Two New Benzoquinone Derivatives from Vietnamese Knema globularia Stems.

The chemical investigation of the stems of Knema globularia led to the isolation of two new benzoquinones derivatives, embenones A and B (1 and 2), along with three known compounds (3-5). The structures of the isolated compounds were determined using spectroscopic techniques, including HRESIMS, 1D and 2D NMR, in conjunction with comparison to existing literature data. Compounds 1 and 2 represent new carbon skeletons in nature. Furthermore, all isolated compounds were evaluated for their α-glucosidase inhibitory activity, with compounds 1-3 exhibiting superior potency relative to the positive control (acarbose, IC50 331 µM). Their IC50 values ranged from 1.40 to 96.1 µM.

Cyclopentenone-Containing Tetrahydroquinoline and Geldanamycin Alkaloids from Streptomyces malaysiensis as Potential Anti-Androgens against Prostate Cancer Cells.

Malaymycin (1), a new cyclopentenone-containing tetrahydroquinoline alkaloid, and mccrearamycin E (2), a geldanamycin analogue bearing a rare ring-contracted cyclopentenone moiety, and a C2-symmetric macrodiolide (7) were isolated from Streptomyces malaysiensis SCSIO41397. Their structures including absolute configurations were determined by detailed analyses of NMR and HRMS data and ECD calculations. The occurrence of mccrearamycin E (2) bearing a ring-contracted cyclopentenone is rare in the geldanamycin class. All isolated compounds were evaluated for their cytotoxicities against five cancer cell lines. As a result, compounds 1, 4, 5, and 7 showed cytotoxicity against some or all of the five cancer cell lines with IC50 values ranging from 0.067 to 7.2 µM. In particular, compound 1 inhibited the growth of C42B and H446 cell lines with IC50 values of 67 and 70 nM, respectively. Malaymycin (1) significantly induced cell cycle arrest at the G0/G1 phase in C42B cell lines and caused cell shrinkage and inhibited the expression of the androgen receptor (AR) at both the mRNA and protein levels in a dose-dependent manner. Further examination by qRT-PCR analysis showed that 1 strongly suppressed the expression of AR target genes KLK2 and KLK3 in the C42B and 22RV1 cell lines, which suggested that 1 might be a promising potential lead compound for the development of a treatment for the castration-resistant prostate cancer (CRPC).

Possible therapeutic effects of Nigella sativa and its thymoquinone on COVID-19.

CONTEXT: COVID-19 is a novel coronavirus that causes a severe infection in the respiratory system. Nigella sativa L. (Ranunculaceae) is an annual flowering plant used traditionally as a natural food supplement and multipurpose medicinal agent. OBJECTIVE: The possible beneficial effects of N. sativa, and its constituent, thymoquinone (TQ) on COVID-19 were reviewed. METHODS: The key words including, COVID-19, N. sativa, thymoquinone, antiviral effects, anti-inflammatory and immunomodulatory effects in different databases such as Web of Science (ISI), PubMed, Scopus, and Google Scholar were searched from 1990 up to February 2021. RESULTS: The current literature review showed that N. sativa and TQ reduced the level of pro-inflammatory mediators including, IL-2, IL-4, IL-6, and IL-12, while enhancing IFN-γ. Nigella sativa and TQ increased the serum levels of IgG1 and IgG2a, and improved pulmonary function tests in restrictive respiratory disorders. DISCUSSION AND CONCLUSIONS: These preliminary data of molecular docking, animal, and clinical studies propose N. sativa and TQ might have beneficial effects on the treatment or control of COVID-19 due to antiviral, anti-inflammatory and immunomodulatory properties as well as bronchodilatory effects. The efficacy of N. sativa and TQ on infected patients with COVID-19 in randomize clinical trials will be suggested.

Sargahydroquinoic Acid, a Cyclooxygenase-2 Inhibitor, Attenuates Inflammatory Responses by Regulating NF-κB Inactivation and Nrf2 Activation in Lipopolysaccharide-Stimulated Cells.

Sargahydroquinoic acid (SHQA) is a major plastoquinone in Sargassum macrocarpum and has shown the capacity to prevent inflammation and oxidative stress. However, the protective mechanisms were unclear. The molecular mechanisms of SHQA on ameliorating inflammation and oxidative stress have been investigated, using lipopolysaccharide (LPS)-stimulated macrophages. SHQA was isolated and purified from S. macrocarpum and the anti-inflammatory mechanisms were explored using LPS-stimulated murine macrophage RAW 264.7 cells. SHQA did not change the expression of cyclooxygenase-2 (COX-2) but inhibited the activity of COX-2. As a result, SHQA significantly diminished the secretions of nitric oxide (NO), prostaglandin E2 (PGE2), and multiple pro-inflammatory cytokines. LPS-induced activation of nuclear factor-κB (NF-κB) was inhibited by SHQA by preventing the degradation of inhibitor κB-α (IκBα). NF-κB activation was also downregulated by the inhibition of Akt phosphorylation in LPS-stimulated cells. Furthermore, SHQA induced the expression of heme oxygenase 1 via Nrf2 activation. These results indicated that SHQA inhibited LPS-induced expressions of inflammatory mediators via suppressing the Akt-mediated NF-κB pathway as well as upregulating the Nrf2/HO-1 pathway. Our findings suggest that SHQA might be a potential therapeutic agent in various inflammatory diseases.

A new prenylated benzoquinone from Cyathocalyx pruniferus abrogates LPS-induced inflammatory responses associated with PGE2, COX-2 and cytokines biosynthesis in human plasma.

In our previous laboratory findings, Cyathocalyx pruniferus extracts exhibited platelet-activating factor inhibition, suggesting their anti-inflammatory potential. Hence, this study was designed with the aim to isolate phyto-constituents from C. pruniferus with potent anti-inflammatory activities. Column and volume liquid chromatography were used for isolation of phyto-constituents. The structure elucidation was carried out using spectroscopic analysis (HRESI-MS, 1H and 13C-NMR) and compared with published literature. For cytotoxicity analysis, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide assay was performed on peripheral blood mononuclear cells. Anti-inflammatory activities were evaluated against the levels of inflammatory cytokines (IL-1ß and IL-6), prostaglandin-E2 (PGE2) and cyclooxegenase-2 (COX-2), in lipopolysaccharide (LPS)-induced human plasma using ELISA and radioimmunoassay (RIA). The chromatographic purification of methanol leaves extract afforded 13 (1-13) secondary metabolites. Additionally, cytotoxicity analysis suggested that isolates were non-cytotoxic at 100 µM. In anti-inflammatory evaluation, 2-octaprenyl-1, 4-benzoquinone (5) produced strong (≥ 70%) inhibition of PGE2, COX-2, IL-1ß and IL-6 at 50 µM. Moreover, 2-octaprenyl-1,4-benzoquinone (5) exhibited concentration-dependent inhibition with IC50 values (µM) of 11.21, 6.61, 2.20 and 3.56 as compared to controls; indomethacin for PGE2 (11.84) and dexamethasone in COX-2 (5.19), IL-1ß (1.83) and IL-6 (3.76) analysis, respectively. In conclusion, two new compounds including 2-octaprenyl-1, 4-benzoquinone (5) and 14-methyloctadec-1-ene (6) are reported for the first time from plant species. Additionally, 2-octaprenyl-1, 4-benzoquinone (5) dose-dependently suppressed the production of pro-inflammatory mediators involved in acute and chronic inflammation at non-cytotoxic concentrations.

Ehretiquinone from Onosma bracteatum Wall Exhibits Antiaging Effect on Yeasts and Mammals through Antioxidative Stress and Autophagy Induction.

The antiaging benzoquinone-type molecule ehretiquinone was isolated in a previous study as a leading compound from the herbal medicine Onosma bracteatum wall. This paper reports the antiaging effect and mechanism of ehretiquinone by using yeasts, mammal cells, and mice. Ehretiquinone extends not only the replicative lifespan but also the chronological lifespan of yeast and the yeast-like chronological lifespan of mammal cells. Moreover, ehretiquinone increases glutathione peroxidase, catalase, and superoxide dismutase activity and reduces reactive oxygen species and malondialdehyde (MDA) levels, contributing to the lifespan extension of the yeasts. Furthermore, ehretiquinone does not extend the replicative lifespan of Δsod1, Δsod2, Δuth1, Δskn7, Δgpx, Δcat, Δatg2, and Δatg32 mutants of yeast. Crucially, ehretiquinone induces autophagy in yeasts and mice, thereby providing significant evidence on the antiaging effects of the molecule in the mammalian level. Concomitantly, the silent information regulator 2 gene, which is known for its contributions in prolonging replicative lifespan, was confirmed to be involved in the chronological lifespan of yeasts and participates in the antiaging activity of ehretiquinone. These findings suggest that ehretiquinone shows an antiaging effect through antioxidative stress, autophagy, and histone deacetylase Sir2 regulation. Therefore, ehretiquinone is a promising molecule that could be developed as an antiaging drug or healthcare product.

Thymoquinone inhibits IL-7-induced tumor progression and metastatic invasion in prostate cancer cells by attenuating matrix metalloproteinase activity and Akt/NF-κB signaling.

Interleukin (IL)-7 acts via the IL-7 receptor in metastatic tumor progression in prostate cancer (PC). The current study aimed to evaluate thymoquinone (Tq), an active constituent from Nigella sativa against IL-7-driven tumor progression and metastatic invasion in PC cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess the proliferation of PC cells. Enzyme-linked immunosorbent assay was used to detect the expression of IL-7 and matrix metalloproteinases (MMPs). Tumor-cell transendothelial, scratch wound and cell scatter assays were performed to mimic metastasis. Western immunoblotting was used to measure the level of proteins. Tq effectively controlled the proliferation of DU-145, PC-3, and LNCaP cells with GI50 of 10.18, 12.40, and 16.78 µM, respectively. IL-7 and IL-7R were natively expressed in all PC types, while maximal expression was detected in DU-145. IL-7 promoted metastatic events, such as transendothelial migration, cell scatter, and cell invasion of DU-145 cells in a dose-dependent manner that was inhibited by Tq. Furthermore, Tq also downregulated p-Akt and NF-κB in DU-145 cells induced by IL-7 antibody and reduced the levels of MMP-3 and MMP-7 in these cells in a dose-dependent manner. Collectively, Tq has excellent efficacy in controlling tumor progression, migration, and invasion of DU-145 cells that were driven by the activation of MMPs through IL-7/Akt/NF-κB signaling.

Wild Blonde Capuchins (Sapajus flavius) Perform Anointing Behaviour Using Toxic Secretions of a Millipede (Spirobolida: Rhinocricidae).

Defensive secretions of millipedes are remarkable for containing toxic quinones known to efficiently repell hematophagous arthropods. Here we show that Endangered blonde capuchin monkeys make use of such secretions. We (i) describe the anointing behavior performed by the monkeys (ii) identify the millipede species used in the process (iii) describe the volatile chemical composition of its secretion. The blonde capuchin monkeys selectively searched for millipedes hidden under the ground. We observed three bouts of anointing behavior, performed by 13 individuals of all age classes (from adults to independent infants), both solitarily (1 event) and socially (10 events). The only millipede species used by the monkeys is an undescribed species of the genus Poecilocricus (Spirobolida, Rhinocricidae). The volatile chemical composition of the secretions was predominantly comprised of a mixture of benzoquinones and hydroquinones. The social nature of the behavior and time of the observations (mosquito season), suggest that social bonding and mosquito avoidance is linked to the anointing behavior of the monkeys.

Cytotoxic mechanisms of primin, a natural quinone isolated from Eugenia hiemalis, on hematological cancer cell lines.

Considering the high morbidity and mortality rates associated with hematological malignancies and the frequent development of drug resistance by these diseases, the search for new cytotoxic agents is an urgent necessity. The new compounds should present higher efficiency and specificity in inducing tumor cell death, be easily administered and have little or negligible adverse effects. Quinones have been reported in the literature by their several pharmacological properties, including antitumor activity, thus, the aim of this study was to investigate the cytotoxic effect of primin, a natural quinone, on hematological malignancies cell lines. Primin was highly cytotoxic against the three cell lines included in this study (K562, Jurkat and MM.1S) in a concentration- and time-dependent manner, as demonstrated by the MTT method. The compound triggered an apoptotic-like cell death, as observed by ethidium bromide/acridine orange staining, DNA fragmentation and phosphatidylserine exposure after labeling with Annexin V. Both intrinsic and extrinsic apoptosis are involved in cell death induced by primin, as well as the modulation of cell proliferation marker KI-67. The activation of intrinsic apoptosis appears to be related to a decreased Bcl-2 expression and increased Bax expression. While the increase in FasR expression signals activate extrinsic apoptosis. The results suggest that primin is a promising natural molecule that could be used in hematological malignancies therapy or as prototypes for the development of new chemotherapics.

Nigella sativa and Cancer: A Review Focusing on Breast Cancer, Inhibition of Metastasis and Enhancement of Natural Killer Cell Cytotoxicity.

BACKGROUND: In the last decade, there have been accumulating data that the use of medicinal plants could bring additional benefits to the supportive treatment of various diseases. Nigella sativa (N. sativa, family Ranunculaceae) is one of these plants that has attracted considerable interest. The extracts and seeds of N. sativa and its active component thymoquinone have been studied extensively and the results suggest that N. sativa might carry some therapeutic potential for many diseases, including cancer. METHODS: The selection criteria for references were applied through Pubmed with "N. sativa and cancer", "N. sativa and breast cancer", "N. sativa and metastasis", "N. sativa and cytotoxicity of natural killer cells". The pathway analysis was performed using the PANTHER tool by using five randomly selected N. sativa affected genes (Cyclin D1, P53, p21 protein (Cdc42/Rac) activated kinase 1 (PAK1), B-cell lymphoma 2 (Bcl-2) and vascular endothelial growth factor (VEGF)) in order to elucidate further potentially affected signaling pathways. RESULTS: The aim of this review was to summarize studies regarding the effects of N. sativa in cancer generally, with a focus on breast cancer, its anti-metastatic effects, and how N. sativa modulates the cytotoxicity of Natural Killer cells that play a crucial role in tumor surveillance. CONCLUSION: In summary, the data suggest that N. sativa might be used for its anti-cancer and antimetastatic properties and as an immune system activator against cancer.

Thymoquinone, an Active Compound of Nigella sativa: Role in Prevention and Treatment of Cancer.

BACKGROUND: Cancer is the leading cause of death worldwide and the current mode of cancer treatment causes side effects on normal cells and are still the key challenges in its' treatment. However, natural products or active compounds of medicinal plants have shown to be safe, affordable, and effective in diseases cure. METHODS: In this context, scientific studies evidence the health-promoting effects of natural products, which work through its anti-oxidant, anti-inflammatory, and anti-cancer activity. Thymoquinone (TM), a predominant active compound of Nigella sativa, has confirmed anti-neoplastic activity through its ability to regulate various genetic pathways. In addition, thymoquinone has established anti-cancerous effects through killing of various cancerous cells,and inhibiting the initiation, migration, invasion, and progression of the cancer. The anti-cancer effects of TM are chiefly mediated via regulating various cell signaling pathways such as VEGF, bcl2/bax ratio, p53, NF-kB, and oncogenes. RESULTS: The anti-cancer drugs have limitations in efficacy and also causes adverse side effects on normal cells. The combination of anti-cancer drugs and thymoquinone improves the efficacy of drugs which is evident by decrease resistance to drugs and regulation of various cell signaling pathways. Moreover, combination of anti-cancer drugs as well as thymoquinone shows synergistic effect on killing of cancer cells and cells viability. Thus, TM, in combination with anti-cancer drugs, can be a good strategy in the management of various types of cancer. CONCLUSION: In this review article, we deliver an outline of thymoquinone role in cancer inhibition and prevention of cancer-based on in vivo and in vitro studies. Further studies on thymoquinone based on clinical trials are highly required to explore the benefits of thymoquinone in cancer management.

Stability study of thymoquinone, carvacrol and thymol using HPLC-UV and LC-ESI-MS.

The aim of this study was to investigate the stability of three major antioxidants of Nigella sativa: thymoquinone (TQ), carvacrol (CR) and thymol (THY), under different stress conditions using HPLC and LC-MS/MS. Forced degradation for each compound was performed under different conditions, including oxidation, hydrolysis, photolysis and thermal decomposition. The results showed that both CR and THY were stable under the studied conditions, whereas TQ was not affected by acidic, basic and oxidative forced conditions but the effect of light and heat was significant. The degradation products of TQ were further investigated and characterized by LC-MS/MS. HPLC-UV method has been fully validated in terms of linearity and range, the limit of detection and quantitation, precision, selectivity, accuracy and robustness. The method was successfully applied to quantitative analysis of the principal antioxidants of Nigella sativa TQ, CR and THY in different phytopharmaceuticals.

New p-terphenyl and benzoquinone metabolites from the bioluminescent mushroom Neonothopanus nambi.

Two new p-terphenyls, neonambiterphenyls A and B (1-2), a new benzoquinone, neonambiquinone A (3), together with six known sesquiterpenes (4-9), were isolated from the bioluminescent mushroom Neonothopanus nambi PW3. The isolated compounds were identified by mass, IR and spectroscopic analyses (1D and 2D NMR). Compounds 1-3 and 5-7 showed cytotoxicity against cancer cell lines such as KB, NCI-H187 and MCF-7 with IC50 values ranging from 1.45 to 49.31 µg/mL. In addition, compounds 1 and 5 showed cytotoxicity against Vero cells with IC50 values of 38.72 and 32.90 µg/mL, respectively.

Effects of Sargaquinoic Acid in Sargassum Serratifolium on Inducing Brown Adipocyte-like Phenotype in Mouse Adipocytes In Vitro.

A previous study showed that the meroterpenoid-rich fraction of an ethanolic extract of Sargassum serratifolium (MES) stimulated adipose tissue browning and inhibited diet-induced obesity and metabolic syndrome. Sargaquinoic acid (SQA) is a major component in MES. We investigated the effects of SQA on the differentiation of preadipocytes to the beige adipocytes. SQA was treated in 3T3-L1 adipocytes differentiated under a special condition that has been reported to induce the browning of adipocytes. SQA at 10 µM reduced lipid accumulation by approximately 23%. SQA at 2.5 - 10 µM induced the differentiation of white adipocytes to beige adipocytes partially by increasing the mitochondrial density and the expression of beige/brown adipocyte markers. In addition, SQA activated lipid catabolic pathways, evidenced by the increased expression levels of perilipin, carnitine palmitoyltransferase 1, and acyl-CoA synthetase long-chain family member 1. As a partial mechanism, biochemical and in silico analyses indicate that SQA activated AMP-activated protein kinase signaling in adipocytes.

A novel automated method for the quantification of ten halobenzoquinones in drinking water using online solid-phase extraction coupled with liquid chromatography tandem mass spectrometry.

When assessing occurrence and exposure to toxic chemicals in drinking water, developing methods that are sensitive and efficient is paramount. A new method was developed for the quantification of ten halobenzoquinones (HBQs), a class of disinfection by-products (DBPs) in drinking water, which have been shown to be more toxic than most regulated DBPs. This method uses a small sample volume with online solid phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Previous methods used offline SPE coupled with standard addition, and a pre-concentration step. This requires larger volumes of sample, solvent, and standards. The current method has comparable limits of quantification (0.2-166 ng/L), requires minimal sample preparation, and analysis is almost entirely automated. It also includes 2,6-dibromo-3­chloro-5-methyl-1,4-benzoquinone which was not included in previous methods. A stability test was conducted over a one-week period with different preservatives, including ascorbic acid, sodium thiosulfate, and formic acid. Method optimization included source temperature, SPE size, sample volume, and SPE loading time. This method was validated using drinking water collected from four different drinking water plants; spike recoveries of HBQs were between 70-111%, relative standard deviations of <20%, and linearity of >0.98. Further, using this method, we report the highest concentration of 2,6-dibromo-1,4-benzoquinone found in drinking water (254 ng/L).

Solvent and temperature effects of accelerated solvent extraction (ASE) coupled with ultra-high pressure liquid chromatography (UHPLC-DAD) technique for determination of thymoquinone in commercial food samples of black seeds (Nigella sativa).

Black seeds (Nigella sativa), is considered a traditional folk medicine in Saudi Arabia where it is widely available in the form of food supplements with limited information warranting its quality. This study aims to develop an effective and reliable method of black seeds evaluation and standardization in terms of Thymoquinone (THQ), obtained from various geographical sources i.e. Pakistan (PK), Saudi Arabia (SA) and India (I). Accelerated solvent extraction (ASE) was utilized for the first time to extract whereas Ultra High pressure liquid chromatography (UHPLC-DAD) was used to quantify THQ. Inductively coupled plasma mass spectrometry (ICP-MS) was used for elemental analysis of the samples. An ideal temperature (70 °C) and solvent (n-hexane) with extraction yield of 97.30% ±â€¯3.98 was observed. In the case of commercial food samples an extraction yield and %recovery within a short time (42 ±â€¯2 min) using least amount of solvent (49.5 ±â€¯2 ml) was observed; SA (18.22 g; 91.1%)  > PK (17.32 g; 86.6%)  > I (16.33 g; 81.65%). UHPLC resulted a RT of 3.29 min for THQ with concentration (ng/ml) in the samples as; SA, 34410.36 > PK, 7778.95 > I, 4106.43. Elemental analysis revealed an order of SA > I > PK for tested elements. ASE resulted a high extract yield as compared to traditional methods of extraction whereas ASE-UHPLC/DAD showed a rapid and sensitive method of THQ quantification and quality determination in market available food samples for black seeds.

Thymoquinone ameliorates Pachycondyla sennaarensis venom-induced acute toxic shock in male rats.

BACKGROUND: For many decades, the sting of Samsun ant (Pachycondyla sennaarensis) has been a serious clinical challenge for the people living in some of the major Middle East and Asian countries. In the present study, the therapeutic potential of Nigella sativa derived plant extract component, thymoquinone (TQ) has been tested against the Samsun ant venom (SAV) at the toxic dose in the rats. METHODS: The adult male rats were divided into four groups (n = 10): control, SAV treated, SAV + TQ treated and TQ alone treated. It was found that the sub-lethal dose of SAV alters not only many of the kidney and liver function markers but also induces oxidative stress in the animals. Moreover, the SAV also disturbs various immunological parameters including expression of PMNs, CD-80, CD-86, interleukins and other cytokines compromising the affected organism towards mild to severe allergic reactions including life-risking anaphylaxis. RESULTS: The plant extract, TQ, effectively restores many of the biochemical and oxidative stress parameters comparable to the normal concomitant with improving the immunological aspects that might attributive in relieving from SAV-induced toxicity and allergic reactions in the affected organism to a greater extent. CONCLUSION: Hence, TQ has an excellent antidote property against SAV-induced toxicities in vivo. Although the study is a vivid indication of the potential therapeutic potential of TQ against the SAV induced in vivo toxicity, yet the actual mechanism of interaction translating the toxicity amelioration warrants further investigations.

SkQThy, a novel and promising mitochondria-targeted antioxidant.

Since thymoquinone (2-isopropyl-5-methylbenzoquinone) isolation from Nigella sativa in 1963, various studies have reported on its diverse pharmacological properties. However, despite its versatile healing abilities, clinical trials involving the use of thymoquinone have not been initiated due to its poor bioavailability. Many attempts have been made to improve the therapeutic efficacy of thymoquinone by synthesizing analogs, as well as by developing nanotechnology-based delivery systems. We hypothesized that some of the issues with thymoquinone delivery and bioavailability could be resolved by targeted delivery to mitochondria of thymoquinone derivatives conjugated to the penetrating lipophilic cationic triphenylphosphonium fragment. As mitochondria are the major site of reactive oxygen species generation in the cell, such a membranotropic thymoquinone derivative can act as an efficient antioxidant or prooxidant depending on the concentration used. Based on these theoretical considerations, a novel mitochondria-targeted compound, SkQThy, was synthesized and its effects on rat liver mitochondria and yeast cells were examined. SkQThy was found to exhibit pronounced antioxidant activity in mammalian mitochondria and yeast cells, decreasing hydrogen peroxide production in mitochondria, as well as preventing prooxidant-induced oxidative stress and mitochondrial fragmentation in yeast cells and increasing cell viability. Moreover, SkQThy proved itself to be the most efficient mitochondria-targeted antioxidant within the SkQs family, showing good therapeutic potential.

Leishmanicidal and antimicrobial activity of primin and primin-containing extracts from Miconia willdenowii.

As a part of an ongoing bioprospective project, searching for potential medicinal plants from the Brazilian Atlantic Forest, Miconia willdenowii was selected for its potential leishmanicidal and antimicrobial activities. The crude ethanolic extract of M. willdenowii showed an inhibition of 99.7% of the promastigote forms of Leishmania amazonensis at the concentration of 80 µg/mL. Further investigation of its antimicrobial activity against pathogenic fungi and Gram positive and negative bacteria, revealed a significant antimicrobial activity. A bioguided study with its liquid-liquid partition fractions revealed the hexane fraction (Hex) as the most active against Leishmania, inhibiting 99.2% and 46.9% of the protozoan at concentrations of 40 and 20 µg/mL, respectively. Hex also showed significant antimicrobial activity against Staphylococcus aureus and Candida krusei with IC50 of 15.6 and 62.5 µg/mL, respectively. Purification of Hex led to the isolation of 2-methoxy-6-pentyl-benzoquinone (1, also known as primin) as the active metabolite, probably responsible for the observed antimicrobial and anti-leishmania effects. Primin (1) disclosed leishmanicidal activity (IC50 = 1.25 µM), showing higher potency than the standard drug amphotericin B (IC50 = 5.08 µM), with additional antifungal effects against all tested fungi species. Compound 1 also showed significant activity against S. aureus (IC50 = 8.94 µM), showing a comparable potency with the reference drug chloramphenicol (IC50 = 6.19 µM), but with a potential cytotoxicity towards peripheral human blood mononuclear cells (CC50 = 255.15 µM). Here in, the antimicrobial and anti-L. amazonensis effects of M. willdenowii are reported for the first time, as well as Primin (1) as its probable bioactive metabolite.

Estrogenic phytochemical from Labisia pumila (Myrsinaceae) with selectivity towards estrogen receptor alpha and beta subtypes.

Labisia pumila var. alata (Myrsinaceae) or "Kacip fatimah" is a famous Malay traditional herb used for the maintenance of women's health. The extracts of L.pumila displayed estrogenic activity in rats. Nonetheless, the estrogenic bioactives were not identified. The aim of the study is to identify estrogenic compounds contributing to the established estrogenic activity. Bioactivity-guided-isolation method guided the isolation of pure bioactives. The hexane extract was subjected to a series of silica gel flash and open column chromatography with increasing amount of ethyl acetate in hexane or methanol in chloroform. Each fraction or pure compounds were evaluated on it's estrogen receptor (ER) binding activity with the fluorescence polarization competitive ERα and ERß binding assay kit. Cytotoxic assay using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method was used to establish the cytotoxic activity of the compounds. Four alkyl resorcinols and a dimeric 1,4-benzoquinone, namely belamcandol B (1), 5-pentadec-10'-(Z)-enyl resorcinol (2), 1,3-dihydroxy-5-pentadecylbenzene (3), 5-(heptadec-12'-(Z)-enyl) resorcinol (4) and demethylbelamcandaquinone B (5) were identified with selective binding affinities towards either ERα or ERß exhibiting selectivity ratio from 0.15-11.9. Alkyl resorcinols (2)-(4) exhibited cytotoxic activity towards HL60 cells with IC50 values from 19.5-22.0 µM. Structural differences between compounds influence the binding affinities to ER subtypes. Further study is needed to establish the agonist or antagonist effect of these compounds on various tissues and to identify if these compounds exert cytotoxic activity through the ERs. When consuming L.pumila as a complementary medicine, careful consideration regarding it's estrogenic compound content should be given due consideration.