Vasoactive peptides from venom of the hornet Vespa orientalis physiochemical and functional characterization

Two peptides having kinin activity have been isolated from hornet venom. The peptides isolated exhibit hypotensive action and a myotropic effect, and they also liberate histamine from mast cells. One of the peptides is a close structural analog of bradykinin while the other differs considerably from it.Institute of Bioorganic Chemistry of the Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 255–258, March–April, 1988.     

Resistance of vasoactive peptides from venom of Vespa orientalis to action of proteolytic enzymes

The kinetics of the hydrolysis by proteolytic enzymes of vasoactive peptides isolated from the venom of the hornetVespa orientalis has been investigated. It has been found that the half-period of decomposition of the peptides exceeds that of bradykinin. These facts are in harmony with in vivo results on the prolonged hypotensive action of the peptides.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 658–661, September–October, 1988.     

A new peptide from venom of the East-European hornet Vespa orientalis. Mass spectrometric de novo sequence

The de novo sequence of a new peptide from venom of the East-European hornet Vespa orientalis L. was determined by mass spectrometry. It was used as an example to show that time-of-flight mass spectrometry with an electrospray ion source can be used effectively to determine the amino-acid sequence of microquantities of peptides. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 49–51, January–February, 2008.     

Novel Sesquiterpenoids from Siegesbeckia orientalis

Five new sesquiterpenoids, namely, 8β‐(angeloyloxy)‐4β,6α,15‐trihydroxy‐14‐oxoguaia‐9,11(13)‐dien‐12‐oic acid 12,6‐lactone ( 1 ), 4β,6α,15‐trihydroxy‐8β‐(isobutyryloxy)‐14‐oxoguaia‐9,11(13)‐dien‐12‐oic acid 12,6‐lactone ( 2 ), 11,12,13‐trinorguai‐6‐ene‐4β,10β‐diol ( 3 ), (1(10)E,4E,8Z)‐8‐(angeloyloxy)‐6α,15‐dihydroxy‐14‐oxogermacra‐(1(10),4,8,11(13)‐tetraen‐12‐oic acid 12,6‐lactone ( 9 ), and (1(10)E,4β)‐8β‐(angeloyloxy)‐6α,14,15‐trihydroxygermacra‐1(10),11(13)‐dien‐12‐oic acid 12,6‐lactone ( 11 ), and three new artifacts, (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α‐ethoxy‐6α,15‐dihydroxy‐14‐oxogermacra‐1(10),4,11(13)‐trien‐12‐oic acid 12,6‐lactone ( 6 ), (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α,13‐diethoxy‐6α,15‐dihydroxy‐14‐oxogermacra‐1(10),4‐dien‐12‐oic acid 12,6‐lactone ( 7 ), and (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α‐ethoxy‐6α,15‐dihydroxy‐13‐methoxy‐14‐oxogermacra‐1(10),4‐dien‐12‐oic acid 12,6‐lactone ( 8 ), together with the three known sesquiterpenoids 4, 5 , and 10 , were isolated from the aerial parts of Siegesbeckia orientalis L. Their structures were established by spectral methods, especially 1D‐ and 2D‐NMR spectral methods.     

Isolation of a ca-channel blocker from the venom of the spiderAgelena labirintica

From the venom of the spider Ageiena labirintica we have isolated the neurotoxin Agll (IV-6-1) with a molecular mass of 1000 Da, which effectively blocks the Ca channels of presynaptic membranes of frog nerve-muscle synapses.Institute of Physiology and Biophysics, Academy of Sciences of the Republic of Uzbekistan, 700095, Tashkent, ul. Niyazova, 1. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 467–470, May–June, 1995. Original article submitted October 24, 1994.     

Four new terpenes from the pericarp of Platycladus orientalis

A new monoterpene, platydiol (1), and three new diterpenes, platyclolactonic acid (2), 14,15-bisnor-8(17)-labdene-16,19-dioic acid (3), and 6,7-dehydrosandaracopimaric acid (4), were isolated from the pericarp of Platycladus orientalis. Their structures were elucidated by spectral and chemical methods.     

ent-pimarane-type diterpenoids from Siegesbeckia orientalis L

A new ent-pimarane glucoside, named hythiemoside B (4), was isolated from the aerial part of Siegesbecikia orientalis L. (Asteraceae) together with four known ent-pimarane-type diterpenoids: darutigenol (1), darutoside (2), hythiemoside A (3), and ent-(15R),16,19-trihydroxypimar-8(14)-ene 19-O-beta-D-glucopyranoside (5). The structure of the new compound was elucidated by spectroscopic analyses and chemical transformation. The NMR data of compounds 1 (1H-) and 5 (1H- and 13C-) were also compiled in this study on the basis of 2D experiments.     

Dehydroalanine-based inhibition of a peptide epimerase from spider venom

Ribosomally produced peptides that contain D-amino acids have been isolated from a number of vertebrate and invertebrate sources. In each case, the D-amino acids are introduced by a posttranslational modification of a parent peptide containing only amino acids of the L-configuration. The only known enzyme to catalyze such a reaction is the peptide epimerase (also known as peptide isomerase) from the venom of the funnel web spider, Agelenopsis aperta. This enzyme interconverts two 48-amino-acid-long peptide toxins that differ only by the stereochemistry at a single serine residue. In this paper we report the synthesis and testing of two pentapeptide analogues that contain modified amino acids at the site normally occupied by the substrate serine residue. When the L-chloroalanine-containing peptide 3 was incubated with the epimerase it was converted into the dehydroalanine-containing peptide 4 via an elimination of HCl. The dehydroalanine peptide 4 was independently synthesized and found to act as a potent inhibitor of the epimerase (IC50 = 0.5 microM). These results support a direct deprotonation/reprotonation mechanism in which a carbanionic intermediate is formed. The observed inhibition by 4 can be attributed to the sp(2)-hybridization of the alpha-carbon in the dehydroalanine unit that mimics the planar geometry of the anionic intermediate.     

Two new sesquiterpenes from Alisma orientalis

Two new sesquiterpenoids named alismorientols A (1) and B (2) were isolated from the rhizomes of Alisma orientalis collected in Sichuan province, People's Republic of China. Their structures were elucidated based on spectroscopic analyses (1D and 2D NMR data including HSQC, HMBC, COSY, and ROESY) and X-ray crystallographic analysis. Anti-hepatitis B virus (HBV) bioassay revealed that compound 1 showed moderate anti-HBV activity in vitro with IC50 for HBsAg: 1.1 microM, for HBeAg: 14.7 microM.