E K Vijayakumar

Publications (16)26.42 Total impact

• Article: L 970843 and L 970844, two new antifungal metabolites from an unidentified fungal species HIL Y-903146.

  E K Vijayakumar, K Roy, C P Hiremath, S K Deshmukh, T Mukhopadhyay, H Kogler
  The Journal of Antibiotics 12/2001; 54(11):973-6. · 1.65 Impact Factor
• Article: Kodaistatins, novel inhibitors of glucose-6-phosphate translocase T1 from Aspergillus terreus thom DSM 11247. Isolation and structural elucidation.

  L Vértesy, H J Burger, J Kenja, M Knauf, H Kogler, E F Paulus, N V Ramakrishna, K H Swamy, E K Vijayakumar, P Hammann
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  ABSTRACT: Two novel compounds, kodaistatin A, C35H34O11, molecular weight 630, and kodaistatin C, C35H34O12, molecular weight 646, have been isolated from cultures of Aspergillus terreus Thom DSM 11247 by solid-phase extraction, size-exclusion chromatography, and various preparative HPLC steps. The use of a range of 2D NMR measurements, in particular 13C-13C correlation measurements, has led to the clarification of the structure of kodaistatin A. Kodaistatin C is a hydroxylated derivative of kodaistatin A. Both natural products contain hydroxylated aspulvinones and identical highly substituted polyketide units. An X-ray single crystal structure analysis of aspulvinon E demonstrated the z-configuration at the central double bond. The kodaistatins are effective inhibitors of the glucose-6-phosphate translocase component of the glucose-6-phosphatase system (EC 3.1.3.9), an enzyme system which is important for the control of blood glucose levels. The IC50 is 80 nM for kodaistatin A and 130 nM for kodaistatin C.
  The Journal of Antibiotics 08/2000; 53(7):677-86. · 1.65 Impact Factor
• Article: Mathemycin A, a new antifungal macrolactone from Actinomycete sp. HIL Y-8620959. II. Structure elucidation.

  T Mukhopadhyay, E K Vijayakumar, S R Nadkarni, H W Fehlhaber, H Kogler, S Petry
  The Journal of Antibiotics 07/1998; 51(6):582-5. · 1.65 Impact Factor
• Article: Structure-activity relationships of new aranorosin analogs to antifungal activity.

  E K Vijayakumar, K Roy, S Chatterjee, T Mukhopadhyay, R G Bhat, B N Ganguli
  The Journal of Antibiotics 06/1998; 51(5):522-4. · 1.65 Impact Factor
• Article: Aranochlor A and aranochlor B, two new metabolites from Pseudoarachniotus roseus: production, isolation, structure elucidation and biological properties.

  T Mukhopadhyay, R G Bhat, K Roy, E K Vijayakumar, B N Ganguli
  The Journal of Antibiotics 05/1998; 51(4):439-41. · 1.65 Impact Factor
• Article: Orbuticin, a new secondary metabolite from Acremonium butyri.

  K Roy, S Chatterjee, S K Deshmukh, E K Vijayakumar, B N Ganguli, H W Fehlhaber
  The Journal of Antibiotics 12/1996; 49(11):1186-7. · 1.65 Impact Factor
• Article: 2-Demethylazalomycins F4a and F5a, two new antifungal metabolites from Actinomycete sp. HIL Y-9120362.

  T Mukhopadhyay, E K Vijayakumar, S R Nadkarni, S N Sawant, J Kenia, B Sachse
  The Journal of Antibiotics 12/1995; 48(11):1350-2. · 1.65 Impact Factor
• Article: Phencomycin, a new antibiotic from a Streptomyces species HIL Y-9031725.

  S Chatterjee, E K Vijayakumar, C M Franco, R Maurya, J Blumbach, B N Ganguli
  The Journal of Antibiotics 12/1995; 48(11):1353-4. · 1.65 Impact Factor
• Article: 5-Hydroxy-9-methylstreptimidone, a new glutarimide from a Streptomyces sp. HIL Y-9065403.

  S Chatterjee, E K Vijayakumar, J Blumbach, B N Ganguli
  The Journal of Antibiotics 04/1995; 48(3):271-3. · 1.65 Impact Factor
• Article: Napsamycins, new Pseudomonas active antibiotics of the mureidomycin family from Streptomyces sp. HIL Y-82,11372.

  S Chatterjee, S R Nadkarni, E K Vijayakumar, M V Patel, B N Ganguli, H W Fehlhaber, L Vertesy
  The Journal of Antibiotics 06/1994; 47(5):595-8. · 1.65 Impact Factor
• Article: Balhimycin, a new glycopeptide antibiotic produced by Amycolatopsis sp. Y-86,21022. Taxonomy, production, isolation and biological activity.

  S R Nadkarni, M V Patel, S Chatterjee, E K Vijayakumar, K R Desikan, J Blumbach, B N Ganguli, M Limbert
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  ABSTRACT: A new glycopeptide antibiotic, balhimycin, has been isolated from the fermentation broth of a Amycolatopsis sp. Y-86,21022. Balhimycin belongs to the vancomycin class of glycopeptides and contains a dehydrovancosamine sugar. The biological activity of balhimycin has been compared extensively with that of vancomycin against methicillin resistant staphylococci and also against anaerobes. Balhimycin is marginally superior to vancomycin in its in vitro activity against anaerobes and in its bactericidal properties.
  The Journal of Antibiotics 04/1994; 47(3):334-41. · 1.65 Impact Factor
• Article: On the structure of alisamycin, a new member of the manumycin class of antibiotics.

  S Chatterjee, E K Vijayakumar, C M Franco, J Blumbach, B N Ganguli, H W Fehlhaber, H Kogler
  The Journal of Antibiotics 07/1993; 46(6):1027-30. · 1.65 Impact Factor
• Article: Aranorosinol A and aranorosinol B, two new metabolites from Pseudoarachniotus roseus: production, isolation, structure elucidation and biological properties.

  K Roy, E K Vijayakumar, T Mukhopadhyay, S Chatterjee, R G Bhat, J Blumbach, B N Ganguli
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  ABSTRACT: Two new secondary metabolites, aranorosinol A (1) and aranorosinol B (2), were isolated from a strain of Pseudoarachniotus roseus. Their structures were elucidated on the basis of their spectral properties and chemical transformations and were found to be similar to aranorosin (3) isolated from the same strain.
  The Journal of Antibiotics 11/1992; 45(10):1592-8. · 1.65 Impact Factor
• Article: Alisamycin, a new antibiotic of the manumycin group. I. Taxonomy, production, isolation and biological activity.

  C M Franco, R Maurya, E K Vijayakumar, S Chatterjee, J Blumbach, B N Ganguli
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  ABSTRACT: Alisamycin is a new member of the manumycin group of antibiotics produced by Streptomyces sp. HIL Y-88,31582, which taxonomically appears to be Streptomyces actuosus. Alisamycin is active against Gram-positive bacteria and fungi, and has a weak antitumour activity.
  The Journal of Antibiotics 01/1992; 44(12):1289-93. · 1.65 Impact Factor
• Article: Butalactin, a new butanolide antibiotic. Taxonomy, fermentation, isolation and biological activity.

  C M Franco, U P Borde, E K Vijayakumar, S Chatterjee, J Blumbach, B N Ganguli
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  ABSTRACT: Butalactin, [2-(4',5'-epoxy-hex-2'(E)-en)oyl-2-hydroxy-3-hydroxymethyl-2, 3-(Z)-butanolide] is a new antibiotic produced by Streptomyces sp. HIL Y-86,36923. Taxonomically, the producing organism most closely resembles Streptomyces corchorusii. The strain also produces cineromycin B. Though butalactin is structurally related to 'signal molecules' such as A-factor, the anthracycline inducing factors and the virginiae butanolides, it does not show inducing activity for antibiotic production or aerial mycelium formation in the indicator strain. Butalactin possesses a weak antibiotic activity against Gram-positive and Gram-negative bacteria.
  The Journal of Antibiotics 03/1991; 44(2):225-31. · 1.65 Impact Factor
• Article: Aranorosin, a novel antibiotic from Pseudoarachniotus roseus. II. Structure elucidation.

  H W Fehlhaber, H Kogler, T Mukhopadhyay, E K Vijayakumar, K Roy, R H Rupp, B N Ganguli
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  ABSTRACT: Aranorosin, a new antifungal antibiotic, has been isolated from the culture filtrate and mycelium of a strain of Pseudoarachniotus roseus Kuehn. The antibiotic, C23H33NO6, contains a novel 1-oxaspiro[4,5]decane ring system. The structure (I) has been elucidated on the basis of spectroscopic and chemical analysis.
  The Journal of Antibiotics 01/1989; 41(12):1785-94. · 1.65 Impact Factor