New developments in the synthesis of emicoron

This paper reports on the modification of two synthetic steps in the usual protocol used for obtaining EMICORON. EMICORON is a benzo[ghi]perylen-diimide, which was synthesized for the first time in our laboratory in 2012, and has shown to have in vivo antitumor activities that interferes with the tumor growth and development using a multi-target mechanism of action. The provided modifications, which involved the reaction times, the reaction conditions, and the work-up procedures, allowed the global yield of the process to be increased from 28% to about 40%. Thus, this new procedure may be more suitable for recovering higher amounts of EMICORON to be used in further preclinical studies

Natural aromatic compounds as scaffolds to develop selective G-quadruplex ligands. From previously reported berberine derivatives to new palmatine analogues

In this paper, the selective interactions of synthetic derivatives of two natural compounds, berberine and palmatine,with DNA G-quadruplex structureswere reported. In particular, the previous works on this subject concerning berberine were further presented and discussed, whereas the results concerning palmatine are presented here for the first time. In detail, these palmatine derivatives were developed by inserting seven different small peptide basic chains, giving several new compounds that have never been reported before. The preliminary studies of the interactions of these compounds with various G-quadruplex-forming sequences were carried out by means of various structural and biochemical techniques, which showed that the presence of suitable side chains is very useful for improving the interaction of the ligands with G-quadruplex structures. Thus, these new palmatine derivatives might act as potential anticancer drugs

New developments in the synthesis of EMICORON, a promising inhibitor of telomerase

EMICORON is a compoud which was synthesized for the first time in our own laboratory in 20121,2. From the chemical point of view, it is a benzo[ghi]perylen-diimmide presenting a piperidin group on the minor axis of the molecule directly linked to the bay area of the perylen core and three ethyl-piperidin chains, one linked to the aromatic area of the core and the other two linked to the major axis by a diimmidic bond. This compound has proved to be able to inhibit the growth of tumor cells through a double mechanism i.e. the inhibition of telomerase at high doses and, at minor concentrations, the induction of apopotosis of the tumor cells by rapidly triggering extensive DNA damage of telomeres, associated with the delocalization of telomeric protein protection of telomeres 1 (POT1)1. EMICORON has also showed to be effective in inhibiting the colon-rectal tumors in rats3 both as single compound both in a synergic effect with other conventional antitumor drugs3,4. In this work, we report the modification of two synthetic steps in respect with the usual ones in order to obtain a final higher yield for this compound. In particular, for what concerns the first one, we modified the times and the work up of the reaction whereas, for what concerns the second one, we completely modified the reaction conditions. We eliminated dioxane and hydroquinone and the new reaction occurred in shorter times, at lower temperatures and piperidine was used as reagent and solvent contemporaneously (Figure). With the modifications made to these two reaction steps, the global yield of the process has increased passing from 28% (original procedure)1 to 40%. Thus, this new procedure may be more suitable in order to get larger amounts of EMICORON to carry out further preclinical studies

Phytochemical study on the leaves of Wollemia nobilis

In this work, a phytochemical study performed on the leaves of the rare species, Wollemia nobilis W.G. Jones, K.D. Hill & J.M. Allen, is reported. By means of classical column chromatography and NMR Spectroscopy and Mass Spectrometry, nine compounds were evidenced. These were: pheophorbide a (1), isocupressic acid (2), acetyl-isocupressic acid (3), sandaracopimaric acid (4), agathic acid (5), 7-4'-4'''-tri-O-methyl-agathisflavone (6), 7-4'-7''-4'''-tetra-O-methyl-agathisflavone (7), caffeic acid (8) and shikimic acid (9). Compared to our previous phytochemical analysis on the male cones, some further compounds were identified i.e. compounds 1, 5, 6, 7 and 8. This confirmed the previous chemotaxonomic considerations of the species but also added new ones which were discussed within the text. In addition, a possible different accumulation of secondary metabolites in the tissues and organs of this plant was even noticed

Composizione molecolare della frazione polare di Ligusticum lucidum (Mill.)

Il Ligusticum lucidum (Mill.) (sinonimo di Coristospermum lucidum (Mill.) Reduron, Charpin & Pimenov) noto anche col nome comune di Motellina lucida, è una pianta erbacea perenne indigena appartenente alla famiglia delle Apiaceae. E’ caratterizzata da un fusto eretto e robusto, con foglie triangolari voluminose e lucide, ed infiorescenze strutturate in ombrelle composte da piccoli fiori bilobati di colore bianco. Il suo areale di distribuzione è individuato prevalentemente nel panorama montano dell’Italia settentrionale ed orientale ad altitudini comprese tra i 200 ed i 1500 m s.l.m., su pietraie e terreni aridi ad elevato coefficiente calcareo. Non sono note proprietà specifiche inerenti la specie, mentre le piante appartenenti al genere Ligusticum sono note per le loro forti proprietà anti-infiammatorie ed analgesiche. Per questo, alcune varietà del genere, hanno avuto largo impiego nella medicina tradizionale cinese, in particolare nel trattamento del dolore e per la terapia di diversi tipi di disordini ematologici, quali ischemie e trombosi, in quanto tali specie sono in grado di incrementare il flusso sanguigno soprattutto a livello cerebrale. In letteratura sono presenti diversi studi riguardanti la composizione della frazione polare e dell’olio essenziale di specie appartenenti al genere Ligusticum mentre risultano limitati gli studi fitochimici eseguiti sulla specie lucidum, riguardanti unicamente lo studio della composizione degli acidi grassi e la caratterizzazione delle cumarine e delle loro proprietà mediche. Ciò rappresenta la ragione per cui abbiamo iniziato tale studio allo scopo di fornire una prima analisi esaustiva della composizione molecolare della frazione polare della specie. L’analisi è stata condotta utilizzando tecniche estrattive, cromatografiche e spettroscopiche classiche quali estrazione con etanolo, cromatografia su colonna per la separazione dei composti, spettroscopia NMR e spettrometria di Massa per l’identificazione. Lo studio dell’estratto della frazione polare del L. lucidum, ha evidenziato la presenza di sei composti quali 3'-acetil-4'-tigloil-khellattone (1), 3'-acetil-4'-diidro-tigloil-khellattone (2), luteolina (3), 7-{[2-O-β-D-glucopiranosil)-β-D-glucopiranosil]ossi}-5-idrossi-2-(3,4-diidrossi)-4H-1-benzopiran-4-one (4), acido clorogenico (5) e acido chinico (6) più altre sostanze naturali la cui struttura è ancora oggetto di studio. I composti (1) e (2) che sono cumarine, rappresentano composti nuovi per il genere mentre sono già stati evidenziati nella famiglia e lo stesso vale per i composti (3) e (4) che sono flavonoidi ed anzi ne rappresentano i marker chemotassonomici. Infine, il composto (5) che è un acido caffeoil-chinico e l’acido chinico libero sono stati precedentemente identificati solo nel genere

Phytochemical Analysis and Trypanocidal Activity of Marrubium incanum Desr.

The rationale inspiring the discovery of lead compounds for the treatment of human parasitic protozoan diseases from natural sources is the well-established use of medicinal plants in various systems of traditional medicine. On this basis, we decided to select an overlooked medicinal plant growing in central Italy, Marrubium incanum Desr. (Lamiaceae), which has been used as a traditional remedy against protozoan diseases, and to investigate its potential against Human African trypanosomiasis (HAT). For this purpose, we assayed three extracts of different polarities obtained from the aerial parts of M. incanum—namely, water (MarrInc-H2O), ethanol (MarrInc-EtOH) and dichloromethane (MarrInc-CH2Cl2)—against Trypanosoma brucei (TC221), with the aim to discover lead compounds for the development of antitrypanosomal drugs. Their selectivity index (SI) was determined on mammalian cells (BALB/3T3 mouse fibroblasts) as a counter-screen for toxicity. The preliminary screening selected the MarrInc-CH2Cl2 extract as the most promising candidate against HAT, showing an IC50 value of 28 μg/mL. On this basis, column chromatography coupled with the NMR spectroscopy of a MarrInc-CH2Cl2 extract led to the isolation and identification of five compounds i.e. 1-α-linolenoyl-2-palmitoyl-3-stearoyl-sn- glycerol (1), 1-linoleoyl-2-palmitoyl-3-stearoyl-sn-glycerol (2), stigmasterol (3), palmitic acid (4), and salvigenin (5). Notably, compounds 3 and 5 were tested on T. brucei, with the latter being five-fold more active than the MarrInc-CH2Cl2 extract (IC50 = 5.41 ± 0.85 and 28 ± 1.4 μg/mL, respectively). Furthermore, the SI for salvigenin was >18.5, showing a preferential effect on target cells compared with the dichloromethane extract (>3.6). Conversely, stigmasterol was found to be inactive. To complete the work, also the more polar MarrInc-EtOH extract was analyzed, giving evidence for the presence of 2″-O-allopyranosyl-cosmosiin (6), verbascoside (7), and samioside (8). Our findings shed light on the phytochemistry of this overlooked species and its antiprotozoal potential, providing evidence for the promising role of flavonoids such as salvigenin for the treatment of protozoal diseases

Essential oil composition and total metabolite content of a chemotype of Ajuga reptans L. (Lamiaceae) collected in Central Italy

In this work, an interesting application of phytochemistry for ethnopharmacological purposes was reported. In particular, the total phytochemical analysis of a single sample of Ajuga reptans L. (Lamiaceae) collected in Central Italy was carried out in order to provide a rationale for the use of this plant in folk medicine. This analysis was conducted on the volatile oil fraction by gas chromatog- raphy–mass spectroscopy (GC-MS) and on the polar one by means of classical column chromatog- raphy and nuclear magnetic resonance and MS. Thirty-nine volatile components were identified in the essential oil whereas 32 compounds were identified in the polar fraction. All of these are known to exert several beneficial medicinal activities and no potentially toxic compounds were identified such as the neo-clerodane diterpenoids, commonly evidenced in the entire genus. This study could provide a phytochemical rationale for the possible ethnopharmacological use of this specific species

Comparative evaluation of subtyping tools for surveillance of newly emerging HIV-1 strains

HIV-1 non-B subtypes/circulating recombinant forms (CRFs) are increasing worldwide. Since subtype identification can be clinically relevant, we assessed the added value in HIV-1 subtyping using updated molecular phylogeny (Mphy) and the performance of routinely used automated tools. Updated Mphy (2015 updated reference sequences), used as a gold standard, was performed to subtype 13,116 HIV-1 protease/reverse transcriptase sequences and then compared with previous Mphy (reference sequences until 2014) and with COMET, REGA, SCUEAL, and Stanford subtyping tools. Updated Mphy classified subtype B as the most prevalent (73.4%), followed by CRF02-AG (7.9%), C (4.6%), F1 (3.4%), A1 (2.2%), G (1.6%), CRF12-BF (1.2%), and other subtypes (5.7%). A 2.3% proportion of sequences were reassigned as different subtypes or CRFs because of misclassification by previous Mphy. Overall, the tool most concordant with updated Mphy was Stanford-v8.1 (95.4%), followed by COMET (93.8%), REGA-v3 (92.5%), Stanford-old (91.1%), and SCUEAL (85.9%). All the tools had a high sensitivity (\ue2\u89\ua598.0%) and specificity (\ue2\u89\ua595.7%) for subtype B. Regarding non-B subtypes, Stanford-v8.1 was the best tool for C, D, and F subtypes and for CRFs 01, 02, 06, 11, and 36 (sensitivity, \ue2\u89\ua592.6%; specificity, \ue2\u89\ua599.1%). A1 and G subtypes were better classified by COMET (92.3%) and REGA-v3 (98.6%), respectively. Our findings confirm Mphy as the gold standard for accurate HIV-1 subtyping, although Stanford-v8.1, occasionally combined with COMET or REGA-v3, represents an effective subtyping approach in clinical settings. Periodic updating of HIV-1 reference sequences is fundamental to improving subtype characterization in the context of an effective epidemiological surveillance of non-B strains