Records of Natural Products Articles

A benzophenone, 2,2’,5,6’-tetrahydroxybenzophenone (1), and one xanthone, 5-hydroxy-3-methoxyxanthone (2), were newly described as natural products from the leaves and the stem barks of Hypericumlanceolatum, along with the known compounds friedelin (3), betulinic acid (4), allanxanthone A (5), 1,3,6-trihydroxyxanthone (6), isogarcinol (7), sitosterol 3-O- β -D-glucopyranoside (8), 1-hydroxy-6-methoxyxanthone (9), 6,7-dihydroxy-1,3-dimethoxyxanthone (10), 3-hydroxy-5-methoxyxanthone (11), 1,7-dihydroxy-3,6-dimethoxyxanthone (12) and calophyllumin A (13). Their structures were elucidated by spectroscopic means and comparison with published data.

In this study, two Sideritis species, endemic to Turkey, S. niveotomentosa Huber – Morathii, S.brevidens P.H. Davis have been studied for their diterpenic compounds and the antioxidant properties. Eight known diterpenoids, which have ent-kaurene skeleton, were isolated from acetone and methanol extracts of these species. The structures of the isolated diterpenes were determined by using the NMR ( 1H-NMR, 13C-NMR, COSY, HMQC, and HMBC ) spectroscopy. The analysis of the phenolic compounds of the extracts was performed by high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Also the antioxidant capacity of the extracts was investigated namely by two methods; free radical scavenging and β-carotene bleaching activities.

I The dried rhizome of Belamcanda chinensis is an important Chinese traditional medicine used for the treatment of inflammation and many other disorders. Previously, we reported the hypo- and antihyper-glycemic effects of the aqueous leaf extract of B. chinensis (BCL) and identified the isoflavones as its principal active fraction. In the present study, the α-glucosidase inhibitory effect of BCL and its rough isoflavone preparation (BIF) was tested in vitro and in vivo. Thirteen isoflavones were isolated from BCL and their α-glucosidase inhibitory activity was screened in vitro. The results showed that BCL (500 and 1000 mg/kg) and BIF (250 and 500 mg/kg) greatly inhibited the increase in blood glucose level after 5 g/kg starch loading in normal mice. Six out of the thirteen isoflavones (swertisin, 2 ” -O-rhamnosylswertisin, genistein, genistin, mangiferin and daidzin) exhibited strong α-glucosidase inhibitory activity in vitro. HPLC analysis showed that swertisin was the most abundant isoflavone in BCL accounting for 1.24% of BCL, 7.44% of BIF, and 11.24% of the total isoflavone fraction of BCL, respectively. These results demonstrate that BCL possesses significant α-glucosidase inhibitory activity and swertisin may be the principal active component of BCL in α-glucosidase inhibition.

 A new natural product, cytochalasin H2 (1), together with cytochalasin H (2) were obtained from the agar cultures of the strain Xylaria sp. A23, which was isolated from Annona squamosa. The chemical structures of them were elucidated by spectroscopic and mass spectrometric analyses, including 1D-, 2D-NMR and HR FTMS. Compound 1 showed week cytotoxicity against HeLa and 293T cell lines by MTT assay.

Three samples of Artemisia absinthium were collected from two different locations in the central-south of Tajikistan. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. A total of 41 compounds were identified representing 72-94% of total oil compositions. The major components of A. absinthium oil were myrcene (8.6-22.7%), cis-chrysanthenyl acetate (7.7-17.9%), a dihydrochamazulene isomer (5.5-11.6%), germacrene D (2.4-8.0%), β-thujone (0.4-7.3%), linalool acetate (trace-7.0%), α-phellandrene (1.0-5.3%), and linalool (5.3-7.0%). The chemical compositions of A. absinthium from Tajikistan are markedly different from those from European, Middle Eastern, or other Asian locations and likely represent new chemotypes.

Essential oils have increasing importance in flavour and fragrance industries. They are obtained by distillation techniques. In order to produce an oil with market potential its optimum production parameters have to be well known prior to its commercial production. Determination of the steam distillation parameters of commercially available Laurel leaves oil in pilot plant scale is described. The effect of steam rate and processing time play a major role in distillation of essential oils. Distillation speed was high in the beginning of the process, then gradually reduced as the distillation proceeded. The main component of the oil of Laurel leaf oil was 1,8-cineole accumulating significantly in the early fractions.

The leaves of Lantana camara L. (Verbenaceae) were subjected to hydrodistillation, and the essential oil extracted was examined with respect to chemical composition, antibacterial and antibiotic modifying activity by gaseous contact. Among the 25 identified components, bicyclogermacrene (26.1%), β-caryophyllene (24.4%), germacrene D (19.2%) and valecene (12.0%) were the main constituents. The essential oil volatile constituents inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa with MIC of 1 and > 1 mg/L, respectively. The activity of the antibiotic amikacin was increased by 65% against S. aureus and P. aeruginosa after contact with the volatile components.

The fatty acid compositions of the n-hexane extracts of the aerial parts of four TurkishCephalariaspecies,(C.stellipilis, C. davisianaand C. elazigensis var. purpurea) were analyzed by GC-MS for the first time. The oil yields of these species were determined as ranging from 0.07% to 0.36 %. Seventeen fatty acids as methyl esters were identified. All extracts were found to contain significant quantities of palmitic, linoleic (LA), stearic and alpha-linolenic acid ( ALA). ALA was the most abundant fatty acid in all species (29.00%, 30.51%, 32.49% and 34.87% for C. stellipilis, C. elazigensis, C. davisiana andC. paphlagonica, respectively). Other dominant fatty acid was palmitic acid, which ranged from 19.10% to 28.23% for all species. LA was detected in a considerable amount of 19.44 % for C. paphlagonica. The n-hexane extracts of the plants were also checked for their antimicrobial and antioxidant activities.

The essential oils of Romanian coriander fruits ( cultivar “Sandra”) were obtained by hydrodistillation and analyzed by means of GC and GC-MS. Sixty compounds were identified in the total essential oils. Monoterpenes were the most dominant class of compounds, with linalool (48.4-54.3%) being the major component. Other significant compounds were γ-terpinene (9.2-12.1%), α-pinene (5.5-9.3%) and limonene (4.7-6.3%).

Leaf and stem essential oils from Crotonpulegioides Müll.Arg. and C. rhamnifolius var. heliotropiifolius (Kunth) Müll.Arg were obtained by hydrodistillation and analyzed using gas chromatography and gas chromatography-mass spectrometry. The composition of the oils from the two Crotonspecies was very different. The main components of the C. pulegioides oils were 1,8-cineole (15.86± 0.23% in leaf), p-cymene (14.40± 0.01% in leaf), camphor (13.28%± 0.12% in leaf) and α-humulene (12.98± 0.22% in leaf), α-calacorene (12.95± 0.45% in stem), cis-isolongifolane (8.94±0.54% in stem) and juniper camphor (6.44±0.45% in stem). The main components of the C. rhamnifolius var. heliotropiifolius oils were β-caryophyllene (20.82±0.48% in leaf), spathulenol (16.37±0.56% in leaf) and β-elemene (17.28±0.06% in stem) and guaiol (18.38±0.84% in stem). Phenylpropanoids common to Crotonspecies were only found in C. rhamnifolius var. heliopropiifolius oils at percentages below 5%. This is the first report of the essential oil constituents of C. pulegioides and C. rhamnifolius var. heliotropiifolius from the Caatinga biome of the state of Pernambuco (Northeastern Brazil).

P terocarpin and isoflavan derivatives were isolated from ethanol extract of Canavalia maritima (Aubl.) Thou on column chromatography. By analyzing spectral data, the structures were elucidated as 2-hydroxy-3, 9-dimethoxypterocarpin (1), 4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (2), medicarpin (3), 7-hydroxy-2',4'-dimethoxy isoflavan (4), 7-hydroxy-4'-methoxyisofalvone (5) 5,7,4'-trihydroxyisoflavone (6), 3,7-dihydroxy-6-methoxylflavone (7) and quercetin (8). This paper firstly reports the compounds of pterocarpan and isoflavan from C . maritima, which would help understand the pharmaceutical mechanisms of these bioactive substances for wide medical applications. T he 1 3C-NMR spectr al data of Compound 1 was reported for the first time.

Flavonoids distribution in three algerian Bupleureum (Apiaceae) species has been investigated. Quercetin (1), quercetin 3-rutinoside (2) and isorhamnetin 3-rutinoside (3) were found in the endemic species B. plantagineum Desf. Three kaempferol glycosides, kaempferol 3-glucoside (4), kaempferol 3-galactoside (5), kaempferol 3-rutinoside (6) and three quercetin glycosides, quercetin 3-rutinoside (2), quercetin 3-glucoside (7) and quercetin 3-galactoside (8), have been isolated from B. fruticosum L. while isorhamnetin (9), isorhamnetin 3-galactoside (10) and isorhamnetin 3-galactorhamnoside (11) were found in B. spinosum L. Seven flavonols are reported here for the first time from the genus.

 The essential oil from the aerial parts of Salvia chrysophylla Staph (Lamiaceae), endemic to Turkey, was investigated by using GC and GC-MS. Fifty-four of 55 components, represented 99.52% of the total oil, were identified. The major components of the essential oil were found to be α-terpinenyl acetate (36.31%), β-caryophyllene (15.29%), linalool (8.12%) and β-elemene (4.26%). The antioxidant activity of the oil was investigated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene/linoleic acid tests. Anticholinesterase activity was screened against acetylcholinesterase and butyrylcholinesterase which are the chief enzymes of Alzheimer’s disease. The essential oil showed weak antioxidant activity. However, at 1 mg/mL concentration, the essential oil exhibited mild acetylcholinesterase (52.5±2.0%) and moderate butyrylcholinesterase (76.5±2.7%) inhibitory activity.

Toxicity tests of wild wormwood essential oils were performed using the brine shrimp (Artemia sp.) test. N auplii lethality (LC 50) ranged 15.7-31.9 µg/mL, depending on oil composition. The most toxic A. absinthium oils were found to be those containing appreciable amount of trans-sabinyl acetate (45.2%) and (cis+trans) thujones (12.3%), while other samples with equivalent amounts of sabinyl acetate, but without thujones were determined to be notably less toxic. Herb material for the tests was collected in Lithuania, the volatile oils were obtained by hydrodistillation from different plant organs (inflorescences and leaves) and analysed by GC-MS.

Water-distilled essential oils from aerial parts of Tanacetum chiliophyllum (Fisch. & Mey.) Schultz Bip. var. monocephalum Grierson from Turkey were analyzed by GC and GC/MS. The flower and stem oils were characterized by camphor (17.3%, 10.4%), 1,8-cineole (8.3%, 2.5%) and unknown compounds M + 218 (6.6%, 10.4%), M + 220 (Stem: 9.2%). Root oil was characterized with hexadecanoic acid (37.5%), alismol (6.3%), geranyl isovalerate (5.3%). Antibacterial activity of the flower and stem oils were evaluated on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter aerogenes, Proteus vulgaris, Salmonella typhimurium, Staphylococcus epidermis, Bacillus cereus, Bacillus subtilis, and Meticillin resistant S. aureusmicroorganisms by using a micro-dilution assay. Flower oil inhibited the growth of Bacillus cereus with the MIC 62.5 µg/mL which was 2 fold less concentration than the positive control chloramphenicol. Both flower and stem oils showed relative toxicity to Vibrio fischeri in the TLC- bioluminescence assay.

In the course of our phytochemical studies of essential oils, the oil obtained from the aerial part of Nepeta deflersiana (Lamiaceae) was analyzed by GC and GC/MS. In parallel to that, evaluation of the antimicrobial and antioxidant activities was also carried out. The investigation led to the identification of 51 components. The oil was rich in oxygenated monoterpenes (31.4%). The oil contained as well a high content of oxygenated sesquiterpenes (28.2%). Hexadecanoic acid (8.0%), caryophyllene oxide (6.4%), 2-methoxy-p-cresol (5.6%), camphor (4.7%) and eugenol (4.7%) were the most abundant constituents. In antimicrobial investigation, the essential oil has shown strong activity for Gram-positive bacteria with MIC-value of 0.4 mg/mL. Moreover, the DPPH-radical scavenging assay exhibited a moderate antioxidant activity (38%) at 1.0 mg/mL.