Biologically active molecules with a "light switch"

Biologically active compounds which are light-responsive offer experimental possibilities which are otherwise very difficult to achieve. Since light can be manipulated very precisely, for example, with lasers and microscopes rapid jumps in concentration of the active form of molecules are possible with exact control of the area, time, and dosage. The development of such strategies started in the 1970s. This review summarizes new developments of the last five years and deals with "small molecules", proteins, and nucleic acids which can either be irreversibly activated with light (these compounds are referred to as "caged compounds") or reversibly switched between an active and an inactive state.     

Anti-inflammatory constituents of topically applied crude drugs. IV. Constituents and anti-inflammatory effect of Paraguayan crude drug "alhucema" (Lavandula latifolia Vill.)

The anti-inflammatory active fraction of the Paraguayan crude drug, "Alhucema," Lavandula latifolia Vill. afforded four compounds: coumarin (1), 7-methoxycoumarin (2), trans-phytol (3) and caryophyllene oxide (4). 1 showed a weakly inhibitory effect on carrageenin-induced paw edema in rats on topical application and 4 showed an inhibitory effect on histamine-induced contraction in guinea pig ileum.     

Biologically active constituents of Aglaia erythrosperma

From the fruits and leaves of Aglaia erythrosperma (Meliaceae), 10 chemical constituents were isolated and identified, i.e. the dammarane triterpenoids cabraleadiol (1), cabraleahydroxylactone (2), ethyl eichlerianoate (3), eichlerialactone (4), aglinin A (5), cabralealactone (6), the aglaialactone 5,6-desmethylenedioxy-5-methoxy-aglalactone (7), the flavagline 4'-demethoxy-3',4'-methylenedioxy-methyl rocaglate (8) and two coumarins: scoparone and scopoletin. Flavagline 8 exhibited antimalarial activity with an IC(50) value of 7.30 μg mL(-1) and was strongly cytotoxic against small cell lung cancer (NCI-H187), epidermoid carcinoma (KB) and breast cancer (BC) cell lines, with IC(50) values of 2.17, 2.10 and 0.11 μg mL(-1), respectively. Aglinin A (5) displayed moderate cytotoxicity against all the three cancer cell lines, whereas ethyl eichlerianoate (3), cabralealactone (6) and the aglaialactone 7 were exclusively cytotoxic to NCI-H187 cell line. Cabraleahydroxylactone (2) showed antiviral activity against herpes simplex virus type-1 with an IC(50) value of 3.20 μg mL(-1), in comparison with the standard acyclovir (IC(50)?= 1.90 μg mL(-1)). When tested for antimycobacterial activity against Mycobacterium tuberculosis H(37)Ra, compounds 1-4 and 6-8 displayed minimum inhibitory concentration in the range of 25-50 μg mL(-1).     

Biologically active proteins of the wormEisenia foetida

Seven protein-peptide fractions have been isolated from the biomass of the wormEisenia foetida. Their influence on the synthesis of RNA, DNA, and protein in animal and plant cells has been investigated.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 118–120, January–February, 1994.     

Biologically active constituents of Centipeda minima: sesquiterpenes of potential anti-allergy activity.

Ether, methanol and aqueous extracts of Centipeda minima (Compositae) herbs were found to have significant anti-allergy activities in passive cutaneous anaphylaxis (PCA) test. Three flavonoids, two sesquiterpene lactones and an amide were isolated from this plant material as inhibitors to induced histamine release from mast cells. The sesquiterpenes were identified as isobutyroylplenolin and senecioylplenolin by spectral investigations. The flavonoids and sesquiterpenes exhibited significant anti-allergy activity in PCA test with p.o. administration.     

Screening for molluscicidal activity in crude drugs

Thirty-four extracts of crude drugs and medicinal plants have been screened for activity against Oncomelania nosophora, the intermediate host of the Japanese strain of Schistosoma japonicum. Strong molluscicidal activity was found in the MeOH extract of Anemarrhenae Rhizoma. Although timosaponin A-III, one of the main saponins of Anemarrhenae Rhizoma, showed very strong killing activity, markogenin-3-O-beta-D-glucopyranosyl (1-2)-O-beta-D-galactopyranoside having the same glycosidic linkage was found to be inactive.     

Biologically active heterocyclic analogs of thiourea (review)

The results of research carried out in the Scientific-Research Institute of Medicinals (Budapest, Hungary) are correlated. The structures of 2-aminothiazolines, which can exist in the tautomeric 2-iminothiazolidine form, and of the corresponding analogs of the thiazine series and their acyl derivatives are discussed. A new method for the synthesis of 3-aryl-substituted 2-iminothiazolidines and 2-iminoperhydro-1,3-thiazines is examined. Data on the biological activity of some of the investigated compounds are presented.For example, it is known that 2-(octahydro-1-azocinyl)ethylguanidine (guanethidine) has excellent antihypertensive properties [6–8].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 878–888, July, 1978.