Hydrocortisone (HC) is widely utilized in the pharmaceutical field for various administration routes, including oral, parenteral, and topical routes. However, its application in ocular disease treatment as a solution is limited due to its poor aqueous solubility. To address this limitation, in this study we aimed to investigate different types of cyclodextrins (CDs) to identify the most effective CD for improving the inherent solubility of HC. Results from scanning electron microscopy, rheology and differential scanning calorimetry (DSC) demonstrated the formation of inclusion complexes, while isothermal titration calorimetry (ITC) investigations accurately determined the thermodynamic parameters associated with the formation of complexes between HC and HP beta CD or beta CD, at 25 and 37(degrees)C. Additionally, phase solubility studies in PBS buffer at 37(degrees)C confirmed the formation of stable inclusion complexes. Collectively, results indicated that HP beta CD was the most effective CD in enhancing the intrinsic solubility of HCs in PBS highlighting its potential for improving the solubility and formulation of HCbased pharmaceutical products.

Chemical analysis of the Indonesian sponge Plakortis cfr. lita afforded two new analogues of the potent trypanocidal agent manadoperoxide B (1), namely 12-isomanadoperoxide B (2) and manadoperoxidic acid B (3). These compounds were isolated along with a new short chain dicarboxylate monoester (4), bearing some interesting relationships with the polyketide endoperoxides found in this sponge. Some semi-synthetic analogues of manadoperoxide B (6-8) were prepared and evaluated for antitrypanosomal activity and cytotoxicity. These studies revealed crucial structure-activity relationships that should be taken into account in the design of optimized and simplified endoperoxyketal trypanocidal agents.

Chemical investigation of the marine sponge Plakortis cfr. lita afforded a library of endoperoxyketal polyketides, manadoperoxides B-K (3-5 and 7-13) and peroxyplakoric esters B(3) (6) and C (14). Eight of these metabolites are new compounds and some contain an unprecedented chlorine-bearing THF-type ring in the side chain. The library of endoperoxide derivatives was evaluated for in vitro activity against Trypanosoma brucei rhodesiense and Leishmania donovani. Some compounds, such as manadoperoxide B, exhibited ultrapotent trypanocidal activity (IC(50) = 3 ng mL(-1)) without cytotoxicity. Detailed examination of the antitrypanosomal activity data and comparison with those available in the literature for related dioxane derivatives enabled us to draw a series of structure-activity relationships. Interestingly, it appears that minor structural changes, such as a shift of the methyl group around the dioxane ring, can dramatically affect the antitrypanosomal activity. This information can be valuable to guide the design of optimized antitrypanosomal agents based on the dioxane scaffold.

Apart from large amounts of cannabidiol, the known stilbenoids 1–4 and the oxylipins 7 and 8, a fibre cultivar of Cannabis sativa derived from the historical Carmagnola variety gave the novel spiranic stilbenoid isocannabispiradienone (5) and the biphenyl-type cannabinoid cannabioxepane (CBX, 6), a tetracyclic compound characterized by an unprecedented C-5/C-8′ oxygen bridge and devoid of cannabinoid activity. Structures were established by analysis of MS and NMR data, and the biogenetic derivation of the new compounds is discussed.

In our search for new antimalarial agents inspired by natural products, we describe herein the synthesis, the evaluation of in vitro antiplasmodial activity, and the SAR studies for a series of endoperoxide antimalarials based on the plakortin scaffold. These simplified analogues are characterized by: (i) a 3,6-dihydro-1,2-dioxin ring or a 1,2-dioxane ring disubstituted at C-4 and C-5; (ii) a pentyl substituent at C-6 (‘western’ alkyl side chain) and they have been prepared from commercially available material using simple reactions.

The new endoperoxyketal polyketides manadoperoxides A-D (2-5) have been isolated from the Indonesian sponge Plakortis cfr. simplex and their stereostructures established by means of spectroscopic data and semisynthetic transformations. Manadoperoxides were assayed in vitro against D10 and W2 strains of Plasmodium falciparum and showed moderate antimalarial activity compared to that of plakortin (1) and peroxyplakoric B(3) ester (9), the latter differing from manadoperoxide B only by minor structural details. This unexpected difference in the antimalarial activity has been rationalized on the basis of our recently published model for the interaction of 1,2-dioxanes with heme and production of C-centered radicals toxic to the parasite. For the manadoperoxides, either the endoperoxide linkage is inaccessible to the heme iron or the O1 radical cannot evolve to produce a C-centered radical.

In the present study,13 bromopyrrole alkaloids, including the oroidin analogs hymenidin (2), dispacamide B (3) and dispacamide D (4), stevensine (5) and spongiacidin B (6), their derivatives lacking the imidazole ring bromoaldisin (7), longamide B (8) and longamide A (9), the dimeric oroidin derivatives sceptrin (10) and dibromopalau’amine (11), and the non-oroidin bromopyrrolohomoarginin (12), manzacidin A (13), and agelongine (14), obtained from marine sponges belonging to Axinella and Agelas generahave been screened in vitro against four parasitic protozoa, i.e., two Trypanosoma species (T. brucei rhodesiense and T. cruzi), Leishmania donovani and Plasmodium falciparum (K1 strain, a chloroquine resistant strain), responsible of human diseases with high morbidity and, in the case of malaria, high mortality. Our results indicate longamide B (8) and dibromopalau’amine (11) to be promising trypanocidal and antileishmanial agents, while dispacamide B (3) and spongiacidin B (6) emerge as antimalarial lead compounds.In addition,evaluation of the activity of the test alkaloids (2–14) against three different enzymes (PfFabI, PfFabG, PfFabZ) involved in the de novo fatty acid biosynthesis pathway of P. falciparum (PfFAS-II) identified bromopyrrolohomoarginin (12) as a potent inhibitor of PfFabZ. The structural similarity within the series of tested molecules allowed us to draw some preliminary structure-activity relationships. Tests against the mammalian L6 cells revealed important clues on therapeutic index of the metabolites. This is the first detailed study on the antiprotozoal potential of marine bromopyrrole alkaloids.

The cover picture shows the formula of cannabimovone, a cannabinoid with a rearranged terpenoid skeleton isolated from an industrial strain of hemp derived from the old Italian variety Carmagnola. The trade of this exceptionally tall plant (up to 5–6 m) from the homonymous Piedmontese town at the foot of the Monviso mountain (see the painting at the right) to Marseille in France was at the origin of the French revolutionary song and dance la Carmagnole . The picture shows the cultivation of Carmagnola hemp at the foot of the Vesuvio, exemplifying the collaboration between the Italian groups from Campania and Piedmont who report the discovery of cannabimovone on p. 2067 ff. The authors acknowledge Mrs. Maria Rosa Gaude for the painting, Assocanapa (Carmagnola) and Dr. Nicola Ghietti for the pictures and their help, and Dr. Alberto Massarotti for the cover page design.

An investigation of the polar fractions from a nonpsychotropic variety of hemp (Cannabis sativa L.) afforded cannabimovone (6), a polar cannabinoid with a rearranged 2(3 -> 4) abeo-terpenoid skeleton, biogenetically originating from the intramolecular aldolization of a 2',3'-seco-menthanyl precursor. The structure of cannabimovone was elucidated by spectroscopic analysis, whereas attempts to mimic its biogenetic derivation from cannabidiol (2) gave only anhydrocannabimovone (12), the intramolecular oxy-Michael adduct of the crotonized version (11b) of the elusive natural products. Biological evaluation of cannabimovone (6) against metabotropic (CB1, CB2) and ionotropic (TRPs) cannabinoid receptors showed a significant activity only for ionotropic receptors, especially TRPV1, whereas anhydrocannabimovone (12) exhibited strong activity at both ionotropic and metabotropic cannabinoid receptors. Overall, the biological profile of anhydrocannabimovone (12) was somewhat similar to that of THC (4), suggesting a remarkable tolerance to constitutional and configurational changes.

A multidisciplinary approach, based on molecular dynamics/mechanics, ab initio calculations, dynamic docking studies, and chemical reactions, has been employed to gain insight into the mechanism of the antimalarial action of plakortin and dihydroplakortin, simple 1,2-dioxanes isolated from the sponge Plakortis simplex. Our results show that these molecules, after interaction of the endoperoxide bond with Fe(II), likely coming from the heme molecule, give rise to the formation of an oxygen radical, followed by rearrangement to give a carbon radical centered on the "western" alkyl side-chain. The carbon radicals generated on the side-chain, amenable for intermolecular reactions, should represent the toxic intermediates responsible for subsequent reactions leading to plasmodium death. The minimal structural requirements necessary for the activity of this class of antimalarial agents have been identified and discussed throughout the paper.

The chlorinated polyene aurantoic acid (1) and the 4-methylene sterol dehydroconicasterol (2) were isolated from the Indonesian sponge Theonella swinhoei, and their structures were elucidated by interpretation of spectroscopic data. Aurantoic acid is a unique member in the class of naturally occurring conjugated polyene derivatives, while dehydroconicasterol is the likely biogenetic precursor of the major Theonella 4-methylene sterols.

Chemical analysis of the secondary metabolites of the Caribbean sponge Plakortis simplex, a source of many bioactive compounds, showed the presence of the new metabolite simplexidine (4), belonging to the extremely rare class of 4-alkyl-pyridinium alkaloids. The structural characterization of this molecule, based on spectroscopic methods, is reported.