A new 2-quinolone alkaloid, iso-oligophyline (1), and two very unusual C34 terpenoids, proposed names ravespanol (2) and ravespanone (3), along with two known compounds, β-sitosterol (4), and methyl linoleate (5), were isolated from the leaf extract of Ravenia spectabilis engl. Methyl linoleate constitutes the first report of isolation from this species. We have already reported the isolation of atanine (6), oligophyline (7), ravenoline (8), and arborinine (9) from the plant. Based on nuclear magnetic resonance (NMR) spectroscopy and mass spectrometric analysis, the structure of the isolated chemicals was determined. The crude fractions and four compounds (6,7,8 and 9) were evaluated for a cytotoxicity study on a panel of six human stomach cancer cell lines (SCL, SCL-6, SCL-37\'6, SCL-9, K-3, N21) by MTT assay. Among the plant extracts and isolated compounds, petroleum ether fraction and compound 7 exhibited the highest cytotoxic activity against SCL and SCL-6 cells, where the IC50 values were 17.9 and 16.56 μM, respectively.

Pentacyclic triterpenoids, recognized for their natural bioactivity, display complex spatiotemporal accumulation patterns within the ecological model plant Nicotiana attenuata. Despite their ecological importance, the underlying biosynthetic enzymes and functional attributes of triterpenoid synthesis in N. attenuata remain unexplored. Here, we show that three cytochrome P450 monooxygenases (NaCYP716A419, NaCYP716C87, and NaCYP716E107) from N. attenuata oxidize the pentacyclic triterpene skeleton, as evidenced by heterologous expression in Nicotiana benthamiana. NaCYP716A419 catalyzed a consecutive three-step oxidation reaction at the C28 position of β-amyrin/lupeol/lupanediol, yielding the corresponding alcohol, aldehyde, and carboxylic acid. NaCYP716C87 hydroxylated the C2α position of β-amyrin/lupeol/lupanediol/erythrodiol/oleanolic acid/betulinic acid, while NaCYP716E107 hydroxylated the C6β position of β-amyrin/oleanolic acid. The genes encoding these three CYP716 enzymes are highly expressed in flowers and respond to induction by ABA, MeJA, SA, GA3, and abiotic stress treatments. Using VIGS technology, we revealed that silencing of NaCYP716A419 affects the growth and reproduction of N. attenuata, suggesting the ecological significance of these specialized metabolite biosynthetic steps.

Allochrusa gypsophiloides is one of the best-known endemic saponin bearing food plants of Central Asia. However, the plant\'s secondary metabolites remain unmapped. The current study aimed to chemical profile of the metabolite in the plant roots by an untargeted UHPLC-ESI-MS, together with the isolation of the major compounds followed by a 2D NMR and HR-MS for identification and evaluation of the antioxidant and enzyme inhibitory activity of the extracts. The results revealed the presence of 48 putatively annotated metabolites comprising triterpene glycosides, phenolic compounds and their derivatives, organic acid glycosides, and lignan glycosides. The chromatographic separation and purification of the extract resulted in the isolation of four compounds where two new compounds and along with two known triterpenes were reported. The ethanol/water extracts showed a maximum effect in antioxidant assays, while the ethyl acetate extract achieved the best effect in the enzyme inhibitory assays.

Phytochemical study on the methanol extract of the stem barks of Aphanamixis polystachya led to the isolation of four previously undescribed (1-4) and ten known compounds (5-14). Their chemical structures were elucidated to be 11-methoxysawaranospiroride C (1), 6α,9S,10,13-tetrahydroxymegastigmane-3-one (2), 11-hydroxyaphanamixin B (3), (2Z,6E,13E)-2,6,13-triene-11,15-dihydroxyphytanic acid (4), cinnacasside D (5), cinnacasside E (6), vilsonol F (7), (3S,5R,6S,7E,9R)-3,5,6,9-tetrahydroxy-7-en-megastigmane (8), (3S,5R,6R,7E,9R)-3,6,9,10-tetrahydroxy-7-en-megastigmane (9), citroside A (10), threo-1-(3,4,5-trimethoxyphenyl)-1,2,3-propanetriol (11), 3,4,5-trimethoxyphenyl-1-O-β-D-glucopyranoside (12), p-coumaric acid (13), ferulic acid (14) by HR-ESI-MS, ECD, 1D-, and 2D-NMR spectra. Compounds 1, 3, 4, and 9 showed NO production inhibitory activity in LPS activated RAW 264.7 cells with IC50 values of 42.0, 67.9, 20.5, and 78.6 μM, respectively, while the remaining compounds were inactive with IC50 values over 100 μM.

BACKGROUND: Triterpenoids are versatile secondary metabolites with a diverse array of physiological activities, possessing valuable pharmacological effects and influencing the growth and development of plants. As more triterpenoids in cereals are unearthed and characterized, their biological roles in plant growth and development are gaining recognition.
OBJECTIVE: This review provides an overview of the structures, biosynthetic pathways, and diverse biological functions of triterpenoids identified in cereals. Our goal is to establish a basis for further exploration of triterpenoids with novel structures and functional activities in cereals, and to facilitate the potential application of triterpenoids in grain breeding, thus accelerating the development of superior grain varieties.
UNASSIGNED: This review consolidates information on various triterpenoid skeletons and derivatives found in cereals, and summarizes the pivotal enzyme genes involved, including oxidosqualene cyclase (OSC) and other triterpenoid modifying enzymes like cytochrome P450, glycosyltransferase, and acyltransferase. Triterpenoid-modifying enzymes exhibit specificity towards catalytic sites within triterpenoid skeletons, generating a diverse array of functional triterpenoid derivatives. Furthermore, triterpenoids have been shown to significantly impact the nutritional value, yield, disease resistance, and stress response of cereals.

A series of triterpenoid pyrones was synthesized and subsequently modified to introduce phthalimide or phthalate moieties into the triterpenoid skeleton. These compounds underwent in vitro cytotoxicity screening, revealing that a subset of six compounds exhibited potent activity, with IC50 values in the low micromolar range. Further biological evaluations, including Annexin V and propidium iodide staining experiment revealed, that all compounds induce selective apoptosis in cancer cells. Measurements of mitochondrial potential, cell cycle analysis, and the expression of pro- and anti-apoptotic proteins confirmed, that apoptosis was mediated via the mitochondrial pathway. These findings were further supported by cell cycle modulation and DNA/RNA synthesis studies, which indicated a significant increase in cell accumulation in the G0/G1 phase and a marked reduction in S-phase cells, alongside a substantial inhibition of DNA synthesis. The activation of caspase-3 and the cleavage of PARP, coupled with a decrease in the expression of Bcl-2 and Bcl-XL proteins, underscored the induction of apoptosis through the mitochondrial pathway. Given their high activity and pronounced effect on mitochondria function, trifluoromethyl pyrones 1f and 2f, and dihydrophthalimide 2h have been selected for further development.

It was found that Argentatins A and B triterpenoids make up approximately 20-30 % of the waste resin produced from the industrial processes to isolate rubber from P. argentatum. We have developed an efficient protocol for synthesizing cycloartane-16β-ol derivatives by opening the oxepane ring of argentatin B acetate (2) with BF3-OEt2. Although three new cycloartenol derivatives showed high cytotoxicity against PC-3 and HCT-15 cancer cell lines, nevertheless, the best results were obtained for (16β,24R) -(16,24-epoxy-cycloartan-2(1H)-ylidene) acetate (14), compound with intact oxepane ring. These results indicate that the substituents in the argentatin nucleus and a side chain account for the cytotoxic activity. However, according to the selectivity index (SI), 14 did not show selectivity activity to cancer cell lines over the HaCat noncancerous cell line. The compound 3β,16β-Dihydroxy-cycloartan-24-one (5), synthesized by oxepane opening, demonstrated high cytotoxic activity to cancer cell lines and showed a remarkable selectivity to cancer cell lines over the noncancerous ones. These results suggest that 5 could lead to the development of new anticancer compounds.

Whitfordiodendron filipes var. tomentosum is an endemic plant in China. There have been no chemical or pharmacological studies of this plant reported before. In the current research, eight triterpenes and two steroids were obtained. Their structures were established by the analysis of NMR data and comparison with those reported in the literature. These ten structurally diverse compounds comprised five distinct carbon frameworks with different functionalities. The chemotaxonomic significance of these secondary metabolites was discussed, disclosing the common components between the variant W. filipes var. tomentosum and the species W. filipe. Evaluation of α-glucosidase inhibitory activities of these isolates disclosed that compounds 1, 2, 4, and 6 exhibited significant α-glucosidase inhibitory activities (IC50 = 16.6-19.2 μM), which were close in value to the positive control acarbose (IC50 = 11.5 μM). Moreover, the binding modes between the biologically active compounds 1, 2, 4, and 6 and the α-glucosidase protein were preliminarily studied using molecular docking. This study not only showed the chemical and biological profile of the plant W. filipes var. tomentosum but also revealed that these components could be developed as hypoglycemic lead compounds.

A new triterpene, aculeastrumone A (1), a new triterpene saponin aculeastrumoside A (2), and eleven known compounds (3-13) were isolated from MeOH/Water (80/20) extract of the fruits of Solanum aculeastrum (Solanaceae). Their structures were established by detailed 1D and 2D NMR spectroscopic studies and mass spectrometry. The isolated compounds were evaluated against three human cancer cells ((MCF-7 (breast cancer), NCI-H460 (lung cancer), and Hela (cervical cancer)) and normal human fibroblast (BJ) cell lines. Among them, saponins 2-5, 7-8, and Carpesterol 10 possess significant cytotoxic activity with IC50 ≤ 10 µM against the three cancer cell lines.

BACKGROUND: Lung cancer is the predominant cause of cancer-related fatalities. This prompted our exploration into the anti-lung cancer efficacy of Labisia pumila, a species meticulously selected from the preliminary screening of 600 plants.
METHODS: Through the strategic implementation of activity-guided fractionation, ardisiacrispin A (1) was isolated utilizing sequential column chromatography. Structural characterization was achieved employing various spectroscopic methods, including nuclear magnetic resonance (NMR), mass spectrometry (MS), and infrared spectroscopy (IR).
RESULTS: L. pumila 70% EtOH extract showed significant toxicity in A549 lung cancer cells, with an IC50 value of 57.04 ± 10.28 µg/mL, as well as decreased expression of oncogenes and induced apoptosis. Compound 1, ardisiacrispin A, induced a 50% cell death response in A549 cells at a concentration of 11.94 ± 1.14 µg/mL.
CONCLUSIONS: The present study successfully investigated ardisiacrispin A extracted from L. pumila leaves, employing a comprehensive spectroscopic approach encompassing NMR, IR, and MS analyses. The anti-lung cancer efficacy of ardisiacrispin A and L. pumila extract was successfully demonstrated for the first time, to the best of our knowledge.