Search

A new lathyrane diterpenoid ester, euphordracunculin C ( 1), together with a phenolic amide, 4-hydroxy-N-[3-(4-hydroxy-3-methoxyphenyl)-1-oxo-2-propen-1-yl]-3-methoxybenzamide ( 2), was isolated from the aerial parts of Euphorbia dracunculoides. The structure of the new compound was elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques. [ABSTRACT FROM AUTHOR]

Extensive phytochemical investigation of the aerial parts of Euphorbia dracunculoides led to the isolation of 19 structurally diversified diterpenoids with five different carbon skeletons, including six new lathyrane glycosides ( 1 – 6 ), three new cyclomyrsinanes ( 7 – 9 ), three new premyrsinanes ( 10 – 12 ), and one new 10,18-dihydromyrsinane ( 13 ). Their structures were elucidated by means of extensive spectroscopic analysis, and the structure of 7 was further confirmed by X-ray crystallography. Compounds 1 – 6 are the first examples of C-17-glycosylated lathyrane diterpenoids. Selected isolates were evaluated for their cytotoxicity against five cancer cell lines. Only the tiglianes exhibited moderate activity. [ABSTRACT FROM AUTHOR]

Several series of 45 acetophenone derivatives bearing various alkyl or benzyl substituents were conveniently synthesized and their structures characterized by 1H and 13C NMR spectroscopy, HRMS and single-crystal X-ray analysis. Their in vitro antifungal activities against a panel of phytopathogenic fungi were evaluated by mycelial growth rate assay. Of them, 12 derivatives (e.g., 3a-c, 4c and 4e) exhibited more potent antifungal effects on some phytopathogens than a commercial fungicide hymexazol as positive control. In particular, compound 3b with IC50 values of 10-19 μg/mL was found to be the most active in this series and might be a potential lead structure for further optimization. The preliminary structure-activity relationship (SAR) studies of a series of acetophenones are also discussed. [ABSTRACT FROM AUTHOR]

Continuous cropping often leads to plant diseases caused by root-knot nematodes (RKN). Owing to the difficulty in laboratory culture of RKN, microbial biocontrol agents are mainly screened for through contact killing assay, which requires a substantial effort to acquire RKN. This study was undertaken to verify the feasibility of using Caenorhabditis elegans – a model nematode that can be easily grown in the laboratory – to screen for microbial antagonists against RKN. Tomato (Solanum lycopersicum L. cv. Houpi Maofen 802) plants were grown in pots containing RKN-infested soil with and without inoculation of an antagonistic actinobacterial strain, designated Streptomyces albidoflavus T4. Exposure to T4 culture filtrate that contained catecholate siderophore and indole acetic acid resulted in a mortality rate of 95.4% for C. elegans and increased seed vigor by 113% for tomato. While root rotting rate and RKN incidence decreased following T4 inoculation, plant survival rate and stem diameter increased correspondingly. The root-associated microbiota of inoculated plants were optimized, as indicated by increased proportions of potentially beneficial bacteria (e.g. Bacillus amyloliquefaciens) and decreased proportions of pathogenic fungi (e.g. Fusarium oxysporum). The results demonstrate the outstanding performance of S. albidoflavus T4 to control root-knot disease and benefit tomato plant growth through multifaceted mechanisms. [ABSTRACT FROM AUTHOR]

A new hygrolidin-type macrolide ( 1 ), together with one known derivative, oxohygrolidin ( 2 ), were isolated from the culture of Streptomyces sp. KIB-H869. The structure of the new compound was elucidated by means of extensive spectroscopic analysis. Moreover, by the biogenesis ratiocination and NMR data comparison, halichomycin and 2 were confirmed to have the same structure, which corrects the structural misrepresentation of halichomycin. The antifungal activities of the two compounds were evaluated. [ABSTRACT FROM AUTHOR]

A new myrinsol diterpenoid ester, 2 α,3 β,5 α,7 β,10-O-pentacetyl-14 α-O-benzoyl-15 β-O-nicotinoyl-10,18-dihydromyrsinol ( 1), along with a known analogue, proliferin C ( 2), were isolated from the aerial parts of Euphorbia dracunculoides Lam. Their structures were elucidated on the basis of spectroscopic evidence and comparison with literatures. [ABSTRACT FROM AUTHOR]

Abstract: A novel polyhydroxylated C29-sterol, 25ξ-methyl-22-homo-5α-cholest-7,22-diene-3β,6β,9α-triol, designated globosterol (1), together with one known tetrahydroxylated ergosterol (22E, 24R)-ergosta-7,22-diene-3β,5α,6β,9α-tetraol (2) has been isolated from the cultures of an endophytic fungus, Chaetomium globosum ZY-22 originated from the plant Ginkgo biloba. The structures and relative configurations of 1 and 2 were established on the basis of extensive spectroscopic analyses including 1D and 2D NMR (1H–1H COSY, HSQC, HMBC, and NOESY) experiments and comparison with the literature. Globosterol (1) possesses an unprecedented 25-methyl Δ22-C10-side chain and Δ7-3β,6β,9α-hydroxy-steroid nucleus, which represents the first example for C29-steroids of the group. [Copyright &y& Elsevier]

[isolation, structure elucidation, and biological activity] [ABSTRACT FROM AUTHOR]

The structural eludication of the title compound (I) confirms the C-9′ configuration to be (S) and therefore also revises the structures of other duclauxin analogues. [ABSTRACT FROM AUTHOR]