Growth inhibitory activity

Cell Division Inhibitors. The most common mode of action of soil-appHed herbicides is growth inhibition, primarily through dkect or indkect interference with cell division (163). Such growth inhibitory activity is the basis for most pre- or post-emergent herbicides intended to control germinating weed seeds. In germinating seeds, cell division occurs in the meristems of the root and the shoot. Meristematic cells go through a cycle... 

Diphenylamine inhibits the development of scald disease during prolonged cold storage of apples and pears (42—45). It prolongs the fresh appearance of cut snapdragons (46), controls weather fleck in tobacco, inhibits algae formation, and shows growth inhibitory activity in potatoes (47). 

Muramyl dipeptide derivatives have also been microencapsulated in lactide/glycolide copolymers for use alone as an immuno potentiator. L-lactide/glycolide copolymers were used to deliver MDP-B30, a lipophilic compound, from very small microspheres (less than 5 pm in diameter). The amount of MDP-B30 required for tumor growth inhibitory activity of mouse peritoneal macrophages was 2000 times less for the controlled release MDP-B30 microspheres than for the unen-capsulated drug (134). 

Table I shows the growth inhibitory activity of the four synthetic isobutylamides on the four lepidopterous larvae. The activity of the synthetic cis isomer (7) of fagaramide (J ) was 2- to 4-fold greater, depending on the insect species tested, than was fagaramide itself. Bioassay of synthetic amides identi-...

Table I. Insect growth inhibitory activity (EDcq natural...

Table IV. Growth-Inhibitory Activity of Some Bioactive Constituents Derived from Geranium viscosissimum var. viscosissimum Fed in an Artificial Diet to First-Instar Larvae of Heliothis virescens...

Although the biological activity of brevifolin as an insect growth inhibitor is unknown, gallic acid exhibited some growth-inhibitory activity against virescens larvae (EC50 = 7.40 mmol/kg diet)... 

The growth-inhibitory activity of azadirachtin fed in artificial diet to three species of agricultural pests, gossypiella, H. zea, and frugiperda, was compared to the activity of a number of limonoids isolated from plants in the Meliaceae and the Rutaceae (Table VI). After azadirachtin, the most active limonoid was cedrelone (Figure 13). Cedrelone was unique among the compounds tested in Table VI since it was the only limonoid, besides azadirachtin, to cause an inhibition in ecdysis (LC50 = 150 ppm) when fed to pink bollworm larvae (54). 

Acetylnimbandiol was insectidical (EI50 = 21 ppm) when fed to the larvae of II. vlrescens, while the structurally related salannin, which lacks the A-ring ketone (Figure 13), was not (Table VII) (57). Nakanishi (58) has pointed out that natural products with electrophilic moieties tend to be cytotoxic and insect antifeedant. Possibly the growth-Inhibitory activity of the limonoids may also be attributed to a nonspecific electrophilic effect. 

Insect Growth-Inhibitory Activity of Some Meliaceae and Rutaceae Limonoids. Values are the Dietary Concentrations for 50% Growth Inhibition (EC50)... 

Table VII. Ecdysis-and Growth-Inhibitory Activities of Some Neem...

Keskin O, Bahar I, Jernigan RL et al. Characterization of anti-cancer agents by their growth inhibitory activity and relationships to mechanism of action and structure. Anti-Cancer Drug Design 2000 15 79-98. 

Acetoxyodontoschismenol 74 (Scheme 12.13), a dolabellane diterpenoid, was isolated from the liverwort Odontoschisma denudatum and displayed moderate growth-inhibitory activity on a series of plant pathogenic fungi [37]. 

Doi, F., Ohara, T., Ogamino, T., Sugai, T., Higashinakasu, K., Yamada, K., Shigemori, H., Hasegawa, K., Nishiyama, S. Plant-growth inhibitory activity of heliannuol derivatives. Phytochemistry 2004 65 1405-1411. 

Other evidence suggesting the existence of growth inhibitors in plants came from analyses of acidic plant extracts by bioassay. This work indicated the presence of a zone in chromatograms with growth-inhibitory activity which was designated as inhibitor g. The most active component of inhibitor g was later shown to be ABA (15). 

Determination of in vitro growth inhibitory activity of several thieno[3,4-d]pyrimidine C-nucleosides against L1210-C1, sarcoma 180, and HL60 cell lines indicated that 4-amino-7-/3-D-ribofuranosylthieno[3,4-t/Jpyrimidine 377 is by far the most cytotoxic, with IC50 values of 0.0046, 0.015 and 0.0092 respectively (93JHC509). 

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