Chemical constituents from the fruits of Sonneratia caseolaris and Sonneratia ovata (Sonneratiaceae)

Nine (1–9) and seven (1–6, 10) compounds were isolated from the fruits of Sonneratia caseolaris and Sonneratia ovata, respectively. Their structures were identified by comparing their MS and NMR data as well as the physical properties with the literature. All the isolated compounds were screened against a rat glioma C-6 cell line using the MTT assay method; only compounds (-)-(R)-nyasol (1), (-)-(R)-4′-O-methylnyasol (2) and maslinic acid (6) were found to show moderate cytotoxic activity. Our findings from these two kinds of fruits can be used as a foundation for further chemotaxonomic studies on Sonneratia species. The nor-lignans (1, 2) and 6H-benzo[b,d]pyran-6-one derivatives (3, 4) were isolated from this genus for the first time, indicating that these two classes of compounds may tentatively be considered as taxonomic markers for Sonneratia genus.     

Bioactive polyhydroxylated sterols from the marine sponge Haliclona crassiloba

Four new polyhydroxylated sterols, named halicrasterols A–D (1–4), together with six known analogs (5–10) were isolated from the marine sponge Haliclona crassiloba. Compounds 1 and 2 represented rare examples of steroids featuring 17(20)E-double bonds. The structures of 1–10 were elucidated by spectroscopic analysis and comparison with reported data. This is the first report of a steroid profile for this species. The antimicrobial activities of 1–10 were evaluated against a panel of bacterial and fungal strains in vitro, and compounds 4 and 9 showed moderate activity against some of the Gram-positive strains with MICs ranging from 4 to 32 μg/mL.     

Cycloartane glycosides from Astragalus aureus

Eight cycloartane-type triterpene glycosides (1-8) were isolated from Astragalus aureus Willd along with ten known cycloartane-type glycosides (9-18). Their structures were established by the extensive use of 1D and 2D-NMR experiments along with ESIMS and HRMS analyses. Compounds 1-5 are cyclocanthogenin glycosides, whereas compounds 6-8 are based on cyclocephalogenin as aglycon, more unusual in the plant kingdom, so far reported only from Astragalus spp. Moreover, for the first time monoglycosides of cyclocanthogenin (5) and cyclocephalogenin (7, 8) are reported. All of the compounds tested for their cytotoxic activities against a number of cancer cell lines. Among the compounds, only 8 exhibited activity versus human breast cancer (MCF7) at 45 μM concentration.     

Non-cannabinoid constituents from a high potency Cannabis sativa variety

Six new non-cannabinoid constituents were isolated from a high potency Cannabis sativa L. variety, namely 5-acetoxy-6-geranyl-3-n-pentyl-1,4-benzoquinone (1), 4,5-dihydroxy-2,3,6-trimethoxy-9,10-dihydrophenanthrene (2), 4-hydroxy-2,3,6,7-tetramethoxy-9,10-dihydrophenanthrene (3), 4,7-dimethoxy-1,2,5-trihydroxyphenanthrene (4), cannflavin C (5) and β-sitosteryl-3-O-β-d-glucopyranoside-2′-O-palmitate (6). In addition, five known compounds, α-cannabispiranol (7), chrysoeriol (8), 6-prenylapigenin (9), cannflavin A (10) and β-acetyl cannabispiranol (11) were identified, with 8 and 9 being reported for the first time from cannabis. Some isolates displayed weak to strong antimicrobial, antileishmanial, antimalarial and anti-oxidant activities. Compounds 2-4 were inactive as analgesics.     

Chemical constituents from Tsoongiodendron odorum Chun

The present study reports the isolation of sixteen lignans (1–16), an aporphine alkaloid (17), two phenolic amides (18 and 19), and a germacrane sesquiterpene lactone (20) from T. odorum. Except for compound 20, the other isolated constituents are firstly reported from T. odorum. And in this study, three polylignans (11–13) and six norlignans (5–7, 14–16) are reported for the first time from the Magnoliaceae family, which may support the opinion to establish Tsoongiodendron as a monotypic genus from a chemotaxonomical point of view.     

Guaiane type sesquiterpenes and other constituents from Daucus carota L.

In a chemosystematic investigation of the fruits of Daucus carota L. we have isolated eleven compounds including four guaiane type sesquiterpenes (1–4), one eudesmane type sesquiterpene (5) and six other constituents (6–11). Among them, the five compounds 1–5 all are new for Daucus carota L. and all have been reported in Torilis japonica. The results show that Daucus carota L. is chemically similar with Torilis japonica providing chemical evidence for both species used as the same traditional Chinese medicine “nanheshi”.     

Essential oil from leaves of Cryptocarya mandioccana Meisner (Lauraceae): Composition and intraspecific chemical variability

The composition of the essential oil from leaves of Cryptocarya mandioccana has been determined by chromatographic fractionation and GC–FID, GC–MS and ¹³C NMR analyses, yielding the identification of 64 compounds with predominance of isomeric sesquiterpenes with molecular weights of 204. The main components of the oil obtained by hydrodistillation were β-caryophyllene, spathulenol, caryophyllene oxide, δ-cadinene, germacrene D, benzaldehyde and bicyclogermacrene. However, the oil obtained by steam distillation contained higher levels of sesquiterpene hydrocarbons, with predominance of β-caryophyllene (C), germacrene D (G) and bicyclogermacrene (B), and was considered to be more representative of the composition of the oil in its natural state. The intraspecific chemical variability of the essential oil obtained by steam distillation was evaluated within populations of trees growing at three separate locations in the state of São Paulo, Brazil. Three distinct chemical groups could be characterised due to differences in the relative percentages of the three main sesquiterpenes from essential oil: CGB [relative contents of C (14–34%), G (5–28%), B (8–15%)], BCG [B (17–34%), C (9–24%), G (12–25%)] and GCB [G (22–42%), C (4–17%), B (7–15%)]. Individuals from groups CGB and BCG were found to be more frequent at south locations while group GCB is predominant in north location.     

Polyphenols from Potentilla recta

From the aerial parts of Potentilla recta, ten compounds were isolated including a neolignan glycoside (1) and nine flavonoids (2–10). The structures of the isolates were elucidated by spectroscopic properties. The presence of a neolignan glycoside in the genus Potentilla is being reported for the first time by this work. Furthermore, compounds 9 and 10 are characterized for the first time from the genus Potentilla. The chemotaxonomic importance of these compounds was also summarized.     

Osteogenic constituents from Pterospermum acerifolium Willd. flowers

Phytochemical investigation of ethanol extracts of the Pterospermumacerifolium flowers led to the isolation and identification of two new flavones, 4′-(2-methoxy-4-(1,2,3-trihydroxypropyl) phenoxy luteolin (1) and 5,7,3′-trihydroxy-6-O-β-d-glucopyranosyl flavone (2), and one new lactone, 3,5-dihydroxyfuran-2(5H)-one (3) along with 14 known compounds (4-17). The structure of compounds 1-17 was established based on MS, 1D and 2D NMR, spectroscopic analysis. Eight of these compounds (1-6, 8 and 9) were assessed for osteogenic activity by using primary cultures of rat osteoblast. The compounds 1, 3 and 4 significantly stimulated osteoblast differentiation and mineralization as evident from a marked increase in expression of alkaline phosphatase and alizarin red-S staining of osteoblasts.     

Itaconic acid derivatives and diketopiperazine from the marine-derived fungus Aspergillus aculeatus CRI322-03

Three metabolites, pre-aurantiamine (1), (−)-9-hydroxyhexylitaconic acid (4) and (−)-9-hydroxyhexylitaconic acid-4-methyl ester (5), together with two known compounds, paraherquamide E (6) and secalonic acid D (7), were isolated from the marine-derived fungus, Aspergillus aculeatus.     

Cinnamate derivatives of fructo-oligosaccharides from Lindelofia stylosa

Phytochemical investigation on the whole plants of Lindelofia stylosa (Kar. and Kir.) has led to the isolation of eight fructo-oligosaccharide cinnamate esters 1-8. Six new compounds 1, 2, and 5-8 were isolated from the butanol extract of the plant. Compounds 1-4 belong to sucrose derivatives, while compounds 5-6 and 7-8 belong to 1-kestose- and nystose-type oligosaccharides, respectively. The fructo-oligosaccharides have been obtained from L. stylosa for the first time.     

Ecdysteroids and a sucrose phenylpropanoid ester from Froelichia floridana

Phytoecdysteroid glycosides (1-5) and a phenylpropanoid ester of sucrose (6) were isolated from the whole plant of Froelichia floridana, along with eight known compounds including three ecdysteroids (7-9), four flavonoids (10-13), and one phenolic compound (14). Structures were determined using a combination of spectroscopic techniques. Compounds 1, 2 and 6-14 were tested in vitro for their activity against human DNA topoisomerase I. Compound 13 (diosmetin) showed marginal inhibition against topoisomerase I with IC₅₀ of 130 μM in conjunction with low intercalation ability.     

Discovery of novel ureas and thioureas of 3-decladinosyl-3-hydroxy 15-membered azalides active against efflux-mediated resistant Streptococcus pneumoniae

A series of novel ureas and thioureas of 3-decladinosyl-3-hydroxy 15-membered azalides, were discovered, structurally characterized and biologically evaluated. They have shown good antibacterial activity against selected Gram-positive and Gram-negative bacterial strains. These include N″ substituted 9a-(N′-carbamoyl-γ-aminopropyl)- (6a,c), 9a-(N′-thiocarbamoyl-γ-aminopropyl)- (7a,e), 9a-[N′-(β-cyanoethyl)-N′-(carbamoyl-γ-aminopropyl)]- (9a-c, 9g) 9a-[N′-(β-cyanoethyl)-N′-(thiocarbamoyl-γ-aminopropyl)]-derivatives (10d-f) of 5-O-desosaminyl-9-deoxo-9-dihydro-9a-aza-9a-homoerythronolide A (3).Among the synthesized compounds thiourea 7a and urea 9b have shown substantially improved activity comparable to azithromycin (1) and significantly better activity than the 3-decladinosyl-azithromycin (2) and the parent 3-cladinosyl analogues against efflux-mediated resistant S. pneumoniae.     

Ecdysteroids from Polypodium vulgare L

Three new compounds (3, 7, and 11) together with eight known phytoecdysteroids (1, 2, 4-6, and 8-10) were isolated from the rhizomes of common polypody, Polypodium vulgare L. The structures of compounds were elucidated by spectroscopic methods including 1D and 2D NMR measurements. The ¹H and ¹³C NMR assignments of compounds 1, 6, 9 and 10 are included.     

Synthesis and evaluation of the antioxidative potential of minoxidil–polyamine conjugates

A series of conjugates (MNX–CO–PA) of minoxidil (MNX) with the polyamines (PAs) putrescine (PUT), spermidine (SPD) and spermine (SPM) as well as dopamine were produced through activation of MNX with N,N′-carbonyldiimidazole, followed by reaction with dopamine or selectively protected PAs and acid-mediated deprotection. These conjugates together with conjugates of the general type MNX–PA or PA–MNX–PA, readily produced using literature protocols, were tested as antioxidants. The most potent inhibitors of lipid peroxidation were the conjugates MNX–SPM (2, 94%), SPM–MNX–SPM (4, 94%) and MNX–N⁴-SPD (7, 91%) and MNX (91%). The most powerful lipoxygenase (LOX) inhibitors were MNX (IC₅₀ = 20 μM) and the conjugates MNX–N⁸-SPD (9, IC₅₀ = 22.1 μM), MNX–CO–dopamine (11, IC₅₀ = 28 μM) and MNX–N¹-SPD (8, IC₅₀ = 30 μM). The most interesting conjugates 2, MNX–CO–PUT (5), 8 and 11 as well as MNX were generally found to exhibit weaker (22–36.5%) or no (conjugate 8) anti-inflammatory activity than indomethacin (47%) with the exception of MNX which showed almost equal potency (49%) to indomethacin. The cytocompatibility of conjugates and MNX at the highest concentration of 100 μM showed a survival percentage of 87–107%, with the exception of conjugates with SPM (compound 2) and MNX–CO–SPM (6), which showed considerable cytotoxicity (survival percentage 8–14%). Molecular docking studies were carried on conjugate 9 and the parent compound MNX and were found to be in accordance with our experimental biological results.     

Synthesis of 4,6-dideoxy-3-fluoro-2-keto-β-d-glucopyranosyl analogues of 5-fluorouracil, N-benzoyl adenine, uracil, thymine, N-benzoyl cytosine and evaluation of their antitumor activities

The synthesis of the unsaturated 4,6-dideoxy-3-fluoro-2-keto-β-d-glucopyranosyl nucleosides of 5-fluorouracil (6a), N⁶-benzoyl adenine (6b), uracil (6c), thymine (6d) and N⁴-benzoyl cytosine (6e), is described. Monoiodination of compounds 1a,b, followed by acetylation, catalytic hydrogenation and finally regioselective 2′-O-deacylation afforded the partially acetylated dideoxynucleoside analogues of 5-fluorouracil (5a) and N⁶-benzoyl adenine (5b), respectively. Direct oxidation of the free hydroxyl group at the 2′-position of 5a,b, with simultaneous elimination reaction of the β-acetoxyl group, afforded the desired unsaturated 4,6-dideoxy-3-fluoro-2-keto-β-d-glucopyranosyl derivatives 6a,b. Compounds 1c-e were used as starting materials for the synthesis of the dideoxy unsaturated carbonyl nucleosides of uracil (6c), thymine (6d) and N⁴-benzoyl cytosine (6e). Similarly a protection-selective deprotection sequence followed by oxidation of the free hydroxyl group at the 2′-position of the dideoxy benzoylated analogues 9c-e with simultaneous elimination reaction of the β-benzoyl group, gave the desired nucleosides 6c-e. None of the compounds was inhibitory to a broad spectrum of DNA and RNA viruses at subtoxic concentrations. The 5-fluorouracil derivative 6a was more cytostatic (50% inhibitory concentration ranging between 0.2 and 12 μM) than the other compounds.     

Antioxidant activity of a new C-glycosylflavone from the leaves of Ficus microcarpa

By bioactive-guided fractionation of methanol extract of the Ficus microcarpa leaves, one new C-glucosylflavone, ficuflavoside (1), one new megastigmane glycoside, ficumegasoside (8), and twelve known compounds including flavonoids (2-6), phenylpropanoids (7), megastigmanes (9-11) and sterol derivatives (12-14) were isolated. Their chemical structures were elucidated by mass, 1D, and 2D NMR spectroscopies. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity methods. Compounds 1-6 exhibited potent antioxidant activities of 6.6-9.5 μM Trolox equivalents at the concentration of 2.0 μM. The results indicated 2, 3, and 5 having meaningful reducing capacity of copper (I) ions concentration of 6.1-8.4 μM.     

New bufadienolides and C23 steroids from the venom of Bufo bufo gargarizans

Six new bufadienolides (1-6) and two new C₂₃ steroids (7 and 8), together with three known compounds (9-11) were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated by spectroscopic analysis and single-crystal X-ray diffraction. In vitro cytotoxicities of all compounds were evaluated in A549 cancer cell line. Compounds 2, 3 and 10 showed significant cytotoxic activities.     

Phenolic compounds with NF-κB inhibitory effects from the fungus Phellinus baumii

Chemical investigation of the fungus Phellinus baumii has resulted in characterization of five previously undescribed hispidin derivatives, phellibaumins A-E (1-5), as well as two pairs of new non-equivalent epimeric benzyl dihydroflavones, methylphelligrin A (9), epi-methylphelligrin A (10), methylphelligrin B (11), and epi-methylphelligrin B (12), together with five known compounds, interfungin B (6), phelligridin H (7), phelligridimer A (8), phelligrin A (13), and epi-phelligrin A (14). Phellibaumin A (1) was a novel hispidin derivative with a unique 3,4-dihydroxybenzofuran unit. These compounds exhibited NF-κB inhibitory activity with IC₅₀ values of 52.96 μM (1), 41.40 μM (2), 52.92 μM (5), 36.44 μM (9 and 10), and 22.46 μM (11 and 12), respectively.     

Contrasting chemistry of fruits and leaves of two Pseudowintera species: Sesquiterpene dialdehyde cinnamates and prenylated flavonoids

Two new sesquiterpene dialdehydes, cinnamate 7 and coumarate 8, were isolated from the fruits of Pseudowintera colorata. The known sesquiterpene dialdehydes polygodial 1 and 9-deoxymuzigadial 2 were also found in these fruits, at 5% w/w compared to 0.5% in the leaves. Fruits of Pseudowintera axillaris contained no sesquiterpene dialdehyde cinnamates, even though these are present in the leaves, but did contain prenylated flavanones 11–13. Compounds 7 and 8 are further examples of the rare sesquiterpene dialdehyde cinnamate combination, found exclusively in the family Winteraceae. This is the first report of the uncommon prenylated flavanones in Winteraceae.