Iridoid mono- and di-glycosides in Mentzelia

Eight species of Mentzelia (Loasaceae) have been investigated for iridoid glycosides. In addition to the known glucosides deutzioside, decaloside, mongolioside, loganin and sweroside, several novel compounds have been isolated and characterized by chemical and spectroscopic means. 6′-O-Acetyl deutzioside was found in a single species, while the diglycosidic compounds glucosyl-decaloside, allosyl-decaloside and quinovosyl-decaloside were each isolated from one or more species. In addition, a novel compound, epoxydecaloside (= 11-hydroxy-deutzioside), together with glucosyl-epoxydecaloside, allosyl-epoxydecaloside and mentzelosyl-epoxydecaloside are described. The last compound contains a 4-deoxy-α-l-erythro-pentopyranosyl moiety, whose parent sugar, named mentzelose, has not been encountered so far in nature. A non-glycosidic iridoid, mentzetriol, has been characterized solely by spectroscopic means and a structure is proposed. The secoiridoid secoxyloganin has been found for the first time in a plant source, and the coumarin glucoside scopolin has been isolated from two species of Mentzelia. ¹³C and ¹H NMR spectra of several iridoid compounds are presented. The biosynthesis of the compounds is considered and the systematic position of Loasaceae discussed concluding in a possible derivation from Cornalean ancestors.     

Cytotoxic components of Zingiber zerumbet,Curcuma zedoaria and C. domestica

One new and five known compounds, which all showed cytotoxic activity, were isolated from the rhizomes of Zingiber zerumbet. The new compound was 3″,4″-O-diacetylafzelin. The known compounds were zerumbone, zerumbone epoxide, diferuloylmethane, feruloyl-p-coumaroylmethane and di-p-coumaroylmethane. Several substituted cinnamoylmethanes were synthesized and tested for cytotoxic properties. Among these were tricinnamoylmethane and triferuloylmethane. The structures were elucidated mainly by spectroscopic methods and ¹³C NMR data are given.     

Two new pyrrole derivatives isolated from Salacia amplifolia Merr

Two new pyrrole derivatives Salaciamole (1), Salaciaglycoside A (2), long with one known compound 1H-pyrrole-3-carboxylic acid (3) were isolated from the roots of Salacia amplifolia Merr (Hippocrateaceae). The structures of the new compounds were deduced from their comprehensive spectroscopic analysis including IR, HR-EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC. And the structure of the known compound was identified by comparison of their spectral data with those reported in the literature.     

A new sesquiterpenoid from Sclerorhachis platyrachis (Boiss.) Podlech ex Rech.f

A new eudesmane-type sesquiterpenoid together with two known flavonoids were isolated from the chloroform extract of the aerial part of Sclerorhachis platyrachis. The structure of the new compound was deduced from its comprehensive spectroscopic analysis including IR, EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC and was shown to be 4R^*-hydroxy-6S^*-tigloyloxyeudesma-7S^*-11 (13)-en-12-oic acid (1). Finally, the structure of the new compound was unambiguously confirmed by single-crystal X-ray analysis. The structure of known compounds 2 and 3 were identified by comparison of their spectral data with those reported in the literature.     

Nematicidal metabolites from the fungusPleurotus ferulae Lenzi

Pleurotus ferulae Lenzi, a species of edible fungus, was found to have nematicidal activity in experiments searching for nematicidal fungi. Three nematicidal metabolities cheimonophyllon E (compound 1), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (compound 2) and 5-hydroxymethyl-furancarbaldehyde (compound 3) were isolated based on bioassay-guided fractionation from the extracts of the fungusP. ferulae. Their structures were determined by spectroscopic data. All of them showed activities against nematodesBursaphelenchus xylophilus (Steiner et Buhrer) Nickle andPanagrellus redivivus (Linn.) Goodey. The median lethal concentrations (LC₅₀) of compounds 1, 2 and 3 at 72 h were 70.8, 174.6, and 54.7 mg L^?1 respectively againstB. xylophilus and were 125.6, 128.1, and 82.8 mg L^?1 respectively againstP. redivivus. The three compounds were obtained fromP. ferulae for the first time.     

Further pyrrolizidine alkaloids and furoeremophilanes from Senecio species

The investigation of 17 Senecio species afforded in addition to 14 known pyrrolizidine alkaloids 20 new ones, including some compounds of a novel type with an additional lactone moiety. Furthermore seven known and 11 new furoeremophilanes, two known and a new eremophilone, a further shikimic acid derivative and an acetylenic compound, most likely formed by intramolecular Diels-Alder reaction were isolated. The structures were elucidated by spectroscopic methods, especially high field ¹H and ¹³C NMR and NOE difference spectroscopy. The configuration of the seneremophilondiol esters has been corrected.     

A new phenolic acid from Zanthoxylum nitidum var. tomentosum (Rutaceae) and its chemotaxonomic significance

A new compound, nitomentosin (1), along with sixteen known compounds (2–17), were isolated from Zanthoxylum nitidum var. tomentosum (Rutaceae). The structure of compound 1 including absolute configurations was determined by detailed spectroscopic information (HRESIMS and NMR) and from the electronic circular dichroism (ECD) spectra. From the present investigation, compound 3 is a new natural compound although it has been reported previously as a synthetic substance, and compound 15 is found for the first time in a plant. All these compounds except 2, 5–10 and 12 were isolated from Z. nitidum for the first time. Furthermore, the chemotaxonomic significance of the isolated compounds is discussed.     

Epiphorellic acids 1 and 2, two diaryl ethers from the lichen Cornicularia epiphorella

From the lichen Cornicularia epiphorella two new diaryl ethers, epiphorellic acids 1 and 2, were isolated besides the known compound atranorin. The structures of the new compounds were established by spectroscopic evidence and chemical transformations. The structure of epiphorellic acid 1 was also confirmed by correlation with a known compound.     

Grayanotoxin-XVIII and grayanoside B,a new a-nor-b-homo-ent-kaurene and its glucoside from Leucothoe grayana

From Leucothoe grayana a new grayanoid (diterpene) and its glucoside have been isolated. The structures of these new natural compounds have been established by chemical and spectroscopic means and by correlation with a known compound.     

New tirucallane triterpenoids from Picrasma quassioides with their potential antiproliferative activities on hepatoma cells

Seven new tirucallane-type triterpenoids (1–7), kumuquassin A-G, along with 20 known analogues (8–27) were isolated from the stems of Picrasma quassioides. The structures and the absolute configurations of new compounds were elucidated by spectroscopic data, electronic circular dichroism (ECD) spectroscopic analyses and quantum ECD calculations. Notably, kumuquassin A (1) contains a rare Δ^{17, 20} double bond, kumuquassin B (2) is the first example of tirucallane triterpenoid possessing a 5/3 biheterocyclic ring system at the side chain. All the compounds were screened for the cytotoxicity against two human hepatoma cell lines, HepG2 and Hep3B, and several compounds exhibited promising activity. The most potential compound 3 was selected for cell cycle analysis, which showed that 3 could cause an accumulation of HepG2 cells at subG1 peak. Annexin V-FITC/PI staining further confirmed that compound 3 caused death of hepatoma cells through apoptosis induction.     

Triterpenoids from Cassine xylocarpa and Celastrus vulcanicola (Celastraceae)

Two new pentacyclic triterpenoids, xyloketal (1), a 3,25-epoxy-olean-12-ene, and 3β,21α-dihydroxyglut-5-ene (2) along with seven known triterpene compounds (3–9) were isolated from the root barks of Cassine xylocarpa and Celastrus vulcanicola. Their structures were characterized by spectroscopic methods, mainly NMR (¹H, ¹³C, HSQC, HMBC and ROESY) and EIMS, and comparison with data reported in the literature. Also molecular mechanic calculations were used to calculate the minimum energy conformer of compound 1 and its epimer.     

Catenulisporidins A and B, 16-membered macrolides of the hygrolidin family produced by the chemically underexplored actinobacterium Catenulispora species

Two new macrolide metabolites of the hygrolidin family, catenulisporidins A and B (1 and 2), together with a known compound hygrolidin (3), were isolated from the culture broth of the rare actinobacterium Catenulispora sp. KCB13F192. Their structures were elucidated on the basis of HRESIMS spectrometric and NMR spectroscopic analyses. Catenulisporidins A and B are the first example of natural hygrolidin and bafilomycin derivatives featuring a modified macrolide ring, and catenulisporidin A possesses a tetrahydrofuran ring through an ether linkage between C-7 and C-10. In cell-based fluorescent imaging and immunoblot assays, the three compounds were shown to inhibit autophagic flux in HeLa cells.     

Bioactivity-guided isolation of antiproliferative compounds from Centaurea carduiformis DC

In this study, antiproliferative activity of methanol extract of Centaura carduiformis DC. subsp. carduiformis var. carduiformis DC (CC) was examined against Vero, HeLa and C6 cell lines in 1000 and 500 μg/mL concentrations using the BrdU ELISA assay. The CC root (CCR) has the most effective antiproliferative activity. The root extract was fractionated using various solvent and determined antiproliferative activities. Two new and two known flavonoids were isolated from CC roots. The isolated known compound of 7-O-β-d-glucopyranosyl-4′-methylapigenin and new compound of 7-O-β-d-6″-O-glucopyranosyl-6″-O-β-d-furanosylpinocembrin were isolated from the ethyl acetate fractions. However, wogonin and new compound of N-(pentyloxy(m-tolyl)methyl)acetamideisowogonin were obtained from chloroform fractions. The chemical structures of pure compounds were elucidated with different chemical and spectroscopic methods (IR, ¹H NMR, ¹³C NMR, HETCOR, COSY, GC-MS, etc.) and their antiproliferative activities were determined against Vero, HeLa and C6 cell lines. The IC₅₀ results showed that the compound 4 has the highest activity against Vero (250 μg/mL) and HeLa (735 μg/mL) cell lines than isolated other compounds from determined values.     

Thiolytic cleavage of the anti-tumour compound 4′-(9-acridinylamino)-methanesulphon-m-anisidine (m-AMSA,NSC 156 303) in blood

4′-(9-acridinylamino)methanesulphon-m-anisidide (m-AMSA), a compound with a broad spectrum of experimental anti-tumour activity, was found to have a short biological half-life in mice bearing L1210 leukaemia. The fate of m-AMSA [³H]-labelled in the acridine nucleus, was determined following injection into mice. There was rapid formation of covalent adducts with plasma proteins. Adducts were also formed in freshly isolated blood samples following incubation at 37°C, and were found to be highly fluorescent. The formation of adducts was accompanied by a decrease in the free thiol concentration in plasma, and the concomitant addition of radioactivity from [³H]acridine nuclei. Acid or alkaline hydrolysis of the plasma protein adduct liberated acridone, while digestion with a protease produced unstable fluorescent compounds. A comparison of the rates of acid hydrolysis of the adducts and of model compounds suggested that the adducts were produced as a result of nucleophilic attack at the C-9 position of m-AMSA by protein thiol groups. The side chain of m-AMSA was liberated as 4-amino-3-methoxymethanesulphonanilide. Several congeners of m-AMSA were shown to form similar or identical adducts both in vivo and in vitro, and at rates which correlated with their reactivity towards simple organic thiols.     

A new C21 steroidal compound from the whole herb of Pachysandra terminalis Sieb. et Zucc

A new C21 steroidal compound (1), along with 12 known compounds (2–13) were isolated from the whole herb of Pachysandra terminalis Sieb. et Zucc. Their structures were determined by extensive analysis using various spectroscopic techniques. Notably, compound 6 was reported for the first time from P. terminalis, and compounds 3–5, 7 and 9 were isolated from the family Buxaceae for the first time.     

Eudesmane derivatives from cyperus corymbosus

From the rhizomes of Cyperus corymbosus a new eudesmane sesquiterpenoid, isocorymbolone, was isolated besides the known compounds corymbolone and (+)-α-cyperone. The structure of the new compound was established by means of spectroscopic methods.     

Identification of a Peptide-like Compound with Antimicrobial and Trypsin Inhibitory Activity from Seeds of Bottle Gourd (Lagenaria siceraria)

A low molecular mass peptide like compound with antimicrobial and trypsin inhibitory activity was isolated from the seeds of Lagenaria siceraria. It was purified by ion-exchange and reverse-phase chromatography. The molecular weight of the compound was 678.9 Dalton as determined by MALDI-MS. The infra-red absorbance at 1639 cm^?1, characteristic of an amide bond, by FTIR spectroscopic studies, and absorption at 214 nm on spectrophotometer indicates the peptidic nature of the compound. The compound exhibited antimicrobial activity when tested against Escherichia coli with minimum inhibitory concentration of 20 μM, and trypsin inhibitory activity inhibiting trypsin at a molar ratio of 1:2.     

Chemical constituents from Nuxia congesta and their chemotaxonomic significance

A phytochemical investigation of the aerial parts of Nuxia congesta led to the isolation and identification of fifteen compounds, including a new flavonoid, nuxiacin (5-hydroxy-3,8-dimethoxy flavone-7-O-β-D-glycopyranoside) (1). The structure of the new compound was determined using various spectroscopic data including 1D and 2D NMR and mass spectroscopy. All compounds were isolated from N. congesta for the first time. The chemotaxonomic significance of the isolated compounds in the family Stilbaceae and order Lamiales are discussed herein.     

Tropane alkaloids from Schizanthus grahamii

Three new tropanol dimers of mesaconic and itaconic acids and 3α-senecioyloxytropane, together with other known alkaloids, were isolated from Schizanthus grahamii. The structures of the new compounds were established by spectroscopic and chemical transformations including 2-D long-range ¹³C-¹H correlations.     

Ganoderic acid derivatives and ergosta-4,7,22-triene-3,6-dione from Ganoderma lucidum

Seven new triterpenoids, ganoderic acid T, ganoderic acid S, ganoderic acid R, ganoderic acid P, ganoderic acid Q, ganoderic acid 0, 7-O-methyl-ganoderic acid 0 and a known ergosterol derivative, ergosta-4,7,22-triene-3,6-dione were isolated from the cultured mycelium of Ganoderma lucidum. The structure of the first compound was determined using spectroscopic and X-ray analysis, and the structures of the other compounds were elucidated by spectroscopic data.