Cytotoxic Bioactivities Research Articles

Generation of lysolipin derivatives by genetic engineering

Lysolipin I is a halogenated, polycyclic xanthone natural product belonging to the polyketide class of antibiotics, naturally produced by Streptomyces violaceoniger TÜ96 and Streptomyces tendae TÜ4042. The biosynthesis is encoded on a 43 kb-spanning biosynthetic gene cluster. Heterologous expression of the gene cluster has been established in previous work by using the cosmid 4H04, which was transferred to Streptomyces albus. In the current study, we demonstrate the optimization of production yields of therapeutically interesting lysolipin derivatives with extended activity against Gram-negatives and less cytotoxic bioactivities, respectively, by using mutated heterologous S. albus producer strains. Production yields were significantly increased by adapting cultivation conditions as well as by inactivating the transcriptional repressor gene llpRI, which lead to increased and consistent lysolipin (derivatives) production. Furthermore, cultivation of a S. albus 4H04∆llpOI mutant strain in bromide-containing fermentation medium resulted in the production of a new brominated lysolipin derivative (C28H20BrNO9).

Biosynthetic novelty index reveals the metabolic potential of rare actinobacteria isolated from highly oligotrophic sediments.

Calculations predict that testing of 5 000-10 000 molecules and >1 billion US dollars (£0.8 billion, £1=$1.2) are required for one single drug to come to the market. A solution to this problem is to establish more efficient protocols that reduce the high rate of re-isolation and continuous rediscovery of natural products during early stages of the drug development process. The study of 'rare actinobacteria' has emerged as a possible approach for increasing the discovery rate of drug leads from natural sources. Here, we define a simple genomic metric, defined as biosynthetic novelty index (BiNI), that can be used to rapidly rank strains according to the novelty of the subset of encoding biosynthetic clusters. By comparing a subset of high-quality genomes from strains of different taxonomic and ecological backgrounds, we used the BiNI score to support the notion that rare actinobacteria encode more biosynthetic gene cluster (BGC) novelty. In addition, we present the isolation and genomic characterization, focused on specialized metabolites and phenotypic screening, of two isolates belonging to genera Lentzea and Actinokineospora from a highly oligotrophic environment. Our results show that both strains harbour a unique subset of BGCs compared to other members of the genera Lentzea and Actinokineospora. These BGCs are responsible for potent antimicrobial and cytotoxic bioactivity. The experimental data and analysis presented in this study contribute to the knowledge of genome mining analysis in rare actinobacteria and, most importantly, can serve to direct sampling efforts to accelerate early stages of the drug discovery pipeline.

Antimicrobial and Cytotoxic Activities Screening of Marine Invertebrate-Derived Fungi Extract from West Sumatera, Indonesia

BACKGROUND: The coral reef on Mandeh Island, West Sumatra, Indonesia, consists of an abundant source of sponge and soft coral. Secondary metabolites of marine-derived fungi isolated from the sponge and soft coral possess numerous biological activities. AIM: This study collected, identified, and screened marine-derived fungi isolated from marine invertebrates for antibacterial and cytotoxic bioactivities. MATERIALS AND METHODS: The marine invertebrates used are sponges; Xestospongia testudinaria and Placortis communis) and soft corals (Sarcophyton elegan and Subergorgia suberosa). The EtOAc extracts were analyzed for antimicrobial and cytotoxic activities using the diffusion agar method and brine shrimps lethality test. RESULTS: After cultivating on rice medium, the EtOAc extracts of 22 isolated fungi showed potent antimicrobial activity with an inhibitory zone of 15.9 mm against Staphylococcus aureus (XT2 extract), and Pseudomonas aeruginosa of 26.7 mm (XT6 extract), and Candida albicans of 29 mm (SE5 extract). XT6 extract showed the potential cytotoxic activity with an LC50 value of 100 μg/ml. CONCLUSION: The ability of the marine-derived fungi to produce bioactive compounds is promising potential as a source of antimicrobial and cytotoxic compounds.

Design, Synthesis and Biological Evaluation of Novel Triazolothiadiazoles Derived from NSAIDs as Anticancer Agents.

Although transplantation, surgical resection, and tumor ablation are treatment options available following early diagnosis of HCC, poor prognosis and high recurrence rates restrict the efficacy of these approaches. Hence, small molecules with high selectivity and bioactivity are urgently required. This study presents the synthesis of a series of new triazolothiadiazole derivatives (1a-3j) with NSAID moieties and their cytotoxic bioactivities. The new synthetic derivatives (1-3; 1a-3j) and NSAIDs ibuprofen, naproxen, and flurbiprofen that commonly used in clinics were screened against human liver (Huh7), breast (MCF7), and colon (HCT116) carcinoma cell lines under in vitro conditions via NCI-sulforhodamine B assay. The 4-methoxyphenyl substituted condensed derivatives 1h, 2h, and 3h were the most active compounds. Based on its high potency, compound 3h was selected for the further biological evaluation of hepatocellular carcinoma cell lines, and the mechanisms underlying cell death induced by 3h were determined. The results revealed that compound 3h induced apoptosis and cell cycle arrest in the sub G1 phase in human liver cancer cells. These new small molecules may be used for the development of new lead compounds.

Overview of Antimicrobial Compounds Produced from Bacteria

Every year more than 10 million lives are lost due to antimicrobial-resistant infections. Therefore, the development of antimicrobial agents has become a necessity. Natural products are being used as therapeutic agents. Antimicrobial beings are one of the most compelling molecules. Microorganisms produce bioactive compounds with antimicrobial and cytotoxic bioactivity. Fungi and bacteria are mostly used as novel antimicrobial agents. In the years 1940 & 1950 marine bacteria were shown to produce antimicrobial compounds. The first marine antibacterials were identified in the year 1960, and in the year 1970 their antibiotic properties has been reported. The majority of identified compounds were isolated from Actinobacteria & Bacilli. The interesting fact is that the molecules that were active against gram-negative were isolated from Bacilli. It is estimated at least 4-5% of the genome of any strain of the B. subtilus group is devoted to antimicrobial compounds (AMCs) production.

THE SYNTHESIS OF CHALCONE COMPOUNDS WITH CL AND BR SUBSTITUENTS AND THEIR POTENTIAL ANTICANCER ACTIVITIES AGAINST MCF-7 BREAST CANCER CELLS

The synthesis of chalcone-based Cl and Br substituents has been successfully synthesized for determining the cytotoxic bioactivities against MCF-7 breast cancer cells. The method of synthesizing the chalcone compounds was carried out by Clasien-Schmidt condensation via aldol condensation aldol. The determination of chalcone chemical structures was conducted via elucidated structure. Characterizations of pure compounds were conducted via 1HNMR, FTIR, Mass spectrophotometer, and Spectrophotometry UV-VIS. The cytotoxicity behaviours were investigated via the addition of PrestoblueTM reagents, while the IC50 score was also included as the parameter of investigation. Our findings show that three chalcone compounds yielded for 60.00%, 60.51%, and 74.38% for (E)-3- (4-chlorophenyl)-1-o-tolilprop-2-en-1-on (1), (E)-1,3-bis(3-bromophenyl) prop-2-en-1-on (2), and (E)-3-(4- bromophenyl)-1-(3-chlorophenyl)prop-2-en-1-on (3) respectively. The synthesis results were in accordance with the target compounds, in which the characteristics of the chalcone compounds of C-Cl and C-Br were confirmed via FTIR spectra, 1H-NMR shows 8 signals which equal to 10 hydrogen atoms, indicated. The cytotoxic activities based on IC50 for chalcones 1, 2, and 3 were 3.66 µg/mL, 51.05 µg/mL, and 21.62 µg/mL respectively with the potential for anti-breast cancer via MCF-7 cells via the morphological changes.

Assessment cytotoxic assay of Rhizophora plants mangrove using brine shrimp (Artemia salina L) model

Rhizophoraceae is the main family of mangroves as a source of bioactive compounds originating from the coast. Ethnophamacologically Rhizophoraceae has been used in various traditional medicine. Natural sources as anticancer from the Rhizophoraceae family are interesting to know. This study aimed to determine the cytotoxic bioactivity of methanolic extracts of roots, bark, leaves, and fruit/hypocotyl from five species of Rhizophoraceae (Bruguieria cylindrica, B. gymnorrhiza, Ceriops decandra, Rhizophora apiculata, and R. mucronata) from the Langsa mangrove forest, Aceh. The method used in this study was the Brine Shrimp Lethality Test (BSLT) bioassay using Artemia salina Leach at extract concentrations of 1, 10, 100, 500, and 1000 μg/ml. Samples were extracted using the maceration method and methanol as the solvent. The cytotoxic activity of 20 Rhizophoraceae methanol extracts showed that 12 extracts were toxic with an LC50 range of 31.5 - 934.9 μg/ml (based on LC50 ≤ 1000 μg/ml). The two extracts of which the closest to highly toxic (based on LC50 ≤ 30 μg/ml) were C. decandra bark showed LC50 of 31.5 μg/ml, and R. mucronata bark showed LC50 31.8 μg/ml. This shows that Rhizophoraceae extract has potential as a natural anticancer agent. In the five rhizophoraceae species, C. decandra was the most active compared to other species. In the four plant parts, the bark was the most toxic.

Systematic activity-oriented separation and structure-activity relationship of tobacco cembranoids

Cembranoids are a class of glandular trichome exudates with a variety of structural variations and biological activities, and are found in high quantities in tobacco (Nicotiana tabacum L.). However, few studies have conducted preparative separation and examined the activities of cembranoids other than (1S,2E,4S,6R,7E,11E)-2,7,11-cembratriene-4,6-diol (α-CBT-diol, 1) and (1S,2E,4R,6R,7E,11E)-2,7,11-cembratriene-4,6-diol (β-CBT-diol, 2); thus, the structure-activity relationship (SAR) of cembranoids remains unclear. Here, to deduce the SAR of cembranoids, raw cembranoid extract was systematically separated through an activity-oriented approach with preparative reversed-phase liquid chromatography. Each fraction was identified, and their antifungal, insecticidal, and cytotoxic bioactivities were evaluated. Composition analysis and activity detection of primary fractions (Fr.1–Fr.10) revealed that cembranoid activity might be influenced by the number of hydroxyl groups and degree of unsaturation (macrocycle and double bonds). Sub-fraction analysis showed that the antifungal activity of cembranoids was related to the number of hydroxyl groups and double bonds, and that their cytotoxic activity was affected by the type and position of substituents. Furthermore, all four factors could influence insecticidal activity. By conducting in-depth studies of single cembranoids, their SARs were summarized. The existence of Δ11,12/Δ7,8 and hydroxylation at C-6/C-4 contributed to the antifungal activity of cembranoids. Variation in the type and position of substituents also significantly affected antifungal activity, of which Δ11,12 was the most influential factor. Additionally, the change in substituent configuration at C-4 and C-12 had no significant effect on antifungal activity. The insecticidal activity of cembranoids benefited from the existence of 4-hydroxyl, which greatly enhanced their binding affinity; however, functional groups substituted at other positions decreased insecticidal activity. Cytotoxic activity was positively correlated with α-configuration at C-4 and hydroxylation at C-6 but inversely correlated with 4-methoxy substitution. Among them, 6-hydroxyl formed the core; the α-/β-configuration at C-12 and 4-/12-substitution of cembranoids did not affect their insecticidal activity. Insecticidal activity might play a key role by restraining acetylcholinesterase activity through hydrophobic interactions between the cembranoid carbon skeleton and residues located at the acetylcholinesterase binding pocket. These findings may provide a foundation for the development of novel cembranoid-based pesticides and medicines.

Polypeptidic Taxol-Tropins: Targeting paclitaxel to the tumor microenvironment

Background and Rationale: Although PTX is widely used as a single chemotherapeutic agent and in various combination regimens, its clinical utility is hindered by acquired drug resistance and serious dose-limiting side effects that result from the ungoverned biodistribution of the taxane. Hypothesis: Conceptually, the precision, validity, and efficiency of paclitaxel delivery to tumor compartments might be substantially improved by “actively targeting” the exposed collagenous (XC-) proteins presented within the tumor microenvironment (TME)—XC-proteins physically exposed by the pathologic biochemical processes of tumor invasion, reactive stroma formation, and neo-angiogenesis. Objective: An adaptive bioengineering approach aims to apply pathotropic tumor-targeting functionality to paclitaxel (PTX), a powerful cytotoxic taxane which exhibits anti-tubulin / anti-mitotic / anti-cancer activities against a broad range of solid tumors. Materials and Methods: Synthetic peptide XC-targeting probes (< 40 aa) and polypeptide aptamers (40 to 53 aa), 85 - 99% purity, were prepared by 9-fluorenylmethyloxycarbonyl (Fmoc) solid phase peptide synthesis, purified by high performance liquid chromatography (HPLC), and verified by mass spectrometry and amino acid analysis, and the XC-targeting probes were FITC-labeled. Analysis of fluorescence in XC-binding assays was visualized with an Ultra Bright Blue Light trans-illuminator equipped with an amber filter; photo-documentation was provided by a Leica V-Lux 1 digital camera; and comparative fluorescence was quantified using a Quantus benchtop fluorimeter (Promega). The tumor-targeting properties of Taxol-Tropins were tested in vitro by Taxol-aptamer binding assays and collagen-agarose binding assays and the bioactivities of PTX bound non-covalently toTaxol-Tropin aptamers were tested on XC-agarose beads. Further, the tumor targeting property of the Taxol-Tropin aptamers was tested in vivo in a murine model of metastatic cancer. Results: Here we report on the first actively targeted delivery of paclitaxel utilizing bifunctional polypeptide targeting onco-aptamers, called Taxol-Tropins, which: (i) bind PTX upon simple mixing with suitably high affinities and; (ii) bind exposed XC-proteins, thereby promoting enhanced partitioning and drug delivery into the TME. The bifunctional peptide sequence-optimized Taxol-Tropins bound tightly non-covalently to PTX and also exhibited high affinity and selectivity for XC-agarose beads in vitro. Importantly, the cytotoxic bioactivity of the Taxol-Tropin-bound-PTX molecule was well preserved in cellulo, as was demonstrated by cytocidal activity observed in MDA-MB-231 breast cancer cell cultures. Tumor-targeted PTX delivery by Taxol-Tropin onco-aptamers in vivo was modeled by subcutaneous xenografts of human pancreatic cancer in nude mice: where intense fluorescence of the PTX probe was observed in tumors of mice injected with the Taxol-Tropin-bound-PTX within minutes after intravenous injection, but not in untreated mice or mice treated with non-targeted PTX probe. Conclusions: These results demonstrate the feasibility of pro-actively targeting PTX, a clinically important small molecule, using Taxol-Tropins: synthetic polypeptide onco-aptamers, revealing optimized drug binding sequences and structural modifications pertinent to further clinical development of the tumor-targeting platform which may indeed shift the Therapeutic Index of PTX to one of greater clinical efficacy at lower drug doses.

Sesbanimide R, a Novel Cytotoxic Polyketide Produced by Magnetotactic Bacteria.

ABSTRACTGenomic information from various magnetotactic bacteria suggested that besides their common ability to form magnetosomes, they potentially also represent a source of bioactive natural products. By using targeted deletion and transcriptional activation, we connected a large biosynthetic gene cluster (BGC) of the trans-acyltransferase polyketide synthase (trans-AT PKS) type to the biosynthesis of a novel polyketide in the alphaproteobacterium Magnetospirillum gryphiswaldense. Structure elucidation by mass spectrometry and nuclear magnetic resonance spectroscopy (NMR) revealed that this secondary metabolite resembles sesbanimides, which were very recently reported from other taxa. However, sesbanimide R exhibits an additional arginine moiety the presence of which reconciles inconsistencies in the previously proposed sesbanimide biosynthesis pathway observed when comparing the chemical structure and the potential biochemistry encoded in the BGC. In contrast to the case with sesbanimides D, E, and F, we were able to assign the stereocenter of the arginine moiety experimentally and two of the remaining three stereocenters by predictive biosynthetic tools. Sesbanimide R displayed strong cytotoxic activity against several carcinoma cell lines.

Phytochemical characterization and effects on cell proliferation ofPinus nigraArn. bark

Pinus nigra Arn. bark extracts from Mokra gora (MG) and Tara mountains were analyzed with regard to their polyphenolic profile andantioxidative and antiproliferative activity. The ethanol extract from MG showed the highest phenolic, flavonoid, tannin, and proanthocyanidin content when compared with the acetone and methanol extracts from both sites. The same extract exhibited the highest ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and ferric reducing antioxidant power (FRAP) radical scavenging ability and total antioxidant activity (TAA). On the basis of high-performance liquid chromatography analysis, catechin, caffeic, syringic, p-coumaric, and ferulic acids were predominantly present in the MG extracts. The ethanol extract from MG was rich in syringic acid, epicatechin and its derivatives, and ferulic acid and its derivatives. The bark extracts also exerted a high cytotoxic bioactivity againstall evaluated cell lines (HeLa, MCF7, HT-29, and MRC-5). The antiproliferative activity of P. nigra bark is probably related to the ferulic acid content and its synergistic activity to caffeic acid and taxifolin. The antioxidative role of the presented phenols was confirmed through the obtained significant linear correlation between the total phenolic content and DPPH (r = .934) as well as the FRAP% of the extracts (r = .948). Also, the TAA significantly depended on the proanthocyanidins (r = .902) and tannin contents (r = .914). The composition of the presented compounds could be related to promising antioxidant and antiproliferative efficacy of MG bark.

Leaf Anatomical-Histophytochemical Study and Evaluation of the Cytotoxicity of Ottonia frutescens Trel (Piperaceae)

To investigate the leaf histochemistry and micromorphology of Ottonia frutescens Schltdl Trel (Piperaceae), the antioxidant potential, and in vitro cytotoxic bioactivity of the leaf extract of this species against human leukemia and colorectal cells. Leaf micromorphology and histoanatomy were detailed and recorded by optical and transmission and scanning electron microscopy. The histochemical results reveal classes of secondary phytometabolites such as alkaloids, anthraquinones, coumarins, polyphenols, and saponins. Cardiotonics, flavonoids, and triterpenes compounds were not detected. All concentrations of leaf extracts showed a significant dose-dependent and time-dependent apoptotic effect with more than 90% apoptosis of U937 cells and about 60% apoptosis of COLO-205 cells in 24 h of culture under 200 μg/mL of leaf extract. In addition, the phenolic compounds present in the fractions of the sample contribute to its strong antioxidant capacity. Ottonia frutescens exhibit anatomical and histochemical characteristics similar to other Piperaceae, and for the first time, provides a new source for secondary metabolite classes that exhibit high antioxidant potential and cytotoxic bioactivity, reduce cell viability and induce apoptosis in U937 leukemic cells and COLO-205 colorectal cells.

Design, Synthesis and In Vitro Cytotoxic Activity of New 6,9-Disubstituted Purine Analogues

A series of new 6,9-disubstituted purine analogs with 4-substituted piperazine at C-6 and 4-substituted benzyl at N-9 were designed and synthesized in four steps. All synthesized compounds (7-26) were screened initially for their in vitro anticancer activity on Huh7 liver, HCT116 colon and MCF7 breast carcinoma cell lines. Cytotoxic bioactivity studies revealed that all compounds screened, with compound 19 being the exception, were found to have promising cytotoxic activities at IC50 range of 0.05-21.8 ∆M against cancer cells Huh7, HCT116 and MCF7. Among the prepared purine analogs, two of them (12 and 22) exhibited excellent cytotoxic activities, with IC50 0.08-0.13 ∆M, on Huh7 cells comparable to camptothecin (CPT) and better than cladribine, fludarabine and 5-FU. Afterwards, the evaluation of cytotoxicity of the most potent purine analogs was screened against further hepatocellular cancer (HCC) cell lines. The 6-(4-(4-trifluoromethylphenyl)piperazine (12) and 6-(4-(3,4-dichlorophenyl)piperazine analogs (25) displayed a significant IC50 values (IC50 < 0.1-0.13 ∆M) comparable to CPT and better cytotoxic bioactivity when compared with 5-FU, cladribine and fludarabine on HCC cells (Huh7 and HepG2).

The Cytotoxic Natural Product Vioprolide A Targets Nucleolar Protein 14, Which Is Essential for Ribosome Biogenesis.

Novel targets are needed for treatment of devastating diseases such as cancer. For decades, natural products have guided innovative therapies by addressing diverse pathways. Inspired by the potent cytotoxic bioactivity of myxobacterial vioprolides A–D, we performed in‐depth studies on their mode of action. Based on its prominent potency against human acute lymphoblastic leukemia (ALL) cells, we conducted thermal proteome profiling (TPP) and deciphered the target proteins of the most active derivative vioprolide A (VioA) in Jurkat cells. Nucleolar protein 14 (NOP14), which is essential in ribosome biogenesis, was confirmed as a specific target of VioA by a suite of proteomic and biological follow‐up experiments. Given its activity against ALL cells compared to healthy lymphocytes, VioA exhibits unique therapeutic potential for anticancer therapy through a novel mode of action.

Brominated Bisindole Alkaloids from the Celtic Sea Sponge Spongosorites calcicola.

As part of an ongoing program to identify new bioactive compounds from Irish marine bioresources, we selected the subtidal sponge Spongosorites calcicola for chemical study, as fractions of this species displayed interesting cytotoxic bioactivities and chemical profiles. The first chemical investigation of this marine species led to the discovery of two new bisindole alkaloids of the topsentin family, together with six other known indole alkaloids. Missing the usual central core featured by the representatives of these marine natural products, the new metabolites may represent key biosynthetic intermediates for other known bisindoles. These compounds were found to exhibit weak cytotoxic activity against HeLa tumour cells, suggesting a specificity towards previously screened carcinoma and leukaemia cells.

Diversity and bioactivity of Armillaria sesquiterpene aryl ester natural products

Species of the basidiomycete genus Armillaria produce bioactive small molecule natural products, referred to as melleolides. With more than 70 described members, this class of natural products is a prime example for diversity-oriented biosynthesis. Chemically, they represent hybrid molecules, composed of a tricyclic, chiral sesquiterpene protoilludene alcohol, esterified with the tetraketide orsellinic acid or its derivatives. In this review article, we summarize the melleolide’s structural diversity and present—to the extent elucidated—the enzymatic basis how their backbone structures are biosynthesized and modified. We also highlight the current knowledge on their antimicrobial, phytotoxic, and cytotoxic bioactivities, along with a view on the molecular targets of the melleolides, their unparalleled structure-activity relationships, and their modes of action.

Abstract 995: A new thiadiazine derivative induces oxidative stress dependent JNK pathway activation and cell death in hepatocellular carcinoma

Abstract Hepatocellular carcinoma (HCC) is the fifth most common and the second lethal cancer worldwide. HCC is resistant to conventional chemotherapy and radiotherapy due to its highly heterogenous structure. Therefore, it is crucial to design and develop novel therapeutic strategies against HCC. Non-steroidal anti-inflammatory drugs (NSAIDs) have long been studied for the treatment of acute and chronic conditions with pain and inflammation. In recent years, evidence from various studies suggested that NSAIDs reduce the incidence and mortality of various types of cancers. Here, investigated the possible cytotoxic bioactivities of a series of triazolothiadiazine derivatives on HCC cells, which have been previously reported as potent analgesic/anti-inflammatory compounds. For this purpose, we first investigated the anticancer effect of our compounds bearing a triazolothiadiazine core. Initially, 30 compounds were tested against cancer cells. Among all the compounds, three of them (7a, 7b and 7c) showed noticeable cytotoxic activities within µM concentrations and were selected to be screened against a panel of HCC cell lines. Compound 7b was identified as a promising anti-cancer agent against liver cancer cells with cytotoxic doses (less than 5µM) assessed by both the SRB assay and RT-CES analysis and was analyzed with further in vitro and in vivo experiments to disclose the underlying mechanism of its action in HCC cells. Time- and dose- dependent growth inhibition upon treatment with compound 7b was observed due to cell cycle arrest at the G2/M phase and apoptosis. After detecting the activation of SAPK/JNK pathway, it was shown that ROS accumulation was triggering the downstream events and eventually apoptotic cell death. Furthermore, upon treatment with compound 7b, overall survival of xenografts increased, while the tumor size decreased compared to control groups. Additionally, we investigated the potential of this compound on liver cancer stem cell population (CD133+/EpCAM+) which are known to be responsible for drug resistance in HCC. Compound 7b was bioactive against LCSCs and decreased the ratio of CD133+/EpCAM+ population significantly in both Huh7 and Mahlavu cells. Altogether, the anti-tumor and anti-resistance effects of compound 7b approves that this small molecule can be considered as an anti-cancer agent for liver cancer therapeutics. Citation Format: Deniz C. Kahraman, Ebru B. Guven, Birsen Tozkoparan, Rengul C. Atalay. A new thiadiazine derivative induces oxidative stress dependent JNK pathway activation and cell death in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 995.

Assignment of the absolute configuration of hepatoprotective highly oxygenated triterpenoids using X-ray, ECD, NMR J-based configurational analysis and HSQC overlay experiments

BackgroundThe plants of the genus Kadsura are widely distributed in China, South Korea, and Japan. Their roots and stems are traditionally used to treat blood diseases and pain. The main bioactive constituents of Kadsura longipedunculata comprise highly oxygenated triterpenoids. Schiartane-type nortriterpenoids showed anti-HIV, anti-HBV, and cytotoxic bioactivities. For such compounds, the absolute configuration influences the bioactivities, and hence its unambiguous determination is essential. In this work, the absolute configurations of three highly oxygenated schiartane-type nortriterpenoids were unequivocally assigned using X-ray, ECD, and J-based configuration analysis and HSQC overlay data. MethodsThe ethanol extract of Kadsura longipedunculata Finet et Gagnep was purified by column chromatography using silica, Sephadex LH-20, and ODS as substrates. To help assign the absolute configuration of schiartane-type nortriterpenoids, X-ray diffraction analysis, ECD experiment compared to ab initio computed data, DP4+ analysis, HSQC overlay, NOESY, and J-based configuration analysis were carried out. Hetero- and homo-nuclear coupling constants were extracted from HETLOC experiments. ResultsThree new highly oxygenated triterpenoids, micrandilactone I (1), micrandilactone J (2), and 22,23-di-epi-micrandilactone J (3) were isolated. Their 2D structures were solved using NMR and HRESIMS data and their absolute configurations were elucidated using X-ray diffraction analysis, ECD experimental results compared to ab initio computed spectra, HSQC overlay, DP4+, NOESY, and J-based configuration analysis. Micrandilactone I (1) and 22,23-di-epi-micrandilactone J (3) showed moderate hepatoprotective activity against APAP-induced toxicity in HepG2 cells with cell survival rates of 53.0 and 50.2%, respectively, at 10μM (bicyclol, 49.0%), while micrandilactone J (2) was inactive. General significanceThis is the first comprehensive stereochemical assignment of a non-crystalline schiartane-type nortriterpenoid like 3. This general protocol may contribute towards solving the problems hampering the assignment of the absolute configurations of other members of this class of nortriterpenoids.

DESIGNER Extracts as Tools to Balance Estrogenic and Chemopreventive Activities of Botanicals for Women's Health.

Botanical dietary supplements contain multiple bioactive compounds that target numerous biological pathways. The lack of uniform standardization requirements is one reason that inconsistent clinical effects are reported frequently. The multifaceted biological interactions of active principles can be disentangled by a coupled pharmacological/phytochemical approach using specialized (“knock-out”) extracts. This is demonstrated for hops, a botanical for menopausal symptom management. Employing targeted, adsorbent-free countercurrent separation, Humulus lupulus extracts were designed for pre- and postmenopausal women by containing various amounts of the phytoestrogen 8-prenylnaringenin (8-PN) and the chemopreventive constituent xanthohumol (XH). Analysis of their estrogenic (alkaline phosphatase), chemopreventive (NAD(P)H-quinone oxidoreductase 1 [NQO1]), and cytotoxic bioactivities revealed that the estrogenicity of hops is a function of 8-PN, whereas their NQO1 induction and cytotoxic properties depend on XH levels. Antagonization of the estrogenicity of 8-PN by elevated XH concentrations provided evidence for the interdependence of the biological effects. A designed postmenopausal hop extract was prepared to balance 8-PN and XH levels for both estrogenic and chemopreventive properties. An extract designed for premenopausal women contains reduced 8-PN levels and high XH concentrations to minimize estrogenic while retaining chemopreventive properties. This study demonstrates the feasibility of modulating the concentrations of bioactive compounds in botanical extracts for potentially improved efficacy and safety.

Dissolution of Water-insoluble Curcumin by Femtosecond-laser Ablation in the Presence of Cyclodextrins and Its Cytotoxic Bioactivity against Lung Cancer Cells

Dissolution of water-insoluble curcumin at a high concentration (>100 µM) is achieved by femtosecond-laser ablation in an aqueous solution containing cyclodextrin compounds at room temperature. The...