in further investigations to obtain more bioactive compounds and their reaction mechanisms.

A new limonoid, pentandricine (1), along with three known limonoids, ceramicine B (2), 6-de(acetyloxy)-23-oxochisocheton (3), 6-de(acetyloxy)-23-oxo-7-O-deacetylchisocheton (4), have been isolated from the stembark of Chisocheton pentandrus. The chemical structures of the new compound were elucidated on the basis of spectroscopic evidence. All of the compounds were tested for their cytotoxic effects against MCF-7 breast cancer cells. Compounds 1-4 showed weak and no cytotoxicity against MCF-7 breast cancer cells with IC 50 values of 369.84, 150.86, 208.93 and 120.09 μM, respectively.