Monoterpene-chalcone conjugates and diarylheptanoids isolated from the seeds of Alpinia katsumadai Hayata with cytotoxic activity.

Five undescribed monoterpene-chalcone conjugates (1-5), one undescribed hypothetical precursor of diarylheptanoid (6), two undescribed diarylheptanoids (7-8), and fourteen known compounds (9-22) were isolated from the seeds of Alpinia katsumadai. Their structures were elucidated through the interpretation of HRESIMS, NMR, ECD, and X-ray diffraction data. MTT assays on human cancer cell lines (HepG2, A549, SGC7901, and SW480) revealed that compounds 3-8, 11, and 13 exhibited broad-spectrum antiproliferative activities with IC50 values ranging from 3.59 to 21.78 µM. B cell lymphoma 2 was predicted as the target of sumadain C (11) by network pharmacology and verified by homogeneous time-resolved fluorescence assay and molecular docking.

Microwave-Assisted Extraction of Anticancer Flavonoid, 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethyl Chalcone (DMC), Rich Extract from Syzygium nervosum Fruits.

2',4'-Dihydroxy-6'-methoxy-3',5'-dimethyl chalcone (DMC) is a biological flavonoid that is present in the fruits of Syzygium nervosum (Ma-Kiang in Thai). Microwave-assisted extraction (MAE), which utilizes microwave radiation to heat the extraction solvent quickly and effectively, was used to recover DMC-rich extract from Syzygium nervosum fruit. To determine the DMC content, a highly accurate and precise HPLC technique was developed. The influences of MAE conditions, including the solid-liquid ratio, microwave power, and microwave duration on the content of DMC, were sequentially employed by a single factor investigation and response surface methodology (RSM) exploratory design. The predicted quadratic models were fitted due to their highly significant (p < 0.0001) and excellent determination coefficient (R2 = 0.9944). The optimal conditions for producing DMC-rich extract were a ratio of sample to solvent of 1:35 g/mL, a microwave power of 350 W, and a microwave time of 38 min. Under the optimal MAE setting, the DMC content reached 1409 ± 24 µg/g dry sample, which was greater than that of the conventional heat reflux extraction (HRE) (1337 ± 37 µg/g dry sample) and maceration (1225 ± 81 µg/g dry sample). The DMC-rich extract obtained from MAE showed stronger anticancer activities against A549 (human lung cancer cells) and HepG2 (human liver cancer cells) than the individual DMC substance, which makes MAE an effective method for extracting essential phytochemicals from plants in the nature.

Complete Assignment of the 1H and 13C NMR Spectra of Carthamin Potassium Salt Isolated from Carthamus tinctorius L.

Carthamin potassium salt isolated from Carthamus tinctorius L. was purified by an improved traditional Japanese method, without using column chromatography. The 1H and 13C nuclear magnetic resonance (NMR) signals of the pure product were fully assigned using one- and two-dimensional NMR spectroscopy, while the high purity of the potassium salt and deprotonation at the 3' position of carthamin were confirmed by atomic adsorption spectroscopy and nano-electrospray ionization mass spectrometry.

Photophysical Study and Biological Applications of Synthetic Chalcone-Based Fluorescent Dyes.

A chalcone series (3a-f) with electron push-pull effect was synthesized via a one-pot Claisen-Schmidt reaction with a simple purification step. The compounds exhibited strong emission, peaking around 512-567 nm with mega-stokes shift (∆λ = 93-139 nm) in polar solvents (DMSO, MeOH, and PBS) and showed good photo-stability. Therefore, 3a-f were applied in cellular imaging. After 3 h of incubation, green fluorescence was clearly brighter in cancer cells (HepG2) compared to normal cells (HEK-293), suggesting preferential accumulation in cancer cells. Moreover, all compounds exhibited higher cytotoxicity within 24 h toward cancer cells (IC50 values ranging from 45 to 100 µM) than normal cells (IC50 value >100 µM). Furthermore, the antimicrobial properties of chalcones 3a-f were investigated. Interestingly, 3a-f exhibited antibacterial activities against Escherichia coli and Staphylococcus aureus, with minimum bactericidal concentrations (MBC) of 0.10-0.60 mg/mL (375-1000 µM), suggesting their potential antibacterial activity against both Gram-negative and Gram-positive bacteria. Thus, this series of chalcone-derived fluorescent dyes with facile synthesis shows great potential for the development of antibiotics and cancer cell staining agents.

Hydroxysafflor yellows alleviate thrombosis and acetaminophen-induced toxicity in vivo by enhancing blood circulation and poison excretion.

BACKGROUND: Hydroxysafflor yellow A (HSYA) from the flower of Carthamus tinctorius (Safflower) has been reported to have various pharmacological effects. However, little is known about the bioactivities of other chemical constituents in Safflower and the relationship between enhancement of blood circulation and hepatoprotection by HSYA. PURPOSE: The present research was to evaluate the antithrombotic and hepatoprotective activities of HSYA and C, examine their mechanisms of actions, including influence on the excretion velocity of acetaminophen, and the relationship between the antithrombotic, hepatoprotective, and other bioactivities. METHODS: The hepatoprotective activities were examined by acetaminophen (APAP)-induced zebrafish toxicity and carbon tetrachloride (CCl4)-induced mouse liver injury. The concentrations of APAP in zebrafish and APAP that was excreted to the culture media were quantified by UHPLC-MS. The anti-thrombosis effect of HSYA and C were examined by the phenylhydrazine (PHZ)-induced zebrafish thrombosis. RESULTS: HSYA and HSYC showed robust protection on APAP-induced toxicity and PHZ-induced thrombosis. The hepatoprotective effects of HSYA and C were more potent than that of the positive control, acetylcysteine (61.7% and 58.0%, respectively, vs. 56.9% at 100 µM) and their antithrombosis effects were more robust than aspirin (95.1% and 86.2% vs. 52.7% at 100 µM). HSYA and C enhanced blood circulation, rescued APAP-treated zebrafish from morphological abnormalities, and mitigated APAP-induced toxicity in liver development in liver-specific RFP-expressing transgenic zebrafish. HSYC attenuated CCl4-induced mouse liver injury and regulated the levels of HIF-1α, iNOS, TNF-α, α-SMA, and NFκB in liver tissues. HSYA was also protective in a dual thrombotic and liver toxicity zebrafish model. By UHPLC-MS, HSYA accelerated the excretion of APAP. CONCLUSION: HSYA and C are the bioactive constituents of Safflower that are responsible for the herbal drug's traditional use in promoting blood circulation to remove blood stasis. Safflower and its chalcone constituents may protect from damage due to exogenous or disease-induced endogenous toxins by enhancing the excretion velocity of toxins.

Anti-inflammatory steroidal sapogenins and a conjugated chalcone-stilbene from Dracaena usambarensis Engl.

Four new steroidal sapogenins, dracaenogenins CF (1-4), a new conjugated chalcone-stilbene, 3''-methoxycochinchinenene H (5) together with eight known compounds namely, (25S)-spirosta-1,4-dien-3-one (6), trans-resveratrol (7), 4,4'-dihydroxy-3'-methoxychalcone (8), N-trans-coumaroyltyramine (9), N-trans-p-coumaroyloctopamine (10), N-trans-feruloyloctopamine (11), 7-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-N2,N3-bis(4-hydroxyphenethyl)-6-methoxy-1,2-dihydronaphthalene-2,3-dicarboxamide (12) and grossamide (13) were isolated from the stems of Dracaena usambarensis Engl. from Kenya. It is important to note that compounds 12 and 13 are being reported from this genus for the first time. Structural elucidation of the isolated compounds was done using spectroscopic (NMR, UV, IR, optical rotation) and spectrometric (HRESIMS) techniques. The absolute and relative configurations of the isolated compounds were determined by employing single crystal X-ray crystallography analysis, NOESY correlations and coupling constants. The anti-inflammatory potencies of the isolated compounds were evaluated by measuring the levels of four cytokines (IL-1ß, IL-2, GM-CSF and TNF-α) in the supernatant media of human peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS). At the tested concentration of 100 µM, the new conjugated chalcone-stilbene 5, the dihydrochalcone, 8 and the lignanamide, 13 were substantially more potent than the standard drug, ibuprofen, inhibiting the release of all the cytokines, IL-1ß, IL-2, GM-CSF and TNF-α from 0.06-58.04% compared to LPS control. These compounds should therefore be considered for development into anti-inflammatory drug candidates. Compound 7 significantly decreased the release of GM-CSF (6.11% of LPS control) and TNF-α (18.35% of LPS control). The cytokine TNF-α was sensitive to all the tested compounds 1-13.

4-Hydroxyderricin and xanthoangelol isolated from Angelica keiskei prevent dexamethasone-induced muscle loss.

Since a decrease in muscle mass leads to an increased risk of mortality, the prevention of muscle wasting contributes to maintaining the quality of life. Recently, we reported that glabridin, a prenylated flavonoid in licorice, prevents dexamethasone-induced muscle loss. In this study, we focused on the other prenylated chalcones 4-hydroxyderricin and xanthoangelol in Ashitaba (Angelica keiskei) and investigated their prevention effect on dexamethasone-induced muscle loss. It was found that 4-hydroxyderricin and xanthoangelol significantly prevented dexamethasone-induced protein degradation in C2C12 myotubes by suppressing the expression of ubiquitin ligases, Cbl-b and MuRF-1. These prenylated chalcones acted as the antagonists of the glucocorticoid receptor and inhibited the binding of dexamethasone to this receptor and its subsequent nuclear translocation. In addition, the chalcones suppressed the phosphorylation of p38 and FoxO3a as the upstream factors for ubiquitin ligases. Dexamethasone-induced protein degradation and upregulation of Cbl-b were attenuated by the knockdown of the glucocorticoid receptor but not by the knockdown of p38. In male C57BL/6J mice, the Ashitaba extract, containing 4-hydroxyderricin and xanthoangelol, suppressed dexamethasone-induced muscle mass wasting accompanied by a decrease in the expression of ubiquitin ligases by inhibiting the nuclear translocation of the glucocorticoid receptor and phosphorylation of FoxO3a. In conclusion, 4-hydroxyderricin and xanthoangelol are effective compounds to inhibit steroid-induced muscle loss.

Simultaneous Optimization of the Ultrasonic Extraction Method and Determination of the Antioxidant Activities of Hydroxysafflor Yellow A and Anhydrosafflor Yellow B from Safflower Using a Response Surface Methodology.

An evaluation of the ultrasonic extraction process and the antioxidant activities of hydroxysafflor yellow A (HSYA) and anhydrosafflor yellow B (AHSYB) from safflower are presented herein. Using response surface methodology (RSM), based on a four-factor-three-level Box-Behnken design (BBD), the extraction parameters, namely, temperature, extraction time, solvent-to-material ratio, and extraction power, were optimized for maximizing the yields of HSYA and AHSYB. The maximum yield was obtained at a temperature of 66 °C with an extraction time of 36 min, solvent-to-material ratio of 16 mL/g, and the extraction power of 150 W, which was adjusted according to the actual conditions. The HSYA and AHSYB contents were determined using high performance liquid chromatography (HPLC). The yield and the comprehensive evaluation value of HSYA and AHSYB were calculated. The antioxidant activities of the extracts were determined using a ferric reducing antioxidant power (FRAP) kit and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The results suggested that the safflower extracts possessed obvious ferric reducing and DPPH radical scavenging activities. The antioxidant activity increased with increasing concentration. The results suggested that optimizing the conditions of ultrasonic extraction using RSM can significantly increase the yields of HSYA and AHSYB from safflower. The safflower extracts showed better antioxidant activity. This study can encourage future research on cardiovascular and cerebrovascular diseases.

Isolation, characterization, and xanthine oxidase inhibitory activities of flavonoids from the leaves of Perilla frutescens.

Phytochemical investigation of the water extract from the leaves of Perilla frutescens (Lamiaceae) led to the isolation of a new flavanone, a new chalcone, and a new aurone, namely, (2S)-5,7-dimethoxy-8,4'-dihydroxyflavanone (1), 2',4'-dimethoxy-4,5',6'-trihydroxychalcone (2), and (Z)-4,6-dimethoxy-7,4'-dihydroxyaurone (3), respectively. The structures were unambiguously elucidated on the basis of spectroscopic data. And the absolute configuration of 1 was determined by analysis of electronic circular dichroism spectrum. The isolated compounds were evaluated for their inhibitory effects on xanthine oxidase in vitro. Among them, 2 showed more potent activity than the positive control allopurinol, a well-known XO inhibitor clinically used for treatment of gout. Lineweaver-Burk transformation of the inhibition kinetics data demonstrated that it was a mixed-type inhibitor.[Formula: see text].

Termipaniculatones A-F, chalcone-flavonone heterodimers from Terminthia paniculata, and their protective effects on hyperuricemia and acute gouty arthritis.

Terminthia paniculata (Sanyeqi) is widely used for treating inflammation and rheumatic arthritis in the folk areas of Yunnan province, China. Its total extract was first revealed with xanthine oxidase (XO) inhibitory activity in vitro and anti-hyperuricemic effect in vivo. Bioassay-guided separation on Fr. A5 yielded six chalcone-flavonone heterodimers, termipaniculatones A-F. Their structures were elucidated based on extensive spectroscopic analyses involving HRESIMS, 1D and 2D NMR, UV, IR and [α]D, and the absolute configuration of termipaniculatone F was verified by ECD calculation. Termipaniculatones A and E showed obvious XO inhibitory activity with IC50 values of 55.6 and 89.5 µM, respectively, which took effects via a mix-type mode. A molecular modeling study revealed that termipaniculatone A was well located into the active site of XO by interacting with Glu802, Arg880, Thr1010 and Val1011 residues. Termipaniculatone A showed anti-hyperuricemic effects by decreasing serum uric acid levels and inhibiting XO activity in both serum and liver on potassium oxonate (PO)-induced hyperuricemia mice, and anti-inflammatory activity through alleviating paw swelling on monosodium urate (MSU)-induced mice, at the concentration of 20 mg/kg. This is the first time to reveal the anti-hyperuricemic and anti-acute gouty arthritis potency of T. paniculata and the characteristic biflavonoids as active constituents, which provides valuable information for searching new XO inhibitors from natural sources.

Autophagy induction by xanthoangelol exhibits anti-metastatic activities in hepatocellular carcinoma.

Xanthoangelol (XAG), a prenylated chalcone isolated from the Japanese herb Angelica keiskei Koidzumi, has been reported to exhibit antineoplastic properties. However, the specific anti-tumor activity of XAG in human hepatocellular carcinoma (HCC), and the relevant mechanisms are not known. Herein, we evaluated the effect of XAG against HCC in vitro and in vivo. Although XAG treatment did not significantly reduce the viability of the Hep3B and Huh7 cell lines, it suppressed cell migration, invasion, and EMT. This anti-metastatic effect of XAG was due to induction of autophagy, because treatment with the autophagy inhibitor 3-methyadenine (3-MA) or knockdown of the pro-autophagy Beclin-1 effectively abrogated the XAG-induced suppression of metastasis. Mechanistically, XAG induced autophagy via activation of the AMPK/mTOR signaling pathway, and XAG treatment dramatically increased the expression of p-AMPK while decreasing p-mTOR expression. In addition, blocking AMPK/mTOR axis with compound C abrogated the autophagy-mediated inhibition of metastasis. The murine model of HCC metastasis also showed that XAG effectively reduced the number of metastatic pulmonary nodules. Taken together, our results revealed that autophagy via the activation of AMPK/mTOR pathway is essential for the anti-metastatic effect of XAG against HCC. These findings not only contribute to our understanding of the anti-tumor activity of XAG but also provide a basis for its clinical application in HCC. Before this study, evidence of XAG on HCC was purely anecdotal; present study provides the first comprehensive assessments of XAG on HCC metastasis and investigates its underlying mechanism. Results suggest that XAG exerts anti-metastatic properties against HCC through inducing autophagy which is mediated by the activation of AMPK/mTOR signaling pathway. This research extends our knowledge about the antineoplastic properties of XAG and suggests that induction autophagy may represent future treatment strategies for metastatic HCC.

Angelica keiskei (Ashitaba) powder and its functional compound xanthoangelol prevent heat stress-induced impairment in sperm density and quality in mouse testes.

Recently, gradual decline in human sperm production has become a serious worldwide concern because it leads to increased rates of infertility. Endocrine disrupters, lifestyle changes, and varicocele, all of which elevate testicular temperature, are thought to be the main causes of this decline. The present study aimed to determine whether the dietary phytochemicals Angelica keiskei (Ashitaba) powder (57.5 mg/kg) and its functional component, xanthoangelol (3 mg/kg), can prevent heat stress-induced impairment in sperm density and quality in mice. Sperm parameters were analyzed 28 days after mice exposure to heat. Supplementation with Ashitaba powder completely prevented heat-induced impairment in sperm parameters, including densities of motile sperms and progressive sperms (> 25 µm/sec), and amplitude of lateral head displacement. Xanthoangelol did not exert a complete protective effect; nevertheless, it significantly prevented heat stress-induced reduction in most parameters. Both Ashitaba powder and xanthoangelol elevated the expression of the widely expressed heat shock proteins (HSPs) Hspa1a and Hsp40 and the antioxidant enzyme glutathione synthase in non-stressed testes. Ashitaba powder significantly prevented heat stress-induced reduction in the expression of Hspa1l and Hspa2, which are highly expressed in the testes and critical for fertility. Our results showed that Ashitaba powder and xanthoangelol protected testicular cells from heat stress, probably by elevating the levels of antioxidant enzymes and HSPs. Supplementation with dietary functional phytochemicals may help prevent heat stress-induced male infertility.

Computer-aided identification of novel anti-paracoccidioidomycosis compounds.

AIM: The shape-based virtual screening was used for the identification of new compounds anti-paracoccidioidomycosis (PCM). MATERIALS & METHODS: The study was performed according to the following steps: collection and curation of a dataset of quinolinyl N-oxide chalcones with anti-PCM activity, development and validation of shape-based models, application of the best model for virtual screening, and experimental validation. RESULTS & CONCLUSION: Among 31 computational hits, eight compounds showed potent antifungal activity and low cytotoxicity for mammalian cells. The checkerboard assay showed that most promising hit (compound 3) displayed additive effects with the antifungal cotrimoxazole and amphotericin B. Therefore, the shape-based virtual screening allowed us to discover promising compounds in prospective hit-to-lead optimization studies for tackling PCM.

Safflower yellow promotes angiogenesis through p-VHL/ HIF-1α/VEGF signaling pathway in the process of osteogenic differentiation.

OBJECTIVE: Safflower yellow (SY) is an active component ofCarthamus tinctorius L. that is widely used in orthopedics. This study aimed to evaluate the role of SY in angiogenesis and osteogenic differentiation. METHODS: The migration and in vitro angiogenesis of SY (4.5, 9.0, 18 µg/ml)-treated human umbilical vein endothelial cells (HUVEC-12) were assessed by transwell and tube formation assay, respectively. Osteogenic differentiation ability was detected by alkaline phosphatase (ALP) and Alizarin Red S staining. The mRNA and protein expressions of related markers were determined by RT-qPCR and Western blot. RESULTS: The migration and tube formation ability of HUVEC-12 were promoted by SY. Furthermore, SY facilitated the angiogenesis and osteogenic differentiation in the co-culture of HUVEC-12 and BMSCs by increasing hypoxia inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), Angiopoietin-2 (Ang-2), ALP, runt-related transcription factor 2 (Runx2) and osteopontin-1 (OPN-1) levels. Inhibition of HIF-1α expression by 3-(5-hydroxymethl-2-furyl)-1-benzylindazole (YC-1), restrained SY-induced proliferation, migration and angiogenesis of HUVEC-12 and the increased protein levels of VEGF, Ang-2, ALP, Runx2 and OPN-1. Finally, WD repeat and SOCS box-containing protein-1 (WSB-1)/Von Hippel-Lindau protein (p-VHL) pathway was involved in the beneficial effect of SY. CONCLUSION: SY promotes osteogenic differentiation via enhancing angiogenesis by regulating pVHL/HIF-1α/VEGF signaling pathway.

Six kanshone C-derived sesquiterpenoid hybrids nardochalaristolones A-D, nardoflavaristolone A and dinardokanshone F from Nardostachys jatamansi DC.

Four sesquiterpenoid-chalcone hybrids (nardochalaristolones A-D, 1-4), a pair of epimeric sesquiterpenoid-flavonone hybrids ((2'S)- and (2'R)-nardoflavaristolone A, 5 and 6), and a sesquiterpenoid dimer (dinardokanshone F, 7), all sharing a kanshone C-derived sesquiterpenoid unit, were isolated from the underground parts of Nardostachys jatamansi (D.Don) DC. Their structures were elucidated by analysis of the extensive spectroscopic data, and the absolute configurations were established by analysis of 2D NMR spectroscopic data including NOESY data, combined with comparisons of experimental and calculated electronic circular dichroism spectra. Further, the plausible biosynthetic pathways for these compounds were proposed. And the results of SERT activity assay revealed that nardochalaristolones C-D (3 and 4) and nardoflavaristolone A (5 and 6) significantly enhanced SERT activity, while other compounds didn't show any SERT regulatory activities.

Chalcone derivatives from the root bark of Morus alba L. act as inhibitors of PTP1B and α-glucosidase.

As part of our continuing research to obtain pharmacologically active compounds from Morus alba L. (Moraceae), four Diels-Alder type adducts (DAs) [morusalbins A-D], one isoprenylated flavonoid [albanin T], together with twenty-one known phenolic compounds were isolated from its root bark. The chemical structures were established using NMR, MS, and ECD spectra. The DAs including morusalbins A-D, albasin B, macrourin G, yunanensin A, mulberrofuran G and K, and albanol B exhibited strong inhibitory activities against both protein tyrosine phosphatase 1B (PTP1B) (IC50, 1.90-9.67 µM) and α-glucosidase (IC50, 2.29-5.91 µM). In the kinetic study, morusalbin D, albasin B, and macrourin G showed noncompetitive PTP1B inhibition, with Ki values of 0.33, 1.00, and 1.09 µM, respectively. In contrast, these DAs together with yunanensin A produced competitive inhibition of α-glucosidase, with Ki values of 0.64, 0.42, 2.42, and 1.19 µM, respectively. Furthermore, molecular docking studies revealed that these active DAs have high affinity and tight binding capacity towards the active site of PTP1B and α-glucosidase.

Antiproliferative Activity of Extracts of Campomanesia adamantium (Cambess.) O. Berg and Isolated Compound Dimethylchalcone Against B16-F10 Murine Melanoma.

Campomanesia adamantium, a native species of the Brazilian Cerrado, is characterized as a natural source of phenolic compounds and has known potential anticancer activities. This study aimed to evaluate the chemical profile of dichloromethane extracts of pulp (DEGPU) and peel (DEGPE) from the fruits of C. adamantium and to identify compounds with antiproliferative effects in vitro against melanoma cells by sulforhodamine B (SRB) assay, apoptosis induction assay, caspase-3 activation assay, nitric oxide (NO) release in coculture of B16-F10 cells and murine peritoneal macrophages. The chemical profiles of DEGPU and DEGPE were analyzed by high performance liquid chromatography coupled to diode array detector and mass spectrometer using the electrospray ionization interface (HPLC-DAD-ESI-MS/MS). Thirteen compounds were identified in both extracts and the chromatographic study of the most active extract in SRB assay DEGPU (GI50 of 16.17 µg/mL) resulted in the isolation of seven compounds. The isolated compound dimethylchalcone (DMC) had the highest antiproliferative activity against B16-F10 with a GI50 of 7.11 µg/mL. DEGPU extract activated caspase-3 in 29% of cells at 25 µg/mL and caused a 50% decrease in NO release in coculture. DEGPU can be characterized as a source of bioactive compounds such as DMC, as seen from its antiproliferative effect in vitro by inducing B16-F10 cells to undergo apoptosis, essential feature in the search for new anticancer drugs.

Integration of Biochemometrics and Molecular Networking to Identify Antimicrobials in Angelica keiskei.

Botanical medicines have been utilized for centuries, but it remains challenging to identify bioactive constituents from complex botanical extracts. Bioassay-guided fractionation is often biased toward abundant or easily isolatable compounds. To comprehensively evaluate active botanical mixtures, methods that allow for the prioritization of active compounds are needed. To this end, a method integrating bioassay-guided fractionation, biochemometric selectivity ratio analysis, and molecular networking was devised and applied to Angelica keiskei to comprehensively evaluate its antimicrobial activity against Staphylococcus aureus. This approach enabled the identification of putative active constituents early in the fractionation process and provided structural information for these compounds. A subset of chalcone analogs were prioritized for isolation, yielding 4-hydroxyderricin (1, minimal inhibitory concentration [MIC] ≤ 4.6 µM, IC50 = 2.0 µM), xanthoangelol (2, MIC ≤ 4.0 µM, IC50 = 2.3) and xanthoangelol K (4, IC50 = 168 µM). This approach allowed for the identification of a low-abundance compound (xanthoangelol K) that has not been previously reported to possess antimicrobial activity and facilitated a more comprehensive understanding of the compounds responsible for A. keiskei's antimicrobial activity.

Molecular dynamics simulation integrating the inhibition kinetics of hydroxysafflor yellow A on α-glucosidase.

Inhibition of α-glucosidase has attracted the attention of researchers due to its connection to type-2 diabetes. Hydroxysafflor yellow A (HSYA) extracted from Carthamus tinctorius L. is a natural antioxidant used in traditional Chinese medicine. In this study, the effect of HSYA on α-glucosidase was evaluated using inhibitory kinetics based on the antioxidant properties of HSYA and by performing computational simulation integration methods. HSYA reversibly inhibited α-glucosidase in a competitive inhibition manner and the evaluated kinetic parameters were IC50 = 1.1 ± 0.22 mM and Ki = 1.04 ± 0.23 mM, respectively. The results of spectrofluorimetry showed that the inner hydrophobic regions of α-glucosidase, which are mostly in the active site, were exposed to the surface with increasing HSYA concentrations, indicating that the inactivation of α-glucosidase by HSYA was accompanied by regional unfolding. The molecular dynamics simulations indicated that the four rings of HSYA interact with four residues such as G217, A278, H279, and G280 at the entrance of the active site. Our study provides insight into the inhibition of α-glucosidase and the accompanying structural changes by HSYA. Based on its α-glucosidase-inhibiting effect and its potential as a natural antioxidant, HSYA is a potential agent for treating α-glucosidase-associated type-2 diabetes.

Hydroxysafflor Yellow A Alleviates Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome in Mice.

Hydroxysafflor yellow A (HSYA) is an effective ingredient of the Chinese herb Carthamus tinctorius L. The present study investigated the protective effect of HSYA on lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in mice, and the underlying mechanisms involved. HSYA (14, 28, 56 mg/kg) was intraperitoneally injected to mice once daily from day 1 to 10 after LPS administration. HSYA attenuated the body weight loss, the augmented left index and the increase of pathologic changes in pulmonary inflammation caused by LPS. Treatment with HSYA also alleviated increased expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, transforming growth factor (TGF)-ß1, collagen (Col) I, Col III, α-smooth muscle actin (α-SMA), myeloid differentiation (MD)-2, Toll-like receptor 4 (TLR4) and cluster differentiation (CD)14 at the mRNA (RT-PCR) and protein levels (Western blot and enzyme-linked immuno sorbent assay). Moreover, HSYA inhibited the elevated levels of nuclear factor (NF)-κB and α-SMA in lung tissue (immunohistochemistry), and alleviated the slight collagen deposition in pulmonary tissues (Masson's trichrome staining). HSYA inhibited the specific binding of fluorescein isothiocyanate (FITC)-LPS on human lung epithelial cell line (A549) or human umbilical vein cell line (Eahy926) cells (flow cytometry). These findings suggested that HSYA has a protective effect on acute respiratory distress syndrome (ARDS) induced by LPS through blocking the TLR4/NF-κB pathway, and that the TLR4 receptor might be a target of HSYA on the cell membrane.