A new alkaloid from Thespesia populnea endophytic fungus Penicillium sp. TM-Y1-1.

A new alkaloid (3), together with three known compounds, were isolated from the Thespesia populnea endophytic fungus TM-Y1-1. Their structures were elucidated by extensive spectroscopic methods. The absolute configuration of compound 3 was determined for the first time by ECD calculation and DP4+ analysis. All compounds were evaluated for antimicrobial activity. The results showed that compounds 1 and 2 both exhibited moderate inhibitory activity against banana Colletotrichum gloeosporioides with MIC value of 31.25 µg/ml.

A new chromone from Kandelia candel endophytic fungus Aspergillus sp. ZJ-68.

One chromone (1), together with four known alkaloids, were isolated from the mangrove endophytic fungus Aspergillus sp. ZJ-68. Their structures were elucidated by a combination of HRESIMS and NMR spectroscopic analyses. Compound 1 showed strong anti-inflammatory activity in vitro by inhibiting nitric oxide (NO) production in lipopolysaccharide-activated RAW264.7 cells with an IC50 value of 4.094 ± 0.8 µM, which was better than positive drug indomethacin (IC50=35.8 ± 0.5 µM).

Ethyl 5,8-dibromo-2-dibromo-methyl-6,7-dimeth-oxyquinoline-3-carb-oxy-late.

The title compound, C(15)H(13)Br(4)NO(4), was obtained via radical bromination reaction of ethyl 6,7-dimeth-oxy-2-methyl-quinoline-3-carboxyl-ate and N-bromo-succinimide (NBS) in the presence of benzoyl peroxide (BPO) under photocatalytic conditions. The quinoline ring system is approximately planar with a maximum deviation from the mean plane of 0.035 (1) Å. The dihedral angle between the six-membered rings is 2.33 (2)°. The meth-oxy O atoms of the two neighboring meth-oxy groups are in-plane while their methyl C atoms are located on either side of the quinolyl ring plane at distances of -1.207 (1) and 1.223 (1) Å.

2-(3-Morpholino-prop-yl)-2,3-dihydro-1H-pyrrolo-[3,4-b]quinolin-1-one monohydrate.

In the title compound, C(18)H(21)N(3)O(2)·H(2)O, the fused-ring system is approximately planar [maximum atomic deviation = 0.028 (3) Å]; the morpholine ring displays a chair conformation. The crystal packing is stabilized by classical inter-molecular O-H⋯O and O-H⋯N hydrogen bonds and weak C-H⋯O hydrogen bonds between the organic mol-ecules and the water mol-ecules.

New furo[3,2-h]isochroman from the mangrove endophytic fungus Aspergillus sp. 085242.

Four new compounds, asperisocoumarin G (1), asperisocoumarin H (2), (±)-asperisocoumarin I [(±)-3], along with the known pergillin (4) and penicisochroman L (5) were isolated from a mangrove endophytic fungus Aspergillus sp. 085242 by further chemical investigation. The structures of the new compounds, including their absolute configurations, were established by analysis of HR-ESI-MS and NMR spectroscopic data, and ECD calculation. Asperisocoumarins G-I (1-3) were new isocoumarins belonging to the class of furo[3, 2-h]isocoumarins which are rarely found in natural sources. All of the isolated compounds were evaluated for their α-glucosidase inhibitory effects, and compounds 1 and 4 showed moderate α-glucosidase inhibitory activity, respectively. In an antimicrobial test, the racemate of 3 showed antibacterial activity against Salmonella.

Amplification of DNA-binding affinities of protoberberine alkaloids by appended polyamines.

This communication describes a synthetic approach toward the amplification of the moderate DNA-binding affinities of protoberberine alkaloids. Specifically, three protoberberine derivatives bearing two to six primary amino groups at the 3- and 9-positions of protoberberine were synthesized and characterized by NMR ((1)H and (13)C) and HRMS. Studies on their affinities toward calf thymus (CT) DNA by ethidium bromide (EB) displacement and spectrophotometric titration experiments indicate that these polyamino protoberberines show more than 10(3)-fold enhanced DNA-binding affinities relative to palmatine and thus are exploitable as strong DNA-binders.

Spacer length and attaching position-dependent binding of synthesized protoberberine dimers to double-stranded DNA.

Six jatrorrhizine homodimers and berberine-jatrorrhizine heterodimers have been synthesized in moderate to good yields from the reaction of jatrorrhizine with alpha,omega-dibromoalkanes and 9-O-(omega-bromoalkyl)berberines, respectively. Their binding activities toward calf thymus (CT) DNA and three double-stranded oligodeoxynucleotides, d(AAGAATTCTT)(2), d(TAAGAATTCTTA)(2), and d(TTAAGAATTCTTAA)(2), were investigated by means of spectrofluorimetric and spectrophotometric titrations. The results indicate that these dimers exhibit enhanced DNA-binding affinities due to the cooperative interaction of the two protoberberine subunits. A comparative study of the DNA-binding behaviors of berberine homodimers, jatrorrhizine homodimers, and berberine-jatrorrhizine heterodimers suggests that spacer length and attaching position are of great importance in modulating their DNA-binding affinities.