Secondary metabolites from Centaurea deusta with antimicrobial activity

The aerial parts of Centaurea deusta Ten. afforded in addition to several known compounds, mainly sesquiterpene lactones, one new eudesmanolide and one new elemane derivative. Structures of the new compounds were elucidated by spectroscopic methods. The in vitro antifungal and antibacterial activities of the isolated compounds was tested, using the microdilution method. All compounds tested showed high antifungal activity.     

Glucosides from the roots of Capparis tenera

Two new lignan glucosides, compounds 2 and 3, two new 1H-indole-alkaloid glucosides, 5 and 6, as well as two new phenolic glucosides, 7 and 10, were isolated from the roots of Capparis tenera, together with five known compounds. Their structures were characterized by chemical and spectroscopic methods. Most of these isolates were obtained for the first time from Capparidaceae. The antioxidant and anti-inflammatory activities of the new compounds were investigated.     

Scaphopetalone and scaphopetalumate,a lignan and a triterpene ester from Scaphopetalum thonneri

From the methanol extract of the stem bark of Scaphopetalum thonneri, two new compounds, including one lignan, named scaphopetalone, one new ester of ferulic acid, named scaphopetalumate were isolated together with three known compounds including: two coumarins (scopoletin and scopolin), and one pentacyclic triterpene (oleanolic acid). The structure of the new compounds were elucidated by means of spectroscopic analyses.     

Three New Constituents with Anti-Inflammatory and Antimicrobial Activities in Vitro from the Roots of Capsicum annuum L.

Three new compounds, including two new sesquiterpenes ( 1–2 ), named Annuumine E−F, and one new natural product, 3-hydroxy-2,6-dimethylbenzenemethanol ( 3 ), together with seventeen known compounds ( 4–20 ) were isolated from the ethanol extract of the roots of Capsicum annuum L. Among them, five compounds ( 4 , 5 , 9 , 10 and 20 ) were isolated from this plant for the first time. The structures of new compounds ( 1–3 ) were determined via detailed analysis of the IR, HR-ESI-MS and 1D and 2D NMR spectra. The anti-inflammatory activities of the isolated compounds were evaluated by their ability to reduce NO release by LPS-induced RAW 264.7 cells. Notably, compound 11 exhibited moderate anti-inflammatory activity (IC₅₀=21.11 μM). Moreover, the antibacterial activities of the isolated compounds were also evaluated.     

Synthesis of biologically active steroid derivatives by the utility of Lawesson's reagent

Steroid derivatives V, VI, VII and VIII reacted with Lawesson's reagent (LR) to produce spiro-oxazaphosphole-4',17-androstene derivative XI, diazaphospholoandrostane XIV and the thionated derivatives XVI and XVII, respectively. The structures of the new compounds were confirmed by analytical and spectroscopic evidence. A mechanism accounting for the formation of the new compounds was given. The in vitro antimicrobial activity of the new compounds were tested.     

6-Hydroxyflavones from Thymbra spicata

Four flavonoids, including two new compounds, were isolated from the leaf extract of Thymbra spicata. The new compounds were the 7,3′-dimethyl and 7,3′,4′-trimethyl ethers of 6-hydroxyluteolin. All the compounds were identified by spectral methods.     

New Antiplasmodial Bromotyrosine Derivatives from Suberea ianthelliformis Lendenfeld, 1888

Four samples of Suberea ianthelliformis were investigated and furnished five new and 13 known brominated tyrosine-derived compounds. Two of the new compounds were identified as araplysillin N20-formamide and its N-oxide derivative. Three other new compounds, araplysillins IV, V, and VI, were isolated and identified as analogs of araplysillin II. Most of these compounds exhibit moderate inhibitory activities against chloroquine-resistant and -sensitive strains of Plasmodium falciparum, and were investigated for their PFTase inhibitory properties. The chemical content of the investigated sponges is correlated with their molecular phylogeny.     

The synthesis and crystal structures of triphenyl(1,2,3-trimethylallyl)tin and triphenyl( 1,1,2-trimethylallyl)tin

In an attempt to isolate new allylating reagents, two new tin compounds, triphenyl(1,2,3-trimethylallyl)tin (3) and triphenyl(1,1,2-trimethylallyl)tin (4) have been prepared and their crystal structures determined. Both compounds are examples of σ-bound allyl complexes. However, the infrared spectra of both compounds do not show the absorptions characteristic of other σ-bound allyl complexes. The chemistry of these new compounds also differs significantly from that of similar triphenyltin(allyl) reagents.     

A new meroterpenoid and a new polyketide from Penicillium expansum GY618 Fungus

Two new compounds, including one meroterpenoid (1) and a polyketide derivative (2), along with six compounds (3−8), were isolated from the rice solid fermentation of Penicillium expansum GY618. The structures of these new compounds were elucidated through interpretations of spectroscopic data and highresolution electrospray ionization mass spectrometry. The absolute configurations of all new compounds were unambiguously established through the optical rotation or calculation of the ECD spectrum. All isolated compounds were evaluated for their antibacterial and antitumor activities. Compound 6 exhibited weak antitumor activity.     

Acidic Aroma Constituents of Turkish Tobacco

The acidic constituents of sun-cured Turkish tobacco have been studied. Of the 93 acidic compounds investigated, 10 compounds are new in nature and 18 are new tobacco constituents. The 93 compounds fall mainly into three groups: fatty acids, aromatic acids, and terpenoid acids, which appear to be derived from macrocyclic thunbergane diterpenoids.     

Design,synthesis and antibacterial activity of novel andrographolide derivatives

A series of andrographolide derivatives were synthesized through a facile condensation reaction with different carboxylic acids. The new compounds were characterized and screened for their antibacterial activities. A number of the new compounds significantly reduced bacterial quorum sensing virulence factors production in Pseudomonas aeruginosa, essential for pathogenesis. Compound 11b showed the best activity among all the new compounds.     

Phenyl indane from acorus calamus

Besides three known compounds, two new compounds, namely Z-3-(2,4,5-trimethoxy phenyl)-2-propenal and a new phenyl indane have been isolated from the rhizomes of Acorus calamus. These compounds have been characterized from their spectral data and by synthesis.     

New 4-(4-methyl-phenyl)phthalazin-1(2H)-one derivatives and their effects on alpha1-receptors

Continuing our research aimed at obtaining new compounds with high affinity and selectivity toward alpha(1)-AR, a new series of arylpiperazine derivatives was designed, synthesized, and biologically tested. The new compounds 1-17 are characterized by a phenylphthalazin-1(2H)-one fragment connected through an alkyl chain to an arylpiperazine residue. The pharmacological profile of these compounds was evaluated for their affinity and selectivity toward alpha(1)-AR, alpha(2)-AR and toward 5HT(1A) serotoninergic receptor. A discussion on the structure-activity relationship (SAR) of these compounds is also reported.     

New pterocarpon flavonoids from Wisteria sinensis tumor

Three new pterocarpon flavonoids, wisterones B-D, together with nine isoflavone known compounds, were isolated from Wisteria sinensis Tumor. The structure of those compounds were elucidated on the basis of spectroscopic analyses, including UV, IR, MS and NMR experiments. These new compounds were investigated for their activities against anti-crop pathogenic fungi.     

Novel imidazo[2,1-b][1,3,4]thiadiazole carrying rhodanine-3-acetic acid as potential antitubercular agents

The increase in the prevalence of multi drug-resistant and extensively drug-resistant strains of Mycobacteriumtuberculosis case demonstrates the urgent need of discovering new promising compounds with antimycobacterial activity. As part of our research program and with a aim of identifying new antitubercular drug candidates, a new class of 2-(trifluoromethyl)-6-arylimidazo[2,1-b][1,3,4]thiadiazole derivatives has been synthesized by both conventional as well as microwave assisted method and evaluated for their in vitro antitubercular activity against M. tuberculosis H(37)Rv. Moreover, various drug-likeness properties of new compounds were predicted. Seven compounds from the series exhibited good activity with MIC in range 3.12-1.56μg/ml. The present study suggests that compounds 6b, 6c, 6d, 6e and 6f may serve as promising lead scaffolds for further generation of new anti-TB agents.     

GC-MS analysis of propolis samples from two different regions of Turkey

Silylated ethanolic extract of two propolis samples from Kazan and Marmaris regions in Turkey were investigated by capillary GC-MS. The compounds were characterized by comparison with library searches. Twenty four compounds from Kazan samples were identified, eight of them were new for propolis. Eighteen compounds from Marmaris samples were identified, two of them were new for propolis.     

Biologically active secondary metabolites from myxobacteria

New chemical structures with proven biological activity still are badly needed for a host of applications and are intensively screened for. Suitable compounds may be used as such, or in the form of their derivatives or, equally important, may serve as lead compounds for designing synthetic analogs. One way to new compounds is the exploitation of new producer organisms. During the past 15 years the myxobacteria have been shown in our laboratories to be a rich source of novel secondary metabolites, many of the compounds showing interesting and sometimes unique mechanisms of action. About 50 basic structures and nearly 300 structural variants have been elucidated, and almost all of them turned out to be new compounds. Several myxobacterial substances may have a good chance of an application.     

Highly oxygenated sesquiterpenes from the liverwort Trocholejeunea sandvicensis

Four pinguisane type sesquiterpenes were isolated from the liverwort Trocholejeunea scandvicensis, together with three aromatic compounds. The structures of the cited compounds were established on the basis of spectroscopic means. The first two compounds were new sesquiterpenes, while the other compounds were previously isolated from other liverworts and lichen sp., respectively. The stereochemistry for lejeuneapinguisanolide was determined by X-ray analysis, a possible biosynthetic pathway to it was postulated. The other new sesquiterpene is lejeuneapinguisenone.     

New 1,4-di-N-oxide-quinoxaline-2-ylmethylene isonicotinic acid hydrazide derivatives as anti-Mycobacterium tuberculosis agents

The increase in the prevalence of drug-resistant tuberculosis cases demonstrates the need of discovering new and promising compounds with antimycobacterial activity. As a continuation of our research and with the aim of identifying new antitubercular drugs candidates, a new series of quinoxaline 1,4-di-N-oxide derivatives containing isoniazid was synthesized and evaluated for in vitro anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv strain. Moreover, various drug-like properties of new compounds were predicted. Taking into account the biological results and the promising drug-likeness profile of these compounds, make them valid leads for further experimental research.     

Isoflavonoid derivatives from Lophira alata stem heartwood

Six isoflavonoid derivatives among which three are new have been isolated from the stem heartwood of Lophira alata. The structures were elucidated from spectroscopic and chemical evidences. Two have unusual carbon skeletons, possibly resulting from a variant of isoflavonoid biogenesis. The two compounds form the first members of a new subclass of flavonoid compounds which we call "isobiflavonoids". The presence of these isoflavonoid compounds in this plant of the Ochnaceae family has important chemotaxonomic implications since it modifies the botanic distribution of isoflavonoid compounds in non-leguminous plants.