Schomburginones A‒J, geranylated benzophenones from the leaves of Garcinia schomburgkiana and their cytotoxic and anti-inflammatory activities.

Ten undescribed benzophenones, schomburginones A-J, together with 14 known analogs were isolated from the leaves of Garcinia schomburgkiana, an edible plant native to the Indochina region. The structures of the undescribed compounds were elucidated by NMR combined with HRMS spectroscopy, while their absolute configurations were determined using ECD and single-crystal X-ray diffraction analysis. The isolated metabolites represent benzophenone derivatives containing a modified monoterpene unit, including tri- and tetracyclic skeletons, which are rarely found in genus Garcinia. The cytotoxic evaluation on three cancerous cell lines demonstrated that schomburginone G, schomburginone H, and 3-geranyl-2,4,6-trihydroxybenzophenone were active against HeLa cells with IC50 values in the range of 12.2-15.7 µM, respectively, and selective compared to the non-cancerous L929 cells (SI > 3.5). In addition, the three cytotoxic compounds together with clusiacyclol A showed significant NO inhibitory activity in RAW 264.7 macrophage cells over 85% inhibition without obvious cytotoxicity at a final concentration of 100 µM. The promising activities of these compounds in cytotoxic and anti-inflammatory assays make them attractive for further study in the development of anticancer drugs.

Garcowacinols A-J, cytotoxic polyprenylated benzoylphloroglucinol derivatives from the twigs of Garcinia cowa.

Ten undescribed polyprenylated benzoylphloroglucinol derivatives named garcowacinols A‒J (1-10) and four known analogues (11-14) were isolated from the twigs of Garcinia cowa. Their structures were determined by spectroscopic data analysis (1D and 2D NMR and HRESIMS), and their absolute configurations were established based on NOESY and ECD data. All isolated compounds were evaluated for their cytotoxicity against five types of human cancer cells (KB, HeLa S3, MCF-7, Hep G2, and HT-29) as well as Vero cells by MTT colorimetric assay. Garcowacinol C was significantly active against all the five cancer cells with IC50 values in the range of 0.61-9.50 µM. Selective proliferative inhibitions were observed on garcowacinol F and 7-epiclusianone against KB cells, and guttiferone Q toward MCF-7 cells with IC50 values less than 10 µM.

Cytotoxic and Anti-Inflammatory Activities of Dihydroisocoumarin and Xanthone Derivatives from Garcinia picrorhiza.

Garcinia picrorhiza, a woody plant native to Sulawesi and Maluku Islands, Indonesia, has been traditionally used as a wound healing ointment. In our continuous search for bioactive compounds from this plant, 15 phenolic compounds were isolated from its stem bark, including a previously undescribed dihydroisocoumarin, 2'-hydroxyannulatomarin, and two undescribed furanoxanthones, gerontoxanthone C hydrate and 3'-hydroxycalothorexanthone. The structures of the new metabolites were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR and HRESIMS. Gerontoxanthone C hydrate possessed cytotoxicity against four cancer cells (KB, HeLa S3, MCF-7, and Hep G2) with IC50 values ranging from 5.6 to 7.5 µM. Investigation on the anti-inflammatory activities showed that 3'-hydroxycalothorexanthone inhibited NO production in RAW 264.7 and BV-2 cell lines with IC50 values of 16.4 and 13.8 µM, respectively, whereas only (-)-annulatomarin possessed inhibition activity on COX-2 enzyme over 10% at 20 µM. This work describes the presence of 3,4-dihydroisocoumarin structures with a phenyl ring substituent at C-3, which are reported the first time in genus Garcinia. These findings also suggest the potential of furanxanthone derivatives as cytotoxic and anti-inflammatory agents for further pharmacological studies.

Four new xanthones and their cytotoxicity from the stems of Garcinia schomburgkiana.

Four new xanthones, named schomburgones C-F (1‒4), along with six known xanthones (5‒10) were isolated from the stems of Garcinia schomburgkiana. Their structures were determined by spectroscopic analysis especially 1D and 2D NMR spectroscopies. The isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines. Furanoxanthones 4‒6 showed potent cytotoxicity against four cell lines (KB, HeLa S3, MCF-7 and Hep G2) with IC50 values in the range of 0.18‒9.95 µM.

Velucarpin D, a new pterocarpan from the stems of Dalbergia velutina and its cytotoxicity.

A new pterocarpan, named velucarpin D (1), along with nine known pterocarpans (2-10) were isolated from the stems of Dalbergia velutina. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines (KB, HeLa S-3, MCF-7, Hep G2, and HT-29). Compound 2 showed potent cytotoxicity against all the five human cancer cell lines with IC50 values in the range of 4.74-8.46 µM. In addition, compounds 1, 3, 4, 5 and 9 showed moderate cytotoxicity against both KB and HeLa S-3 cells with IC50 values in the range of 14.23-29.35 µM.

Picrorhizones A-H, Polyprenylated Benzoylphloroglucinols from the Stem Bark of Garcinia picrorhiza.

Eight new polyprenylated benzoylphloroglucinol derivatives (1-8) and four known analogues (9-12) were isolated from the stem bark of Garcinia picrorhiza. Their structures were determined by spectroscopic data analysis (1D and 2D NMR and HRESIMS), and the absolute configurations were established by single-crystal X-ray diffraction combined with experimental and calculated ECD data. The new metabolites represent rare examples of benzoylphloroglucinols bearing a cyclobutyl-containing side chain. The isolated compounds were evaluated for their cytotoxic properties against five types of human cancer cells (KB, HeLa S3, MCF-7, Hep G2, and HT-29 cells) and their inhibitory activities against COX-1 and COX-2 enzymes. The cytotoxicity results showed that compound 6 was active against KB, HeLa S3, MCF-7, and Hep G2 cancer cells, with IC50 values ranging from 5.9 to 9.4 µM. Among the compounds tested for cyclooxygenase inhibition, compound 8 possessed the highest inhibitory effect toward COX-1 (35.2 ± 9.6% inhibition at 20 µM).

Correction to: Two new xanthones from the roots of Cratoxylum cochinchinense and their cytotoxicity.

In the original publication of the article, figure 1 was published incorrectly. The correct version of figure 1 is provided below.

Two new xanthones from the roots of Cratoxylum cochinchinense and their cytotoxicity.

Two new xanthones namely cratochinone A (1) and cratochinone B (2), along with 16 known xanthones, were isolated from the roots of Cratoxylum cochinchinense. Their structures were characterized by spectroscopic methods, especially 1D and 2D NMR as well as comparison with those reported in the literature for known xanthones. All isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines (KB, HeLa S-3, HT-29, MCF-7 and Hep G2 cell lines). Compounds 2, 5, and 7 showed significant cytotoxic effects against all cell lines with IC50 values in the range of 0.91-9.93 µM, while 10 exhibited cytotoxicity against the KB, HeLa S-3, and HT-29 cells with IC50 values of 7.39, 6.07, and 8.11 µM, respectively. Compound 12 exhibited cytotoxicity against both KB and HeLa S-3 cells with IC50 values of 7.28 and 9.84 µM.

Tetrandraxanthones A-I, Prenylated and Geranylated Xanthones from the Stem Bark of Garcinia tetrandra.

Nine new xanthones, tetrandraxanthones A-I (1-9), and 22 known xanthones (10-31) were isolated from Garcinia tetrandra stem bark. The structures of 1-9 were characterized through detailed spectroscopic analysis, including HRESIMS and 2D NMR data. Among the compounds tested for their cytotoxicity, 26 showed significant cytotoxic effects against five human cancer cell lines, including MCF-7, HT-29, KB, Hep G2, and HeLa S3, with IC50 values in the range of 1.6-3.4 µM, while 10 and 11 were cytotoxic against the MCF-7, HeLa S3, and KB cell lines, with IC50 values of 4.3-9.0 µM.

Veluflavanones A-P, Cytotoxic Geranylated Flavanones from Dalbergia velutina Stems.

Sixteen new geranylated flavanones, named veluflavanones A-P (1-16), and a known analogue (17), were isolated from Dalbergia velutina. The chemical structures of 1-17, as well as their absolute configurations, were determined by spectroscopic analysis and experimental ECD data. All isolated compounds were tested for their cytotoxicity against five human cancer cell lines. Compound 9 showed cytotoxicity toward KB, HeLa S3, and MCF-7 cells with IC50 values of 9.9, 8.1, and 10.0 µM, respectively. In addition, compounds 10, 11, 14, and 16 exhibited selective cytotoxicity against HeLa S3 cells with IC50 values of 6.6-9.9 µM.

Calaxanthones A-C, three new xanthones from the roots of Calophyllum calaba and the cytotoxicity.

Three new xanthones, named calaxanthones A-C (1-3), along with 17 known xanthones (4-20) were isolated from the roots of Calophyllum calaba. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicity against five cancer cell lines (KB, HeLa S-3, HT-29, MCF-7 and HepG-2). Compound 3 showed potent cytotoxicity against all the five cancer cell lines with IC50 values in the range of 0.82-5.04 µM. Furthermore, compound 6 showed potent cytotoxicity against KB, HeLa S-3 and HepG2 cells with IC50 values of 7.06, 5.27 and 9.64 µM, respectively. Additionally, compound 7 showed potent cytotoxicity against KB cell with an IC50 value of 4.62 µM.

Two new xanthones and cytotoxicity from the bark of Garcinia schomburgkiana.

Two new xanthone derivatives, named schomburgones A (1) and B (2), along with eight known compounds, including xanthones (3-8) and anthraquinones (9-10) were isolated from the bark of Garcinia schomburgkiana. Their structures were determined by spectroscopic analysis especially 1D and 2D NMR spectroscopies. All isolated compounds were evaluated for their cytotoxicity against five cancer cell lines (KB, HeLa S-3, HT-29, MCF-7 and HepG-2). Compounds 3-6 and 8 showed good cytotoxicity against all the five cancer cell lines with IC50 values in the range of 1.45-9.46 µM.

A sesquiterpenoid tropolone and 1,2,3,4-tetrahydronaphthalene derivatives from Olax imbricata roots.

The methanol extract of Olax imbricata roots afforded one new sesquiterpenoid tropolone and three new 1,2,3,4-tetrahydronaphthalene derivatives, olaximbrisides A-D (1-4). Their structures were determined by 1D and 2D NMR experiments in combination of HRESIMS. The relative configurations were assigned by the NOESY experiments. The absolute configurations were established by a combination of X-ray diffraction analysis and electronic circular dichroism (ECD) experiments. All isolated compounds were evaluated for their cytotoxic effects against some cancer cell lines. Among them, compound 1 exhibited the cytotoxicities against MCF-7, HepG2 and LU cell lines with IC50 values of 16.3, 34.3 and 8.0 µM, respectively.

Xanthones and biphenyls from the stems of Garcinia cylindrocarpa and their cytotoxicity.

Six new compounds including four new xanthones, cylindroxanthones D-G (1-4), and two new biphenyls, cylindrobiphenyls A and B (5 and 6), were isolated from the stems of Garcinia cylindrocarpa together with 28 known compounds (7-34). The structures of the new compounds were established on the basis of extensive 1D and 2D NMR and HRESIMS spectroscopic analysis. Their cytotoxicity was evaluated against five human cancer cell lines including KB, HeLa S-3, MCF-7, Hep G2, and HT-29. Compound 23 showed strong cytotoxicity against KB, HeLa S-3, MCF-7, and Hep G2 cells with IC50 values in the range of 2.20-6.00 µM. Furthermore, compound 25 selectively exhibited good cytotoxicity against MCF-7 cells with IC50 value of 8.77 µM, while 31 showed good cytotoxicity against HT-29 cells with IC50 value of 9.18 µM.

Erythrosaponins A-J, triterpene saponins from the roots and stem bark of Gardenia erythroclada.

Ten undescribed triterpene saponins, named erythrosaponins A-J, along with one known analogue were isolated from the roots and stem bark of Gardenia erythroclada. Their structures were determined on the basis of extensive 1D and 2D NMR analyses. Absolute structure of erythrosaponin A was unequivocally affirmed by single-crystal X-ray crystallography. All isolated compounds were evaluated for their cytotoxicity against cancer cell lines (KB and HeLa S-3) and their anti-inflammatory activity based on the inhibition of NO production in RAW264.7 cells. Erythrosaponin D showed moderate cytotoxicity against KB and HeLa S-3 cells with IC50 values of 25.8 and 29.5 µM, respectively. Erythrosaponins D, F, G, I and J showed moderate anti-inflammatory with IC50 values in the range of 63.0-81.4 µM.

Caloinophyllin A, a new chromanone derivative from Calophyllum inophyllum roots.

A new chromanone derivative, namely caloinophyllin A (1), along with eight known compounds (2-9), nobiletin (2), pentamethylquercetin (3), 3,5,7,4'-tetramethoxyflavone (4), 5,7,4'-trimethoxyflavone (5), 1,5-dihydroxyxanthone (6), 1,8-dimethoxy-2-hydroxyxanthone (7), 1,6-dihydroxy-7-methoxyxanthone (8) and 4-methoxycaffeic acid (9) were isolated from the roots of Calophyllum inophyllum. The structures of all the isolated compounds (1-9) were fully characterised using spectroscopic data, as well as comparison with the previous literature data. In addition, the quantum chemical calculation has been used to confirm the conformation of 1. Moreover, all isolated compounds were assessed for their in vitro cytotoxicity against five human cancer cell lines.

Cytotoxic Flavones from the Stem Bark of Bougainvillea spectabilis Willd.

Five new flavones possessing a fully substituted A-ring with C-6 and C-8 methyl groups, bougainvinones I - M (1: -5: ), along with three known congeners, 2'-hydroxydemethoxymatteucinol (6: ), 5,7,3',4'-tetrahydroxy-3-methoxy-6,8-dimethylflavone (7: ) and 5,7,4'-trihydroxy-3-methoxy-6,8-dimethylflavone (8: ), were isolated from the EtOAc extract of the stem bark of Bougainvillea spectabilis. Their structures were established by means of spectroscopic data (ultraviolet, infrared, high-resolution electrospray ionization mass spectrometry, and one-dimensional and two-dimensional nuclear magnetic resonance) and single-crystal X-ray crystallographic analysis. The in vitro cytotoxicity of all isolated compounds against five cancer cell lines (KB, HeLa S-3, MCF-7, HT-29, and HepG2) was evaluated. Compound 5: showed promising cytotoxic activity against the KB and HeLa S-3 cell lines, with IC50 values of 7.44 and 6.68 µM. The other compounds exhibited moderate cytotoxicity against the KB cell line.

Catomentosaponin, a new triterpene saponin from the roots of Catunaregam tomentosa.

A new triterpene saponin, catomentosaponin (1) and 11 known analogues (2-12) were isolated from the roots of Catunaregam tomentosa. The structures of 1-12 were determined on the basis of extensive NMR and MS data analysis. The sugar residues were identified by co-TLC and HPLC analysis after hydrolysis. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cell lines. Compound 2 showed moderate cytotoxicity against KB cell with IC50 value of 24.84 µM.

Identification of highly potent α-glucosidase inhibitory and antioxidant constituents from Zizyphus rugosa bark: enzyme kinetic and molecular docking studies with active metabolites.

CONTEXT: Previous studies have shown that extracts of Zizyphus rugosa Lam. (Rhamnaceae) bark contained phytoconstituents with antidiabetic potential to lower blood glucose levels in diabetic rats. However, there has been no report on the active compounds in this plant as potential antidiabetic inhibitors. OBJECTIVE: We evaluated the α-glucosidase inhibitory and antioxidant activities of Z. rugosa extract. Moreover, the active phytochemical constituents were isolated and characterized. MATERIALS AND METHODS: The α-glucosidase inhibition of crude ethanol extract obtained from the bark of Z. rugosa was assayed as well as the antioxidant activity. Active compounds (1-6) were isolated, the structures were determined, and derivatives (2a-2 l) were prepared. All compounds were tested for their α-glucosidase inhibitory (yeast and rat intestine) and antioxidant (DPPH) activities. RESULTS: The active α-glucosidase inhibitors (1-6) were isolated from Z. rugosa bark and 12 derivatives (2a-2 l) were prepared. Compound 2 showed the most powerful yeast α-glucosidase inhibitory activity (IC50 16.3 µM), while compounds 3 and 4 display only weak inhibition toward rat intestinal α-glucosidase. Moreover, compound 6 showed the most potent antioxidant activity (IC50 42.8 µM). The molecular docking results highlighted the role of the carboxyl moiety of 2 for yeast α-glucosidase inhibition through H-bonding. DISCUSSION AND CONCLUSIONS: These results suggest the potential of Z. rugosa bark for future application in the treatment of diabetes and active compounds 1 and 2 have emerged as promising molecules for therapy.

A novel pyrrole alkaloid from the fruit peels of Strychnos nux-blanda.

A novel pyrrole alkaloid, strychnuxin (1), along with five known compounds (2-6) was isolated from the fruit peels of Strychnos nux-blanda. The structures of all the isolated compounds (1-6) were fully characterised using spectroscopic data, as well as comparison with the previous literature data. Moreover, all isolated compounds were assessed for their α-glucosidase and acetylcholinesterase inhibitory activities.