In the last eight years, a lot of interesting work has been done on developing salvinorin analogues. Probably the most interesting result of these studies is the development of the compound herkinorin (2-benzoyl salvinorin B). It possesses only weak activity at the kappa-opioid receptor (the primary site of action of salvinorin A), but is a relatively potent and fully efficacious agonist at the mu-opioid receptor (the primary site of action of morphine).

Since it was first reported in 2005, the compound has been the subject of several studies. At some point I'll try to follow up with a concise summary of the data, but for now at least here's a bibliography of papers concerned with this analogue.

Notice that some of these studies are very new, the most recent (Lamb et al. 2011) hasn't even been printed yet, and has only been available online for less than a month... Now that's a paper I'd love to read!

• Butelman, E.R., S. Rus, D.S. Simpson, A. Wolf, T.E. Prisinzano, and M.J. Kreek. 2008. "The effects of herkinorin, the first μ-selective ligand from a salvinorin A-derived scaffold, in a neuroendocrine biomarker assay in nonhuman primates." The Journal of Pharmacology and Experimental Therapeutics 327(1): 154-160. [link]
  
• Groer, C.E., K. Tidgewell, R.A. Moyer, W.W. Harding, R.B. Rothman, T.E. Prisinzano, and L.M. Bohn. 2007. "An opioid agonist that does not induce μ-opioid receptor–arrestin interactions or receptor internalization." Molecular Pharmacology 71(2): 549-557. [link]
  
• Harding, W.W., K. Tidgewell, N. Byrd, H. Cobb, C.M. Dersch, E.R. Butelman, R.B. Rothman, and T.E. Prisinzano. 2005. "Neoclerodane diterpenes as a novel scaffold for μ opioid receptor ligands." Journal of Medicinal Chemistry 48(15): 4765-4771. [link]
  
• Ji, F., Z. Wang, J. Riley, R. Liu, and W.M. Armstead. "Herkinorin dilates cerebral vessels via kappa opioid receptor and cAMP in a piglet model." Abstract of a presentation given at the American Society of Anesthesiologists Annual Meeting, Chicago, Illinois, 16 Oct 2011. [link]
  
• Lamb, K., K. Tidgewell, D.S. Simpson, L.M. Bohn, and T.E. Prisinzano. 2011. "Antinociceptive effects of herkinorin, a MOP receptor agonist derived from salvinorin A in the formalin test in rats: New concepts in mu opioid receptor pharmacology." Drug and Alcohol Dependence (article in press). doi:10.1016/j.drugalcdep.2011.10.026. [no link]
  
• Tidgewell, K.J. 2007. "Development of novel analgesics from the neoclerodane diterpene natural product salvinorin A." PhD thesis, University of Iowa. [see notes in post #37]
  
• Tidgewell, K., W.W. Harding, A. Lozama, H. Cobb, K. Shah, P. Kannan, C.M. Dersch, D. Parrish, J.R. Deschamps, R.B. Rothman, and T.E. Prisinzano. 2006. "Synthesis of salvinorin A analogues as opioid receptor probes." Journal of Natural Products 69(6): 914-918. [link]
  
• Tidgewell, K., C.E. Groer, W.W. Harding, A. Lozama, M. Schmidt, A. Marquam, J. Hiemstra, J.S. Partilla, C.M. Dersch, R.B. Rothman, L.M. Bohn, and T.E. Prisinzano. 2008. "Herkinorin analogues with differential β-arrestin-2 interactions." Journal of Medicinal Chemistry 51(8): 2421-2431. [link]
  
• Xu, H., J.S. Partilla, X. Wang, J.M. Rutherford, K. Tidgewell, T.E. Prisinzano, L.M. Bohn, and R.B. Rothman. 2007. "A comparison of noninternalizing (herkinorin) and internalizing (DAMGO) μ-opioid agonists on cellular markers related to opioid tolerance and dependence." Synapse 61(3): 166-175.
  
• Xu, H., X. Wang, J.S. Partilla, K. Bishop-Mathis, T.S. Benaderet, C.M. Dersch, D.S. Simpson, T.E. Prisinzano, R.B. Rothman. 2008. "Differential effects of opioid agonists on G protein expression in CHO cells expressing cloned human opioid receptors." Brain Research Bulletin 77(1): 49-54. [link]
  

Good enough to get me into the credits part ?

..now that's up-to-date..

Danke schön! And yes, I am doing my best to keep track of everyone who has helped me along the way

For some bizarre reason, I keep on continuously re-experiencing this same album whilst under the influence of S. Divinorum (oral, buccal/sublingual, smoalked (plain leaf & especially in-situ with changa)

http://www.youtube.com/watch?v=tRJ3wQFoMHc

I also tend to listen to this exact album on high-quality "audiophile-grade" headphones (sennheiser HD 598 for all the interested audio-phallic noise-connoisseurs out there) when I use salvia (mostly as a changa additive b/c i use caapi & sally leaf as a base for DMT: harmalas 5:1 mix 1:1 herb: alkaloid changa blends), and, especially so when its changa; I also see an alien which looks loosely like this but with his super long tentacle attached to a 4-pronged stearing wheel shooting rainbow-flashing-fractaline knowlege-balls straight up into my PFC. The rotating 4-spoked knowledge-ball spewing wheel with an alien attached to it is a common entity found in sally space. He doesn't speak; he speaks indirectly through the knowledge balls, which explode in a sea of rainbow-ey goodness all over my closed eye visual field, each one speaking a sentence of wisdom to me via my own consciousness. I have come to regard him as the Isamic-Salvinoidical Wisdom Freak (ISWF), a loved and highly regarded foreign bringer of knowledge to my PFC; A typical dose of salvinoidal changa coadministered with ISAM tends to result in a 40-60 minute encounter with the ISWF; I was wondering if any other members have experienced any similar such effects from salvinoidal changa whilst under the influence of ISAM, and/or if the two are closely interrelated in your own experience. I know that many of salvia's novel psychoactive phenomena are common among her chosen scribes/users, and would like some critique and/or comparison with your typical salvinoidical changa trips, as well as if the theme of ISWF/ISAM/4-spoked rainbow-fractallinical knowledge-ball-spewing circus freak aliens has been a common appearance in your trips on either and/or both of these three substances (changa, salvia, and/or ISAM); any and all input from the community at large is highly appreciated.

Once on sally feeling weightless..Ive seen a spoked wheel slowly spinning through space...
The wheel i saw looked like a wagon wheel only the spokes apeared to be human arms and legs with a human form in the center..
The human form looked like some one from ancient greece or rome and the wheel continued to turn in a vast eternal space ..
This vision experiance was emiting an eternal message as old as time itself...

It Was quite an experiance for me..this may be similar to your steering wheel experiance//

I seem to have found an interesting article that is not mentioned on the forum.

Forensic analysis of Salvia divinorum using multivariate statistical procedures. Part I: discrimination from related Salvia species
Melissa A. Bodnar Willard, Victoria L. McGuffin & Ruth Waddell Smith
Anal Bioanal Chem (2012) 402:833–842
DOI: 10.1007/s00216-011-5479-0

There is a very meticulous analysis of various extraction parameters (solvents, extraction and storage times, etc).

The results imply that the most efficient extraction solvent is DCM (dichloromethane) - 1.255 times better than acetone. Also Salvinorin A is more stable in DCM than in other solvents.