RK-270A−C, new oxindole derivatives isolated from a microbial metabolites fraction library of Streptomyces sp. RK85-270

Octaminomycins A and B, Cyclic Octadepsipeptides Active against Plasmodium falciparum

“…Plasmodium falciparum 3D7, Dd2, and K1 strains were cultured at 37 °C under 5.0% CO 2 in human erythrocytes (3% hematocrit) in RPMI1640 (Thermo Fisher Scientific), supplemented with 10% human plasma. The assay methodology was followed as in the previously described method …”

“…In addition, the efforts for identifying known compounds are reduced significantly. We recently discovered novel compounds, namely, verticilactam, 7 spirotoamides A and B, 8 pyrrolizilactone, 9 RK-270A, -B, and -C, 10 RK-1355A and -B, 11 and unantimycin A, 12 which were obtained from NPPlot searches. Herein, we report the purification, structure elucidation, and biological activities of new cyclic octadepsipeptides, designated octaminomycins A (1) and B (2).…”

Two new triterpenoids from the roots of Pinus densiflora

“…1(A)) were also isolated and identified by the analysis of spectroscopic data and comparison with previous reports. [17][18][19][20][21][22] To determine the Two new triterpenoids from P. densiflora roots bioactivity of the terpenoids, all compounds isolated (1-9) were evaluated for antiproliferative activity against malarial causing protozoa, cancer cell lines, bacteria and fungi (Supplemental materials). [23][24] .…”

Naphthoquinone–Oxindole Alkaloids, Coprisidins A and B, from a Gut-Associated Bacterium in the Dung Beetle, Copris tripartitus

“…Recent actinomycete-originated oxindole representatives are prenylated oxindoles from Actinoplanes missouriensis 14 and Streptomyces sp. 15 The formation of the naphthoquinone−oxindole backbone in the coprisidins is biosynthetically intriguing. A ready hypothetical biosynthesis could be via a hybrid pathway composed of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) involving a tryptophan building unit as proposed for the fungal metabolites codinaeopsin 16 and cyclopiazonic acid.…”

“…Although the oxindole structure is relatively common in fungi, it is rarely reported in actinomycetes. Recent actinomycete-originated oxindole representatives are prenylated oxindoles from Actinoplanes missouriensis and Streptomyces sp …”