Aporphine alkaloids and a naphthoquinone derivative from the leaves of Phaeanthus lucidus Oliv. and their α-glucosidase inhibitory activity.

Three previously undescribed aporphine alkaloids, phaeanthuslucidines E-G, one previously undescribed naphthoquinone derivative, phaeanthusnaphthoquinone, and three known compounds were isolated from an EtOAc extract of the leaves of Phaeanthus lucidus Oliv. The structures of all previously undescribed compounds were established through extensive spectroscopic investigations and high-resolution mass spectroscopy. The 6aR configuration of phaeanthuslucidines E-G was assigned by comparing their ECD spectra and specific rotation values with the reported known compounds. Some isolated compounds were evaluated for their α-glucosidase inhibitory activity. Among these compounds, phaeanthuslucidine E showed the highest α-glucosidase inhibitory activity with an IC50 value of 17.9 ± 0.4 µM. The molecular docking of phaeanthuslucidine E was further studied.

Styryl lactone derivatives and aristolactam alkaloids from Goniothalamus tapis Miq. and their α-glucosidase inhibitory activity.

Two new styryl lactone derivatives, goniothapic acids A (1) and B (2), and 18 known compounds, were isolated from the twig and leaf extracts of Goniothalamus tapis Miq. The structures of new compounds were characterised by spectroscopic methods and HRESITOFMS. Their absolute configuration was established by comparing the experimental and calculated ECD spectra. Eleven compounds were evaluated for their α-glucosidase inhibitory activity. Of these, (-)-goniothalamin (5) and oldhamactam (16) showed the best α-glucosidase inhibitory activity with IC50 values of 54.8 and 57.9 µM, respectively.

Anti-inflammatory potential of a Thai traditional remedy called Prabchompoothaweep in an animal model of acute and sub-acute inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Prabchompoothaweep (PCT) is a Thai remedy which is composed of 23 herbs and has been added onto the National List of Essential Medicines (NLEM) of Thailand. This remedy has been used to treat allergic rhinitis and asthma in Thai traditional medicine for many years. Furthermore, a few studies have reported anti-allergic, anti-malarial, anti-inflammatory and antioxidant activities. AIM OF THE STUDY: This study aims to evaluate anti-inflammatory activity of PCT extract in an animal model. MATERIALS AND METHODS: The animal model of acute inflammation was studied over a 24-h period, utilizing the method of carrageenan-induced paw oedema. In addition, sub-acute inflammation was examined over 7 days, using the formalin-induced paw oedema method. The treatment groups received PCT extracts, via the oral route, at 1-h prior to injection and then the sub plantar of the rat right paw was injected with the named substances to generate paw oedema. The paw thickness was measured by vernier caliper at regular intervals after injection. At the end of experiment, the blood and paw tissues were collected for measurement of pro-inflammatory cytokines and histological examination respectively. RESULTS: In acute inflammation, all doses of PCT extract (250, 500 and 1000 mg/kg p.o.) significantly reduced paw thickness after the first 3 h in a dose-dependent manner and the percentage of inhibition was 38.7%, 47.8% and 49.5% respectively. The pro-inflammatory cytokines, including TNF-α and IL-1ß, statistically decreased with all doses of the extracts. However, the histological examination did not reveal significant results due to the short time duration. As regards to sub-acute inflammation, all doses of PCT extract significantly reduced paw thickness with 12.78%, 23.64% and 35.78%, in a dose dependent manner. Also, the pro-inflammatory cytokines (TNF-α and IL-1ß) significantly decreased at day 7. Interestingly, the histological examination of paw tissue demonstrated reductions of mononuclear infiltrations of inflammatory cells, this was observed in the group receiving PCT extracts, also in a dose-dependent manner. CONCLUSION: Therefore, PCT exerted anti-inflammatory activity in an animal model of acute and sub-acute inflammation, suggesting that it could be used as a new source for treatment of inflammatory diseases.

Study of Optimal Conditions to Grow Thai Ganoderma, Fruiting Test, Proximate and Their Alpha Glucosidase Inhibitory Activity.

Ganoderma (Ganodermataceae) has a worldwide distribution and has been widely used in traditional medicines. In this study, we report wild strains of Ganoderma that include two G. sichuanense and one G. orbiforme from northern Thailand. Optimal conditions for mycelium growth were ensured. The most favourable medium was potato sucrose agar for G. sichuanense and oatmeal agar for G. orbiforme and at 25 °C and 30 °C and pH 4-8. All types of cereal grains can be used to promote the growth of the mycelia of Ganoderma species. Fruiting tests were performed. All strains of Ganoderma produce fruiting bodies successfully in bag culture at 28 ± 1 °C with 75-85% relative humidity. Only G. orbiforme produced fruiting bodies in field cultivation at the laboratory scale. In the first flush yields, the G. sichuanense strain MFLUCC 22-0064 gave better production (the B.E was 152.35 ± 6.98 g). This study is the first to document the bag and field cultivation of wild Thai G. orbiforme. Ganoderma species are revealed to contain high amounts of fiber (47.90-52.45% d.b.), protein (12.80-14.67% d.b.), fat (4.90-5.70% d.b.), and carbohydrates (3.16-4.02% d.b.). Additionally, G. sichuanense and G. orbiforme were preliminarily screened for biological activity for inhibition of alpha-glucosidase enzyme activity. The IC50 values of G. orbiforme (MFLUCC 22-0066) was 105.97 ± 1.36 µg/mL and G. sichuanense (MFLUCC 22-0064) was 126.94 ± 0.87 µg/mL. Both strains had better inhibition than acarbose (168.18 ± 0.89 µM). These results on wild strains of Ganoderma will be useful for further studies on the applications of Ganoderma. Later the species can be introduced to domestic markets for cultivation and medicinal use.

Phaeanthuslucidines A-D, dimeric aporphine alkaloid derivatives from Phaeanthus lucidus Oliv.

The first phytochemical investigation of the twigs of Phaeanthus lucidus Oliv. resulted in the isolation and identification of four undescribed alkaloids, including two aporphine dimers, phaeanthuslucidines A and B, a hybrid of aristolactam-aporphine, phaeanthuslucidine C, and a C-N linked aporphine dimer, phaeanthuslucidine D, together with two known compounds. Their structures were determined by extensive analysis of spectroscopic data, and by comparison of their spectroscopic and physical data with previous reports. Phaeanthuslucidines A-C and bidebiline E were analysed and resolved by chiral HPLC to yield the (Ra) and (Sa) atropisomers, whose absolute configurations were respectively determined by ECD calculations. Phaeanthuslucidines A and B, bidebiline E, and lanuginosine showed α-glucosidase inhibitory activities with IC50 values in the range of 6.7-29.2 µM. Moreover, molecular docking simulations of α-glucosidase inhibition of active compounds were studied.

Alkaloids and Styryl lactones from Goniothalamus ridleyi King and Their α-Glucosidase Inhibitory Activity.

Gonioridleylactam (1), a new compound, is a unique dimeric aristolactam isolated from the EtOAc extract of the twigs of Goniothalamus ridleyi King. The structure of gonioridleylactam (1) consists of two different aristolactams linked together with two methylenedioxy bridges at C-3/C-3' and C-4/C-4', generating a ten-membered ring of [1,3,6,8]tetraoxecine. A new natural product, gonioridleyindole (3-hydroxymethyl-1-methyl-1H-benz[f]indole-4,9-dione, 2), together with eight known compounds (3-10) were also isolated from this plant. Their structures were extensively characterized by spectroscopic methods and comparisons were made with the literature. Compounds 1-4, 7, and 9 were evaluated for their α-glucosidase inhibitory activity. Of these, 3,5-demethoxypiperolide (7) displayed the highest α-glucosidase inhibitory activity, with an IC50 value of 1.25 µM.

Dimeric aporphine alkaloids from the twigs of Trivalvaria costata (Hook.f. & Thomson) I.M.Turner.

A phytochemical investigation of the twig extract of Trivalvaria costata (Hook.f. & Thomson) I.M.Turner has identified ten undescribed dimeric aporphine alkaloids, trivalcostatines A-J, one undescribed isoquinoline alkaloid, trivalcostaisoquinoline, and four known aporphine alkaloids. Their structures were elucidated by detailed analysis of NMR and HRESITOFMS data. Three of the dimeric aporphine structures were confirmed by single crystal X-ray diffraction analysis. All of the dimeric aporphine alkaloids were isolated as mixtures of atropisomers. Several of them were resolved by chiral-phase HPLC and the absolute configurations of the pure atropisomers were assigned by calculated and experimental ECD analysis. Bidebilines A and B, heteropsine, and urabaine showed α-glucosidase inhibitory activities with IC50 values in the range of 4.1-11 µM.

Xanthones from the latex and twig extracts of Garcinia nigrolineata Planch. ex T. Anderson (Clusiaceae) and their antidiabetic and cytotoxic activities.

A new geranylated xanthone, nigrolineaxanthone AA (1) together with 18 known compounds (2-19) were isolated from latex and twig extracts of Garcinia nigrolineata Planch. ex T. Anderson. Some of the isolated compounds were assessed for their antidiabetic activities and cytotoxicity against three cancer cell lines. Of these, compounds 12 (IC50 value of 25.8 ± 0.2 µM), 16 (IC50 value of 124.8 ± 0.7 µM), and 17 (IC50 value of 44.4 ± 1.1 µM) exhibited the highest α-glucosidase inhibitory, α-amylase inhibitory, and glycation inhibition activities, respectively. Compound 11 showed glucose consumption and glucose uptake with IC50 values of 14.2 ± 0.8 µM and 3.1-fold. Compound 10 displayed cytotoxic activity against colon cancer (SW480) with an IC50 value of 4.3 ± 0.1 µM), while compound 2 showed cytotoxicity against leukemic cancer (K562) with IC50 value of 4.4 ± 0.3 µM.

Rotenoids and isoflavones from the leaf and pod extracts of Millettia brandisiana Kurz.

Phytochemical investigations of the leaf and pod extracts of Millettia brandisiana Kurz led to the isolation and identification of four previously undescribed rotenoids, (-)-(6aS,12aS)-millettiabrandisins A-C and (-)-(6aS,12aS)-6-deoxyclitoriacetal, two previously undescribed isoflavones, millettiabrandisins D and E, and 20 known compounds. The structures of previously undescribed compounds were determined on the basis of NMR and MS data. The absolute configurations of (-)-(6aS,12aS)-millettiabrandisins A-C were determined from the comparison of their experimental and calculated ECD spectra. (-)-(6aR,12aR)-12a-Hydroxy-α-toxicarol was also confirmed by X-ray crystallographic data. Some isolated compounds were evaluated for their cytotoxicity against three cancer cell lines, including lung cancer (A549), colorectal cancer (SW480), and leukemic cells (K562). Of these, α-toxicarol displayed the best cytotoxicity against lung cancer (A549) and leukemic cells (K562) with the IC50 values of 104.4 and 67.5 µM, respectively. 6″,6″-Dimethylchromene-[2″,3″:7,8]-flavone showed the highest cytotoxicity against colorectal cancer (SW480) with an IC50 value of 97.2 µM.

Kaempferia parviflora Rhizome Extract as Potential Anti-Acne Ingredient.

Kaempferia parviflora (Black ginger) is used widely in medical fields as an anti-microorganism and anti-inflammation. In this study, the aim was to evaluate the in vitro and in vivo anti-acne efficacy of black ginger extract. The results indicate that the methanol and ethanol extracts showed the highest total phenolic contents, without a significant difference, whereas the n-hexane extract showed the highest total flavonoid content. Nine flavones were detected using UPLC-QTOF-MS, and the ethyl acetate extract showed the highest amount of 5,7-dimethoxyflavone (DMF) according to HPLC. Antibacterial activity against Staphylococcus aureus, S. epidermidis, and Cutibacterium acnes was observed. All the extracts showed antimicrobial activity against C. acnes, revealing MICs in the range of 0.015 to 0.030 mg/mL, whereas the ethyl acetate extract inhibited the growth of S. epidermidis with a MIC of 3.84 mg/mL. In addition, the ethyl acetate extract showed the highest activity regarding nitric oxide inhibition (IC50 = 12.59 ± 0.35 µg/mL). The ethyl acetate extract was shown to be safe regarding cell viability at 0.1 mg/mL. The anti-acne efficacy was evaluated on volunteers. The volunteers were treated in two groups: one administered a 0.02% ethyl acetate extract gel-cream (n = 9) and one administered a placebo (n = 9) for 6 weeks. The group treated with the gel-cream containing the extract showed 36.52 and 52.20% decreases in acne severity index (ASI) after 4 and 6 weeks, respectively, and 18.19 and 18.54% decreases in erythema, respectively. The results suggest that K. parviflora could be a potent active ingredient in anti-inflammatory and anti-acne products.

Antidiabetic and Cytotoxic Activities of Rotenoids and Isoflavonoids Isolated from Millettia pachycarpa Benth.

A phytochemical investigation of the root and leaf extracts of Millettia pachycarpa Benth resulted in the isolation and identification of 16 compounds, including six rotenoids (1-6) and 10 prenylated isoflavonoids (7-16). Compound 4 was isolated as a scalemic mixture, which was resolved by chiral HPLC to afford (-)-(6aS,12aS)-12a-hydroxy-α-toxicarol (4) and (+)-(6aR,12aR)-12a-hydroxy-α-toxicarol (4). (+)-(6aR,12aR)-Millettiapachycarpin (3) and (-)-(6aS,12aS)-12a-hydroxy-α-toxicarol (4) were isolated as new compounds. The absolute configuration of (-)-(6R)-pachycarotenoid (2), (+)-(6aR,12aR)-millettiapachycarpin (3), (-)-(6aS,12aS)-4 and (+)-(6aR,12aR)-12a-hydroxy-α-toxicarol (4), (+)-(6aS,12aS)-(5), and (-)-(6aS,12aS,2″R)-sumatrol (6) were identified by electronic circular dichroism (ECD) data. (-)-(6aS,12aS,2″R)-Sumatrol (6) was also confirmed by X-ray diffraction analysis using Cu-Kα radiation. Antidiabetic activities, including α-glucosidase and α-amylase inhibitory activities, and cytotoxicities against lung cancer A549, colorectal cancer SW480, and leukemic K562 cells of some isolated compounds were evaluated. Of these, isolupalbigenin (11) exhibited the highest α-glucosidase inhibitory activity, with an IC50 value of 11.3 ± 0.2 µM, whereas the scalemic mixture of 12a-hydroxy-α-toxicarol (4) displayed the best α-amylase inhibitory activity, with an IC50 value of 106.9 ± 0.2 µM. Euchrenone b10 (15) exhibited the highest cytotoxicity against lung cancer A549, colorectal cancer SW480, and leukemic K562 cells, with IC50 values of 40.3, 39.1, and 15.1 µM, respectively. In addition, molecular docking simulations of α-glucosidase inhibition of the active compounds were studied.

Special Thai Oolong Tea: Chemical Profile and In Vitro Antidiabetic Activities.

Special Thai oolong tea is oolong tea (Camellia sinensis (L.) Kuntze) steamed with selected Thai botanical drugs. Oolong tea steamed with ginger (Zingiber officinale), lemongrass (Cymbopogon citratus), and celery (Anathallis graveolens L.) is called eternity tea (EN), whereas peaceful rest (PR) tea is made of oolong tea leaves steamed with Indian gooseberry (Phyllanthus emblica), Turkey berry (Solanum torvum), and wild betel leaf bush leaves (Piper sarmentosum). Oolong tea is known for its numerous biological activities including antidiabetic properties. However, the effect of the additional botanical drugs on the biological activities of special oolong teas has not yet been explored. From the results, the PR extract exhibited the best activity in the in vitro assays relevant to antidiabetic properties such as chemical antioxidant, anti-inflammation, anti-adipogenesis, enzyme inhibition, and glucose uptake and consumption. The UHPLC-QTOF-MS/MS profiles of PR and EN extracts indicated chemical profiles different from oolong tea. For instance, gingerdiol and gingerol were detected in EN, whereas piperettine I was detected in PR. Therefore, it was inferred that among the three tea extracts, the additional compounds in PR contributed to good activities compared to oolong and EN. It is also important to highlight that the PR extract inhibited glucose uptake and consumption by adipocytes and skeletal muscles at concentrations of 500 and 100 µg/ml, respectively, as well as metformin activity (p < 0.05). Findings from this study support the antidiabetic potential of PR tea.

α-Glucosidase inhibitory and α-amylase inhibitory activities of compounds isolated from Uvaria rufa Blume.

A new C-benzylated flavone, uvariaruflavone (1), along with 13 known compounds (2-14) were isolated from the twig and leaf extracts of Uvaria rufa Blume. Their structures were established by extensive spectroscopic methods. Flavones (5-8) and cyclohexene (10) were isolated from U. rufa for the first time. Most of the isolated compounds were evaluated for their α-glucosidase and α-amylase inhibitory activities. Of these, uvariaruflavone (1) showed the highest α-glucosidase inhibitory activity with an IC50 value of 44.3 µM, while ferrudiol (12) displayed the highest α-amylase inhibitory activity with an IC50 value of 73.5 µM.

Chemical composition, antioxidant, and antimicrobial activity of Elsholtzia beddomei C. B. Clarke ex Hook. f. essential oil.

The essential oil of Elsholtzia beddomei C. B. Clarke ex Hook. f. was investigated for its chemical composition and tested for antioxidant and antimicrobial activities. The E. beddomei essential oil was extracted using hydrodistillation for 4 h (yield of 1.38% w/w). Forty-three volatile compounds were identified in the E. beddomei essential oil, including linalool (83.67%), perillaldehyde (4.68%), neral (3.68%), perillene (1.65%), E-caryophyllene (1.55%), and α-zingiberene (1.06%) as the major compounds. The antioxidant activity of the E. beddomei essential oil was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging activity. The IC50 values calculated using the DPPH and ABTS methods were 148.31 and 172.22 µg/mL, respectively. In addition, using disc diffusion and broth microdilution methods, the antimicrobial activities of the E. beddomei essential oil against Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, and Candida albicans were evaluated. The E. beddomei essential oil possessed an inhibitory effect with the minimum inhibitory concentration in the range of 31.25-250.00 µg/mL among these pathogens. The results indicated that E. beddomei essential oil is an alternative raw material of food, and medicinal products for use in pharmaceutical applications.

Nitric oxide production inhibitory activity of clerodane diterpenes from Monoon membranifolium.

A new clerodane diterpene, 2ß-methoxyhardwickiic acid (1), and four known compounds (2-5) were isolated from the twigs of Monoon membranifolium. The structure of the new compound was determined by extensive spectroscopic methods and ESITOFMS data. The absolute configuration of 1 was established by a comparison of its ECD spectrum and specific rotation with those of related previously reported compounds. All compounds were evaluated for their nitric oxide (NO) production inhibitory activities in RAW264.7 macrophage cells. Compounds 3 and 5 inhibited NO production with IC50 values of 16.1 and 28.9 µM, respectively, which were better than that of standard compound, indomethacin (IC50 = 32.2 µM).

Chemical composition and biological activity of Peucedanum dhana A. Ham essential oil.

The essential oil was extracted from Peucedanum dhana A. Ham, which grows in Thailand, using a Clevenger apparatus, resulting in an oil yield of 0.76% w/w. Forty-two compounds were identified using gas chromatography-mass spectrometry. The major compounds were trans-piperitol (51.23%), ß-pinene (11.72%), o-cymene (11.12%), γ-terpinene (9.21%), and limonene (4.91%). The antimicrobial activity of the P. dhana essential oil was investigated by measuring the inhibition zone diameter, minimum inhibitory concentration (MIC), and minimum microbicidal concentration (MMC). The inhibition zone diameters of P. dhana essential oil (1000 µg/mL) against tested pathogens ranged from 10.70 to 40.80 mm. Significant antimicrobial activity against tested pathogens was obtained, with MIC and MMC values of 62.50-250 µg/mL and 250-1000 µg/mL, respectively. Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes exposed to P. dhana essential oil at the MIC were analysed by flow cytometry using propidium iodide (PI) and SYTO9 to assess membrane integrity compared to trans-piperitol and ß-pinene. After 24 h, treatments with trans-piperitol resulted in the most significant cell membrane alteration and depolarization followed by P. dhana essential oil and ß-pinene, respectively. It was demonstrated that the P. dhana essential oil presented antibacterial action against E. coli, P. aeruginosa, and E. aerogenes. The antioxidant activity of P. dhana essential oil was measured using 2,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) scavenging activity assays. The IC50 values obtained from the DPPH and ABTS methods were 9.13 and 9.36 mg/mL, respectively. The cytotoxic effect of P. dhana oil was tested against human colonic adenocarcinoma (SW480), human lung adenocarcinoma (A549), cervical cancer (Hela), and murine fibroblast (3T3L1) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The essential oil had cytotoxicity against all cancer cells, with significant cytotoxicity towards SW480 cells. As a control experiment, two pure compounds-trans-piperitol and ß-pinene, were also tested for their antimicrobial, antioxidant, and cytotoxic activity. Both compounds showed varied activity in all assays. The results indicate that P. dhana essential oil could be used as a source of functional ingredients in food and pharmaceutical applications.

Cytotoxicity and Nitric Oxide Production Inhibitory Activities of Compounds Isolated from the Plant Pathogenic Fungus Curvularia sp.

Chemical investigation of the mycelia of the pathogenic fungus Curvularia sp. which was isolated from a leaf of Dactyloctenium aegyptium (crowfoot grass), resulted in the isolation of a new compound, curvulariahawadride (5), along with five known compounds (1-4, and 6). Their structures were determined on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS. The absolute configuration of 5 was established from experimental and calculated electronic circular dichroism (ECD). Compounds 1, 3, and 5 showed nitric oxide (NO) production inhibitory activity with IC50 values of 53.7, 32.8, and 12.8 µM, respectively. Compounds 2 and 4 showed significant cytotoxicity against lung cancer A549, colorectal cancer SW480, and leukemic K562 cells with an IC50 ranging value of 11.73 to 17.59 µM.

Daldiniaeschsone A, a Rare Tricyclic Polyketide Having a Chromone Unit Fused to a δ-Lactone and Its Symmetrical Biphenyl Dimer, Daldiniaeschsone B, from an Endophytic Fungus Daldinia eschscholtzii SDBR-CMUNKC745.

Daldiniaeschsone A (1), a rare tricyclic polyketide having a chromone unit fused to a δ-lactone and its symmetrical 6,6'-biphenyl dimer, daldiniaeschsone B (2), together with three known compounds (3-5), were isolated from a plant-derived endophytic fungus, Daldinia eschscholtzii SDBR-CMUNKC745. Their structures were elucidated by extensive 1D and 2D NMR spectroscopic data and HRESIMS. All compounds showed α-glucosidase inhibitory activity with IC50 values ranging from 0.16-0.85 mM and compound 1 was the best α-glucosidase inhibitory activity (IC50 = 0.16 mM).

Anti-inflammatory activity and chemical constituents of red limestone.

Red limestone is a mixture of turmeric (Curcuma longa L.) powder and limestone which is made from burning shells at high temperature. The yellow mixture turns to red color or deep orange because of the reaction between turmeric and calcium carbonate in limestone. Red limestone is traditionally used to treat many diseases such as abscess, cut wound and insect bite. The purpose of this study was to investigate anti-inflammatory activity and chemical constituents of red limestone. The chemical analysis of red limestone extract by liquid chromatography with tandem mass spectrometry revealed that red limestone consisted of alpha-turmerone and curcumanolide B as major components. These compounds were related with the chemical constituents in C. longa extract which is a main ingredient of red limestone. However, curcuminoids were not detected in red limestone extract. Cytotoxicity of red limestone extract was investigated. Macrophage cell lines (RAW 264.7) and human keratinocyte cell lines (HaCaT cells) were investigated cell viability using MTT assay. Red limestone extract was nontoxic to normal cells such as macrophage cells and human keratinocyte cells. Moreover, the inflammatory activity was detected nitric oxide (NO) secretion in RAW 264.7 cells. The result showed that the extracts inhibited NO in dose-dependent manner and IC50 was found to be 102.42 µg/ml. It suggested that red limestone extract had a potential for anti-inflammatory activity.

Antidiabetic and antimicrobial flavonoids from the twigs and roots of Erythrina subumbrans (Hassk.) Merr.

The phytochemical investigation of the twig and root extracts of Erythrina subumbrans (Hassk.) Merr. (Fabaceae) resulted in the isolation and identification of a new pterocarpan, erythrinocarpan (1), along with 27 known compounds (2-28). All isolated compounds were evaluated for their antidiabetic, antimicrobial, and anti-inflammatory properties. Compounds 3, 8, 9, and 22 had α-glucosidase inhibitory activity with IC50 values of 13.4 ± 0.05, 24.5 ± 0.13, 29.0 ± 0.05, and 12.8 ± 0.14 µM, respectively, while compound 2 inhibited α-amylase activity with an IC50 value of 67.6 ± 1.12 µM. Compounds 22 and 24 inhibited glycation activity with the IC50 values of 36.9 ± 0.62 and 40.5 ± 0.37 µM, respectively. From cell-based assays, compound 27 showed the highest ability to induce glucose consumption (IC50 29.1 ± 0.86 µM) and glucose uptake (2.8-fold), and to inhibit nitric oxide (NO) production (IC50 52.5 ± 0.56 µM) without cell toxicity. Furthermore, compound 9 showed antimicrobial activities against Gram-positive bacteria and fungi with MIC values ranging from 2-4 µg/mL.