Secondary metabolites by chemical screening. I. Calcium 3-hydroxyquinoline-2-carboxylate from a Streptomyces

Streptomyces griseoflavus subsp. (G? 3592) was investigated by chemical screening methods. The mycelium contained gilvocarcin V (1). The culture filtrate contained the calcium salt of 3-hydroxyquinoline-2-carboxylic acid (2) confirmed by spectroscopic methods and by a 5-step partial synthesis of the free acid (3).     

链霉菌I08A1776产生的水溶性链丝菌素

目的分离纯化链霉菌I08A 1776发酵液中的水溶性抗耐药结核活性成分。方法利用离子交换、反相和亲水作用等多种色谱技术进行分离纯化,通过现代波谱学方法鉴定活性成分结构。结果分离得到3个水溶性活性成分,其结构分别确定为链丝菌素E(1)、Nβ-乙酰链丝菌素E(2)和Nβ-乙酰链丝菌素D(3)。链丝菌素E(1)对结核分枝杆菌H37Rv和临床分离耐药株的MIC值为0.25~1.0μg/mL。结论首次利用亲水作用色谱分离纯化微生物发酵液中的水溶性活性化合物。亲水作用色谱在微生物水溶性次级代谢产物的分离纯化中具有广阔的应用前景。链丝菌素E具有较强的体外抗耐药结核分枝杆菌活性。     

A new trichostatin analog from Streptomyces sp. CPCC 203909

A new trichostatin analog (1) and two known analogs (2, 3) have been isolated from the rice fermentation of the Streptomyces sp. CPCC 203909. Their structures were determined by spectroscopic and chemical methods. The absolute configurations of 1 were assigned by Marfey's method, combined with comparing the NMR and circular dichroism spectroscopic data of 2 and 3. Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC₅₀ value of 39.2 μM.     

A bisamide and four diketopiperazines from a marine-derived Streptomyces sp.

A new bisamide N ₁-acetyl-N ₇-phenylacetyl cadaverine (1) and a series of diketopiperazines including a new diketopiperazine cyclo(2-hydroxy-Pro-R-Leu) (2), together with a new natural product cyclo(4-hydroxy-S-Pro-S-Trp) (3) and two known leucine-based diketopiperazines cyclo(4-hydroxy-R-Pro-S-Leu) (4) and cyclo (S-Pro-R-Leu) (5), were isolated from ethyl acetate extract of a fermentation broth of a marine-derived Streptomyces sp. Their structures were elucidated by the interpretation of spectroscopic analysis. The antitumor activities of compounds 1–3 against HL-60 cell lines were tested by MTT assay.     

Indole alkaloids with in vitro antiproliferative activity from the ammoniacal extract of Nauclea orientalis.

Nine angustine-type alkaloids were isolated from ammoniacal extracts of Nauclea orientalis L. (Rubiaceae). Three of them, 10-hydroxyangustine and the two diastereoisomeric 3,14-dihydroangustolines, have not been described in the literature thus far. The structures of the isolates were determined with spectroscopic methods, mainly 1D- and 2D-NMR spectroscopy. The compounds were found to exhibit in vitro anti-proliferative activity against the human bladder carcinoma T-24 cell line and against EGF (epidermal growth factor)-dependent mouse epidermal keratinocytes. By using overpressure layer chromatography, it was shown that minor quantities of these alkaloids occur in dried Nauclea orientalis leaves. The use of ammonia in the extraction process results in a significant increase in the formation of angustine-type alkaloids from strictosamide-type precursors.     

A new fungicide produced by a Streptomyces sp. GAAS7310

Directed bioassay guided fraction led to a new macrodiolide antimycin A(17) (1), isolated from a Streptomyces sp. GAAS7310, which showed significant antimicrobial activity against eleven fungal species, including Curvularia lunata (Wakker) Boed, Rhizopus nigrtcans Ehrb and Colletotrichum nigrum EL. et Halst. The structure was unambiguously established by interpretation of 1D and 2D NMR data and comparison with the known antimycin A(1a).     

Atacamycins A-C, 22-membered antitumor macrolactones produced by Streptomyces sp. C38

Three new 22-membered macrolactone antibiotics, atacamycins A-C, were produced by Streptomyces sp. C38, a strain isolated from a hyper-arid soil collected from the Atacama Desert in the north of Chile. The metabolites were discovered in our HPLC-diode array screening and isolated from the mycelium by extraction and chromatographic purification steps. The structures were determined by mass spectrometry and NMR experiments. Atacamycins A, B and C exhibited moderate inhibitory activities against the enzyme phosphodiesterase (PDE-4B2), whereas atacamycin A showed a moderate antiproliferative activity against adeno carcinoma and breast carcinoma cells.     

A new staurosporine analog from Actinomycetes Streptomyces sp. (172614)

A new staurosporine analog, 10'-{5″-[(methoxycarbonyl)amino]-2″-methyl}-phenylaminocarbonylstaurosporine (1), together with staurosporine (2), was obtained from the culture broth of Actinomycetes Streptomyces sp. (172614). Their structures were elucidated by comprehensive spectroscopic analysis including UV, MS, NMR, and CD spectra. Pharmacological experiments revealed that 1 and 2 showed significant cytotoxicity against human colon tumor cell HCT-116.     

A new spectinabilin derivative with cytotoxic activity from ant-derived Streptomyces sp. 1H-GS5

A new spectinabilin derivative (1) was isolated from the fermentation broth of the ant-derived Streptomyces sp. 1H-GS5, and the structure was elucidated by extensive spectroscopic analysis. Compound 1 showed cytotoxicity against human tumor cell lines A549, HCT-116, and HepG2 with IC₅₀ values of 9.7, 12.8, and 9.1 μg/ml, respectively, which was relative higher than that of spectinabilin.     

A new staurosporine analog from Actinomycetes Streptomyces sp. (172614)

A new staurosporine analog, 10′-{5″-[(methoxycarbonyl)amino]-2″-methyl}-phenylaminocarbonylstaurosporine (1), together with staurosporine (2), was obtained from the culture broth of Actinomycetes Streptomyces sp. (172614). Their structures were elucidated by comprehensive spectroscopic analysis including UV, MS, NMR, and CD spectra. Pharmacological experiments revealed that 1 and 2 showed significant cytotoxicity against human colon tumor cell HCT-116.