An unexpected role of EasD: catalyzing the conversion of chanoclavine aldehyde to chanoclavine acid.

Ergot alkaloids (EAs) are a diverse group of indole alkaloids known for their complex structures, significant pharmacological effects, and toxicity to plants. The biosynthesis of these compounds begins with chanoclavine-I aldehyde (CC aldehyde, 2), an important intermediate produced by the enzyme EasD or its counterpart FgaDH from chanoclavine-I (CC, 1). However, how CC aldehyde 2 is converted to chanoclavine-I acid (CC acid, 3), first isolated from Ipomoea violacea several decades ago, is still unclear.

Diterpenoids from Euphorbia peplus possessing cytotoxic and anti-inflammatory activities.

Phytochemical investigation into the medium polar fraction of the ethanol extract of Euphorbia peplus led to the identification of 32 diterpenoids with five structural types. Compounds 1-5 and 7-11 are reported for the first time, while the configuration of 6,7-epoxy group of 6 was revised to be β-oriented. Compounds 1-5 feature a rare structural variation of the double bond at Δ migrating to Δ in the tigliane-type diterpenoid family.

Bioactive Alpha-Pyrone and Phenolic Glucosides from the Marine-Derived sp. P2100.

Glycoside compounds have attracted great interest due to their remarkable and multifarious bioactivities. In this study, four hitherto unknown 4-methoxy--D-glucosyl derivatives were obtained and identified from the marine-derived fungus sp. P2100, including three alpha-pyrone glycosides (-) and one phenolic glycoside ().

A combined strategy for the overproduction of complex ergot alkaloid agroclavine.

Microbial cell factories (MCFs) and cell-free systems (CFSs) are generally considered as two unrelated approaches for the biosynthesis of biomolecules. In the current study, two systems were combined together for the overproduction of agroclavine (AC), a structurally complex ergot alkaloid. The whole biosynthetic pathway for AC was split into the early pathway and the late pathway at the point of the FAD-linked oxidoreductase EasE, which was reconstituted in an MCF () and a four-enzyme CFS, respectively.

Natural Enantiomers: Occurrence, Biogenesis and Biological Properties.

The knowledge that natural products (NPs) are potent and selective modulators of important biomacromolecules (e.g., DNA and proteins) has inspired some of the world's most successful pharmaceuticals and agrochemicals.

Diarylheptanoids with NO production inhibitory activity from Amomum kravanh.

Seven new diarylheptanoids, kravanhols C-I (1-7), along with two known analogues (8 and 9), were isolated from the fruits of Amomum kravanh. The structures of compounds 1-7 were elucidated by analysis of spectroscopic data, and the absolute configurations of selective ones were determined by time-dependent density functional theory (TD-DFT) based electronic circular dichroism (ECD) calculations. All compounds were evaluated for their inhibitory effects on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine RAW264.

Bioactive terpenoid constituents from Eclipta prostrata.

Chemical fractionation of the ethanolic extract of Eclipta prostrata yielded a series of unreported terpenoid constituents, including a rare 6/6/6/6-fused tetracyclic triterpenoid, a pentacyclic triterpenoid, two pentacyclic triterpenoid saponins, a diterpenoid and a sesquiterpenoid. Structures were assigned to these compounds on the basis of comprehensive spectroscopic analyses, with the absolute configurations of the tetracyclic triterpenoid, the diterpenoid and the sesquiterpenoid being determined via explanation of electronic circular dichroism data. Screening of these isolates in an array of bioassays revealed antibacterial, cytotoxic and α-glucosidase inhibitory activities for selective compounds.

New cinnamic acid-pregenolone hybrids as potential antiproliferative agents: Design, synthesis and biological evaluation.

A series of new cinnamic acid-pregenolone hybrids (5a-5o) was designed, synthesized and evaluated for their in vitro antiproliferative activity. Some of them showed potential antiproliferative activity and selectivity towards a panel of cancer cell lines, including A549, H157, HepG2, MCF-7, and HL-60. Among these analogs, compound 5f showed the most promising activity with IC values ranging from 3.

New e:b-Friedo-Hopane Type Triterpenoids from with Simiarendiol Possessing Significant Cytostatic Activity against HeLa Cells by Induction of Apoptosis and S/G2 Cell Cycle Arrest.

Seven rare e:b-friedo-hopane-type triterpenoids including four new (-) and three known (-) ones with being first reported as a natural product, together with five other known triterpenoids (-), were isolated from the nonpolar fractions of the ethanolic extract of . Structural assignments for these compounds were based on spectroscopic analyses and quantum chemical computation method. The structural variations for the C-21 isopropyl group, including dehydrogenation ( and ) and hydroxylation at C-22 (simiarendiol, ), were the first cases among e:b-friedo-hopane-type triterpenoids.

Bioactive sesquiterpenoids and sesquiterpenoid glucosides from the flowers of Inula japonica.

Three new sesquiterpenoids (1-3) and two new sesquiterpenoid glucosides (4 &5), along with 24 known analogues (6-29), were obtained from the flowers of Inula japonica. Structures of the new compounds were determined by interpretation of spectroscopic data, and their absolute configurations were established via comparison of experimental with computed ECD curves. All the isolates were tested in an in vitro cytotoxic assay against human A549, MCF-7 and MDA-MB-231 cancer cell lines, and selective ones displayed significant activity close to the positive control adriamycin.

Cuceolatins A-D: New Bioactive Diterpenoids from the Leaves of Cunninghamia lanceolata.

Four new diterpenoids named cuceolatins A-D, including three labdane-type (1-3) and one abietane-type (4) as well as three known labdane analogs (5-7), were reported from the leaves of Cunninghamia lanceolata. Structural assignments for these compounds were conducted by analyses of spectroscopic data, and their absolute configurations were determined by time-dependent density functional theory (TD-DFT) based electronic circular dichroism (ECD) calculations. Among them, the abietane-type diterpenoid (11-hydroxy-12-methoxyabieta-8,11,13-trien-3-one (4)) showed significant cytotoxicity against human MDA-MB-231, MCF-7, and HeLa tumor cell lines with IC measurements of 4.

Absolute structure assignment of an iridoid-monoterpenoid indole alkaloid hybrid from Dipsacus asper.

Iridoid-monoterpenoid indole alkaloid hybrids (IMIAHs) represent a rare class of natural products reported from only several plants of Rubiaceae and Dipsacaceae families, while their structural assignments remain a very challenging work due to complexity and flexibility. In the current study, a new IMIAH (1) was isolated from the roots of Dipsacus asper and its structure with absolute configuration was unambiguously established by a combination of spectroscopic analyses, chemical degradation and ECD calculation. A new oleanane-type triterpenoid saponin (2) and 15 known co-metabolites were also obtained and structurally characterized.

Triterpenoids and triterpenoid saponins from Dipsacus asper and their cytotoxic and antibacterial activities.

Phytochemical investigation of the ethyl acetate soluble part, generated from the ethanol extract of the roots of Dipsacus asper, led to the separation and identification of three undescribed triterpenoids including one arborinane type, one ursane type and one oleanane type, two unreported oleanane type triterpenoid arabinoglycosides, and 18 known analogues. Structures of these compounds were determined by comprehensive spectroscopic analyses, with the absolute configurations of 25-acetoxy-28-dehydroxyrubiarbonone E and 2α,3β-dihydroxy-23-norurs-4(24),11,13(18)-trien-28-oic acid being established by evaluation of their experimental and calculated ECD spectra. 25-Acetoxy-28-dehydroxyrubiarbonone E features an oxygenated C-25 that is the first case among arborinane type triterpenoids, while 2α,3β,24-trihydroxy-23-norurs-12-en-28-oic acid incorporates a sp C-24 that is a rare structural feature of 23-norursane type triterpenoids.

Structural characterization and biological evaluation of chemical constituents from .

One new ursane-type triterpenoid (), one new ursane-type triterpenoid glycoside (), and one new oleanane-type triterpenoid glycoside (), along with 20 known compounds, were isolated from the leaves of . The structures of these natural products were elucidated on the basis of detailed spectroscopic analyses and chemical derivation. Our biological evaluation established that selective compounds showed moderate to significant antioxidant activities in the 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods.