Methoxychalcone Research Articles

Pharmacophore Modeling and Binding Affinity of Secondary Metabolites from Angelica keiskei to HMG Co-A Reductase.

Statins are cholesterol-lowering drugs with a mechanism of inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase, but long-term use can cause side effects. An example of a plant capable of reducing cholesterol levels is Angelica keiskei (ashitaba). Therefore, this study aimed to obtain suitable compounds with inhibitory activity against the HMG-CoA reductase enzyme from ashitaba through in silico tests. The experiment began with screening and pharmacophore modeling, followed by molecular docking on ashitaba's compounds, statins groups, and the native ligand was (3R,5R)-7-[4-(benzyl carbamoyl)-2-(4-fluorophenyl)-5-(1-methylethyl)-1H-imidazole-1-yl]-3,5-dihydroxyheptanoic acid (4HI). Based on the results of the molecular docking simulations, 15 hit compounds had a small binding energy (ΔG). Pitavastatin, as the comparator drug (ΔG = -8.24 kcal/mol; Ki = 2.11 µM), had a lower ΔG and inhibition constant (Ki) than the native ligand 4HI (ΔG = -7.84 kcal/mol; Ki = 7.96µM). From ashitaba's compounds, it was found that 4'-O-geranylnaringenin, luteolin, isobavachalcone, dorsmannin A, and 3'-carboxymethyl-4,2'-dihydroxy-4'-methoxychalcone have low ΔG of below -6 kcal/mol. The lowest ΔG value was found in 3'-carboxymethyl-4,2'-dihydroxy-4'-methoxy chalcone with a ΔG of -6.67 kcal/mol and Ki value of 16.66 µM, which was lower than the ΔG value of the other comparator drugs, atorvastatin (ΔG = -5.49 kcal/mol; Ki = 1148.17 µM) and simvastatin (ΔG = -6.50 kcal/mol; Ki = 22.34 µM). This compound also binds to the important amino acid residues, including ASN755D, ASP690C, GLU559D, LYS735D, LYS691C, and SER684C, through hydrogen bonds. Based on the results, the compound effectively binds to six important amino acids with good binding affinity and only requires a small concentration to reduce half of the enzyme activity.

Molecular docking studies of novel s-triazine derivatives incorporating amino methoxy chalcone for EGFR inhibitor in breast cancer

Background: The Epidermal growth factor receptor (EGFR) receptor is involved in both apoptosis and angiogenesis. An upregulation of EGFR activity can potentially expedite the proliferation of malignant cells. Anticancer activity is among the many pharmacological activities of s-triazine derivative compounds. The potential of amino chalcone derivatives as anticancer agents has been documented. The anticipated outcome is that the derivatives of these two compounds will enhance their efficacy as antiproliferative agents. Objective: Through molecular docking, this study aimed to assess the potential of eight novel trichlorotriazin compounds derived from amino chalcone as EGFR inhibitors in breast cancer. Method: The molecular docking process was carried out with the assistance of the software package identified as the molecular docking environment (MOE) 2023.0901. Results: Compounds two and four, which have a similar binding orientation to the positive control, have the potential to inhibit EGFR, according to molecular docking results. For developing new s-triazine derivatives that are potent agents against breast cancer, the molecular docking outcomes of compounds two and four may require additional consideration. Conclusion: Compounds which are two and four have surfaced as noteworthy contenders.

Mechanisms of 4-Dimethylamino-4'-Methoxy Chalcone in Promoting Melanin Synthesis

Background and aims: Vitiligo, a pigmentation-associated disease, affects 1–2% of the global population andis difficult to treat. The pathogenetic mechanism of vitiligo remains unclear. Vernonia anthelmintica (L.) Willd. extract for vitiligo treatment was initially recorded 300 years ago. Itschalcone compounds are believed to play essential roles in this treatment. In a previous study, chalcones were shown to enhance melanin production and tyrosinase activity inmouse B16 cells. Materials and methods: In this study, the effects were investigated of 4-dimethylamino-4'-methoxy chalcone (DMC) on theexpression of tyrosinase (TYR), tyrosinase-related protein (TRP)-1, tyrosinase-relatedprotein (TRP)-2, and microphthalmia-associated transcription factor (MITF)on murine B16 cells. Moreover, the signaling pathways of melanogenesis regulation,and the effects of DMCon the AC/cAMP/PKA/CREB (CREB and p-CREB), p38mitogen-activated protein kinase (MAPK) (MAPK, p-p38 MAPK, ERK andp-ERK), Wnt/β-catenin (β-catenin), and SWI/SNF pathways (SOX-10) proteinexpression levels were examined by Western blot. Results: The data showed that DMCcould promote melanin production by upregulating the p-CREB, p-p38,p-ERK and β-catenin proteins.

GREEN SYNTHESIS, CHARACTERIZATION, AND ANTIBACTERIAL ACTIVITY OF METHOXY CHALCONES

The purpose of this research is to develop the synthesis of chalcone through a green chemical approach that has the potential as an antibacterial. Chalcone synthesis was carried out using a grinding technique through a Claisen-Schmidt condensation reaction at room temperature for 30 minutes by grinding benzaldehyde (4-bromobenzaldehyde or 4- hydroxybenzaldehyde), 4'-methoxyacetophenone, and NaOH. The reaction product was purified by recrystallization through 96% ethanol. The purity of the compound was tested by TLC. Characterization of chalcones by FT IR, 1HNMR, 13C-NMR, and GC-MS showed that 4-hydroxy-4'-methoxy chalcone and 4-Bromo-4'-methoxy chalcone were formed. The antibacterial activity of Methoxy chalcone was determined in vitro by a disc diffusion test for grampositive and gram-negative bacteria. The test results showed that the second compound chalcone had weak activity against Staphylococcus aureus and was not active against Escherichia coli.

Preparation, characterization and study on the nonlinear optical parameters of novel biphenyl-4-carbohydrazide derivative

We report here the preparation, characterization and the 3rd order nonlinear optical properties of (N-[(E)-(3-Nitrophenyl) methylidene]) biphenyl-4-carbohydrazide, a novel organic NLO material. The characterization of the compound for molecular structural study was carried out by FTIR and X-ray Diffraction. A Photoluminescence and UV–vis spectrum was selected to study the linear optical properties. In dimethyl formamide (DMF) solution, the 3rd order NLO properties have been measured at 532 nm by DPSS continuous wave laser using the Z-scan technique. Open aperture data indicates the presence of two photon absorption (TPA) at 532 nm. The measured experimental values of nonlinear absorption coefficient (β) is 10-8 (cmW−1), the nonlinear refractive index(n2) is 10-11(cm2W−1), and third order susceptibility (χ(3)) is 10-9esu. Due to TPA at 532 nm the compound shows good optical limiting behavior. The values obtained are comparable with the values obtained for 4- methoxy chalcone derivatives and dibenzylidene acetone derivatives. The optical limiting threshold of the compound is 2.8 KJ/cm2 .The comparatively high value obtained indicates that this material may be used in optical device applications like optical limiters and optical switches.

Flavonoids of Tripodanthus acutifolius inhibit TNF–α production in LPS–activated THP–1 and B16–F10 cells

Ethnopharmacological relevanceT. acutifolius is an endemic species from South America which has been used in traditional medicine since ancient times due to its biological properties, including its anti–inflammatory effects.Aim of the study: The aim of the article is to investigate the inhibitory activity of T. acutifolius over TNF–α production in THP–1 and B16–F10 cells. To achieve this, phytochemical analysis has been used to determine the compounds present in the species with anti–inflammatory effects. Materials and methodsLeaves and stems of T. acutifolius were extracted with n–heptane, dichloromethane, methanol and water. The resulting extracts were analysed in THP–1 and B16–F10 cells by measuring their inhibitory capacity over the production of TNF–α stimulated with LPS. ResultsThe guided–bioassay led to the isolation of 6,2',4'–trimethoxyflavone (1), 5,3',4'–trihydroxy–6,7,8–trimethoxyflavone (2), (E)–2',4'–dihydroxy–6'–methoxy–chalcone (3) and 5,4'–dihydroxy–6,7,8–trimethoxyflavone (4) from the dichloromethanic extract. Compounds showed an inhibitory activity of TNF–⍺ production in THP–1 cells, with IC50 of 2.38 ± 0.02 μM, 12.36 ± 0.17 μM, 1.12 ± 0.01 μM and 8.09 ± 0.04 μM, respectively. In addition, the compounds showed an inhibitory activity of TNF–⍺ production in B16–F10 cells with IC50 of 1.32 ± 0.03 μM, 5.63 ± 0.09 μM, 0.60 ± 0.02 μM and 3.77 ± 0.15 μM, respectively. ConclusionsWe identified 3 flavones (6,2',4'–trimethoxyflavone, 5,3',4'–trihydroxy–6,7,8–trimethoxyflavone, 5,4'–dihydroxy–6,7,8–trimethoxyflavone) and a chalcone ((E)–2',4'–dihydroxy–6'–methoxy–chalcone) present in the leaves and stems of T. acutifolius. These compounds are an alternative for the treatment of immune–mediated inflammatory disorders, acting as negative modulators over the TNF–α production.

DESIGN, SYNTHESIS AND MOLECULAR MECHANISM OF FEW NEURAMINIDASE INHIBITORS IN TREATMENT OF H1N1 BY NMR TECHNIQUES

Considering the issue of resistance to anti-influenza drugs, there is a need for discovery of new antiviral drugs. In view of this, flavones and their synthetic precursors i.e. chalcones were designed as inhibitors of influenza virus - H1N1 neuraminidase enzyme using structure-based drug design. Based on the best docking scores, some chalcone and flavone derivatives were synthesized and characterized by IR and proton NMR. Few of them were selected for 31P NMR studies, in order to probe the molecular mechanism of their antiviral action. Reasonably good correlation between docking scores and 31P NMR results were observed. As antiviral drugs are known to show membrane stabilizing effect on host cell, 31P NMR data for methoxy chalcone showed stabilization effect on model membrane pointing towards good antiviral activity which remained unaffected even after its cyclization to flavone. These derivatives can be explored further to provide a future therapeutic option for the treatment and prophylaxis of H1N1 viral infections.

Synthesis, growth and characterization of a long-chain π-conjugation based methoxy chalcone derivative single crystal; a third order nonlinear optical material for optical limiting applications

Organic material (chalcone derivative 4-[(1E)-3-(4-methoxyphenyl)-3-oxoprop-1-en-1-yl]phenyl 4-methylbenzene-1-sulfonate {4MPMS}) has been grown by solvent evaporation technique. The structural properties have been carried out by powder XRD and single crystal XRD data. The linear optical properties (band gap, extinction co-efficient, optical conductivity and complex dielectric constant) were studied by UV-VIS-NIR spectrometer. In addition, defect states were identified and analyzed by creation of color center mechanism using photoluminescence spectroscopy. In Thermal analysis, crystal (4MPMS) is found to be stable up to 158 °C. Hence it may be used for the fabrication of device below the melting point. The electrical properties (dielectric constant and dielectric loss factor) have been carried out. The electronic polarizability is the major contribution for the high frequency dielectric constant values. Therefore, using theoretical aspects, the electronic polarizability values were calculated using Clausius–Mossotti relation as well as band structure approach of Penn model. Laser damage threshold for 4MPMS crystal was determined by using Nd:YAG laser with 532 nm. The nonlinear optical absorption coefficient and third order nonlinear optical susceptibility (χ(3)) values are reasonably larger than those of the other chalcone derivative crystals. High second order molecular hyperpolarizability enhances the third order optical nonlinear efficiency. Increased χ(3) and coupling factor (less than 1/3) indicates that the optical nonlinearity is electronic in origin. The behavior of nonlinear optical absorption curve confirms that the mechanism belongs to reverse saturable absorption (RSA).

Synergistic effects of para-hydroxy meta-methoxy chalcone (pHmMC)- doxorubicin treatments on T47D breast cancer cells

Resistance to some cancer chemotherapeutic drugs has been identifed. One strategy to overcome that problem is by combining two or more of the drugs to get co-chemotherapeutic effects. A derivate chalcone, 3 - (4’-hydroxy-3’-methoxyphenyl)-1-phenyl-2-propene-1-on or para hydroxy meta methoxy chalcone (pHmMC), has been reported to have cytotoxic activity on some cancer cells through some pathways. The aim of this study was to investigate the effects of combinations of pHmMC and Doxorubicin (Dox) on the cytotoxicity, anti-proliferation, apoptosis, and the cell cycle of T47D (breast cancer cell-lines) in vitro. The cytotoxic and antiproliferative activity were determined by MTT (3-[4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] assay. The combination index (CI) was used to determine the synergistic, additive or antagonistic effects of the combinations. Flowcytometry method was performed to determine the combination effects on the apoptosis and cell cycle. The results indicated that the combinations had a higher inhibitory effect on the cell growth compared to those of single treatments of pHmMC and Dox. All the doses used in the combinations were lower of the single doses at their IC50s. The results showed all the combinations gave synergistic (CI: 0.3 – 0.7) up to strong synergistic (CI: 0.1 – 0.3) effects. The synergistic effects of the combinations were due to increased apoptosis and induced cell cycle arrest in S and G2/M phases on the cancer cell lines.

How methoxy groups change nature of the thiophene based heterocyclic chalcones from p-channel to ambipolar transport semiconducting materials

Chalcone derivatives gained significant consideration from scientific community due to their potential applications ranging from better biological activity to the efficient semiconducting properties. Present investigation deals with the in-depth study of three chalcone derivatives (2E)-1-(2,5-Dimethyl-3-thienyl)-3-(2-methoxyphenyl)prop-2-en-1-one (1), (2E)-3-(3,4-Dimethoxyphenyl)-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one (2), and (E)-1-(2,5-Dimethyl-3-thienyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (3) highlighting their optoelectronic, charge transport (CT) and nonlinear optical (NLO) response. The ground and excited state geometries are optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The effect of electron donating groups on the frontier molecular orbitals, absorption and emission wavelengths are investigated and discussed thoroughly using the quantum chemical calculations. The comprehensive intra-molecular charge transfer (ICT) is perceived from the occupied orbitals to the unoccupied molecular orbitals. A novel structure-property relationship is established on the basis of their calculated electronic structures, frontier orbitals and density of states. The electro-optical and nonlinear optical (NLO) properties are finely tuned in the chalcone derivatives comprising of di- and tri-methoxy groups at peripheral. The nature of the p-type and ambipolar charge transport behavior of the compounds 1–3 is limelighted on the basis of their ionization potentials, electron affinities, reorganization energies, transfer integrals and intrinsic mobility. The mono- and di-substituted methoxy chalcone derivatives show the ambipolar performance owing to the better transfer integral and intrinsic mobility values for hole and electron. Whilst tri-methoxy at peripheral would lead the p-channel characteristics due to the balanced reorganization energy (hole and electron) and superior hole transfer integrals leads to higher hole intrinsic mobility.

PENGARUH p-HIDROKSI m-METOKSI KALKON (pHmMK) TERHADAP EKSPRESI PROTEIN Bcl-2 dan Bax PADA SEL KANKER PAYUDARA MCF-7

Senyawa derivat kalkon yaitu 3-(4’-hidroksi-3’-metoksifenil)-1-fenil-2-propen-1-on) atau para hidroksi meta metoksi kalkon (pHmMK) telah diteliti mampu memacu apoptosis (kematian sel) pada sel kanker payudara MCF-7. Penelitian ini bertujuan untuk mempelajari jalur mekanisme apoptosis senyawa pHmMK pada sel kanker MCF-7 dengan mengamati pengaruhnya terhadap ekspresi protein Bcl-2 dan Bax. Pengamatan ekspresi protein dilakukan dengan metode imunositokimia (ICC) dan dianalisis menggunakan software ImageJ. Hasil penelitian menunjukkan bahwa pemacuan apoptosis oleh pHmMK terjadi melalui mekanisme penurunan ekspresi Bcl-2 dan peningkatan ekspresi Bax

Abstract 2611: Effects of chalcones, nicotinamide, and resveratrol on PPAR gamma activation in oral cancer cells

Abstract Several classes of natural products have cancer prevention potential and PPAR gamma is an intriguing chemoprevention target as a nuclear receptor that controls multiple growth and differentiation processes. We have previously tested many classes of natural products in A/J mice and have found that the following chemoprevention compounds had no significant dietary toxicities: inositol, eucalyptol, chalcones, nicotinamides, and resveratrol. We tested these compounds for their capacity to activate PPAR gamma reporter genes in CA-9-22 oral cancer cells. In several repeated experiments we found that Inositol hexaphosphate did not activate PPAR gamma reporter genes at high concentrations of 1-4 mM. We found that eucalyptol, trans-Chalcone, 4 methoxy chalcone, Nicotinic Acid, and Nicotinamide had the capacity for statistically significant activation of PPAR gamma reporter genes in oral cancer cells from 20-60% at concentrations of 1-100 uM. We found that resveratrol was the most potent agent and could activate PPAR gamma reporter genes 2 fold. As a reference, this was about half the activity of the prototypic PPAR gamma activator pioglitazone. We performed additional experiments with resveratrol and found that it could activate the PPAR gamma dependent squamous differentiation gene Involucrin in oral cancer cells and BEAS 2B cells. Additionally, resveratrol significantly decreased BEAS 2 B proliferation from 48-96 hours at concentrations of 10 uM. From this data we conclude that resveratrol has the capacity to activate PPAR gamma in vitro and resveratrol and its derivatives may also function as PPAR gamma activators as an additional mechanism of action. We also conclude that inositol, eucalyptol, chalcones, and nicotinamides do not activate PPAR gamma. Citation Format: Jennifer Diaz, Beverly Wuertz, Art Galbraith, Frank G. Ondrey. Effects of chalcones, nicotinamide, and resveratrol on PPAR gamma activation in oral cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2611.

Chemical Composition and Antinociceptive Potential of Campomanesia reitziana Fruits.

The methanolic extract from Campomanesia reitziana fruits and the main active principle, identified as 4',6'-dihydroxy-3',5'-dimethyl-2'-methoxy chalcone or dimethyl cardamonin (1), exhibited pronounced antinociceptive effects against two models of pain in mice. Compound 1 caused dose-dependent inhibition of abdominal constrictions, with a calculated ID50 value of 8.1 (6.5-10.1) μmol/kg (i.p.), being about 16-fold more potent than two reference analgesic drugs. Methanolic extract and 1 were also effective against the formalin model, inhibiting both phases of pain, causing reductions of 39.9% and 26.8% (extract, 10 mg/kg) and 52.9% and 57.6% (compound 1, 5 mg/kg) for the first and second phases, respectively.

LC Determination of Five Flavonoid Aglycones in the Tibetan Medicinal Plant Oxytropis falcata Bunge

A simple, efficient and accurate liquid chromatographic method was established to determine five flavonoid aglycones, 7-hydroxy flavonone, pinocembrin, 2′,4′-dihydroxy chalcone, 2′-hydroxy-4′-methoxy chalcone and pinostrobin in the whole plant powder of Oxytropis falcata Bunge. These five compounds were separated on an Agilent Zorbax Eclipse XDB-C8 column (150 × 4.6 mm, 5 μm). Mobile phases were composed of water containing 0.1% v/v formic acid and acetonitrile using gradient elution. The established method was validated for linearity, accuracy, precision, limit of detection and quantitation, repeatability and stability.

Third order nonlinear optical properties and optical limiting in donor/acceptor substituted 4′-methoxy chalcone derivatives

The third order nonlinear optical properties of 4′-methoxy chalcone and its derivatives have been investigated using a single-beam Z-scan technique with nanosecond laser pulses at 532 nm. The 4′-methoxy chalcone and its derivatives are donor–acceptor–acceptor (D–A–A) and donor–acceptor–donor (D–A–D) type intramolecular charge transfer molecules. The nonlinear response in these molecules was found to increase with increase in (a) the electron acceptor strength in D–A–A type and (b) the donor strength of the substituted group in D–A–D type molecules. The χ(3) value in these molecules is found to be of the order of 10-13 esu. The observed increase in the third order nonlinearity in these molecules clearly indicates the electronic origin. The compounds exhibit good optical limiting at 532 nm. The best optical limiting behavior was observed with the molecule substituted by a strong electron donor.

Antioxidant properties of natural flavonoids: quenching and generation of singlet molecular oxygen

Summary This paper describes the interaction between photochemically generated singlet molecular oxygen [O2(1Δg)] and a series of naturally occurring flavonoids (FL) (2′,4′‐dihydroxychalcone (I), 2′,4′‐dihydroxy, 3′‐methoxy chalcone (II), 7‐hydroxyflavanone (III) and 7‐hydroxy‐8‐methoxyflavanone (IV) all obtained from Zuccagnia punctata Cav. The properties of these compounds as generators and quenchers of the known oxidative species O2(1Δg), upon direct and dye‐sensitized photoirradiation, were investigated. Time‐resolved phosphorescence detection, and conventional spectroscopic measurements demonstrate that compounds I‐IV are fairly good O2(1Δg) deactivators with overall rate constant for the process of quenching in the range of 3.7 x 106 (IV) to 2.8 × 108 M−1s−1 (I). Because the O2(1Δg) quenching possesses an exclusively physical component, O2(1Δg) scavenging is not accompanied by consumption of the flavonoid. Compounds I, III and IV are poor O2(1Δg) generators upon direct (near UV) photoirradiation, whereas compound II does not generate any of the oxidative species. Experiments measuring inhibition by flavonoids I‐IV of the photosensitized lipid peroxidation employed linoleic acid as a photoxidizable substrate and Rose Bengal and Methylene Blue as photosenstizers. Results demonstrate that the interesting properties of flavonoids I‐IV as O2(1Δg) scavengers cannot be straightforwardly extrapolated to their potential activity as photoprotectors for lipid peroxidation.

Growth and characterization of single crystal cored fibers (SCCF) of novel nonlinear organic optical materials

Single crystal cored fibers (SCCF) of 4-nitro-4′-methylbenzyledene aniline (NMBA), (−)2-(α-methylbenzylamino)-5-nitropyridine (MBA-NP), and ethoxy methoxy chalcone (EMC) have been grown in glass capillaries from their melts with internal diameters ranging from 20 to 50 μm and lengths up to 5 cm for use as waveguides. The details about the experimental procedure and the technique adopted to fabricate SCCF of the above mentioned materials are reported. The fibers have been characterized using X-ray diffraction and polarizing microscopic techniques.

Microstructural and non-linear optical properties of hot-pressed ethoxy methoxy chalcone (EMC)

Abstract The Chalcone derivative, ethoxy methoxy chalcone (EMC), has been prepared by the condensation of paraethoxybenzaldehyde and paramethoxyacetophenone. The NMR and X-ray powder diffraction studies confirm the formation of the compound. It was hot-pressed under various hot-pressing conditions and optimised to yield near-transparent samples. The X-ray diffraction patterns obtained for the hot-pressed samples are consistent with that of the starting material. The microstructural characteristics of these samples have been studied as a function of the hot-pressing conditions. The avarage size of the crystallite has been found to increase on annealing at 80°C. The dielectric property has been found to depend on the microstructural characteristics of the hot-pressed samples. The second harmonic generation (SHG) studies have been carried out using the 1064 nm radiation of a Nd:YAG laser. The SHG efficiency of these samples has been found to vary as a function of the hot-pressing conditions.

Trigonelline and Stachydrine Released from Alfalfa Seeds Activate NodD2 Protein in Rhizobium meliloti

Spectroscopic data (nuclear magnetic resonance, mass spectrometry, ultraviolet-visible) in this study identify trigonelline and stachydrine as major components of alfalfa (Medicago sativa L.) seed rinse. Moreover, biological assays show that these natural products induce nodulation (nod) gene transcription in Rhizobium meliloti by activating the regulatory protein NodD2, but not the homologous NodD1 protein. These findings contrast with the fact that the only previously identified NodD2 activator, 4,4' -dihydroxy-2' -methoxychalcone (MCh), also activates NodD1 protein. Trigonelline and stachydrine induce nod genes only at much higher concentrations than MCh, but they are released from seeds in correspondingly greater amounts. The existence of these amphoteric, nonflavonoid nod gene inducers broadens our understanding of the biochemical processes and ecological mechanisms that a legume host uses to regulate its microbial symbiont.

Homoisoflavonoids from Caesalpinia sappan

Three new homoisoflavonoids, 7-hydroxy-3-(4′-hydroxybenzylidene)-chroman-4-one, 3,7-dihydroxy-3-(4′-hydroxybenzyl)-chroman-4-one and 3,4,7-trihydroxy-3-(4′-hydroxybenzyl)-chroman were isolated from the dried heartwood of Caesalpinia sappan, together with the known compounds 4,4′-dihydroxy-2′-methoxychalcone, 8-methoxybonducellin, quercetin, rhamnetin and ombuin.