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Six new tirucallane-type triterpenoids, named munropenes A-F ( 1 - 6 ), were extracted from the whole plants of Munronia pinnata using a water extraction method. Their chemical structures were determined based on detailed spectroscopic data. The relative configurations of the acyclic structures at C-17 of munropenes A-F ( 1 - 6 ) were established using carbon-proton spin-coupling constants ( 2,3 J C,H ) and inter-proton spin-coupling constants ( 3 J H,H ). Furthermore, the absolute configurations of munropenes A-F ( 1 - 6 ) were determined through high-performance liquid chromatography (HPLC), single-crystal X-ray diffraction, and electronic circular dichroism (ECD) analyses. The antiproliferative effects of munropenes A-F were evaluated in five tumor cell lines: HCT116, A549, HepG2, MCF7, and MDAMB. Munropenes A, B, D, and F ( 1 , 2 , 4 , and 6 ) inhibited proliferation in the HCT116 cell line with IC 50 values of 40.90, 19.13, 17.66, and 32.62 µM, respectively.

The Euphorbiaceae plant Euphorbia neriifolia L. is distributed widely in India, Thailand, Southeastern China, and Taiwan and used as a carminative and expectorant to treat several inflammation-related diseases, such as gonorrhoea, asthma, and cancer. In the course of our search for potential anti-inflammatory agents from the titled plant, 11 triterpenes from the stem of E. neriifolia were isolated and reported in our previous endeavor. Given its rich abundance in triterpenoids, the ethanolic extract in this follow-up exploration has led to the isolation of additional eight triterpenes, including six new euphanes-neritriterpenols H and J-N ( 1 and 3 - 7 )-one new tirucallane, neritriterpenol I ( 2 ), and a known compound, 11-oxo-kansenonol ( 8 ). Their chemical structures were elucidated on the basis of spectroscopic data, including 1D- and 2D NMR, and HRESIMS spectra. The absolute stereochemistry of neritriterpenols was determined by single-crystal X-ray diffraction analysis, ICD spectra, and DP4+ NMR data calculations. Compounds 1 - 8 were also evaluated for their anti-inflammatory activity by using lipopolysaccharide (LPS)-stimulated IL-6 and TNF-α on RAW 264.7 macrophage cells. Intriguingly, the euphane-type triterpenes ( 1 and 3 - 8 ) showed an inhibitory effect on LPS-induced IL-6 but not on TNF-α, while tirucallane-type triterpene 2 showed strong inhibition on both IL-6 and TNF-α., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Chang, Huang, Wei, Lo, Lin, Chao, Liao, Shen, Chen, Li, Lin, Tai, Kuo and Liaw.)

Nine undescribed protolimonoids, including two apotirucallane and seven tirucallane triterpenoids, as well as five known compounds, were isolated from the root bark of Dictamnus dasycarpus Turcz. Their structures were elucidated by extensive spectroscopic analysis. Compounds 4-8, with an undescribed 22,25-epoxytirucallene part, were established their absolute configuration by single-crystal X-ray diffraction of 4. Such compounds might provide evidence for the degradation of protolimonoids to limonoids, bridging an oxidative cleavage biogenetic pathway between these structurally diverse triterpenoids. None of them showed anti-inflammatory, hepatoprotective, or monoamine oxidase B inhibitory activity., Competing Interests: Declaration of Competing Interest These authors have no conflict of interest to declare., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Euphorbia neriifolia L. is widely distributed in India, Thailand, and China and has been used to treat diseases such as rotten sores and asthma as well as for its antidiabetic and anticancer effects. In this study, seven undescribed triterpenes, including six euphanes, neritriterpenols A-B and D-G, and a tirucallane, neritriterpenol C, together with four known triterpenes, were isolated from ethanolic extracts of E. neriifolia stems. Their structures with absolute configurations were determined through detailed spectroscopic data, including 1D and 2D NMR data analyses, single-crystal X-ray diffraction analysis, ECD spectra, and DP4+ NMR data calculations as well as Mo 2 (OAc) 4 -induced ECD analysis. Furthermore, preliminarily evaluation of the anti-inflammatory and anti-proliferative effects of the isolated triterpenes leads to the structure-activity relationship (SAR) studies implying that the unsaturated functional group at the end of the C17 side chain on euphane-type triterpenes may be correlated with the increase of anti-inflammatory and anti-proliferative activities., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The phytochemical investigation of Euphorbia tirucalli L. (Euphorbiaceae) yielded four new compounds, including a rare cadalene-type sesquiterpene (tirucadalenone), two tirucallane triterpenoids, euphorol L and euphorol M, with the latter being described as an epimeric mixture, and a euphane triterpene, namely, euphorol N, together with 7 known compounds. Their structures and absolute configurations were elucidated from analysis of 1D (1H, J-modulated 13 C) and 2D NMR (HSQC, HMBC and NOESY), high-resolution mass spectrometry (HRESIMS), optical rotation, and GIAO NMR shift calculation followed by CP3 analysis, along with comparison with literature reports. All these compounds were tested for cytotoxicity against K562, MCF-7 and/or and HepG2 tumor cell lines. Only tirucadalenone displayed a mild cytotoxic activity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ten new triterpenoid compounds with structure diversity of the C-17 side-chain, including nine tirucallanes, named xylocarpols A⁻E ( 1 ⁻ 5 ) and agallochols A⁻D ( 6 ⁻ 9 ), and an apotirucallane, named 25-dehydroxy protoxylogranatin B ( 10 ), were isolated from the mangrove plants Xylocarpus granatum , Xylocarpus moluccensis , and Excoecaria agallocha . The structures of these compounds were established by HR-ESIMS and extensive one-dimensional (1D) and two-dimensional (2D) NMR investigations. The absolute configurations of 1 and 2 were unequivocally determined by single-crystal X-ray diffraction analyses, conducted with Cu K α radiation; whereas those of 4 , 6 ⁻ 8 were assigned by a modified Mosher's method and the comparison of experimental electronic circular dichroism (ECD) spectra. Most notably, 5 , 6 , 7 , and 9 displayed potent activation effects on farnesoid⁻X⁻receptor (FXR) at the concentration of 10.0 μM; 10 exhibited very significant agonistic effects on pregnane⁻X⁻receptor (PXR) at the concentration of 10.0 nM.

Chemical investigation of the roots of Entandrophragma congoënse (Meliaceae) led to the isolation of two new 3,4-seco-tirucallane triterpenes, namely seco-tiaminic acids B and C (1 and 2) together with nine known compounds: 3,4-secotirucalla-21-formyl-23-oxo-4(28),7,24-trien-3-oic acid (3), methyl angolensate (4), molucensin N (5), molucensin O (6), piscidinol A (7), 7α,20(S)-dihydroxy-4,24(28)-ergostadien-3-one (8), 24-methylene-cholest-5-en-3β,7α-diol (9), entilin A (10), and entilin B (11). Their structures were determined using extensive spectroscopic methods including 1D and 2D NMR, HRMS, and CD analyses; new results were compared to existing data in the literature. The two newly identified seco-tiaminic acids showed moderate antiplasmodial and cytotoxic activities against a chloroquine-sensitive strain of the malaria parasite (Plasmodium falciparum NF54) and were cytotoxic toward an L6 rat skeletal myoblast cell line, respectively., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A new tirucallane, 3β-hydroxy-3-decarbonyl-24-epi-piscidinol A (1), and two new pairs of tetranortriterpene 23-epimers, named thaimoluccepimers A (2) and B (3), were isolated from the seeds of a Thai mangrove, Xylocarpus moluccensis. The structures of these compounds were elucidated by HRESIMS and NMR spectroscopic analysis.

A novel series of elemonic acid derivatives were synthesized and evaluated for their inhibitory activity on Pin1. Five compounds displayed significantly improved ability to inhibit Pin1 activity at micromolar levels. Compound 10 with 2-carboxylmethylene was the most active one with an IC50 value of 0.57 μM. The docking models of Pin1 support that introduction of an acidic group to elemonic acid enhance the Pin1 inhibitory activity., (Copyright © 2014. Published by Elsevier Ltd.)