Columnaris disease, enteric septicemia of catfish, and streptococcosis are common bacterial diseases of certain freshwater fish and are caused by Flavobacterium columnare , Edwardsiella ictaluri , and Streptococcus iniae , respectively. During the process of evaluating several species of plants to isolate and identify compounds with toxicity against these bacteria, a promising extract from the aerial parts of the terrestrial plant Atraphaxis laetevirens (Ledeb.) Jaub. et Spach (Polygonaceae Juss.) was selected for bioassay-guided fractionation using a rapid microplate bioassay. The active dichloromethane extract was subjected to liquid-liquid partitioning, and active fractions were further separated by normal-phase column chromatography and normal-phase high-performance liquid chromatography (HPLC). Nepodin (3) and emodin (4) were isolated from two fractions with strong toxicities against S. iniae . A chloroform fraction was further separated by normal-phase column chromatography to yield two active fractions against F. columnare , and these fractions contained chrysophanol (1), physcion (2), and nepodin (3). Compound 1 had strong activity, and compound 3 had moderate activity against F. columnare , while compounds 2 and 4 were not toxic at the concentrations tested.

The aim of this study is to investigate the phenolic profiles and evaluate the brine shrimp cytotoxic activity of the ethanolic extract from the aerial part of C. alatavicus, an endemic species of Kazakhstan flora. Nine phenolic compounds were identified and quantified in the extract by high-performance liquid chromatography method. Preliminary cytotoxicity of the extract was determined by the brine shrimp (Artemiasalina) assay. The results reveal that the ethanolic extract from the aerial part of Crocus alatavicus exhibit a high cytotoxicity with LC50 15.71 μg/mL.

Phytochemical analysis of C. alatavicus revealed the presence of phenols, flavonoids, anthocyanins, carotenoids, amino acids and carbohydrates. The flavonoid, amino acids and carotenoid contents were higher in aerial part (1.50%, 7.49% and 9.78mg%, respectively) than in bulb (0.43%, 3.88% and 0.91 mg%, respectively). Total phenolic content (TPC), total antioxidant (TAA), 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and antibacterial activities of water, methanol, ethanol and dichloromethane extracts from aerial part and bulb were tested. TPC ranged from 13.63 to 72.29 mg gallic acid equivalents (GAE)/g extract. The maximum TAA were observed in ethanol (61.34%) and methanol extracts (46.13%) from aerial part with a high TPC (72.29 and 62.37 mgGAE/g extract, respectively). Ethanol extracts from aerial part and bulb had good scavenger of DPPH radicals (65.5% and 54.08%, respectively) with an IC50 387 and 447 µg/ml. Ethanol extract from aerial part was most effective against gram-positive bacterial strains S. aureus, B. subtilis and B. cereus. Biological activities of the extracts were correlated with the TPC. It can be deduced that ethanol and methnol extracts of C. alatavicus contains useful potent bioactive compounds with antioxidant and antimicrobial activities.

The results of evaluating the laboratory seed germination of endemic Allochrusa gypsophiloides (Turkestan soap root), depending on storage conditions in combination with gibberellic acid treatment (GA3), are presented. In dry storage, control seeds were characterised by a long after-ripening period and a fluctuating germination behaviour upon removal from storage, with a maximum value of 23%. The sensitivity of seeds to GA3 during dry storage varied significantly, with two germination peaks at 5-7 months, and 12 months (37.5 and 50% germination, respectively). Cold stratification and cryo-preservation accelerated seed after-ripening, promoted germination synchronisation and increased seed sensitivity to GA3. The cold stratification of seeds increased germination four months earlier than during dry storage. GA3 increased germination from 16.7 and 18.3% for the control to 37.5 and 45% for seeds cryopreserved for 5 and 12 months, respectively. We recommend cryopreserving Turkestan soap root seeds to avoid viability loss and to then germinate the seeds after pretreatment with GA3.

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