Anticancer Drug Taxol Research Articles

Isolation of anticancer bioactive secondary metabolites from the sponge-derived endophytic fungi Penicillium sp. and in-silico computational docking approach.

Fungus-derived secondary metabolites are fascinating with biomedical potential and chemical diversity. Mining endophytic fungi for drug candidates is an ongoing process in the field of drug discovery and medicinal chemistry. Endophytic fungal symbionts from terrestrial plants, marine flora, and fauna tend to produce interesting types of secondary metabolites with biomedical importance of anticancer, antiviral, and anti-tuberculosis properties. An organic ethyl acetate extract of Penicillium verruculosum sponge-derived endophytic fungi from Spongia officinalis yielded seven different secondary metabolites which are purified through HPLC. The isolated compounds are of averufin (1), aspergilol-A (2), sulochrin (3), monomethyl sulochrin (4), methyl emodin (5), citreorosein (6), and diorcinol (7). All the seven isolated compounds were characterized by high-resolution NMR spectral studies. All isolated compounds', such as anticancer, antimicrobial, anti-tuberculosis, and antiviral, were subjected to bioactivity screening. Out of seven tested compounds, compound (1) exhibits strong anticancer activity toward myeloid leukemia. HL60 cell lines have an IC50 concentration of 1.00μm, which is nearly significant to that of the standard anticancer drug taxol. A virtual computational molecular docking approach of averufin with HL60 antigens revealed that averufin binds strongly with the protein target alpha, beta-tubulin (1JFF), with a -10.98 binding score. Consecutive OSIRIS and Lipinski ADME pharmacokinetic validation of averufin with HL60 antigens revealed that averufin has good pharmacokinetic properties such as drug score, solubility, and mutagenic nature. Furthermore, aspergilol-A (2) is the first report on the Penicillium verruculosum fungal strain. We concluded that averufin (1) isolated from Penicillium verruculosum can be taken for further preliminary clinical trials like animal model in-vivo studies and pharmacodynamic studies. A future prospect of in-vivo anticancer screening of averufin can be validated through the present experimental findings.

Increased paclitaxel recovery from Taxus baccata vascular stem cells using novel in situ product recovery approaches

In this study, several approaches were tested to optimise the production and recovery of the widely used anticancer drug Taxol® (paclitaxel) from culturable vascular stem cells (VSCs) of Taxus baccata, which is currently used as a successful cell line for paclitaxel production. An in situ product recovery (ISPR) technique was employed, which involved combining three commercial macro-porous resin beads (HP-20, XAD7HP and HP-2MG) with batch and semi-continuous cultivations of the T. baccata VSCs after adding methyl jasmonate (Me-JA) as an elicitor. The optimal resin combination resulted in 234 ± 23 mg of paclitaxel per kg of fresh-weight cells, indicating a 13-fold improved yield compared to the control (with no resins) in batch cultivation. This resin treatment was further studied to evaluate the resins’ removal capacity of reactive oxygen species (ROS), which can cause poor cell growth or reduce product synthesis. It was observed that the ISPR cultivations had fourfold less intracellular ROS concentration than that of the control; thus, a reduced ROS concentration established by the resin contributed to increased paclitaxel yield, contrary to previous studies. These paclitaxel yields are the highest reported to date using VSCs, and this scalable production method could be applied for a diverse range of similar compounds utilising plant cell culture.Graphical

Heavy water (D2O) induces autophagy-dependent apoptotic cell death in non-small cell lung cancer A549 cells by generating reactive oxygen species (ROS) upon microtubule disruption.

ObjectiveDeuterium oxide (D2O) or heavy water is known to have diverse biological activities and have a few therapeutic applications due to its limited toxicity to human subjects. In the present study, we investigated the mechanism of D2O-induced cytotoxicity in non-small cell lung cancer A549 cells. ResultsWe found that D2O-treatment resulted in cytotoxicity, cell cycle arrest, and apoptosis in A549 cells in a dose-dependent fashion. In contrast, limited cytotoxicity was observed in lung fibroblasts WI38 cells. Moreover, D2O-treatment resulted in the disruption of the cellular microtubule network, accompanied by the generation of ROS. On further investigation, we observed that the intracellular ROS triggered autophagic responses in D2O-treated cells, leading to apoptosis by inhibiting the oncogenic PI3K/ Akt/ mTOR signaling. D2O-treatment was also found to enhance the efficacy of paclitaxel in A549 cells. SignificanceD2O induces autophagy-dependent apoptosis in A549 cells via ROS generation upon microtubule depolymerization and inhibition of PI3K/ Akt/ mTOR signaling. It augments the efficacy of other microtubule-targeting anticancer drug taxol, which indicates the potential therapeutic importance of D2O as an anticancer agent either alone or in combination with other chemotherapeutic drugs.

The synergetic effect from the combination of different adsorption resins in batch and semi-continuous cultivations of S. Cerevisiae cell factories to produce acetylated Taxanes precursors of the anticancer drug Taxol.

In situ product recovery is an efficient way to intensify bioprocesses as it can perform adsorption of the desired natural products in the cultivation. However, it is common to use only one adsorbent (liquid or solid) to perform the product recovery. For this study, the use of an in situ product recovery method with three combined commercial resins (HP-20, XAD7HP, and HP-2MG) with different chemical properties was performed. A new yeast strain of Saccharomyces cerevisiae was engineered using CRISPR Cas9 (strain EJ2) to deliver heterologous expression of oxygenated acetylated taxanes that are precursors of the anticancer drug Taxol ® (paclitaxel). Microscale cultivations using a definitive screening design (DSD) were set to get the best resin combinations and concentrations to retrieve high taxane titers. Once the best resin treatment was selected by the DSD, semi-continuous cultivation in high throughput microscale was performed to increase the total taxanes yield up to 783 ± 33 mg/L. The best T5α-yl Acetate yield obtained was up to 95 ± 4 mg/L, the highest titer of this compound ever reported by a heterologous expression. It was also observed that by using a combination of the resins in the cultivation, 8 additional uncharacterized taxanes were found in the gas chromatograms compared to the dodecane overlay method. Lastly, the cell-waste reactive oxygen species concentrations from the yeast were 1.5-fold lower in the resin's treatment compared to the control with no adsorbent aid. The possible future implications of this method could be critical for bioprocess intensification, allowing the transition to a semi-continuous flow bioprocess. Further, this new methodology broadens the use of different organisms for natural product synthesis/discovery benefiting from clear bioprocess intensification advantages.

Design of a Molecular Dynamics Model for High-Performance Computing of Conformational Changes in Microtubule Protofilaments Associated with the Anticancer Drug Taxol

Molecular dynamics models of tubulin tetramers in complex with the anticancer drug taxol were created based on high-resolution spatial structures (PDB ID 3J6G). We tested performance of various computational architectures in molecular dynamics calculations of tubulin tetramers. We revealed the optimal computer architecture and carried out three 1 μs molecular dynamic trajectories of taxol-bound tubulin tetramer. We analyzed the conformational flexibility of tubulin tetramers in a complex with taxol, calculated the Euler angles for intra- and inter-dimer interfaces of the protofilament, as well as the degree and direction of protofilament bending. The stiffness of protofilaments was studied using the energy equipartition theorem. The results allowed us to conclude that taxol binding reduces stiffness at both the inter- and intra-dimer interfaces, which may facilitate the process of microtubule assembly.

Taxol and β-tubulins from endophytic fungi isolated from the Himalayan Yew, Taxus wallichiana Zucc.

Paclitaxel, better known as the anticancer drug Taxol®, has been isolated from several plant species and has been shown to be produced by fungi, actinomycetes, and even bacteria isolated from marine macroalgae. Given its cytostatic effect, studies conducted in the 1990's showed that paclitaxel was toxic to many pathogenic fungi and oomycetes. Further studies led to the idea that the differences in paclitaxel sensitivity exhibited by different fungi were due to differences in the β-tubulin protein sequence. With the recent isolation of endophytic fungi from the leaves and bark of the Himalayan Yew, Taxus wallichiana Zucc., and the availability of genomes from paclitaxel-producing fungi, we decided to further explore the idea that endophytic fungi isolated from Yews should be well-adapted to their environment by encoding β-tubulin proteins that are insensitive to paclitaxel. Our results found evidence of episodic positive/diversifying selection at 10 sites (default p-value threshold of 0.1) in the β-tubulin sequences, corresponding to codon positions 33, 55, 172, 218, 279, 335, 359, 362, 379, and 406. Four of these positions (i.e., 172, 279, 359, and 362) have been implicated in the binding of paclitaxel by β-tubulin or formed part of the binding pocket. As expected, all the fungal endophytes grew in different media regardless of the paclitaxel concentration tested. Furthermore, our results also showed that Taxomyces andreanae CBS 279.92, the first fungus shown to produce paclitaxel, is a Basidiomycete fungus as the two beta tubulins encoded by the fungus clustered together with other Basidiomycete fungi.

Endophytic Fungi: Key Insights, Emerging Prospects, and Challenges in Natural Product Drug Discovery.

Plant-associated endophytes define an important symbiotic association in nature and are established bio-reservoirs of plant-derived natural products. Endophytes colonize the internal tissues of a plant without causing any disease symptoms or apparent changes. Recently, there has been a growing interest in endophytes because of their beneficial effects on the production of novel metabolites of pharmacological significance. Studies have highlighted the socio-economic implications of endophytic fungi in agriculture, medicine, and the environment, with considerable success. Endophytic fungi-mediated biosynthesis of well-known metabolites includes taxol from Taxomyces andreanae, azadirachtin A and B from Eupenicillium parvum, vincristine from Fusarium oxysporum, and quinine from Phomopsis sp. The discovery of the billion-dollar anticancer drug taxol was a landmark in endophyte biology/research and established new paradigms for the metabolic potential of plant-associated endophytes. In addition, endophytic fungi have emerged as potential prolific producers of antimicrobials, antiseptics, and antibiotics of plant origin. Although extensively studied as a “production platform” of novel pharmacological metabolites, the molecular mechanisms of plant–endophyte dynamics remain less understood/explored for their efficient utilization in drug discovery. The emerging trends in endophytic fungi-mediated biosynthesis of novel bioactive metabolites, success stories of key pharmacological metabolites, strategies to overcome the existing challenges in endophyte biology, and future direction in endophytic fungi-based drug discovery forms the underlying theme of this article.

On the three-dimensional dynamics of microtubule by considering initially stress

To design anticancer drug Taxol working more efficiently, looking at details of microtubules' dynamic behavior has become more important for researchers worldwide. According to this issue, dynamic stability analysis of microtubule-associated proteins (MAPs) using the state-space technique based on three-dimension elasticity theory is presented. Besides, the MAPs structure is under various body pressure. The state-space technique is applied along the radial direction, and the differential quadrature method (DQM) along the axial direction in the case of another end supports. The novelty of the current study considers the various boundary conditions for MAPs structure and body pressure, which is implemented on the proposed model using the theory of Three-dimension (3D) elasticity. The validity of applied solutions is examined by comparing results with those of available literature, experimental data, and molecular dynamic (MD) simulation outcomes. A thorough parametric investigation is conducted on the effect of initial stress, boundary conditions, and geometry of the shell (such as mid-radius to thickness and length to mid-radius ratios) on the dynamic stability of the MAPs structures under initial stress.

Trichostatin A sensitizes hepatoma cells to Taxol more than 5-Aza-dC and dexamethasone.

This work was designed to compare the sensitizing effects of epigenetic modifiers on cancer cells vs. that of glucocorticoids. Also, to evaluate their effects on genes involved in epigenetic changes and drug metabolism. Hepatoma cells (HepG2) were treated with the anticancer drug (Taxol), with a histone deacetylase inhibitor (Trichostatin A [TSA]), DNA methyltransferase inhibitor (5-Aza-dC) or dexamethasone (DEX). Cytotoxicity was assessed by MTT assay and the apoptosis was determined by Annexin V-FITC. The expression levels of HDAC1, HDAC3, Dnmt1, Dnmt3α, CYP1A2, CYP3A4, CYP2B6, CYP2C19 and CYP2D6 were monitored by qRT-PCR. TSA, synergistically enhanced cells sensitivity with the anticancer effect of Taxol more than 5-Aza-dC and DEX. This was evidenced by the relative decrease in IC50 in cells cotreated with Taxol+TSA, Taxol+5-Aza-dC or Taxol+DEX. Apoptosis was induced in 51.2, 16.9 and 41.3% of cells, respectively. In presence of Taxol, TSA induced four-fold increase in the expression of HDAC1 and downregulated Dnmt1&3α genes. CYP2D6 demonstrated progressive expression (up to 28-fold) with the increasing number of drugs. Moreover, the isoform overexpressed in cells treated with TSA+Taxol>DEX+Taxol>5-Aza-dC+Taxol (6.4, 4.6 and 2.99, respectively). The investigated genes were clustered in two distinct subsets, where no coregulation was observed between HDAC1 and HDAC3. However, tight pairwise correlation-based cluster was seen between (CYP3A4/Dnmt3α and CYP2D6/CYP2C19). The data reflects the sensitizing effect of acetylation modification by TSA on the responsiveness of hepatoma cells to anticancer therapy. The effect of histone deacetylase inhibition was more than hypomethylation and glucocorticoid effects. TSA exerts its role through its modulatory role on epigenetics and drugs metabolizing genes. Other modifiers (5-Aza-dC and DEX), however may adopt different mechanisms.

Trichostatin A sensitizes hepatoma cells to Taxol more than 5-Aza-dC and dexamethasone.

This work was designed to compare the sensitizing effects of epigenetic modifiers on cancer cells vs. that of glucocorticoids. Also, to evaluate their effects on genes involved in epigenetic changes and drug metabolism. Hepatoma cells (HepG2) were treated with the anticancer drug (Taxol), with a histone deacetylase inhibitor (Trichostatin A [TSA]), DNA methyltransferase inhibitor (5-Aza-dC) or dexamethasone (DEX). Cytotoxicity was assessed by MTT assay and the apoptosis was determined by Annexin V-FITC. The expression levels of HDAC1, HDAC3, Dnmt1, Dnmt3α, CYP1A2, CYP3A4, CYP2B6, CYP2C19 and CYP2D6 were monitored by qRT-PCR. TSA, synergistically enhanced cells sensitivity with the anticancer effect of Taxol more than 5-Aza-dC and DEX. This was evidenced by the relative decrease in IC50 in cells cotreated with Taxol+TSA, Taxol+5-Aza-dC or Taxol+DEX. Apoptosis was induced in 51.2, 16.9 and 41.3% of cells, respectively. In presence of Taxol, TSA induced four-fold increase in the expression of HDAC1 and downregulated Dnmt1&3α genes. CYP2D6 demonstrated progressive expression (up to 28-fold) with the increasing number of drugs. Moreover, the isoform overexpressed in cells treated with TSA+Taxol>DEX+Taxol>5-Aza-dC+Taxol (6.4, 4.6 and 2.99, respectively). The investigated genes were clustered in two distinct subsets, where no coregulation was observed between HDAC1 and HDAC3. However, tight pairwise correlation-based cluster was seen between (CYP3A4/Dnmt3α and CYP2D6/CYP2C19). The data reflects the sensitizing effect of acetylation modification by TSA on the responsiveness of hepatoma cells to anticancer therapy. The effect of histone deacetylase inhibition was more than hypomethylation and glucocorticoid effects. TSA exerts its role through its modulatory role on epigenetics and drugs metabolizing genes. Other modifiers (5-Aza-dC and DEX), however may adopt different mechanisms.

Anticancer activity of new cationic arylthiophenes against hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is the second most common cancer-related death in the world. No effective curative option exists for the treatment of HCC. The available drugs exhibit severe toxic effects and low therapeutic index. AimThis work aimed to examine different monocationic arylthiophene derivatives for possible use as chemotherapeutic agents against HCC. MethodsThe IC50 values for the compounds were determined. The mechanism of cytotoxicity was further investigated using different methods. ResultsCompound 2j proved to retain the highest cytotoxicity in comparison to as a positive control. The selectivity index of compound 2j revealed the safety to normal cells. Moreover, compound 2j was able to inhibit HepG2 cells´ migration and division. The anticancer effect of compound 2j was found to be partially via cell cycle arrest, activation of the tumour suppressor p53 protein, and induction of apoptosis via both intrinsic and extrinsic pathways. Compound 2j has a potential sensitization activity and significantly reduced the IC50 values for the anticancer drugs doxorubicin, cisplatin, and taxol. ConclusionThe tested arylthiophenes showed a potent cytotoxicity against HepG2 cells and were safe to normal cells. The most active compound 2j was found to be able to inhibit cell division and migration and also to induce apoptosis. Compound 2j also proved to have a sensitization effect on standard anticancer drugs.

Discovery of facile amides-functionalized rhodanine-3-acetic acid derivatives as potential anticancer agents by disrupting microtubule dynamics

Microtubule dynamics are crucial for multiple cell functions, and cancer cells are particularly sensitive to microtubule-modulating agents. Here, we describe the design and synthesis of a series of (Z)-2-(5-benzylidene-4-oxo-2-thioxothiazolidin-3-yl)-N-phenylacetamide derivatives and evaluation of their microtubule-modulating and anticancer activities in vitro. Proliferation assays identified I20 as the most potent of the antiproliferative compounds, with 50% inhibitory concentrations ranging from 7.0 to 20.3 µM with A549, PC-3, and HepG2 human cancer cell lines. Compound I20 also disrupted cancer A549 cell migration in a concentration-dependent manner. Immunofluorescence microscopy, transmission electron microscopy, and tubulin polymerisation assays suggested that compound I20 promoted protofilament assembly. In support of this possibility, computational docking studies revealed a strong interaction between compound I20 and tubulin Arg β369, which is also the binding site for the anticancer drug Taxol. Our results suggest that (Z)-2-(5-benzylidene-4-oxo-2-thioxothiazolidin-3-yl)-N-phenylacetamide derivatives could have utility for the development of microtubule-stabilising therapeutic agents.

CYP2D6 EXPRESSION IS CUMULATIVELY UP REGULATED IN MULTIDRUG TREATED HEPATOMA CELLS: A PREDECTIVE PHARMACOGENETICS IN VITRO MODEL

Cancer and many other diseases require concomitant treatments with combinations of many drugs.Debrisoquine 4-Hydroxylayase (CYP2D6) is microsomal enzyme involved in phase I metabolism of a long list of drugs. Also, it is a marker of inter-individual variability in drug responsiveness. This study was designated to explore the regulation of CYP2D6 in hepatoma cells exposed to combinations of anticancer and epigenetic modifying drugs. HepG2 cell were treated with combinations of anticancer drug (Taxol), glucocorticoid (dexamethasone, DEX) and epigenetic modifiers: Trichostatin A (TSA) and 5 aza-deoxycytidine (5 aza-dC). The expression of CYP2D6 was determined by quantitative RT-PCR and compared to other CYPs and the corresponding cumulative apoptotic effect was determined by flow cytometry. The obtained results revealed thatUnder non-induced conditions, CYP2D6 was stably expressed and sub micromolar concentration of DEX mildly increased its expression. Individual treatments as DEX, Taxol, TSA and 5-azadC induced 2-6-fold increase in the transcript level, where the TSA was the most potent inducer. Combinations of 2 drugs as (Taxol+DEX), (Taxol+TSA), (Taxol+5-aza-dC) and (TSA+5-aza-dC). led to 3-10-fold increase (average 6.2), whereas cocktails of 3 drugs as (Taxol+DEX+5-aza-dC), (Taxol+DEX+TSA) and (Taxol+TSA+5-aza-dC) led to further up regulatory effect (11-27-fold). The highest increment (28-fold) was observed when cells were treated with 4 drugs as (Taxol+TSA+5-aza-dC+DEX). The progressive induction of CYP2D6 was correlated with the cumulative apoptotic effect (r=0.79). Conclusively, the data suggest, for the first time, that anticancer, epigenetic regulatory factors and dexamethasone cumulatively enhanced the baseline expression of CYP2D6

Could COVID-19 Cause ‘Biopharming’ to Bloom?

At an accelerated rate in response to the COVID-19 pandemic, academic and corporate scientists are using genetic engineering techniques to reprogram plants to produce significant concentrations of high-value pharmaceuticals. The concept is not new. Many common medicines, such as certain opiates, the laxative Metamucil, and the anti-cancer drug Taxol, are all purified from plants, and efficacy has been shown for some herbals in Traditional Chinese Medicine. There is great potential for cost-cutting in the process: The energy for product synthesis comes from the sun, and the primary raw materials are water and carbon dioxide. In addition, biopharming offers tremendous flexibility and economy when adjustments in production are necessary. The need for inexpensive, flexible production techniques for COVID-19 therapeutics and vaccines could be a potent stimulus to biopharming research and development.

Evaluation of the anticancer activity of enzymatically synthesized Baccatin III: an intermediate precursor of Taxol®.

Baccatin III is an important precursor for the synthesis of clinically important anticancer drug Taxol. Previously, we have characterized a key enzyme of 10-deacetylbaccatin III-10-β-O-acetyltransferase (DBAT) which catalyses the 10-deacetylbaccatin III into baccatin III in taxol biosynthesis. Here, in the present study, we have evaluated and compared the cytotoxic properties of the enzymatically synthesized baccatin III (ESB III) with standard baccatin III in different human cancer cell lines, namely human cervical cancer (HeLa), human lung cancer (A549), human skin cancer (A431) and human liver cancer cells (HepG2). Among the various cancer lines tested, HeLa was more susceptible to ESB III with IC50 of 4.30µM while IC50 values for A549, A431 and HepG2 ranged from 4 to 7.81µM. Further, it showed G2/M phase cell cycle arrest, production of reactive oxygen species and depolarised mitochondrial membrane potential. In addition, annexin V-FITC staining was performed which showed the apoptotic cell death of HeLa cells, when treated with ESB III. Hence, ESB III was capable to show anticancer activities by inducing apoptotic cell death which could further be used for the semisynthesis of taxol in future.

Molecular level investigation of curcumin self-assembly induced by trigonelline and nanoparticle formation.

Nanoparticle-facilitated drug delivery forms the core of medicine nowadays with the drug being delivered right at the target, reducing side effects and enhancing therapeutic value. Nanoparticles derived from natural compounds are further a point of focus being biocompatible and safe by and large. In this study, we have performed HF/6-31G calculations coupled with intermolecular interaction calculations and nanoscale molecular dynamics simulations to investigate self-assemblage in curcumin induced by trigonelline. Similar to recently reported self-assemblage in curcumin induced by sugar, trigonelline, a natural antidiabetic derived from fenugreek, can also induce auto-catalyzed self-assemblage in curcumin to form nanoparticles. It has been shown that these nanoparticles may be utilized for the delivery of drugs with severe side effects especially for diabetic patients with triple benefit of being antidiabetic, biocompatible and safe. As an example, carriage of antidiabetic drug pioglitazone and anticancer drug taxol have been depicted utilizing nanoparticles of curcumin and trigonelline. Twenty five taxol molecules could be comfortably carried in a 50 nm nanoparticle with an average overall root mean square deviation of 2.89 Å with reference to initial positions. For the first time, this study shows the possibility of developing antidiabetic nanoparticles with plethora of opportunities for diabetic patients. The study is expected to motivate experimental verification and has a long lasting impact in medicinal chemistry.Electronic supplementary materialThe online version of this article (10.1007/s13204-020-01526-4) contains supplementary material, which is available to authorized users.

Production of the anticancer drug taxol by the endophytic fungus Epicoccum nigrum TXB502: enhanced production by gamma irradiation mutagenesis and immobilization technique.

Taxol, a phyto-extracted diterpenoid, is the most commercially needed drug in cancer chemotherapy. In spite of the microbial production of taxol being successful and prospective, the reported yields are still not sufficient for large-scale production. Thus, the discovery of new taxol-producing microbial strains and production enhancement methodologies such as process optimization, strain improvement, and immobilization technique are the main objectives. In this paper, a taxol-producing start strain Epicoccum nigrum TXB502 (initial yield 61.35 μg L-1) was isolated from Taxus baccata and identified by morphological and molecular tools. The optimum cultivation and nutritional conditions were assessed by testing one parameter at a time approach that resulted in 88.59% significant production increase. In addition, a stable mutant with improved productivity (40.07% yield increase in comparison with the parent strain) was successfully developed after gamma irradiation mutagenesis of the start strain. The taxol titer was further improved via testing different immobilization carriers for both spores and mycelia of this mutant. Over taxol production was achieved using alginate-immobilized mycelia with the feasibility of conducting six successive production cycles in a semi-continuous form. The final total concentration reached 8187.77 μg taxol 6 L-1 which represents approximately 22-fold increase, as compared to the initial titer of the start strain. These findings can pave the way for the prospective industrial manufacturing of taxol, as the achieved taxol production in this study is the highest reported by academic laboratories for microbial cultures. KEY POINTS: • Discovery of a new taxol-producing endophytic fungus E. nigrum TXB502 strain. • Taxol yield was successfully improved via bioprocess optimization and strain mutagenesis. • Alginate-immobilized mycelia were efficient for a semi-continuous production of taxol. • The final total concentration of taxol showed approximately 22-fold increase as compared to the initial titer.

Size-dependent dynamic stability analysis of the cantilevered curved microtubule-associated proteins (MAPs)

A pathway to the design of even more effective versions of the powerful anti-cancer drug Taxol is opened with the most detailed look ever at the dynamic and static behaviors of MAPs. Regarding this issue, the dynamic stability analysis of cantilevered microtubules in axons with attention to different size effect parameters based on the generalized differential quadrature method is presented. Supporting the effects of MAP Tau proteins and surrounding cytoplasm are considered as an elastic foundation. The better understanding modeled as a moderately thick curved cylindrical nanoshell. The real property of the living biological cells is presented as the Kelvin-Voight viscoelastic properties. Hamilton’s principle is employed to establish the Clamped-Free boundary conditions and governing equations, which is finally solved by the Fourier-expansion based generalized differential quadrature method (FGDQM). Considering length scale and nonlocal parameters (l = 3h, =h/2) in nonlocal strain gradient theory (NSGT) leads to a better agreement with experimental results in comparison by other theories that in the results section is presented, in details. Based on presented semi-numerical results, for a specific value of the cantilevered microtubule length, the influence of the parameter on the amplitude of MAPs is much more considerable, that should be attention to this value. Another important consequence is that when the property of the MAPs is not considered viscoelastic, the relation between axial load and frequency of the living structure is nonlinear but by considering the time-dependent viscoelastic property the relation could be linear. Communicated by Ramaswamy H. Sarma

Canataxpropellane in 26 steps

Meet the popular anticancer drug Taxol’s quirky cousin: canataxpropellane. Chemists at the University of Konstanz have now synthesized the elusive compound for the first time, creating enough of the taxane for scientists to study its bioactivity (Science 2020, DOI: 10.1126/science.aay9173). Because canataxpropellane’s natural source, the Taxus canadensis shrub, ekes out the compound in minuscule quantities, scientists haven’t been able to evaluate its biological properties. Even though it has just 24 carbon atoms, canataxpropellane’s complex architecture makes it a beast to synthesize. It has Taxol’s core skeleton, but it also contains three additional C–C bonds that bridge the compound. Those three bonds “totally change the overall strategy of approaching the molecule” so that it must be distinct from Taxol syntheses, says Tanja Gaich, who led the synthetic effort. Canataxpropellane’s other structural challenges include two propellanes—motifs in which three rings share a single C–C bond. Canataxpropellane has 12 contiguous stereocenters. Five of

Mycosynthesis of anticancer drug taxol by Aspergillus oryzae, an endophyte of Tarenna asiatica, characterization, and its activity against a human lung cancer cell line

Abstract Taxol is a member of the taxane family of chemotherapy drugs, which includes cabazitaxel and docetaxel that have a promising role as anti-cancer drugs for specific human cancers. Hence, in order to meet the requirement, an alternative source for Taxol production, such as filamentous fungi is needed. In this study, a different endophytic fungus was obtained from a particular medicinal plant, Tarenna asiatica, and was selected for Taxol production. Among 28 screened fungi, only six fungal species produced Taxol in the modified liquid medium. The novel Taxol-producing endophytic fungi were identified through morphological and molecular identification using DNA sequencing and phylogenetic tree construction as Aspergillus oryzae. The structure of Taxol obtained from A. oryzae was identified with the appropriate control using an ultraviolet–visible (UV–Vis) spectrophotometer (235 nm), thin layer chromatography (TLC), liquid chromatography-mass spectrometry (LC-MS), and Fourier-transform infrared (FTIR) analysis. The fungal Taxol (95.04 μg/L) from the A. oryzae exhibits potent in vitro activity against selected cell line (Human Lung Cancer Cell Line- NCI–H460).