Abstract The main concern of today's agricultural production around the world is a cleaner and greener approach to crop production. Streptomyces species with distinct characteristics can be found in soil. The current research focuses on Streptomyces species isolated from marine sediment samples. To evaluate the morphology and biochemical properties of the isolated Streptomyces strain ukm1, it was grown in Starch Casein Nitrate (SCN) agar medium. Morphological, biochemical, and 16s rRNA analysis were performed on the strain. Streptomyces sp. was identified based on these findings. The production of bioactive metabolites by strain nkm1 was carried out in five different fermentative media. After 10 days of incubation, M6 medium was found to be efficient and was extracted with ethyl acetate. The MIC values revealed that the ethyl acetate extract inhibited the growth of plant pathogenic fungi such as Phytophthora palmivora (31.25 g/ml), Aspergillus flavus (15.62 g/ml), Rhizoctonia solani (31.25 g/ml), and Cladosporium herbarum (31.25 g/ml). The GC-MS analysis of the ethyl acetate extract revealed 26 components, the major volatile bioactive compound being nonadecane.

Abstract Currently Streptomyces is one of the most important antibiotic producing microorganisms against several diseases. In the present study Streptomyces olivochromogenes ERINLG-261 was isolated from the soil samples of the Mudumalai hills, Western Ghats, India. Morphological, physiological, biochemical and 16S rRNA studies strongly suggested that this isolate belonged to the genus Streptomyces. ERINLG-261 showed good antimicrobial activity against different bacteria and fungi in Micromonospora fermentation medium. The active ethyl acetate extract was packed in column chromatography over silica gel which led to the isolation of 2-hydroxy-9,10-anthraquinone as the active principle. The isolated compound showed good antimicrobial activity against tested bacteria and fungi in minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) studies. The compound showed moderate in vitro antiproliferative activity against A549 and COLO320 cells. The compound was subjected to molecular docking studies for the inhibition of Topoisomerase, TtgR and Beta-lactamase enzymes which are targets for antimicrobials. Docking results of the compound showed low docking energy with these enzymes indicating its usefulness as antimicrobial agent. This is the first report of antimicrobial and antiproliferative activity of 2-hydroxy-9,10-anthraquinone isolated from Streptomyces olivochromogenes along with molecular docking studies.

Abstract The hypolipidemic activity of friedelin isolated from Azima tetracantha Lam., Salvadoraceae, was studied in Triton WR-1339 and high-fat diet-induced hyperlipidemic rats. In Triton WR-1339 induced hyperlipidemic rats, treatment with friedelin (50 and 70 mg/kg) showed a significant (p < 0.01) lipid-lowering effect as assessed by reversal of plasma levels of total cholesterol (TC), triacylglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). In high-fat diet fed hyperlipidemic rats, treatment with friedelin (50 and 70 mg/kg) caused lowering of lipid levels in plasma and liver. The hypolipidemic activity of friedelin was compared with fenofibrate, a known lipid-lowering drug, in both models.

The endophytic fungus is have rich source of secondary metabolites which act as biological active agent in the higher plants. The fungal derivatives play vital part in human life and their compounds are the source of drug for cancer, microbial and viral diseases. The natural compounds from the endophytes acts as growth inhibitor of plant pathogenic organism. Endophytes are rich sources of natural products which are used in agriculture (plant growth and insecticidal), pharmaceutical industries and also used for phytoremediation.

Flindersine, an alkaloid isolated from Toddalia asiatica, was evaluated for their antifeedant, larvicidal and growth inhibitory activities against Helicoverpa armigera, Spodoptera litura and larvicidal activity against vector mosquitoes Anopheles stephensi and Culex quinquefasciatus. For this, leaf disc no choice method was used for agricultural pests; larvicidal activity was tested on second and fourth instar larvae for mosquitoes at different concentrations. Flindersine showed antifeedant, larvicidal and growth inhibitory activities against H. armigera and S. litura and larvicidal activity against vector mosquitoes An. stephensi and Cx. quinquefasciatus. It showed high regression (R2) values of 0.91 and 0.87 against H. armigera and S. litura, respectively for antifeedant activity. Flindersine exhibited more than 65% larvicidal activity against both the pests with LC50 values of 443.04 and 568.88 ppm and R2 values of 0.87 and 0.90 against H. armigera and S. litura, respectively. The larval and pupal duration of tested insects increased to more than five days at 1000 ppm when compared with the control. The adult emergence was reduced when the concentration of flindersine was increased. At 1000 ppm, no adult emergence was observed in both the pests. Flindersine exhibited 100% larvicidal activity against both the tested mosquitoes at 20 ppm concentration, which showed LC50 values of 2.90, 4.19, 1.68 and 2.71 ppm for 2nd and 4th instar larvae of Cx. quinquefasciatus and An. Stephensi, respectively. High regression values were observed for antifeedant, larvicidal and growth inhibitory activities. Flindersine could be used to develop an ecofriendly pesticide formulation to control the agricultural pests and vector mosquitoes.

Larvicidal activity of pectolinaringenin from Clerodendrum phlomidiswas evaluated against Anopheles stephensi and antifeedant, larvicidal and growth inhibitory activities were evaluated against Earias vittella. Pectolinaringenin exhibited larvicidal activity of 100 and 98.24% against 2nd and 4th instar larvae of Anopheles stephensi at 5ppm concentration. It exhibited LC50 values of 0.35 and 0.55 ppm for 2nd and 4th instar larvae, respectively. At 100 ppm concentration, pectolinaringenin exhibited maximum antifeedant activity of 74.00% and larvicidal activity of 89.98%. The LC50 values were 36.2 and 10.23 ppm for antifeedant and larvicidal, respectively. The compound completely prevented the adult emergence at 50 and 100 ppm concentrations. This is the first report of pectolinaringenin from C. phlomidis evaluated against An. stephensi and E. vittella. The results suggested that the pectolinaringenin from C. philomidis could be used to develop a new botanical formulation to manage vector mosquitoes and agricultural pests.

Twelve fractions from chloroform extract of Clerodendrum phlomidis and 5,7-dihydroxy- 4',6-dimethoxy-flavone (pectolinaringenin) were evaluated against Helicoverpa armigera. Maximum antifeedant (89.41%), larvicidal (83.77%) and ovicidal (69.25%) activities were observed in fraction 5. The least LC50 value for antifeedant (178.09 ppm) and larvicidal (198.23 ppm) were observed in fraction 5. No adult emergence was recorded in fractions 4-6 at 1000 ppm. The oviposition deterrent activity was 100% in fraction 5 at all the concentrations. Pectolinaringenin recorded maximum antifeedant (74.68%) and larvicidal (81.11%) activities at 100 ppm; it completely prevented the adult emergence of H. armigera at 100 ppm. Maximum ovicidal activity at 100 ppm concentration was 67.95%. The oviposition deterrent activity was 100% in 100 and 50 ppm concentrations. C. phlomidis could be effectively used to develop a new formulation to control the economically important pests.